Dr. Diep is a board-certified, fellowship-trained hematologist with Stanford’s Hematology Program and Hematologic Cancer Program. He is also a clinical assistant professor with the Department of Medicine, Division of Hematology.

He diagnoses and treats patients with a wide range of nonmalignant hematology conditions. His special interests include clotting disorders, bleeding disorders, hemoglobinopathies, and disorders affecting blood count. Subspecialty interests include anticoagulation and thrombosis.

Dr. Diep’s practice style emphasizes shared decision-making by building patient-physician relationships and using the best available evidence to create treatment plans. He is passionate about improving care for patients with blood disorders and has helped expand access to hematology care by launching an electronic consult service for primary care providers.

Dr. Diep’s research interests include anticoagulation, thrombosis, and bleeding disorders. He has participated in research projects that have received funding from the National Heart, Lung, and Blood Institute.

Dr. Diep has published in multiple peer-reviewed journals, and has presented to his peers at national and regional meetings.

He is a member of the American Society of Hematology, American Society of Clinical Oncology, Hemostasis and Thrombosis Research Society, International Society of Hemostasis and Thrombosis, and Anticoagulation Forum. Dr. Diep serves as quality director for the Division of Hematology.

Clinical Focus

  • Hematology

Academic Appointments

Honors & Awards

  • Alpha Omega Alpha, Renaissance School of Medicine at Stony Brook University (2015)
  • Gold Humanism Honor Society, Renaissance School of Medicine at Stony Brook University (2015)

Boards, Advisory Committees, Professional Organizations

  • Panel Member, Cancer-Associated Venous Thromboembolic Disease Guideline Committee, National Comprehensive Cancer Network (2023 - Present)

Professional Education

  • Board Certification: American Board of Internal Medicine, Medical Oncology (2021)
  • Residency: Duke University School of Medicine (2018) NC
  • Board Certification: American Board of Internal Medicine, Hematology (2021)
  • Fellowship: University of Washington Hem/Onc Fellowship Pgm (2021) WA
  • Board Certification: American Board of Internal Medicine, Internal Medicine (2018)
  • Medical Education: Stony Brook University School of Medicine (2015) NY

All Publications

  • In COVID-19, therapeutic vs. prophylactic anticoagulation did not improve clinical outcomes and increased bleeding. Annals of internal medicine Diep, R., Garcia, D. 2021


    Lopes RD, de Barros E Silva PG, Furtado RH, et al. Therapeutic versus prophylactic anticoagulation for patients admitted to hospital with COVID-19 and elevated D-dimer concentration (ACTION): an open-label, multicentre, randomised, controlled trial. Lancet. 2021;397:2253-63. 34097856.

    View details for DOI 10.7326/ACPJ202110190-112

    View details for PubMedID 34606319

  • Does aspirin prevent venous thromboembolism? Hematology. American Society of Hematology. Education Program Diep, R., Garcia, D. 2020; 2020 (1): 634-641


    Venous thromboembolism (VTE; deep vein thrombosis and/or pulmonary embolism) is a well-established cause of morbidity and mortality in the medical and surgical patient populations. Clinical research in the prevention and treatment of VTE has been a dynamic field of study, with investigations into various treatment modalities ranging from mechanical prophylaxis to the direct oral anticoagulants. Aspirin has long been an inexpensive cornerstone of arterial vascular disease therapy, but its role in the primary or secondary prophylaxis of VTE has been debated. Risk-benefit tradeoffs between aspirin and anticoagulants have changed, in part due to advances in surgical technique and postoperative care, and in part due to the development of safe, easy-to-use oral anticoagulants. We review the proposed mechanisms in which aspirin may act on venous thrombosis, the evidence for aspirin use in the primary and secondary prophylaxis of VTE, and the risk of bleeding with aspirin as compared with anticoagulation.

