Ronald Witteles

All Publications

• The State of Medical Student Performance Evaluations: Improved Transparency or Continued Obfuscation? Academic medicine Hom, J., Richman, I., Hall, P., Ahuja, N., Harman, S., Harrington, R., Witteles, R. 2016; 91 (11): 1534-1539

  Abstract

  The medical student performance evaluation (MSPE), a letter summarizing academic performance, is included in each medical student's residency application. The extent to which medical schools follow Association of American Medical Colleges (AAMC) recommendations for comparative and transparent data is not known. This study's purpose was to describe the content, interpretability, and transparency of MSPEs.This cross-sectional study examined one randomly selected MSPE from every Liaison Committee on Medical Education-accredited U.S. medical school from which at least one student applied to the Stanford University internal medical residency program during the 2013-2014 application cycle. The authors described the number, distribution, and range of key words and clerkship grades used in the MSPEs and the proportions of schools with missing or incomplete data.The sample included MSPEs from 117 (89%) of 131 medical schools. Sixty schools (51%) provided complete information about clerkship grade and key word distributions. Ninety-six (82%) provided comparative data for clerkship grades, and 71 (61%) provided complete key word data. Key words describing overall performance were extremely heterogeneous, with a total of 72 used and great variation in the assignment of the top designation (median: 24% of students; range: 1%-60%). There was also great variation in the proportion of students awarded the top internal medicine clerkship grade (median: 29%; range: 2%-90%).The MSPE is a critical component of residency applications, yet data contained within MSPEs are incomplete and variable. Approximately half of U.S. medical schools do not follow AAMC guidelines for MSPEs.

  View details for PubMedID 26703411

• Changing outcomes after heart transplantation in patients with amyloid cardiomyopathy JOURNAL OF HEART AND LUNG TRANSPLANTATION Davis, M. K., Lee, P. H., Witteles, R. M. 2015; 34 (5): 658-666

  Abstract

  Amyloid cardiomyopathy (ACM) is associated with a poor prognosis. Previous reports have suggested unfavorable post-heart transplant (HT) survival in this population compared with other HT recipients.Data from the United Network for Organ Sharing (UNOS) registry were used to study outcomes among ACM patients undergoing HT in the modern era (Era 2, 2008 to 2013) as compared with the historical era (Era 1, 1987 to 2007).One hundred eighty-eight ACM patients underwent primary single-organ HT. Ninety-seven patients (51.6%) were transplanted in Era 1 and 91 (48.4%) in Era 2. ACM patients undergoing HT in Era 2 were older (p < 0.0001), had higher body mass index (p = 0.008) and longer ischemic times (p = 0.02), and were more likely to be African-American (p < 0.0001), UNOS Status 1A (p < 0.0001), male (p = 0.01) and highly sensitized (p < 0.0001) compared with those in Era 1. Compared with patients with other etiologies of restrictive cardiomyopathy (RCM; n = 339 in Era 1, n = 164 in Era 2), adjusted hazard ratios (HRs) for post-HT mortality of ACM were 2.08 (p < 0.0001) in Era 1 and 1.22 (p = not statistically significant) in Era 2. Adjusted HRs for mortality of ACM vs all other diagnoses (n = 36,334 in Era 1, n = 9,225 in Era 2) were 1.84 (p < 0.0001) in Era 1 and 1.38 (p = NS) in Era 2. Although post-HT survival did not change with time among non-ACM RCM patients, post-HT mortality was lower in Era 2 compared with Era 1 among ACM patients (HR 0.49, p = 0.03).Although historically associated with inferior survival, post-HT outcomes in ACM patients in the modern era are now approaching those of non-ACM patients. Changes in patients' demographics suggest that this may be related to improved patient selection, including an increased proportion of patients with transthyretin ACM. HT should be considered for appropriate candidates with ACM.

  View details for DOI 10.1016/j.healun.2014.09.006

  View details for Web of Science ID 000354230800006

  View details for PubMedID 25444369

• Outcomes after heart transplantation for amyloid cardiomyopathy in the modern era. American journal of transplantation Davis, M. K., Kale, P., Liedtke, M., Schrier, S., Arai, S., Wheeler, M., Lafayette, R., Coakley, T., Witteles, R. M. 2015; 15 (3): 650-658

  Abstract

  We conducted a review of patients undergoing heart transplantation (HT) at our institution for amyloid cardiomyopathy (ACM) between 2008 and 2013. Complete follow-up was available for all patients. Nineteen patients with ACM underwent HT during the study period, accounting for 9.4% of all HT performed at our institution during this period. Amyloid subtype was light chain (AL) in 9 patients and transthyretin (ATTR) in 10 (2 wild-type, 7 familial, 1 unknown). Eight of nine patients with AL amyloidosis began chemotherapy prior to HT, six have resumed chemotherapy since HT, and five have undergone autologous stem cell transplantation. Most recent free light chain levels in AL patients decreased by a median of 85% from peak values. Only one patient developed recurrent graft amyloidosis, occurring at 3.5 years post-HT and asymptomatic. After a median follow-up of 380 days, 17 (89.5%) patients are alive. To our knowledge, this is the largest single-center series reported of ACM patients undergoing HT in the modern era. Our results suggest that acceptable outcomes following HT can be achieved in the short-to-intermediate term and that this is a feasible option for end-stage ACM with careful patient selection and aggressive control of amyloidogenic light chains in AL patients.

  View details for DOI 10.1111/ajt.13025

  View details for PubMedID 25648766

• Implantable cardioverter-defibrillator placement in patients with cardiac amyloidosis HEART RHYTHM Varr, B. C., Zarafshar, S., Coakley, T., Liedtke, M., Lafayette, R. A., Arai, S., Schrier, S. L., Witteles, R. M. 2014; 11 (1): 158-162

  View details for DOI 10.1016/j.hrthm.2013.10.026

  View details for Web of Science ID 000329119200027

  View details for PubMedID 24121001

• Variation in Use of Left Ventriculography in the Veterans Affairs Health Care System CIRCULATION-CARDIOVASCULAR QUALITY AND OUTCOMES Heidenreich, P. A., Lin, S., Knowles, J. W., Perez, M., Maddox, T. M., Ho, M. P., Rumsfeld, J. S., Sahay, A., Massie, B. M., Tsai, T. T., Witteles, R. M. 2013; 6 (6): 687-693

  Abstract

  Contrast left ventriculography is a method of measuring left ventricular function usually performed at the discretion of the invasive cardiologist during cardiac catheterization. We sought to determine variation in the use of left ventriculography in the Veterans Affairs (VA) Health Care System.We identified adult patients who underwent cardiac catheterization including coronary angiography between 2000 and 2009 in the VA Health Care System. We determined patient and hospital predictors of the use of left ventriculography as well as the variation in use across VA facilities. Results were validated using data from the VA's Clinical Assessment, Reporting, and Tracking (CART) program. Of 457 170 cardiac catheterization procedures among 336 853 patients, left ventriculography was performed on 263 695 (58%) patients. Use of left ventriculography decreased over time (64% in 2000 to 50% in 2009) and varied markedly across facilities (<1->95% of cardiac catheterizations). Patient factors explained little of the large variation in use between facilities. When the cohort was restricted to those with an echocardiogram in the prior 30 days and no intervening event, left ventriculography was still performed in 50% of cases.There is large variation in the use of left ventriculography across VA facilities that is not explained by patient characteristics.

  View details for DOI 10.1161/CIRCOUTCOMES.113.000199

  View details for Web of Science ID 000330362400017

  View details for PubMedID 24192569

• Underestimating Cardiac Toxicity in Cancer Trials: Lessons Learned? JOURNAL OF CLINICAL ONCOLOGY Witteles, R. M., Telli, M. 2012; 30 (16): 1916-1918

  View details for DOI 10.1200/JCO.2011.40.4012

  View details for Web of Science ID 000304596800010

  View details for PubMedID 22454419

• Use and overuse of left ventriculography AMERICAN HEART JOURNAL Witteles, R. M., Knowles, J. W., Perez, M., Morris, W. M., Spettell, C. M., Brennan, T. A., Heidenreich, P. A. 2012; 163 (4): 617-?

