John W. MacArthur

All Publications

• Bioengineered analog of stromal cell-derived factor 1α preserves the biaxial mechanical properties of native myocardium after infarction. Journal of the mechanical behavior of biomedical materials Wang, H. n., Wisneski, A. n., Paulsen, M. J., Imbrie-Moore, A. n., Wang, Z. n., Xuan, Y. n., Hernandez, H. L., Lucian, H. J., Eskandari, A. n., Thakore, A. D., Farry, J. M., Hironaka, C. E., von Bornstaedt, D. n., Steele, A. N., Stapleton, L. M., Williams, K. M., Wu, M. A., MacArthur, J. W., Woo, Y. J. 2019; 96: 165–71

  Abstract

  Adverse remodeling of the left ventricle (LV) after myocardial infarction (MI) results in abnormal tissue biomechanics and impaired cardiac function, often leading to heart failure. We hypothesized that intramyocardial delivery of engineered stromal cell-derived factor 1α analog (ESA), our previously-developed supra-efficient pro-angiogenic chemokine, preserves biaxial LV mechanical properties after MI. Male Wistar rats (n = 45) underwent sham surgery (n = 15) or permanent left anterior descending coronary artery ligation. Rats sustaining MI were randomized for intramyocardial injections of either saline (100 μL, n = 15) or ESA (6 μg/kg, n = 15), delivered at four standardized borderzone sites. After 4 weeks, echocardiography was performed, and the hearts were explanted. Tensile testing of the anterolateral LV wall was performed using a displacement-controlled biaxial load frame, and modulus was determined after constitutive modeling. At 4 weeks post-MI, compared to saline controls, ESA-treated hearts had greater wall thickness (1.68 ± 0.05 mm vs 1.42 ± 0.08 mm, p = 0.008), smaller end-diastolic LV internal dimension (6.88 ± 0.29 mm vs 7.69 ± 0.22 mm, p = 0.044), and improved ejection fraction (62.8 ± 3.0% vs 49.4 ± 4.5%, p = 0.014). Histologic analysis revealed significantly reduced infarct size for ESA-treated hearts compared to saline controls (29.4 ± 2.9% vs 41.6 ± 3.1%, p = 0.021). Infarcted hearts treated with ESA exhibited decreased modulus compared to those treated with saline in both the circumferential (211.5 ± 6.9 kPa vs 264.3 ± 12.5 kPa, p = 0.001) and longitudinal axes (194.5 ± 6.5 kPa vs 258.1 ± 14.4 kPa, p < 0.001). In both principal directions, ESA-treated infarcted hearts possessed similar tissue compliance as sham non-infarcted hearts. Overall, intramyocardial ESA therapy improves post-MI ventricular remodeling and function, reduces infarct size, and preserves native LV biaxial mechanical properties.

  View details for PubMedID 31035067

• SDF 1-alpha Attenuates Myocardial Injury Without Altering the Direct Contribution of Circulating Cells. Journal of cardiovascular translational research Goldstone, A. B., Burnett, C. E., Cohen, J. E., Paulsen, M. J., Eskandari, A., Edwards, B. E., Ingason, A. B., Steele, A. N., Patel, J. B., MacArthur, J. W., Shizuru, J. A., Woo, Y. J. 2018

  Abstract

  Stromal cell-derived factor 1-alpha (SDF) is a potent bone marrow chemokine capable of recruiting circulating progenitor populations to injured tissue. SDF has known angiogenic capabilities, but bone marrow-derived cellular contributions to tissue regeneration remain controversial. Bone marrow from DsRed-transgenic donors was transplanted into recipients to lineage-trace circulating cells after myocardial infarction (MI). SDF was delivered post-MI, and hearts were evaluated for recruitment and plasticity of bone marrow-derived populations. SDF treatment improved ventricular function, border zone vessel density, and CD31+ cell frequency post-MI. Bone marrow-derived endothelial cells were observed; these cells arose through both cell fusion and transdifferentiation. Circulating cells also adopted cardiomyocyte fates, but such events were exceedingly rare and almost exclusively resulted from cell fusion. SDF did not significantly alter the proportion of circulating cells that adopted non-hematopoietic fates. Mechanistic insight into the governance of circulating cells is essential to realizing the full potential of cytokine therapies.

  View details for PubMedID 29468554

• The tip of the iceberg: Evaluating the mechanism behind dehiscence of mitral annuloplasty rings. The Journal of thoracic and cardiovascular surgery MacArthur, J. W., Boyd, J. 2017

  View details for PubMedID 28947191

• Stem Cell Therapy: Healing or Hype? Why Stem Cell Delivery Doesn't Work CIRCULATION RESEARCH Steele, A. N., MacArthur, J. W., Woo, Y. 2017; 120 (12): 1868–70

  View details for PubMedID 28596172

• Injectable Bioengineered Hydrogel Therapy in the Treatment of Ischemic Cardiomyopathy. Current treatment options in cardiovascular medicine MacArthur, J. W., Steele, A. N., Goldstone, A. B., Cohen, J. E., Hiesinger, W., Woo, Y. J. 2017; 19 (4): 30-?

