A retrospective analysis of anticoagulant safety among heart transplant recipients undergoing endomyocardial biopsy

Abstract Background Transvenous endomyocardial biopsy is an invasive procedure which is used to diagnose rejection following an orthotopic heart transplant. Endomyocardial biopsy is widely regarded as low risk with all‐cause complication rates below 5% in most safety studies. Following transplant, some patients require therapeutic anticoagulation. It is unknown whether anticoagulation increases endomyocardial biopsy bleeding risk. Methods Records from 2061 endomyocardial biopsies performed for post‐transplant rejection surveillance at our institution between November 2016 and August 2022 were reviewed. Bleeding complications were defined as vascular access‐related hematoma or bleeding, procedure‐related red blood cell transfusion, and new pericardial effusion. Relative risk and small sample‐adjusted 95% confidence interval was calculated to investigate the association between bleeding complications and anticoagulation. Results and Conclusions The overall risk of bleeding was 1.2% (25/2061 cases). There was a statistically significant increase in bleeding among patients on intravenous (RR 4.46, CI 1.09–18.32) but not oral anticoagulants (RR .62, CI .15–2.63) compared to patients without anticoagulant exposure. There was a trend toward increased bleeding among patients taking warfarin with INR ≥ 1.8 (RR 3.74, CI .90–15.43). Importantly, no bleeding events occurred in patients taking direct oral anticoagulants such as apixaban. Based on these results, intravenous rather than oral anticoagulation was associated with a significantly higher risk of bleeding complications following endomyocardial biopsy.