  Abstract

  Left ventriculography provided the first imaging of left ventricular function and was historically performed as part of coronary angiography despite a small but significant risk of complications. Because modern noninvasive imaging techniques are more accurate and carry smaller risks, the routine use of left ventriculography is of questionable utility. We sought to analyze the frequency that left ventriculography was performed during coronary angiography in patients with and without a recent alternative assessment of left ventricular function.We performed a retrospective analysis of insurance claims data from the Aetna health care benefits database including all adults who underwent coronary angiography in 2007. The primary outcome was the concomitant use of left ventriculography during coronary angiography.Of 96,235 patients who underwent coronary angiography, left ventriculography was performed in 78,705 (81.8%). Use of left ventriculography was high in all subgroups, with greatest use in younger patients, those with a diagnosis of coronary disease, and those in the Southern United States. In the population who had undergone a very recent ejection fraction assessment by another modality (within 30 days) and who had had no intervening diagnosis of new heart failure, myocardial infarction, hypotension, or shock (37,149 patients), left ventriculography was performed in 32,798 patients (88%)-a rate higher than in the overall cohort.Left ventriculography was performed in most coronary angiography cases and often when an alternative imaging modality had been recently completed. New clinical practice guidelines should be considered to decrease the overuse of this invasive test.

  View details for DOI 10.1016/j.ahj.2011.12.018

  View details for Web of Science ID 000303106800023

  View details for PubMedID 22520528

• Heart transplantation and cardiac amyloidosis: Approach to screening and novel management strategies JOURNAL OF HEART AND LUNG TRANSPLANTATION Varr, B. C., Liedtke, M., Arai, S., Lafayette, R. A., Schrier, S. L., Witteles, R. M. 2012; 31 (3): 325-331

  Abstract

  Limited data exist regarding screening methods and outcomes for orthotopic heart transplantation (OHT) in cardiac amyloidosis. As a result, uncertainty exists over the best approach to OHT for cardiac amyloidosis and for the timing of critical post-transplant therapies. This article reviews 6 patients who underwent OHT for cardiac amyloidosis at the Stanford University Amyloid Center from 2008 to present. All patients with light-chain amyloidosis received chemotherapy in the interval between OHT and autologous hematopoietic stem cell transplant. Five patients remain alive up to 25 months after OHT, without evidence of recurrent cardiac amyloid deposition. A novel strategy of OHT, followed by light-chain suppressive chemotherapy before autologous hematopoietic stem cell transplant, is feasible for patients with light-chain amyloidosis.

  View details for DOI 10.1016/j.healun.2011.09.010

  View details for Web of Science ID 000300806500015

  View details for PubMedID 22051505

• Chemotherapy-Associated Cardiotoxicity: How Often Does it Really Occur and How Can it Be Prevented? HEART FAILURE CLINICS Witteles, R. M., Fowler, M. B., Telli, M. L. 2011; 7 (3): 333-?

  Abstract

  Cardiotoxicity remains the limiting factor for many forms of cancer therapy and is the focus of growing research and clinical emphasis. This article outlines the current clinical evidence for left ventricular dysfunction and heart failure for the two most important classes of cardiotoxic chemotherapeutic agents, examines the potential pitfalls that have led to underestimated rates of left ventricular dysfunction from these agents, and reviews strategies for screening for and providing prophylaxis against chemotherapy-associated left ventricular dysfunction.

  View details for DOI 10.1016/j.hfc.2011.03.005

  View details for Web of Science ID 000307494700006

  View details for PubMedID 21749885

• Radiation Therapy for Breast Cancer Buyer Beware JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Witteles, R. M. 2011; 57 (4): 453-454

  View details for DOI 10.1016/j.jacc.2010.08.637

  View details for Web of Science ID 000286376500011

  View details for PubMedID 21251586

• Left Ventricular Dysfunction in Patients Receiving Cardiotoxic Cancer Therapies Are Clinicians Responding Optimally? JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Yoon, G. J., Telli, M. L., Kao, D. P., Matsuda, K. Y., Carlson, R. W., Witteles, R. M. 2010; 56 (20): 1644-1650

  Abstract

  The purpose of this study was to examine treatment practices for cancer therapy-associated decreased left ventricular ejection fraction (LVEF) detected on echocardiography and whether management was consistent with American College of Cardiology/American Heart Association guidelines.Patients treated with anthracyclines or trastuzumab are at risk of cardiotoxicity. Decreased LVEF represents a Class I indication for drug intervention according to American College of Cardiology/American Heart Association guidelines.Patients receiving anthracycline or trastuzumab at Stanford University from October 2005 to October 2007 and who had undergone echocardiography before and after receiving an anthracycline or trastuzumab were identified. Chart review examined chemotherapy regimens, cardiac risk factors, imaging results, concomitant medications, and cardiology consultations.Eighty-eight patients received therapy with an anthracycline or trastuzumab and had a pre-treatment and follow-up echocardiogram. Ninety-two percent were treated with anthracyclines, 17% with trastuzumab after an anthracycline, and 8% with trastuzumab without previous treatment with anthracycline. Mean baseline LVEF was 60%, with 14% having a baseline <55%. Forty percent had decreased LVEF (<55%) after anthracycline and/or trastuzumab treatment. Of these patients, 40% received angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy, 51% beta-blocker therapy, and 54% cardiology consultation. Of patients with asymptomatic decreased LVEF, 31% received angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy, 35% beta-blocker therapy, and 42% cardiology consultation. Of those with symptomatic decreased LVEF, 67% received angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy, 100% beta-blocker therapy, and 89% cardiology consultation.Many cancer survivors are not receiving treatment consistent with heart failure guidelines. There is substantial opportunity for collaboration between oncologists and cardiologists to improve the care of oncology patients receiving cardiotoxic therapy.

  View details for DOI 10.1016/j.jacc.2010.07.023

  View details for Web of Science ID 000283737600007

  View details for PubMedID 21050974

• Heart Failure in Hispanics JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Vivo, R. P., Krim, S. R., Cevik, C., Witteles, R. M. 2009; 53 (14): 1167-1175

  Abstract

  Although large-scale heart failure (HF) studies in Hispanic Americans are lacking, some compelling data indicate that they are a particularly vulnerable population and underscore the need for further research. Hispanics comprise the largest and fastest-growing ethnic group in the U.S., in whom the impact of this burgeoning public health problem may be magnified. Current data show that Hispanics with HF are more likely to be younger and underinsured than non-Hispanic whites. They have higher rates of readmissions but have lower in-hospital and short-term mortality rates. Epidemiologic studies demonstrate that Hispanics have excessive rates of diabetes, obesity, dyslipidemia, and metabolic syndrome. Although hypertension and ischemic heart disease are established risk factors in this ethnic group, it may be considered that insulin resistance plays a significant role in the pathogenesis of HF in Hispanics, accounting for their inordinate cardiometabolic risk burden and the growing evidence of novel metabolic risk factors for HF. Hispanics encounter multiple barriers to health care influenced by socioeconomic, linguistic, and cultural factors that, in turn, have an adverse impact on disease prognosis. Recognition of predominant risk factors and health care disparities in this population is crucial to tailoring appropriate management strategies. This review summarizes epidemiologic and clinical data on Hispanics with HF, details risk factors and health care impediments, and presents an agenda for future investigation.