  Abstract

  Over the past two decades, the field of cardiovascular medicine has seen the rapid development of multiple different modalities for the treatment of ischemic myocardial disease. Most research efforts have focused on strategies aimed at coronary revascularization, with significant technological advances made in percutaneous coronary interventions as well as coronary artery bypass graft surgery. However, recent research efforts have shifted towards ways to address the downstream effects of myocardial infarction on both cellular and molecular levels. To this end, the broad application of injectable hydrogel therapy after myocardial infarction has stimulated tremendous interest. In this article, we will review what hydrogels are, how they can be bioengineered in unique ways to optimize therapeutic potential, and how they can be used as part of a treatment strategy after myocardial infarction.

  View details for DOI 10.1007/s11936-017-0530-x

  View details for PubMedID 28337717

• An innovative biologic system for photon-powered myocardium in the ischemic heart. Science advances Cohen, J. E., Goldstone, A. B., Paulsen, M. J., Shudo, Y. n., Steele, A. N., Edwards, B. B., Patel, J. B., MacArthur, J. W., Hopkins, M. S., Burnett, C. E., Jaatinen, K. J., Thakore, A. D., Farry, J. M., Truong, V. N., Bourdillon, A. T., Stapleton, L. M., Eskandari, A. n., Fairman, A. S., Hiesinger, W. n., Esipova, T. V., Patrick, W. L., Ji, K. n., Shizuru, J. A., Woo, Y. J. 2017; 3 (6): e1603078

  Abstract

  Coronary artery disease is one of the most common causes of death and disability, afflicting more than 15 million Americans. Although pharmacological advances and revascularization techniques have decreased mortality, many survivors will eventually succumb to heart failure secondary to the residual microvascular perfusion deficit that remains after revascularization. We present a novel system that rescues the myocardium from acute ischemia, using photosynthesis through intramyocardial delivery of the cyanobacterium Synechococcus elongatus. By using light rather than blood flow as a source of energy, photosynthetic therapy increases tissue oxygenation, maintains myocardial metabolism, and yields durable improvements in cardiac function during and after induction of ischemia. By circumventing blood flow entirely to provide tissue with oxygen and nutrients, this system has the potential to create a paradigm shift in the way ischemic heart disease is treated.

  View details for PubMedID 28630913

• Biochemically engineered stromal cell-derived factor 1-alpha analog increases perfusion in the ischemic hind limb. Journal of vascular surgery Edwards, B. B., Fairman, A. S., Cohen, J. E., Macarthur, J. W., Goldstone, A. B., Woo, J. B., Hiesinger, W., Woo, Y. J. 2016; 64 (4): 1093-1099

  Abstract

  Despite promising therapeutic innovation over the last decade, peripheral arterial disease remains a prevalent morbidity, as many patients are still challenged with peripheral ischemia. We hypothesized that delivery of engineered stromal cell-derived factor 1-alpha (ESA) in an ischemic hind limb will yield significant improvement in perfusion.Male rats underwent right femoral artery ligation, and animals were randomized to receive a 100 μL injection of saline (n = 9) or 6 μg/kg dosage of equal volume of ESA (n = 12) into the ipsilateral quadriceps muscle. Both groups of animals were also given an intraperitoneal injection of 40 μg/kg of granulocyte macrophage colony-stimulating factor (GMCSF). Perfusion was quantified using a laser Doppler imaging device preoperatively, and on postoperative days 0, 7, and 14. Immunohistochemistry was performed to quantify angiogenesis on day 14, and an mRNA profile was evaluated for angiogenic and inflammatory markers.Compared with the saline/GMCSF group at day 14, the ESA/GMCSF-injected animals had greater reperfusion ratios (Saline/GMCSF, 0.600 ± 0.140 vs ESA/GMCSF, 0.900 ± 0.181; group effect P = .006; time effect P < .0001; group×time effect P < .0001), elevated capillary density (10×; Saline/GMCSF, 6.40 ± 2.01 vs ESA/GMCSF, 18.55 ± 5.30; P < .01), and increased mRNA levels of vascular endothelial growth factor-A (Saline/GMCSF [n = 6], 0.298 ± 0.205 vs ESA/GMCSF [n = 8], 0.456 ± 0.139; P = .03).Delivery of ESA significantly improves perfusion in a rat model of peripheral arterial disease via improved neovasculogenesis, a finding which may prove beneficial in the treatment strategy for this debilitating disease.

