MedicalResearch.com: What are the main findings of the study?
Dr. Pilote: Our study found that in patients with atrial fibrillation (AF) undergoing dialysis, warfarin use, compared to no-warfarin use, did not reduce the risk for stroke (adjusted hazard ratio (HR): 1.14, 95% confidence interval (CI): 0.78 to 1.67) but it was associated with a 44% higher risk for bleeding event (adjusted HR: 1.44, 95% CI: 1.13 to 1.85). However, warfarin use in non-dialysis patients with AF was associated with a 13% lower risk for stroke (adjusted HR: 0.87, 95% CI: 0.85 to 0.90) and only a 19% higher risk for bleeding event (adjusted HR: 1.19, 95% CI: 1.16 to 1.22).
MedicalResearch.com: Were any of the findings unexpected?
Dr. Pilote: Historically, warfarin is considered the most preferred anticoagulant for reducing stroke risk in most patients with Atrial Fibrillation. Theoretically, warfarin use should also reduce the stroke risk in patients with AF undergoing dialysis. However, in our study, we found that warfarin was not associated with reduction in stroke risk in patients with AF undergoing dialysis.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Pilote: Patients with Atrial Fibrillation undergoing dialysis or having end stage renal disease (ESRD) are definitely different than non-dialysis/non-ESRD patients with AF. Patients with AF undergoing dialysis have higher stroke and bleeding risk due to coagulation and platelet abnormalities, associated comorbidities (such as hypertension, diabetes), routine heparinization during dialysis, and warfarin associated vascular calcification. Our study and most of the previous studies on this issue indicate that warfarin use is not beneficial in reducing stroke risk in patients with AF undergoing dialysis but associated with a higher risk for bleeding.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Pilote: Due observational nature of our and previous studies, the study results may have limit clinical interpretability. A large multi-centre randomized controlled trial on this issue can only provide definite solution to this burning issue.
- Mitesh Shah,
- Meytal Avgil Tsadok,
- Cynthia A. Jackevicius,
- Vidal Essebag,
- Mark J. Eisenberg,
- Elham Rahme,
- Karin H. Humphries,
- Jack V. Tu,
- Hassan Behlouli,
- Helen Guo,
- and Louise Pilote