  View details for DOI 10.1016/j.jacc.2008.12.037

  View details for Web of Science ID 000264724500001

  View details for PubMedID 19341856

• Clinical problem-solving. Fool's Gold. New England journal of medicine Leeper, N. J., Dhaliwal, G., Saint, S., Witteles, R. M. 2008; 359 (19): 2035-2041

  View details for DOI 10.1056/NEJMcps0802668

  View details for PubMedID 18987372

• Insulin-resistant cardiomyopathy JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Witteles, R. M., Fowler, M. B. 2008; 51 (2): 93-102

  Abstract

  Increasing evidence points to insulin resistance as a primary etiologic factor in the development of nonischemic heart failure (HF). The myocardium normally responds to injury by altering substrate metabolism to increase energy efficiency. Insulin resistance prevents this adaptive response and can lead to further injury by contributing to lipotoxicity, sympathetic up-regulation, inflammation, oxidative stress, and fibrosis. Animal models have repeatedly demonstrated the existence of an insulin-resistant cardiomyopathy, one that is characterized by inefficient energy metabolism and is reversible by improving energy use. Clinical studies in humans strongly support the link between insulin resistance and nonischemic HF. Insulin resistance is highly prevalent in the nonischemic HF population, predates the development of HF, independently defines a worse prognosis, and predicts response to antiadrenergic therapy. Potential options for treatment include metabolic-modulating agents and antidiabetic drugs. This article reviews the basic science evidence, animal experiments, and human clinical data supporting the existence of an "insulin-resistant cardiomyopathy" and proposes specific potential therapeutic approaches.

  View details for DOI 10.1016/j.jacc.2007.10.021

  View details for Web of Science ID 000252422800001

  View details for PubMedID 18191731

• Impact of nesiritide on renal function in patients with acute decompensated failure an pre-existing renal dysfunction - A randomized, double-blind, placebo-controlled clinical trial JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Witteles, R. M., Kao, D., Christopherson, D., Matsuda, K., Vagelos, R. H., Schreiber, D., Fowler, M. B. 2007; 50 (19): 1835-1840

  Abstract

  Our purpose was to evaluate the impact of nesiritide on renal function in patients with acute decompensated heart failure and baseline renal dysfunction.Although nesiritide is approved for the treatment of acute decompensated heart failure, retrospective analyses have raised concerns that it may cause worsened renal function. To date, no randomized clinical trials have prospectively evaluated this issue.Consecutive patients with acute decompensated heart failure and baseline renal dysfunction were enrolled in this randomized, double-blind, placebo-controlled clinical trial. Subjects were randomized to receive nesiritide (0.01 microg/kg/min with or without a 2-microg/kg bolus) or placebo (5% dextrose in water) for 48 h in addition to their usual care. Predefined primary end points of the trial were a rise in serum creatinine by > or =20% and change in serum creatinine.Seventy-five patients were enrolled (39 nesiritide, 36 placebo). The groups had similar baseline age (74.9 vs. 75.5 years, respectively), blood pressure (123/64 vs. 125/64 mm Hg) and serum creatinine (1.82 vs. 1.86 mg/dl). There were no significant differences in the incidence of a 20% creatinine rise (23% vs. 25%) or in the change in serum creatinine (-0.05 vs. +0.05 mg/dl). There were no significant differences in the secondary end points of change in weight (-2.19 vs. -1.58 kg), intravenous furosemide (125 vs. 107 mg), discontinuation of the infusion due to hypotension (13% vs. 6%), or 30-day death/hospital readmission (33% vs. 25%).In this randomized, double-blind, placebo-controlled clinical trial, nesiritide had no impact on renal function in patients with acute decompensated heart failure. (BNP-CARDS trial; http://www.clinicaltrials.gov/ct/show/NCT00186329?order=1; NCT00186329).

  View details for DOI 10.1016/j.jacc.2007.03.071

  View details for Web of Science ID 000250788300003

  View details for PubMedID 17980248

• Cardiomyopathy of insulin resistance. Heart failure clinics Witteles, R. M., Fowler, M. B. 2006; 2 (1): 13-23

  View details for PubMedID 17386873

• Insulin resistance in idiopathic dilated cardiomyopathy - A possible etiologic link JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Witteles, R. M., Tang, W. H., Jamali, A. H., Chu, J. W., Reaven, G. M., Fowler, M. B. 2004; 44 (1): 78-81

  Abstract

  This study was designed to quantify the prevalence of abnormal glucose tolerance and insulin resistance in patients with idiopathic dilated cardiomyopathy (IDCM).Insulin resistance is an independent risk factor for mortality in patients with heart failure (HF) and is a known risk factor for ischemic cardiomyopathy. Though potential physiologic links between insulin resistance and HF have been hypothesized, the relationship between insulin resistance and IDCM remains unclear.A total of 230 consecutive patients from a university HF clinic were screened for IDCM, the absence of diabetes mellitus, and the lack of significant co-morbid conditions. Oral glucose tolerance tests were performed in the 43 patients with IDCM who met these criteria, and their plasma glucose and insulin responses were compared with those of 40 healthy volunteers, matched for age, gender, and body mass index.Plasma glucose responses were higher during the oral glucose tolerance tests in patients with IDCM (p < 0.01), associated with significantly higher plasma insulin concentrations following the oral glucose challenge (p < 0.01). In addition, abnormalities of glucose tolerance were significantly (p < 0.05) more common in patients with IDCM (49% vs. 23%).Insulin resistance and abnormal glucose tolerance are more prevalent in patients with IDCM and represent potentially reversible metabolic derangements in these individuals.

  View details for DOI 10.1016/j.jacc.2004.03.037

  View details for Web of Science ID 000222421500016

  View details for PubMedID 15234411

• Patient Outcomes when Housestaff Exceed 80 Hours per Week. American journal of medicine Ouyang, D., Chen, J. H., Krishnan, G., Hom, J., Witteles, R., Chi, J. 2016; 129 (9): 993-999 e1

  Abstract

  It has been posited that high workload and long work hours for trainees could affect the quality and efficiency of patient care. Duty hour restrictions seek to balance patient care and resident education by limiting resident work hours. Through a retrospective cohort study, we investigate whether patient care on an inpatient general medicine service at a large academic medical center is impacted when housestaff work greater than eighty hours per week METHODS: We identified all admissions to a housestaff-run general medicine service between June 25, 2013 and June 29, 2014. Each hospitalization was classified by whether or not the patient was admitted by housestaff who have worked more than eighty hours a week during their hospitalization. Housestaff computer activity and duty hours were calculated by institutional electronic heath record audit, as well as length of stay and a composite of in-hospital mortality, ICU transfer rate, and 30-day readmission rate.We identified 4,767 hospitalizations by 3,450 unique patients; of which 40.9% of hospitalizations were managed by housestaff who worked more than eighty hours that week during their hospitalization. There was a significantly higher rate of the composite outcome (19.2% vs. 16.7%, p = 0.031) for patients admitted by housestaff working more than eighty hours a week during their hospitalization. We found a statistically significant higher length of stay (5.12 vs. 4.66 days, p = 0.048) and rate of ICU transfer (3.18% vs. 2.38%, p = 0.029). There was no statistically significant difference in 30-day readmission rate (13.7% vs. 12.8%, p = 0.395), or in-hospital mortality rate (3.18% vs. 2.42%, p = 0.115).There was no correlation with team census on admission and patient outcomes.Patients taken care of by housestaff working more than eighty hours a week had increased length of stay and number of ICU transfers. There was no association between resident work-hours and patient in-hospital mortality or 30-day readmission rate.

  View details for DOI 10.1016/j.amjmed.2016.03.023

  View details for PubMedID 27103047

• A resident-created hospitalist curriculum for internal medicine housestaff. Journal of hospital medicine Kumar, A., Smeraglio, A., Witteles, R., Harman, S., Nallamshetty, S., Rogers, A., Harrington, R., Ahuja, N. 2016; 11 (9): 646-649

  Abstract

  The growth of hospital medicine has led to new challenges, and recent graduates may feel unprepared to meet the expanding clinical duties expected of hospitalists. At our institution, we created a resident-inspired hospitalist curriculum to address the training needs for the next generation of hospitalists. Our program provided 3 tiers of training: (1) clinical excellence through improved training in underemphasized areas of hospital medicine, (2) academic development through required research, quality improvement, and medical student teaching, and (3) career mentorship. In this article, we describe the genesis of our program, our final product, and the challenges of creating a curriculum while being internal medicine residents. Journal of Hospital Medicine 2016. © 2016 Society of Hospital Medicine.