  View details for DOI 10.1016/j.jvs.2015.06.140

  View details for PubMedID 26372192

• Cell transplantation in heart failure: where do we stand in 2016? EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY MacArthur, J. W., Goldstone, A. B., Cohen, J. E., Hiesinger, W., Woo, Y. 2016; 50 (3): 396–99

  View details for PubMedID 27587719

• Isolation and trans-differentiation of mesenchymal stromal cells into smooth muscle cells: Utility and applicability for cell-sheet engineering. Cytotherapy Shudo, Y., Cohen, J. E., Goldstone, A. B., MacArthur, J. W., Patel, J., Edwards, B. B., Hopkins, M. S., Steele, A. N., Joubert, L., Miyagawa, S., Sawa, Y., Woo, Y. J. 2016; 18 (4): 510-517

  Abstract

  Bone marrow (BM)-derived mesenchymal stromal cells (MSCs) have shown potential to differentiate into various cell types, including smooth muscle cells (SMCs). The extracellular matrix (ECM) represents an appealing and readily available source of SMCs for use in tissue engineering. In this study, we hypothesized that the ECM could be used to induce MSC differentiation to SMCs for engineered cell-sheet construction.Primary MSCs were isolated from the BM of Wistar rats, transferred and cultured on dishes coated with 3 different types of ECM: collagen type IV (Col IV), fibronectin (FN), and laminin (LM). Primary MSCs were also included as a control. The proportions of SMC (a smooth muscle actin [aSMA] and SM22a) and MSC markers were examined with flow cytometry and Western blotting, and cell proliferation rates were also quantified.Both FN and LM groups were able to induce differentiation of MSCs toward smooth muscle-like cell types, as evidenced by an increase in the proportion of SMC markers (aSMA; Col IV 42.3 ± 6.9%, FN 65.1 ± 6.5%, LM 59.3 ± 7.0%, Control 39.9 ± 3.1%; P = 0.02, SM22; Col IV 56.0 ± 7.7%, FN 74.2 ± 6.7%, LM 60.4 ± 8.7%, Control 44.9 ± 3.6%) and a decrease in that of MSC markers (CD105: Col IV 64.0 ± 5.2%, FN 57.6 ± 4.0%, LM 60.3 ± 7.0%, Control 85.3 ± 4.2%; P = 0.03). The LM group showed a decrease in overall cell proliferation, whereas FN and Col IV groups remained similar to control MSCs (Col IV, 9.0 ± 2.3%; FN, 9.8 ± 2.5%; LM, 4.3 ± 1.3%; Control, 9.8 ± 2.8%).Our findings indicate that ECM selection can guide differentiation of MSCs into the SMC lineage. Fibronectin preserved cellular proliferative capacity while yielding the highest proportion of differentiated SMCs, suggesting that FN-coated materials may be facilitate smooth muscle tissue engineering.

  View details for DOI 10.1016/j.jcyt.2016.01.012

  View details for PubMedID 26971679

• A Tissue-Engineered Chondrocyte Cell Sheet Induces Extracellular Matrix Modification to Enhance Ventricular Biomechanics and Attenuate Myocardial Stiffness in Ischemic Cardiomyopathy TISSUE ENGINEERING PART A Shudo, Y., Cohen, J. E., MacArthur, J. W., Goldstone, A. B., Otsuru, S., Trubelja, A., Patel, J., Edwards, B. B., Hung, G., Fairman, A. S., Brusalis, C., Hiesinger, W., Atluri, P., Hiraoka, A., Miyagawa, S., Sawa, Y., Woo, Y. J. 2015; 21 (19-20): 2515-2525

  Abstract

  There exists a substantial body of work describing cardiac support devices to mechanically support the left ventricle (LV); however, these devices lack biological effects. To remedy this, we implemented a cell sheet engineering approach utilizing chondrocytes, which in their natural environment produce a relatively elastic extracellular matrix (ECM) for a cushioning effect. Therefore, we hypothesized that a chondrocyte cell sheet applied to infarcted and borderzone myocardium will biologically enhance the ventricular ECM and increase elasticity to augment cardiac function in a model of ischemic cardiomyopathy (ICM). Primary articular cartilage chondrocytes of Wistar rats were isolated and cultured on temperature-responsive culture dishes to generate cell sheets. A rodent ICM model was created by ligating the left anterior descending coronary artery. Rats were divided into two groups: cell sheet transplantation (1.0 × 10(7) cells/dish) and no treatment. The cell sheet was placed onto the surface of the heart covering the infarct and borderzone areas. At 4 weeks following treatment, the decreased fibrotic extension and increased elastic microfiber networks in the infarct and borderzone areas correlated with this technology's potential to stimulate ECM formation. The enhanced ventricular elasticity was further confirmed by the axial stretch test, which revealed that the cell sheet tended to attenuate tensile modulus, a parameter of stiffness. This translated to increased wall thickness in the infarct area, decreased LV volume, wall stress, mass, and improvement of LV function. Thus, the chondrocyte cell sheet strengthens the ventricular biomechanical properties by inducing the formation of elastic microfiber networks in ICM, resulting in attenuated myocardial stiffness and improved myocardial function.

