Safety of reduced anti-thrombotic strategies in HeartMate II patients: A one-year analysis of the US-TRACE Study

Background Patients with bleeding complications during left ventricular assist device (LVAD) support often require a reduction in the recommended warfarin plus aspirin regimen. To characterize those who can be safely managed with a reduced anti-thrombotic strategy, the TRACE (STudy of Reduced Anti-Coagulation/Anti-platelEt Therapy in Patients with the HeartMate II LVAS) study was initiated in the United States (U.S.) and Europe. Methods The TRACE U.S. arm enrolled HeartMate II (HMII; Thoratec) outpatients on a regimen of reduced anti-thrombotic therapy (RT), defined as vitamin K antagonist (warfarin) only, aspirin only, or no anti-thrombotic agent. The indication for RT, changes in anti-thrombotic therapies, and patient outcomes after RT were documented. Results for patients reaching 12 months or outcome are presented here. Results Between April 2012 and June 2013, 100 HMII outpatients (85% men) on RT (median age 64.5 [interquartile range, 32, 82] years, 61% with ischemic etiology, 69% destination therapy) were enrolled from 9 U.S. sites. The primary reason for RT initiation was in response to a bleeding event (82%). Pharmacotherapy at RT initiation included warfarin only (38%), aspirin only (28%), or no anti-thrombotic agent (34%). Freedom from ischemic stroke at 1 year was 93.8% ± 2.5%, and freedom from device thrombosis was 92.7% ± 2.7%. Despite RT, a subsequent bleeding event occurred in 52%. Conclusions Reducing anti-thrombotic therapies in response to bleeding among HMII patients was achievable but may be associated with a higher risk for device thrombosis. Furthermore, despite an RT strategy, bleeding often will persist in those prone to such events.