  View details for DOI 10.1002/jhm.2590

  View details for PubMedID 27079160

• Genotype and Phenotype of Transthyretin Cardiac Amyloidosis: THAOS (Transthyretin Amyloid Outcome Survey). Journal of the American College of Cardiology Maurer, M. S., Hanna, M., Grogan, M., Dispenzieri, A., Witteles, R., Drachman, B., Judge, D. P., Lenihan, D. J., Gottlieb, S. S., Shah, S. J., Steidley, D. E., Ventura, H., Murali, S., Silver, M. A., Jacoby, D., Fedson, S., Hummel, S. L., Kristen, A. V., Damy, T., Planté-Bordeneuve, V., Coelho, T., Mundayat, R., Suhr, O. B., Waddington Cruz, M., Rapezzi, C. 2016; 68 (2): 161-172

  Abstract

  Transthyretin amyloidosis (ATTR) is a heterogeneous disorder with multiorgan involvement and a genetic or nongenetic basis.The goal of this study was to describe ATTR in the United States by using data from the THAOS (Transthyretin Amyloidosis Outcomes Survey) registry.Demographic, clinical, and genetic features of patients enrolled in the THAOS registry in the United States (n = 390) were compared with data from patients from other regions of the world (ROW) (n = 2,140). The focus was on the phenotypic expression and survival in the majority of U.S. subjects with valine-to-isoleucine substitution at position 122 (Val122Ile) (n = 91) and wild-type ATTR (n = 189).U.S. subjects are older (70 vs. 46 years), more often male (85.4% vs. 50.6%), and more often of African descent (25.4% vs. 0.5%) than the ROW. A significantly higher percentage of U.S. patients with ATTR amyloid seen at cardiology sites had wild-type disease than the ROW (50.5% vs. 26.2%). In the United States, 34 different mutations (n = 201) have been reported, with the most common being Val122Ile (n = 91; 45.3%) and Thr60Ala (n = 41; 20.4%). Overall, 91 (85%) of 107 patients with Val122Ile were from the United States, where Val122Ile subjects were younger and more often female and black than patients with wild-type disease, and had similar cardiac phenotype but a greater burden of neurologic symptoms (pain, numbness, tingling, and walking disability) and worse quality of life. Advancing age and lower mean arterial pressure, but not the presence of a transthyretin mutation, were independently associated with higher mortality from a multivariate analysis of survival.In the THAOS registry, ATTR in the United States is overwhelmingly a disorder of older adult male subjects with a cardiac-predominant phenotype. Val122Ile is the most common transthyretin mutation, and neurologic phenotypic expression differs between wild-type disease and Val122Ile, but survival from enrollment in THAOS does not. (Transthyretin-Associated Amyloidoses Outcome Survey [THAOS]; NCT00628745).

  View details for DOI 10.1016/j.jacc.2016.03.596

  View details for PubMedID 27386769

• Genotype and Phenotype of Transthyretin Cardiac Amyloidosis THAOS (Transthyretin Amyloid Outcome Survey) JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Maurer, M. S., Hanna, M., Grogan, M., Dispenzieri, A., Witteles, R., Drachman, B., Judge, D. P., Lenihan, D. J., Gottlieb, S. S., Shah, S. J., Steidley, D. E., Ventura, H., Murali, S., Silver, M. A., Jacoby, D., Fedson, S., Hummel, S. L., Kristen, A. V., Damy, T., Plante-Bordeneuve, V., Coelho, T., Mundayat, R., Suhr, O. B., Cruz, M. W., Rapezzi, C. 2016; 68 (2): 161-172

  Abstract

  Transthyretin amyloidosis (ATTR) is a heterogeneous disorder with multiorgan involvement and a genetic or nongenetic basis.The goal of this study was to describe ATTR in the United States by using data from the THAOS (Transthyretin Amyloidosis Outcomes Survey) registry.Demographic, clinical, and genetic features of patients enrolled in the THAOS registry in the United States (n = 390) were compared with data from patients from other regions of the world (ROW) (n = 2,140). The focus was on the phenotypic expression and survival in the majority of U.S. subjects with valine-to-isoleucine substitution at position 122 (Val122Ile) (n = 91) and wild-type ATTR (n = 189).U.S. subjects are older (70 vs. 46 years), more often male (85.4% vs. 50.6%), and more often of African descent (25.4% vs. 0.5%) than the ROW. A significantly higher percentage of U.S. patients with ATTR amyloid seen at cardiology sites had wild-type disease than the ROW (50.5% vs. 26.2%). In the United States, 34 different mutations (n = 201) have been reported, with the most common being Val122Ile (n = 91; 45.3%) and Thr60Ala (n = 41; 20.4%). Overall, 91 (85%) of 107 patients with Val122Ile were from the United States, where Val122Ile subjects were younger and more often female and black than patients with wild-type disease, and had similar cardiac phenotype but a greater burden of neurologic symptoms (pain, numbness, tingling, and walking disability) and worse quality of life. Advancing age and lower mean arterial pressure, but not the presence of a transthyretin mutation, were independently associated with higher mortality from a multivariate analysis of survival.In the THAOS registry, ATTR in the United States is overwhelmingly a disorder of older adult male subjects with a cardiac-predominant phenotype. Val122Ile is the most common transthyretin mutation, and neurologic phenotypic expression differs between wild-type disease and Val122Ile, but survival from enrollment in THAOS does not. (Transthyretin-Associated Amyloidoses Outcome Survey [THAOS]; NCT00628745).

  View details for DOI 10.1016/j.jacc.2016.03.596

  View details for Web of Science ID 000379123800005

  View details for PubMedCentralID PMC4940135

• Biomarkers as Predictors of Cardiac Toxicity From Targeted Cancer Therapies JOURNAL OF CARDIAC FAILURE Witteles, R. M. 2016; 22 (6): 459-464

  Abstract

  Cardiac biomarkers have been extensively investigated as early detectors of cardiac toxicity from cancer therapies. Whereas the role of biomarkers in monitoring anthracycline toxicity is generally well understood, substantial uncertainty remains regarding their role in monitoring newer targeted cancer therapies.This review article examines all major published studies using cardiac troponins and/or N-terminal pro-B-type natriuretic peptide (NT-proBNP) in monitoring for cardiac toxicity with trastuzumab, tyrosine kinase inhibitors, and mammalian target of rapamycin (mTOR) inhibitors. There is substantial variability among studies regarding biomarker assays used, sensitivity of the assays, and definitions of abnormal results. In general, troponin I predicts early but not late cardiac events when trastuzumab is administered after anthracyclines, but troponin increases likely reflect anthracycline injury rather than trastuzumab injury. NT-proBNP detects cardiac toxicity with tyrosine kinase inhibitors and mTOR inhibitors, but not independently from echocardiography.Troponin I can serve as a marker for susceptibility to cardiac toxicity during early trastuzumab treatment in patients who have received recent anthracyclines. NT-proBNP can serve as a useful marker of cardiac toxicity in patients treated with tyrosine kinase inhibitors or mTOR inhibitors if echocardiographic screening is not being used.

  View details for DOI 10.1016/j.cardfail.2016.03.016

  View details for Web of Science ID 000377844300008

  View details for PubMedID 27038641

• Human induced pluripotent stem cell-derived cardiomyocytes recapitulate the predilection of breast cancer patients to doxorubicin-induced cardiotoxicity NATURE MEDICINE Burridge, P. W., Li, Y. F., Matsa, E., Wu, H., Ong, S., Sharma, A., Holmstrom, A., Chang, A. C., Coronado, M. J., Ebert, A. D., Knowles, J. W., Telli, M. L., Witteles, R. M., Blau, H. M., Bernstein, D., Altman, R. B., Wu, J. C. 2016; 22 (5): 547-556

  Abstract

  Doxorubicin is an anthracycline chemotherapy agent effective in treating a wide range of malignancies, but it causes a dose-related cardiotoxicity that can lead to heart failure in a subset of patients. At present, it is not possible to predict which patients will be affected by doxorubicin-induced cardiotoxicity (DIC). Here we demonstrate that patient-specific human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) can recapitulate the predilection to DIC of individual patients at the cellular level. hiPSC-CMs derived from individuals with breast cancer who experienced DIC were consistently more sensitive to doxorubicin toxicity than hiPSC-CMs from patients who did not experience DIC, with decreased cell viability, impaired mitochondrial and metabolic function, impaired calcium handling, decreased antioxidant pathway activity, and increased reactive oxygen species production. Taken together, our data indicate that hiPSC-CMs are a suitable platform to identify and characterize the genetic basis and molecular mechanisms of DIC.