  View details for DOI 10.1089/ten.tea.2014.0155

  View details for PubMedID 26154752

• Evaluation of late aortic insufficiency with continuous flow left ventricular assist device†. European journal of cardio-thoracic surgery Hiraoka, A., Cohen, J. E., Shudo, Y., Macarthur, J. W., Howard, J. L., Fairman, A. S., Atluri, P., Kirkpatrick, J. N., Woo, Y. J. 2015; 48 (3): 400-406

  Abstract

  The aim of this study was to evaluate late development of aortic insufficiency (AI) with continuous flow left ventricular assist device (CLVAD). Development of AI is an increasingly recognized important complication in CLVAD therapy, but there are still few reports about this topic.We analysed data from 99 patients who underwent CLVAD implantation. De novo AI was defined as the development of mild or greater AI in patients with none or trace preoperative AI. Anatomic and functional correlates of de novo AI were investigated.Among the 17 patients with preoperative mild AI, no improvements were observed in mitral regurgitation or LV end-systolic dimension. Of the remaining 82 patients, de novo AI was identified in 43 patients (52%), on the most recent follow-up echocardiography, and did not influence survival nor improvement of LV geometry. Rate of freedom from de novo AI at 1 year after CLVAD implantation was 35.9%. Development of significantly greater AI was observed in patients without valve opening (AI grade 1.3 ± 1.0 vs 0.7 ± 0.9; P = 0.005). By multivariate Cox hazard model, smaller body surface area (BSA) [hazard ratio: 0.83 [95% confidence interval (CI): 0.72-0.97], P = 0.018], larger aortic root diameter (AOD) [hazard ratio: 1.11 (95% CI: 1.02-1.22), P = 0.012] and higher pulmonary artery systolic pressure (PASP) [hazard ratio: 1.24 (95% CI: 1.10-1.41), P < 0.001] were identified as the independent preoperative risk factors for de novo AI. In a subset of patients with speed adjustments, increase of CLVAD speed worsened AI and led to insufficient LV unloading in patients with aortic dilatation (AOD ≥ 3.5 cm).Any significant mortality difference related to preoperative or development of postimplant AI was not found. AI was associated with changes in LV size, and there appears to be an interaction between BSA, preoperative PASP, time since implant, aortic valve opening, aortic size and development of AI. Longitudinal clinical management in CLVAD patients, particularly in terms of CLVAD speed optimization, should include careful assessment.

  View details for DOI 10.1093/ejcts/ezu507

  View details for PubMedID 25653250

• A "Repair-All" Strategy for Degenerative Mitral Valve Disease Safely Minimizes Unnecessary Replacement ANNALS OF THORACIC SURGERY Goldstone, A. B., Cohen, J. E., Howard, J. L., Edwards, B. B., Acker, A. L., Hiesinger, W., MacArthur, J. W., Atluri, P., Woo, Y. J. 2015; 99 (6): 1983-1991

  Abstract

  We examined the feasibility and efficacy of a "repair-all" strategy applied in all patients with degenerative mitral regurgitation, regardless of valve complexity, risk profile, and surgical approach.Between 2002 and 2011, 4,241 patients underwent mitral operations at our institution. Analysis was limited to 525 consecutive patients with mitral regurgitation due to leaflet prolapse (posterior, 75%; anterior, 5%; bileaflet, 20%) who underwent isolated mitral operations. A right minithoracotomy was used in 46% of procedures. Propensity scores identified 153 well-matched patient pairs for evaluation of the effect of surgical approach on valve reparability.Mitral repair was successful in 99% (520 of 525) of patients. The location of the leaflet prolapse did not significantly influence the repair rate or the need for intraoperative revision of the initial repair. The repair rate and the need for intraoperative repair revision also did not significantly differ by surgical approach. Intraoperative revision did not confer a greater risk of perioperative morbidity or longer length of stay. At 8 years, freedom from severe mitral regurgitation was 97% ± 2%. Development of residual mitral regurgitation did not differ by location of the leaflet prolapse, need for repair revision, or surgical approach. After discharge, the survival trend did not differ between patients who did and did not require intraoperative repair revision.In experienced centers, a "repair-all" strategy for degenerative mitral regurgitation can be used with nearly 100% repair rates and excellent outcomes, regardless of valve complexity. When necessary, intraoperative revision of the initial repair may be performed in most patients without a significant incremental risk, thereby further enhancing repair rates.

