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

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.