  View details for DOI 10.1038/nm.4087

  View details for Web of Science ID 000375514000018

  View details for PubMedID 27089514

• Radiation-induced heart disease: an under-recognized entity? Current treatment options in cardiovascular medicine Davis, M., Witteles, R. M. 2014; 16 (6): 317-?

  Abstract

  Radiation-induced heart disease (RIHD) represents a spectrum of cardiovascular disease in patients who have undergone mediastinal, thoracic, or breast radiotherapy (RT). RIHD may involve any cardiac structure and is a major cause of morbidity and mortality in cancer survivors. While large cohort studies have demonstrated that symptomatic RIHD is a common late finding in this population, the incidence of asymptomatic disease is likely to be even higher. Long-term follow-up with regular screening for RIHD plays an important role in the management of cancer survivors who have undergone RT. Aggressive modification of traditional cardiovascular risk factors such as hypertension, dyslipidemia, and cigarette smoking is essential in patients at risk for RIHD, as these have been shown to potentiate the risks of radiation. In patients with symptomatic RIHD, medical and/or percutaneous therapies are often preferable to surgical interventions in view of the increased surgical risk associated with radiation damage to surrounding tissues. Percutaneous revascularization should generally be favored over surgical revascularization. Transcatheter valve replacements have not been widely used in this population but may offer an alternative to high-risk surgical valve procedures. Pericardiectomy is usually associated with extremely poor short-term and long-term outcomes in patients with RIHD and should be avoided in most cases. Heart transplantation is also higher risk in patients with RIHD than in patients with other etiologies of heart failure, but may be considered in young patients without other comorbidities.

  View details for DOI 10.1007/s11936-014-0317-2

  View details for PubMedID 24756471

• Reply to "heart failure and breast cancer: emerging controversies regarding some cardioprotective strategies". Journal of cardiac failure Witteles, R. M., Thakur, A. 2014; 20 (6): 457-?

  View details for DOI 10.1016/j.cardfail.2014.04.015

  View details for PubMedID 24747785

• Cancer therapy-induced left ventricular dysfunction: interventions and prognosis. Journal of cardiac failure Thakur, A., Witteles, R. M. 2014; 20 (3): 155-158

  Abstract

  For multiple chemotherapeutics, cardiotoxicity is dose limiting and can lead to substantial morbidity and mortality. Early cardiac intervention has the potential to positively affect clinical course.We reviewed 247 consecutive patients referred to the Stanford cardiology clinic for cancer therapy-associated cardiac abnormalities from 2004 to 2012. A comprehensive review of records was performed, with documentation of baseline characteristics, cardiac imaging, medications, and clinical course. Seventy-nine patients who had left ventricular ejection fraction (LVEF) declines temporally associated with cancer therapy were included. The most common malignancies were breast (46%) and hematologic (35%); 71% of the patients were female, and overall mean age was 52 years. The primary cancer therapeutics associated with LVEF decline included anthracyclines, trastuzumab, and tyrosine kinase inhibitors. The mean LVEF was 60% before cancer therapy and 40% after cancer therapy. The most common cardiac interventions included beta-blockers (84%) and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (83%). Mean LVEF after cardiac intervention rose to 53%; 77% of patients had LVEF recovery to ≥50%, and 68% of these patients had recovery within 6 months of starting cardiac therapy; 76% of patients were able to continue their planned cancer therapy.With appropriate cardiac intervention, the majority of patients with LVEF decline from cancer therapy can achieve LVEF recovery and complete their cancer therapy.

  View details for DOI 10.1016/j.cardfail.2013.12.018

  View details for PubMedID 24378722

• Lenalidomide, melphalan and dexamethasone in a population of patients with immunoglobulin light chain amyloidosis with high rates of advanced cardiac involvement. Haematologica Dinner, S., Witteles, W., Afghahi, A., Witteles, R., Arai, S., Lafayette, R., Schrier, S. L., Liedtke, M. 2013; 98 (10): 1593-1599

  Abstract

  Immunoglobulin light chain amyloidosis remains incurable despite recent therapeutic advances, and is particularly difficult to treat in patients with amyloid cardiomyopathy. Based on evidence of activity in multiple myeloma, we designed a pilot study of an oral regimen of lenalidomide in combination with dexamethasone and low dose melphalan in order to evaluate its safety and efficacy in patients with amyloidosis, including those with advanced cardiac involvement. Twenty-five patients were enrolled. Ninety-two percent of patients had cardiac involvement by amyloidosis, and 36% of patients met criteria for Mayo Clinic cardiac stage III disease. Patients received up to 9 cycles of treatment, consisting of lenalidomide 10 mg/day orally on days 1 - 21 (28 day cycle); melphalan 0.18mg/kg orally on days 1-4; and dexamethasone 40 mg orally on days 1, 8, 15, 22. High rates (33%) of cardiac arrhythmias and low rates of treatment completion (12.5%) were observed. Ten patients died during the study, all within the first several months of treatment due to acute cardiac events. The overall hematologic response rate was 58%, however organ responses were seen in only 8% of patients. Overall survival at one year was 58%. While we confirmed the hematologic response rates observed with similar regimens, front line treatment with melphalan, lenalidomide and dexamethasone was toxic, ineffective, and did not alter survival outcomes for patients with high risk cardiac disease. Our data highlight the importance of developing novel treatment approaches for amyloid cardiomyopathy. The trial was registered at www.clinicaltrials.gov (NCT00890552).

  View details for DOI 10.3324/haematol.2013.084574

  View details for PubMedID 23716538

• AG10 inhibits amyloidogenesis and cellular toxicity of the familial amyloid cardiomyopathy-associated V122I transthyretin PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Penchala, S. C., Connelly, S., Wang, Y., Park, M. S., Zhao, L., Baranczak, A., Rappley, I., Vogel, H., Liedtke, M., Witteles, R. M., Powers, E. T., Reixach, N., Chan, W. K., Wilson, I. A., Kelly, J. W., Graef, I. A., Alhamadsheh, M. M. 2013; 110 (24): 9992-9997

  Abstract

  The misassembly of soluble proteins into toxic aggregates, including amyloid fibrils, underlies a large number of human degenerative diseases. Cardiac amyloidoses, which are most commonly caused by aggregation of Ig light chains or transthyretin (TTR) in the cardiac interstitium and conducting system, represent an important and often underdiagnosed cause of heart failure. Two types of TTR-associated amyloid cardiomyopathies are clinically important. The Val122Ile (V122I) mutation, which alters the kinetic stability of TTR and affects 3% to 4% of African American subjects, can lead to development of familial amyloid cardiomyopathy. In addition, aggregation of WT TTR in individuals older than age 65 y causes senile systemic amyloidosis. TTR-mediated amyloid cardiomyopathies are chronic and progressive conditions that lead to arrhythmias, biventricular heart failure, and death. As no Food and Drug Administration-approved drugs are currently available for treatment of these diseases, the development of therapeutic agents that prevent TTR-mediated cardiotoxicity is desired. Here, we report the development of AG10, a potent and selective kinetic stabilizer of TTR. AG10 prevents dissociation of V122I-TTR in serum samples obtained from patients with familial amyloid cardiomyopathy. In contrast to other TTR stabilizers currently in clinical trials, AG10 stabilizes V122I- and WT-TTR equally well and also exceeds their efficacy to stabilize WT and mutant TTR in whole serum. Crystallographic studies of AG10 bound to V122I-TTR give valuable insights into how AG10 achieves such effective kinetic stabilization of TTR, which will also aid in designing better TTR stabilizers. The oral bioavailability of AG10, combined with additional desirable drug-like features, makes it a very promising candidate to treat TTR amyloid cardiomyopathy.