  View details for DOI 10.1016/j.athoracsur.2014.12.076

  View details for Web of Science ID 000357521600028

  View details for PubMedID 25865766

• A "Repair-All" Strategy for Degenerative Mitral Valve Disease Safely Minimizes Unnecessary Replacement. Annals of thoracic surgery Goldstone, A. B., Cohen, J. E., Howard, J. L., Edwards, B. B., Acker, A. L., Hiesinger, W., Macarthur, J. W., Atluri, P., Woo, Y. J. 2015; 99 (6): 1983-1990

  Abstract

  We examined the feasibility and efficacy of a "repair-all" strategy applied in all patients with degenerative mitral regurgitation, regardless of valve complexity, risk profile, and surgical approach.Between 2002 and 2011, 4,241 patients underwent mitral operations at our institution. Analysis was limited to 525 consecutive patients with mitral regurgitation due to leaflet prolapse (posterior, 75%; anterior, 5%; bileaflet, 20%) who underwent isolated mitral operations. A right minithoracotomy was used in 46% of procedures. Propensity scores identified 153 well-matched patient pairs for evaluation of the effect of surgical approach on valve reparability.Mitral repair was successful in 99% (520 of 525) of patients. The location of the leaflet prolapse did not significantly influence the repair rate or the need for intraoperative revision of the initial repair. The repair rate and the need for intraoperative repair revision also did not significantly differ by surgical approach. Intraoperative revision did not confer a greater risk of perioperative morbidity or longer length of stay. At 8 years, freedom from severe mitral regurgitation was 97% ± 2%. Development of residual mitral regurgitation did not differ by location of the leaflet prolapse, need for repair revision, or surgical approach. After discharge, the survival trend did not differ between patients who did and did not require intraoperative repair revision.In experienced centers, a "repair-all" strategy for degenerative mitral regurgitation can be used with nearly 100% repair rates and excellent outcomes, regardless of valve complexity. When necessary, intraoperative revision of the initial repair may be performed in most patients without a significant incremental risk, thereby further enhancing repair rates.

  View details for DOI 10.1016/j.athoracsur.2014.12.076

  View details for PubMedID 25865766

• Non-resectional leaflet remodeling mitral valve repair preserves leaflet mobility: A quantitative echocardiographic analysis of mitral valve configuration INTERNATIONAL JOURNAL OF CARDIOLOGY Shudo, Y., Cohen, J. E., MacArthur, J. W., Goldstone, A. B., Hiraoka, A., Howard, J., Fairman, A. S., Patel, J., Edwards, B. B., Atluri, P., Woo, Y. J. 2015; 186: 16-18

  View details for DOI 10.1016/j.ijcard.2015.03.239

  View details for PubMedID 25804458

• Shear-Thinning Supramolecular Hydrogels with Secondary Autonomous Covalent Crosslinking to Modulate Viscoelastic Properties In Vivo ADVANCED FUNCTIONAL MATERIALS Rodell, C. B., MacArthur, J. W., Dorsey, S. M., Wade, R. J., Wang, L. L., Woo, Y. J., Burdick, J. A. 2015; 25 (4): 636-644

  Abstract

  Clinical percutaneous delivery of synthetically engineered hydrogels remains limited due to challenges posed by crosslinking kinetics - too fast leads to delivery failure, too slow limits material retention. To overcome this challenge, we exploit supramolecular assembly to localize hydrogels at the injection site and introduce subsequent covalent crosslinking to control final material properties. Supramolecular gels were designed through the separate pendant modifications of hyaluronic acid (HA) by the guest-host pair cyclodextrin and adamantane, enabling shear-thinning injection and high target site retention (>98%). Secondary covalent crosslinking occurred via addition of thiols and Michael-acceptors (i.e., methacrylates, acrylates, vinyl sulfones) on HA and increased hydrogel moduli (E=25.0±4.5kPa) and stability (>3.5 fold in vivo at 28 days). Application of the dual-crosslinking hydrogel to a myocardial infarct model showed improved outcomes relative to untreated and supramolecular hydrogel alone controls, demonstrating its potential in a range of applications where the precise delivery of hydrogels with tunable properties is desired.

