Implant Strategies Change Over Time and Impact Outcomes: Insights From the INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support)

Abstract

This study investigated how the initial intended strategy at left ventricular assist device (LVAD) implantation influenced patient outcomes. Left ventricular assist device implantation strategy impacts candidate selection, reimbursement, and clinical trial design; however, concepts of device strategy are continuing to evolve. For patients entered in the INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) receiving a primary continuous flow LVAD between March 2006 and March 2011, initial strategies were bridge to transplant (BTT), bridge to candidacy (BTC) for transplant, and destination therapy (DT). Primary analyses compared BTT, BTC, and DT outcomes at 6, 12, and 24 months. Among 2,816 primary LVAD recipients, implant strategy was 1,060 (38%) BTT, 1,162 (42%) BTC (likely to be listed 796, moderately likely 282, unlikely 84), and 553 (20%) DT. Compared with BTC/DT, those listed at implant (BTT) had similar degrees of ventricular dysfunction and hemodynamic derangement but generally less comorbidity. Survival (alive with LVAD or transplanted) was superior at 24 months for BTT versus BTC versus DT (77.7% vs.70.1% vs. 60.7%, respectively, p < 0.0001). Strategic intent changed over time, at 2 years 43.5% of BTT patients were no longer listed for transplant, but 29.3% of BTC patients were listed for transplant. The currently accepted indications only account for 58% of LVAD implants. Across indications, patients differ by the number and types of comorbidities rather than the need for hemodynamic support. Regardless of initial implant strategy, patients often have long durations of support, and strategies often change over time, challenging the regulatory categorization of LVAD recipients as either BTT or DT.