  View details for DOI 10.1073/pnas.1300761110

  View details for Web of Science ID 000320930100085

  View details for PubMedID 23716704

• The prognostic value of diagnosing concurrent multiple myeloma in immunoglobulin light chain amyloidosis BRITISH JOURNAL OF HAEMATOLOGY Dinner, S., Witteles, W., Witteles, R., Lam, A., Arai, S., Lafayette, R., George, T. I., Schrier, S. L., Liedtke, M. 2013; 161 (3): 367-372

  Abstract

  The prevalence and prognostic value of a concomitant diagnosis of symptomatic or asymptomatic multiple myeloma (MM), as defined by the current International Myeloma Working Group (IMWG) criteria, in patients with immunoglobulin light chain amyloidosis (AL), are unknown. We studied 46 consecutive patients with AL who underwent quantification of serum M-protein and clonal bone marrow plasma cells, as well as a comprehensive evaluation for end organ damage by MM. Using standard morphology and CD138 immunohistochemical staining, 57% and 80% of patients were found to have concomitant MM, respectively. Nine patients exhibited end organ damage consistent with a diagnosis of symptomatic MM. While overall survival was similar between AL patients with or without concurrent myeloma (1-year overall survival 68% vs. 87%; P = 0.27), a diagnosis of symptomatic myeloma was associated with inferior outcome (1-year overall survival 39% vs. 81%; P = 0.005). Quantification of bone marrow plasma cells by both standard morphology and CD138 immunohistochemistry identified a much higher prevalence of concurrent MM in patients with AL than previously reported. Evaluation of bone marrow plasma cell infiltration and presence of myeloma associated end organ damage could be clinically useful for prognostication of patients with AL.

  View details for DOI 10.1111/bjh.12269

  View details for Web of Science ID 000317602300009

  View details for PubMedID 23432783

• Cardiac Testing to Manage Cardiovascular Risk in Cancer Patients SEMINARS IN ONCOLOGY Davis, M., Witteles, R. M. 2013; 40 (2): 147-155

  Abstract

  Cardiovascular toxicity is one of the most feared complications of cancer treatment. Recent advances in oncologic therapies have resulted in improved cancer outcomes but also a new set of cardiovascular adverse effects. Common toxicities include left ventricular dysfunction/heart failure, hypertension, and myocardial ischemia. Accurate risk stratification allows avoidance of potentially harmful treatments in those patients at greatest risk while maintaining the ability to deliver high doses of effective therapies to the lower-risk population. Cardiac investigations, including echocardiography, nuclear imaging, magnetic resonance imaging, biomarker measurement, blood pressure monitoring, electrocardiography, stress testing, and invasive angiography, can help to risk-stratify selected patients. In this review, common complications are discussed in terms of the factors used to identify patients with elevated risk, the monitoring strategies available, and selected interventions that have been used to modify outcomes in patients identified as being at high risk for cardiac complications of cancer treatment.

  View details for DOI 10.1053/j.seminoncol.2013.01.003

  View details for Web of Science ID 000317870900003

  View details for PubMedID 23540740

• The Frequency and Severity of Cardiovascular Toxicity From Targeted Therapy in Advanced Renal Cell Carcinoma Patients. JACC. Heart failure Hall, P. S., Harshman, L. C., Srinivas, S., Witteles, R. M. 2013; 1 (1): 72-78

  Abstract

  The purpose of this study was to document the incidence and extent of cardiovascular toxicity among advanced renal cell carcinoma patients treated with newer targeted cancer agents.The potential for targeted cancer agents to induce cardiovascular toxicity has been increasingly recognized, but the overall incidence and extent of toxicity have not been well characterized. Early detection of asymptomatic patients could preempt symptomatic toxicity and reduce treatment-related morbidity and mortality.The incidence of hypertension, left ventricular dysfunction, and heart failure was assessed for all advanced renal cell carcinoma patients treated with targeted therapies at our institution between 2004 and 2011. Grading was performed according to the Common Terminology Criteria for Adverse Events version 4.0.Cardiovascular toxicity developed in 116 of 159 patients (73%), including 52 of 159 patients (33%) when hypertension was excluded. Toxicity varied from occurrences of asymptomatic drops in left ventricular ejection fraction to rises in N-terminal-pro-B-type natriuretic peptide to severe heart failure. The tyrosine kinase inhibitor sunitinib was the agent most frequently used, with 66 of 101 sunitinib-treated patients (65%) developing a form of cardiovascular toxicity, including 32 of 101 patients (32%), excluding hypertension. Other VEGF inhibitors such as bevacizumab, sorafenib, and pazopanib also elicited significant cardiovascular toxicity with incidences ranging from 51% to 68%.The frequency and severity of cardiovascular toxicity in advanced renal cell carcinoma patients treated with targeted cancer therapies are high.

  View details for DOI 10.1016/j.jchf.2012.09.001

  View details for PubMedID 24621801

• The Frequency and Severity of Cardiovascular Toxicity From Targeted Therapy in Advanced Renal Cell Carcinoma Patients JACC-HEART FAILURE Hall, P. S., Harshman, L. C., Srinivas, S., Witteles, R. M. 2013; 1 (1): 72-78

  Abstract

  The purpose of this study was to document the incidence and extent of cardiovascular toxicity among advanced renal cell carcinoma patients treated with newer targeted cancer agents.The potential for targeted cancer agents to induce cardiovascular toxicity has been increasingly recognized, but the overall incidence and extent of toxicity have not been well characterized. Early detection of asymptomatic patients could preempt symptomatic toxicity and reduce treatment-related morbidity and mortality.The incidence of hypertension, left ventricular dysfunction, and heart failure was assessed for all advanced renal cell carcinoma patients treated with targeted therapies at our institution between 2004 and 2011. Grading was performed according to the Common Terminology Criteria for Adverse Events version 4.0.Cardiovascular toxicity developed in 116 of 159 patients (73%), including 52 of 159 patients (33%) when hypertension was excluded. Toxicity varied from occurrences of asymptomatic drops in left ventricular ejection fraction to rises in N-terminal-pro-B-type natriuretic peptide to severe heart failure. The tyrosine kinase inhibitor sunitinib was the agent most frequently used, with 66 of 101 sunitinib-treated patients (65%) developing a form of cardiovascular toxicity, including 32 of 101 patients (32%), excluding hypertension. Other VEGF inhibitors such as bevacizumab, sorafenib, and pazopanib also elicited significant cardiovascular toxicity with incidences ranging from 51% to 68%.The frequency and severity of cardiovascular toxicity in advanced renal cell carcinoma patients treated with targeted cancer therapies are high.

  View details for DOI 10.1016/j.jchf.2012.09.001

  View details for Web of Science ID 000209535300010

• Broken Heart Syndrome (Takotsubo Cardiomyopathy) Triggered by Acute Mania: A Review and Case Report PSYCHOSOMATICS Maldonado, J. R., Pajouhi, P., Witteles, R. 2013; 54 (1): 74-79

  View details for Web of Science ID 000313609900010

  View details for PubMedID 22795622

• Capecitabine-Induced Chest Pain Relieved by Diltiazem AMERICAN JOURNAL OF CARDIOLOGY Ambrosy, A. P., Kunz, P. L., Fisher, G. A., Witteles, R. M. 2012; 110 (11): 1623-1626

  Abstract

  Five patients with primary colorectal adenocarcinoma or anal squamous cell carcinoma were started on a 2-weeks-on, 1-week-off capecitabine dosing regimen in addition to other chemotherapeutic agents and/or radiation. Within the first few doses, patients experienced chest pain and/or dyspnea at rest or with exertion. Acute electrocardiographic findings suggestive of ischemia were found in some cases at initial presentation, and 1 patient had troponin elevation consistent with an acute ST-segment elevation myocardial infarction. Subsequent ischemia evaluations were not suggestive of clinically significant coronary artery disease. All patients experienced immediate and sustained relief from chest pain after discontinuation of capecitabine and were able to successfully tolerate retreatment using a novel management strategy based on secondary prophylaxis with diltiazem. In conclusion, guidelines for the evaluation of and therapy for capecitabine-induced chest pain are proposed.