  View details for DOI 10.1002/adfm.201403550

  View details for Web of Science ID 000348856500015

  View details for PubMedCentralID PMC4624407

• Shear-Thinning Supramolecular Hydrogels with Secondary Autonomous Covalent Crosslinking to Modulate Viscoelastic Properties In Vivo. Advanced functional materials Rodell, C. B., MacArthur, J. W., Dorsey, S. M., Wade, R. J., Wang, L. L., Woo, Y. J., Burdick, J. A. 2015; 25 (4): 636-644

  Abstract

  Clinical percutaneous delivery of synthetically engineered hydrogels remains limited due to challenges posed by crosslinking kinetics - too fast leads to delivery failure, too slow limits material retention. To overcome this challenge, we exploit supramolecular assembly to localize hydrogels at the injection site and introduce subsequent covalent crosslinking to control final material properties. Supramolecular gels were designed through the separate pendant modifications of hyaluronic acid (HA) by the guest-host pair cyclodextrin and adamantane, enabling shear-thinning injection and high target site retention (>98%). Secondary covalent crosslinking occurred via addition of thiols and Michael-acceptors (i.e., methacrylates, acrylates, vinyl sulfones) on HA and increased hydrogel moduli (E=25.0±4.5kPa) and stability (>3.5 fold in vivo at 28 days). Application of the dual-crosslinking hydrogel to a myocardial infarct model showed improved outcomes relative to untreated and supramolecular hydrogel alone controls, demonstrating its potential in a range of applications where the precise delivery of hydrogels with tunable properties is desired.

  View details for DOI 10.1002/adfm.201403550

  View details for PubMedID 26526097

  View details for PubMedCentralID PMC4624407

• Natural history of coexistent tricuspid regurgitation in patients with degenerative mitral valve disease: Implications for future guidelines JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Goldstone, A. B., Howard, J. L., Cohen, J. E., MacArthur, J. W., Atluri, P., Kirkpatrick, J. N., Woo, Y. J. 2014; 148 (6): 2802-2809

  Abstract

  The management of coexistent tricuspid regurgitation in patients with mitral regurgitation remains controversial. We sought to define the incidence and natural history of coexistent tricuspid regurgitation in patients undergoing isolated mitral surgery for degenerative mitral regurgitation, as well as the effect of late secondary tricuspid regurgitation on cardiovascular symptom burden and survival.To minimize confounding, analysis was limited to 495 consecutive patients who underwent isolated mitral surgery for degenerative mitral valve disease between 2002 and 2011. Patients with coexistent severe tricuspid regurgitation were excluded because such patients typically undergo concomitant tricuspid intervention.Grade 1 to 3 coexistent tricuspid regurgitation was present in 215 patients (43%) preoperatively. Actuarial freedom from grade 3 to 4 tricuspid regurgitation 1, 5, and 9 years after surgery was 100% ± 0%, 90% ± 2%, and 64% ± 7%, respectively. Older age (P < .001) and grade of preoperative tricuspid regurgitation (P = .006) independently predicted postoperative progression of tricuspid regurgitation on multivariable analysis. However, when limited to patients with mild or absent tricuspid regurgitation, indexed tricuspid annular diameter was the only significant risk factor for late tricuspid regurgitation (P = .04). New York Heart Association functional class and long-term survival did not worsen with development of late secondary tricuspid regurgitation (P = .4 and P = .6, respectively). However, right ventricular dysfunction was significantly more common in patients with more severe late tricuspid regurgitation (P = .007).Despite durable correction of degenerative mitral regurgitation, less than severe tricuspid regurgitation is likely to progress after surgery if uncorrected. Given the low incremental risk of tricuspid annuloplasty, a more aggressive strategy of concomitant tricuspid repair may be warranted.

  View details for DOI 10.1016/j.jtcvs.2014.08.001

  View details for PubMedID 25218532

• Tissue-engineered, hydrogel-based endothelial progenitor cell therapy robustly revascularizes ischemic myocardium and preserves ventricular function. journal of thoracic and cardiovascular surgery Atluri, P., Miller, J. S., Emery, R. J., Hung, G., Trubelja, A., Cohen, J. E., Lloyd, K., Han, J., Gaffey, A. C., MacArthur, J. W., Chen, C. S., Woo, Y. J. 2014; 148 (3): 1090-1098