    View details for DOI 10.1182/hematology.2020000150

    View details for PubMedID 33275727

    View details for PubMedCentralID PMC7727539

  • Should we monitor the direct oral anticoagulants? Journal of thrombosis and thrombolysis Diep, R., Garcia, D. 2020; 50 (1): 30-32

    View details for DOI 10.1007/s11239-020-02119-2

    View details for PubMedID 32323189

    View details for PubMedCentralID PMC7433889

  • A novel nucleotide substitution in the 5' untranslated region of ANKRD26 gene is associated with inherited thrombocytopenia: a report of two new families. Annals of hematology Diep, R. T., Corey, K., Arcasoy, M. O. 2019; 98 (7): 1789-1791

    View details for DOI 10.1007/s00277-019-03632-y

    View details for PubMedID 30747248

  • A rare CALR variant mutation and a review of CALR in essential thrombocythemia. Journal of thrombosis and thrombolysis Diep, R., Metjian, A. 2018; 45 (3): 457-462


    Essential thrombocythemia (ET) is an indolent myeloproliferative neoplasm characterized by megakaryocyte hyperplasia, thrombocytosis, thrombotic and hemorrhagic complications, and potential transformation into myelofibrosis and acute myeloid leukemia. The vast majority of cases are driven by a somatic mutation in JAK2, CALR, or MPL. CALR, a gene that codes for the calcium-binding chaperone calreticulin, is the predominant mutation in patients with non-mutated JAK2 essential thrombocythemia, accounting for 20-25% of the overall somatic mutation frequency in ET. In this brief review of ET, we introduce a rare CALR mutation through a case presentation of a 58-year-old man with diffuse pulmonary emboli in the setting of thrombocytosis. We subsequently characterize the main types of CALR mutations and their value in diagnosis and prognosis of disease course, and lastly discuss the current clinical approach to ET.

    View details for DOI 10.1007/s11239-018-1619-0

    View details for PubMedID 29411299

  • Pregnancy in patients with thrombocytopenia and absent radii (TAR) syndrome. Annals of hematology Diep, R. T., Arcasoy, M. O. 2017; 96 (9): 1589-1590

    View details for DOI 10.1007/s00277-017-3053-3

    View details for PubMedID 28730453

  • Awareness of Chronic Kidney Disease and Depressive Symptoms: National Health and Nutrition Examination Surveys 2005-2010. American journal of nephrology Shirazian, S., Diep, R., Jacobson, A. M., Grant, C. D., Mattana, J., Calixte, R. 2016; 44 (1): 1-10


    Depressive symptoms are common in patients with chronic kidney disease (CKD) and may stem from distress associated with CKD awareness. So far, no studies have examined this association. The objective of this study was to evaluate the association between awareness of CKD and depressive symptoms.We included adults with stages 1-4 CKD (estimated glomerular filtration rate 15-60 ml/min/1.73 m2 or urine albumin-to-creatinine ratio ≥30 mg/g) using the National Health and Nutrition Examination Surveys from 2005 to 2010. Depressive symptoms were categorized as minimal (9-item Patient Health Questionnaire (PHQ-9) score 0-4), subthreshold (PHQ-9 score 5-14) and severe (PHQ-9 score ≥15). Participants were classified as aware of CKD if they answered yes to the question: 'Have you ever been told you have weak or failing kidneys?' Multivariable logistic regression was used to identify variables independently associated with at least subthreshold depressive symptoms (PHQ-9 ≥5).In 2,500 participants with CKD, the weighted prevalence was 21.4% for subthreshold and 3.1% for severe depressive symptoms. The weighted prevalence of CKD awareness was 6.4%. Independent predictors of depressive symptoms included younger age, female gender, never been married, less than high-school education, annual family income <$20,000, obesity, smoking, cardiovascular comorbidity and mental health visit in the past year. CKD awareness was independently associated with a 1.66 greater odds of depressive symptoms (95% CI 1.01-2.74, p < 0.05).Awareness of CKD is significantly associated with depressive symptoms independent of known confounding factors. Future studies should examine mediators of this association, especially in light of national efforts to promote CKD awareness.

    View details for DOI 10.1159/000446929

    View details for PubMedID 27322107

  • Cough and wheeze events are temporally associated with increased pain in individuals with sickle cell disease without asthma. British journal of haematology Diep, R. T., Busani, S., Simon, J., Punzalan, A., Skloot, G. S., Glassberg, J. A. 2015; 170 (5): 732-4

    View details for DOI 10.1111/bjh.13325

    View details for PubMedID 25753135

    View details for PubMedCentralID PMC4534319