  View details for DOI 10.1016/j.amjcard.2012.07.026

  View details for Web of Science ID 000311868000011

  View details for PubMedID 22939579

• Dipeptidyl Peptidase 4 Inhibition Increases Myocardial Glucose Uptake in Nonischemic Cardiomyopathy JOURNAL OF CARDIAC FAILURE Witteles, R. M., Keu, K. V., Quon, A., Tavana, H., Fowler, M. B. 2012; 18 (10): 804-809

  Abstract

  Glucose and fatty acids comprise the primary substrates for myocardial energy metabolism. The normal myocardium switches toward glucose metabolism in the setting of stress; the inability to affect such a switch is a fundamental mechanism behind "diabetic" or "insulin-resistant" cardiomyopathy. The purpose of this mechanistic study was to evaluate the effects of treatment with the dipeptidyl peptidase (DPP) 4 inhibitor sitagliptin on myocardial glucose uptake in patients with nonischemic cardiomyopathy.Twelve nondiabetic subjects with nonischemic cardiomyopathy underwent metabolic testing and assessment of myocardial glucose uptake by (18)F-fluorodeoxyglucose positron-emission tomographic/computerized tomographic imaging at baseline and after 4 weeks of sitagliptin therapy. Sitagliptin therapy resulted in a significant increase in myocardial glucose uptake (19% increase; P = .04). Although most patients had at least a slight increase in glucose uptake, there was an overall bimodal response, with 6 patients ("responders") demonstrating large increases (>20%) in glucose uptake and 6 patients ("nonresponders") demonstrating <5% increases or slight decreases. Triglyceride-high-density lipoprotein ratios significantly dropped in the 6 responders compared with the 6 nonresponders (P < .02).Therapy with the DPP-4 inhibitor sitagliptin results in increased myocardial glucose uptake in nondiabetic patients with nonischemic cardiomyopathy.

  View details for DOI 10.1016/j.cardfail.2012.07.009

  View details for Web of Science ID 000310179900009

  View details for PubMedID 23040117

• More Than a Frog in the Throat A Case Series and Review of Localized Laryngeal Amyloidosis ARCHIVES OF OTOLARYNGOLOGY-HEAD & NECK SURGERY Stevenson, R., Witteles, R., Damrose, E., Arai, S., Lafayette, R. A., Schrier, S., Afghahi, A., Liedtke, M. 2012; 138 (5): 509-511

  View details for Web of Science ID 000305415100012

  View details for PubMedID 22652951

• Cardiac Amyloidosis: Screening Criteria for Heart Transplantation and New Strategies for Post-Transplant Therapy 15th Annual Scientific Meeting of the Heart-Failure-Society-of-America Varr, B. C., Liedtke, M., Arai, S., Lafayette, R. A., Schrier, S. L., Witteles, R. M. CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS. 2011: S45–S46

  View details for Web of Science ID 000293938700145

• OVERUSE OF LEFT VENTRICULOGRAPHY 60th Annual Scientific Session and Expo of the American-College-of-Cardiology (ACC) / I2 Summit / ACCF/Herman K. Gold Young Investigator's Award in Molecular and Cellular Cardiology Witteles, R., Knowles, J. W., Perez, M., Morris, W. H., Spettell, C. M., Brennan, T. A., Heidenreich, P. A. ELSEVIER SCIENCE INC. 2011: E1289–E1289

  View details for Web of Science ID 000291695101292

• Trastuzumab-Related Cardiac Dysfunction JOURNAL OF THE NATIONAL COMPREHENSIVE CANCER NETWORK Telli, M. L., Witteles, R. M. 2011; 9 (2): 243-249

  Abstract

  The use of trastuzumab in the adjuvant and metastatic treatment of breast cancer is associated with both symptomatic and asymptomatic cardiotoxicity. The long-term significance of these events, isolating known cardiotoxic effects of anthracyclines from those of trastuzumab, and the appropriateness of referring to trastuzumab-related cardiotoxicity as reversible rather than responsive to trastuzumab withdrawal and heart failure medical therapy, are issues that continue to be debated. This article provides an overview of the available cardiac safety data from the major trastuzumab clinical trials in breast cancer, highlighting areas of ongoing controversy. Important recent data documenting the occurrence and prognostic use of cardiac troponin I elevations among patients treated with trastuzumab are placed into context with the mechanistic insight these data provide and the implications for clinical practice today.

  View details for Web of Science ID 000287942900005

  View details for PubMedID 21310845

• Renal sympathetic denervation in patients with treatment-resistant hypertension (The Symplicity HTN-2 Trial): a randomised controlled trial LANCET Esler, M. D., Krum, H., Sobotka, P. A., Schlaich, M. P., Schmieder, R. E., Boehm, M., Mahfoud, F., Sievert, H., Wunderlich, N., Rump, L. C., Vonend, O., Uder, M., Lobo, M., Caulfield, M., Erglis, A., Azizi, M., Sapoval, M., Thambar, S., Persu, A., Renkin, J., Schunkert, H., Weil, J., Hoppe, U. C., Walton, T., Scheinert, D., Binder, T., Januszewicz, A., Witkowski, A., Ruilope, L. M., Whitbourn, R., Bruck, H., Downes, M., Luescher, T. F., Jardine, A. G., Webster, M. W., Zeller, T., Sadowski, J., Bartus, K., Straley, C. A., Barman, N. C., Lee, D. P., Witteles, R. M., Bhalla, V., Massaro, J. M. 2010; 376 (9756): 1903-1909

  Abstract

  Activation of renal sympathetic nerves is key to pathogenesis of essential hypertension. We aimed to assess effectiveness and safety of catheter-based renal denervation for reduction of blood pressure in patients with treatment-resistant hypertension.In this multicentre, prospective, randomised trial, patients who had a baseline systolic blood pressure of 160 mm Hg or more (≥150 mm Hg for patients with type 2 diabetes), despite taking three or more antihypertensive drugs, were randomly allocated in a one-to-one ratio to undergo renal denervation with previous treatment or to maintain previous treatment alone (control group) at 24 participating centres. Randomisation was done with sealed envelopes. Data analysers were not masked to treatment assignment. The primary effectiveness endpoint was change in seated office-based measurement of systolic blood pressure at 6 months. Primary analysis included all patients remaining in follow-up at 6 months. This trial is registered with ClinicalTrials.gov, number NCT00888433.106 (56%) of 190 patients screened for eligibility were randomly allocated to renal denervation (n=52) or control (n=54) groups between June 9, 2009, and Jan 15, 2010. 49 (94%) of 52 patients who underwent renal denervation and 51 (94%) of 54 controls were assessed for the primary endpoint at 6 months. Office-based blood pressure measurements in the renal denervation group reduced by 32/12 mm Hg (SD 23/11, baseline of 178/96 mm Hg, p<0·0001), whereas they did not differ from baseline in the control group (change of 1/0 mm Hg [21/10], baseline of 178/97 mm Hg, p=0·77 systolic and p=0·83 diastolic). Between-group differences in blood pressure at 6 months were 33/11 mm Hg (p<0·0001). At 6 months, 41 (84%) of 49 patients who underwent renal denervation had a reduction in systolic blood pressure of 10 mm Hg or more, compared with 18 (35%) of 51 controls (p<0·0001). We noted no serious procedure-related or device-related complications and occurrence of adverse events did not differ between groups; one patient who had renal denervation had possible progression of an underlying atherosclerotic lesion, but required no treatment.Catheter-based renal denervation can safely be used to substantially reduce blood pressure in treatment-resistant hypertensive patients.Ardian.