  Abstract

  Cell-based angiogenic therapy for ischemic heart failure has had limited clinical impact, likely related to low cell retention (<1%) and dispersion. We developed a novel, tissue-engineered, hydrogel-based cell-delivery strategy to overcome these limitations and provide prolonged regional retention of myocardial endothelial progenitor cells at high cell dosage.Endothelial progenitor cells were isolated from Wistar rats and encapsulated in fibrin gels. In vitro viability was quantified using a fluorescent live-dead stain of transgenic enhanced green fluorescent protein(+) endothelial progenitor cells. Endothelial progenitor cell-laden constructs were implanted onto ischemic rat myocardium in a model of acute myocardial infarction (left anterior descending ligation) for 4 weeks. Intramyocardial cell injection (2 × 10(6) endothelial progenitor cells), empty fibrin, and isolated left anterior descending ligation groups served as controls. Hemodynamics were quantified using echocardiography, Doppler flow analysis, and intraventricular pressure-volume analysis. Vasculogenesis and ventricular geometry were quantified. Endothelial progenitor cell migration was analyzed by using endothelial progenitor cells from transgenic enhanced green fluorescent protein(+) rodents.Endothelial progenitor cells demonstrated an overall 88.7% viability for all matrix and cell conditions investigated after 48 hours. Histologic assessment of 1-week implants demonstrated significant migration of transgenic enhanced green fluorescent protein(+) endothelial progenitor cells from the fibrin matrix to the infarcted myocardium compared with intramyocardial cell injection (28 ± 12.3 cells/high power field vs 2.4 ± 2.1 cells/high power field, P = .0001). We also observed a marked increase in vasculogenesis at the implant site. Significant improvements in ventricular hemodynamics and geometry were present after endothelial progenitor cell-hydrogel therapy compared with control.We present a tissue-engineered, hydrogel-based endothelial progenitor cell-mediated therapy to enhance cell delivery, cell retention, vasculogenesis, and preservation of myocardial structure and function.

  View details for DOI 10.1016/j.jtcvs.2014.06.038

  View details for PubMedID 25129603

• Combined heart and liver transplantation can be safely performed with excellent short- and long-term results. Annals of thoracic surgery Atluri, P., Gaffey, A., Howard, J., Phillips, E., Goldstone, A. B., Hornsby, N., MacArthur, J. W., Cohen, J. E., Gutsche, J., Woo, Y. J. 2014; 98 (3): 858-862

  Abstract

  Heart transplant has become the gold standard therapy for end-stage heart failure. Short- and long-term outcomes after orthotopic heart transplant have been excellent. Many patients with heart failure manifest hepatic failure as a result of a chronically elevated central venous pressure. Concomitant hepatic failure has been a contraindication to heart transplant in most centers. A few select institutions are currently performing combined heart-liver transplantation to treat dual organ failure. The outcomes after dual organ transplant are largely unknown, with limited data from a few select centers. We undertook this study to analyze our large experience with combined heart-liver transplant and determine the short-term and long-term outcomes associated with this procedure.We have performed 1,050 heart transplants at our center to date. Of these patients, 26 underwent combined heart and liver transplant (largest single-center experience). We reviewed demographic, perioperative, and short- and long-term outcomes after this combined procedure.All 26 patients underwent successful dual organ transplant, without any episodes of primary graft dysfunction. Average length of intensive care unit stay was 10 ± 5 days, and average hospital stay was 25 ± 11 days. Kaplan-Meier analysis demonstrated excellent short-term survival (1 year, 87% ± 7%) and long-term survival (5 years, 83% ± 8%). Interestingly, only 3 patients (11%) demonstrated any evidence of rejection long-term by myocardial biopsy, suggesting that concomitant hepatic transplantation may provide immunologic protection for the cardiac allograft.We present the largest single-center series of combined heart and liver transplant. This dual organ strategy is highly feasible, with excellent long-term survival. Concomitant liver transplant may confer immunologic protection for the cardiac allograft.

  View details for DOI 10.1016/j.athoracsur.2014.04.100

  View details for PubMedID 25069688

• Bioengineered Stromal Cell- Derived Factor-1 alpha Analogue Delivered as an Angiogenic Therapy Significantly Restores Viscoelastic Material Properties of Infarcted Cardiac Muscle JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME Trubelja, A., MacArthur, J. W., Sarver, J. J., Cohen, J. E., Hung, G., Shudo, Y., Fairman, A. S., Patel, J., Edwards, B. B., Damrauer, S. M., Hiesinger, W., Atluri, P., Woo, Y. J. 2014; 136 (8)

  Abstract

  Ischemic heart disease is a major health problem worldwide, and current therapies fail to address microrevascularization. Previously, our group demonstrated that the sustained release of novel engineered stromal cell-derived factor 1-a analogue (ESA) limits infarct spreading, collagen deposition, improves cardiac function by promoting angiogenesis in the region surrounding the infarct, and restores the tensile properties of infarcted myocardium. In this study, using a well-established rat model of ischemic cardiomyopathy, we describe a novel and innovative method for analyzing the viscoelastic properties of infarcted myocardium. Our results demonstrate that, compared with a saline control group, animals treated with ESA have significantly improved myocardial relaxation rates, while reducing the transition strain, leading to restoration of left ventricular mechanics.

  View details for DOI 10.1115/1.4027731

  View details for Web of Science ID 000338507000012

• A bioengineered hydrogel system enables targeted and sustained intramyocardial delivery of neuregulin, activating the cardiomyocyte cell cycle and enhancing ventricular function in a murine model of ischemic cardiomyopathy. Circulation. Heart failure Cohen, J. E., Purcell, B. P., Macarthur, J. W., Mu, A., Shudo, Y., Patel, J. B., Brusalis, C. M., Trubelja, A., Fairman, A. S., Edwards, B. B., Davis, M. S., Hung, G., Hiesinger, W., Atluri, P., Margulies, K. B., Burdick, J. A., Woo, Y. J. 2014; 7 (4): 619-626

  Abstract

  Neuregulin-1β (NRG) is a member of the epidermal growth factor family possessing a critical role in cardiomyocyte development and proliferation. Systemic administration of NRG demonstrated efficacy in cardiomyopathy animal models, leading to clinical trials using daily NRG infusions. This approach is hindered by requiring daily infusions and off-target exposure. Therefore, this study aimed to encapsulate NRG in a hydrogel to be directly delivered to the myocardium, accomplishing sustained localized NRG delivery.NRG was encapsulated in hydrogel, and release over 14 days was confirmed by ELISA in vitro. Sprague-Dawley rats were used for cardiomyocyte isolation. Cells were stimulated by PBS, NRG, hydrogel, or NRG-hydrogel (NRG-HG) and evaluated for proliferation. Cardiomyocytes demonstrated EdU (5-ethynyl-2'-deoxyuridine) and phosphorylated histone H3 positivity in the NRG-HG group only. For in vivo studies, 2-month-old mice (n=60) underwent left anterior descending coronary artery ligation and were randomized to the 4 treatment groups mentioned. Only NRG-HG-treated mice demonstrated phosphorylated histone H3 and Ki67 positivity along with decreased caspase-3 activity compared with all controls. NRG was detected in myocardium 6 days after injection without evidence of off-target exposure in NRG-HG animals. At 2 weeks, the NRG-HG group exhibited enhanced left ventricular ejection fraction, decreased left ventricular area, and augmented borderzone thickness.Targeted and sustained delivery of NRG directly to the myocardial borderzone augments cardiomyocyte mitotic activity, decreases apoptosis, and greatly enhances left ventricular function in a model of ischemic cardiomyopathy. This novel approach to NRG administration avoids off-target exposure and represents a clinically translatable strategy in myocardial regenerative therapeutics.

  View details for DOI 10.1161/CIRCHEARTFAILURE.113.001273

  View details for PubMedID 24902740

• Preclinical evaluation of the engineered stem cell chemokine stromal cell-derived factor 1a analog in a translational ovine myocardial infarction model. Circulation research Macarthur, J. W., Cohen, J. E., McGarvey, J. R., Shudo, Y., Patel, J. B., Trubelja, A., Fairman, A. S., Edwards, B. B., Hung, G., Hiesinger, W., Goldstone, A. B., Atluri, P., Wilensky, R. L., Pilla, J. J., Gorman, J. H., Gorman, R. C., Woo, Y. J. 2014; 114 (4): 650-659

  Abstract

  After myocardial infarction, there is an inadequate blood supply to the myocardium, and the surrounding borderzone becomes hypocontractile.To develop a clinically translatable therapy, we hypothesized that in a preclinical ovine model of myocardial infarction, the modified endothelial progenitor stem cell chemokine, engineered stromal cell-derived factor 1α analog (ESA), would induce endothelial progenitor stem cell chemotaxis, limit adverse ventricular remodeling, and preserve borderzone contractility.Thirty-six adult male Dorset sheep underwent permanent ligation of the left anterior descending coronary artery, inducing an anteroapical infarction, and were randomized to borderzone injection of saline (n=18) or ESA (n=18). Ventricular function, geometry, and regional strain were assessed using cardiac MRI and pressure-volume catheter transduction. Bone marrow was harvested for in vitro analysis, and myocardial biopsies were taken for mRNA, protein, and immunohistochemical analysis. ESA induced greater chemotaxis of endothelial progenitor stem cells compared with saline (P<0.01) and was equivalent to recombinant stromal cell-derived factor 1α (P=0.27). Analysis of mRNA expression and protein levels in ESA-treated animals revealed reduced matrix metalloproteinase 2 in the borderzone (P<0.05), with elevated levels of tissue inhibitor of matrix metalloproteinase 1 and elastin in the infarct (P<0.05), whereas immunohistochemical analysis of borderzone myocardium showed increased capillary and arteriolar density in the ESA group (P<0.01). Animals in the ESA treatment group also had significant reductions in infarct size (P<0.01), increased maximal principle strain in the borderzone (P<0.01), and a steeper slope of the end-systolic pressure-volume relationship (P=0.01).The novel, biomolecularly designed peptide ESA induces chemotaxis of endothelial progenitor stem cells, stimulates neovasculogenesis, limits infarct expansion, and preserves contractility in an ovine model of myocardial infarction.

  View details for DOI 10.1161/CIRCRESAHA.114.302884

  View details for PubMedID 24366171