  View details for DOI 10.1016/S0140-6736(10)62039-9

  View details for Web of Science ID 000285439800031

  View details for PubMedID 21093036

• A Pilot Study of Melphalan, Lenalidomide and Dexamethasone In AL Amyloidosis: Interim Results 52nd Annual Meeting and Exposition of the American-Society-of-Hematology (ASH) Afghahi, A., Witteles, W., Witteles, R., Liedtke, M., Lafayette, R., Arai, S., Schrier, S. L. AMER SOC HEMATOLOGY. 2010: 810–11

  View details for Web of Science ID 000289662202170

• Measurement Precision in the Optimization of Cardiac Resynchronization Therapy CIRCULATION-HEART FAILURE Turcott, R. G., Witteles, R. M., Wang, P. J., Vagelos, R. H., Fowler, M. B., Ashley, E. A. 2010; 3 (3): 395-404

  Abstract

  Cardiac resynchronization therapy improves morbidity and mortality in appropriately selected patients. Whether atrioventricular (AV) and interventricular (VV) pacing interval optimization confers further clinical improvement remains unclear. A variety of techniques are used to estimate optimum AV/VV intervals; however, the precision of their estimates and the ramifications of an imprecise estimate have not been characterized previously.An objective methodology for quantifying the precision of estimated optimum AV/VV intervals was developed, allowing physiologic effects to be distinguished from measurement variability. Optimization using multiple conventional techniques was conducted in individual sessions with 20 patients. Measures of stroke volume and dyssynchrony were obtained using impedance cardiography and echocardiographic methods, specifically, aortic velocity-time integral, mitral velocity-time integral, A-wave truncation, and septal-posterior wall motion delay. Echocardiographic methods yielded statistically insignificant data in the majority of patients (62%-82%). In contrast, impedance cardiography yielded statistically significant results in 84% and 75% of patients for AV and VV interval optimization, respectively. Individual cases demonstrated that accepting a plausible but statistically insignificant estimated optimum AV or VV interval can result in worse cardiac function than default values.Consideration of statistical significance is critical for validating clinical optimization data in individual patients and for comparing competing optimization techniques. Accepting an estimated optimum without knowledge of its precision can result in worse cardiac function than default settings and a misinterpretation of observed changes over time. In this study, only impedance cardiography yielded statistically significant AV and VV interval optimization data in the majority of patients.

  View details for DOI 10.1161/CIRCHEARTFAILURE.109.900076

  View details for Web of Science ID 000277825800009

  View details for PubMedID 20176716

• Rosiglitazone Increases Myocardial Glucose Metabolism in Insulin-Resistant Cardiomyopathy JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Kao, D. P., Witteles, R. M., Quon, A., Wu, J. C., Gambhir, S. S., Fowler, M. B. 2010; 55 (9): 926-927

  View details for DOI 10.1016/j.jacc.2009.08.085

  View details for Web of Science ID 000274865100015

  View details for PubMedID 20185047

• Nesiritide, Heart Failure, and Renal Dysfunction: Irrational Exuberance or Throwing the Baby out with the Bathwater Editorial to: "Impact of Nesiritide on Renal Function and Mortality in Patients Suffering from Heart Failure" by Dontas et al. CARDIOVASCULAR DRUGS AND THERAPY Witteles, R. M. 2009; 23 (3): 183-186

  View details for DOI 10.1007/s10557-009-6169-4

  View details for Web of Science ID 000268200100001

  View details for PubMedID 19353257

• Left ventricular dysfunction in patients receiving cardiotoxic cancer therapies: Are clinicians responding appropriately? 45th Annual Meeting of the American-Society-of-Clinical-Oncology (ASCO) Telli, M. L., Yoon, G., Kao, D., Matsuda, K., Witteles, R. M. AMER SOC CLINICAL ONCOLOGY. 2009

  View details for Web of Science ID 000276606606146

• Left Ventricular Dysfunction in Patients Receiving Cardiotoxic Cancer Therapies: Are Clinicians Responding Appropriately? 58th Annual Scientific Session of the American-College-of-Cardiology Yoon, G., Telli, M., Kao, D., Matsuda, K., Witteles, R. ELSEVIER SCIENCE INC. 2009: A173–A173

  View details for Web of Science ID 000263864200721

• Cardiotoxicity associated with the cancer therapeutic agent sunitinib malate ANNALS OF ONCOLOGY Telli, M. L., Witteles, R. M., Fisher, G. A., Srinivas, S. 2008; 19 (9): 1613-1618

  Abstract

  In the pivotal phase III metastatic renal cell carcinoma trial, updated data indicates that 21% of sunitinib-treated patients experienced a decline in left ventricular ejection fraction to below normal. This cardiotoxicity was reported to be reversible and without clinical sequelae. We conducted a retrospective analysis of our institutional experience of cardiotoxicity with sunitinib after observing a high incidence of symptomatic heart failure.Patients receiving sunitinib at Stanford University from 1 July 2004 to 1 July 2007 were identified. Medical records were reviewed and those patients experiencing symptomatic grade 3/4 left ventricular systolic dysfunction were identified. Potential cardiac risk factors were analyzed.Forty-eight patients treated with sunitinib were assessable. Seven patients experienced symptomatic grade 3/4 left ventricular dysfunction 22-435 days after initiation of sunitinib. Three patients had persistent cardiac dysfunction after discontinuation of sunitinib and initiation of heart failure therapy. A history of congestive heart failure, coronary artery disease and lower body mass index were factors associated with increased risk.Among patients treated with sunitinib at our institution, 15% developed symptomatic grade 3/4 heart failure. Future studies of sunitinib-related cardiotoxicity are urgently needed, particularly as the oncologic indications for this drug continue to expand.

  View details for DOI 10.1093/annonc/mdn168

  View details for Web of Science ID 000259505400015

  View details for PubMedID 18436521

• Trastuzumab cardiotoxicity: Clinical management of asymptomatic declines in left ventricular function The American Journal of Hematology/Oncology Telli ML, Witteles RM, Hunt SA, Carlson RW, Guardino AE 2008; 7 (1): 38-41
• Reversible high-output cardiac failure, an unusual marker of disease status in multiple myeloma Leukemia and Lymphoma Kohrt H, Logan A, Temmins C, Witteles R, Liedtke M, Medeiros B 2008; 49: 581-585
• Reversibility of trastuzumab cardiotoxicity: Is the concept alive and well? Journal of Clinical Oncology Telli ML, Carlson RW, Guardino AE, Hunt SA, Witteles RM. 2007; 25 (34): 5533-5534
• Premature ventricular contractions causing pacemaker-mediated tachycardia: A failure of postventricular atrial refractory period after premature ventricular contraction extension? HEART RHYTHM Witteles, R., Engel, G., Wang, P. J., Al-Ahmad, A. 2005; 2 (12): 1389-1390

  View details for DOI 10.1016/j.hrthm.2005.08.023

  View details for Web of Science ID 000234241200023

  View details for PubMedID 16360099

• B-type natriuretic peptide is effective therapy before cardiac transplantation Annals of Internal Medicine Witteles R, Matsuda K, Fowler MB 2004; 141 (11): 895
• High prevalence of impaired glucose metabolism in patients with idiopathic dilated cardiomyopathy Jamali, A. H., Witteles, R. M., Tang, W. H., Chu, J. W., Reaven, G. M., Fowler, M. B. ELSEVIER SCIENCE INC. 2002: 181A–181A

  View details for Web of Science ID 000174106700803

• Parathyroid carcinoma Surgery of the thyroid and parathyroid glands Witteles RM, Straus FH, Koka MLR, Kaplan EL 2002: 46.1-46.13
• Neuroendocrine tumors of the pancreas The Practice of General Surgery Buell J, Witteles RM, Koka MLR, Sugg SL, Kaplan EL 2002: 1083-1093
• Adult-onset nesidioblastosis causing hypoglycemia: An important clinical entity and continuing treatment dilemma Archives of Surgery Witteles RM, Straus II FH, Sugg SL, Koka MR, Costa EA, Kaplan EL 2001; 136 (6): 656-663
• Episodic hypertension associated with sitting on hard surfaces Journal of General Internal Medicine Witteles RM 2001; 16: 70
• A new provocative test for the diagnosis of pheochromocytoma? American Journal of Anesthesiology Witteles R, Roizen MF 2001; 28: 446-447
• Sensitivity of diagnostic and localization tests for pheochromocytoma in clinical practice Archives of Internal Medicine Witteles RM, Kaplan EL, Roizen MF 2000; 160 (16): 2521-2524
• Safe and cost-effective preoperative preparation of patients with pheochromocytoma Anesthesia and Analgesia Witteles RM, Kaplan EL, Roizen MF 2000; 91 (2): 302-304