Ventricular Assist Device using a Thoracotomybased Implant Technique: Multi-center HeartMate 3 SWIFT Study

Objectives The HeartMate 3 (HM3) left ventricular assist device (LVAD) provides substantial improvement in long-term morbidity and mortality in advanced heart failure patients. The SWIFT study compares thoracotomy-based implantation clinical outcomes with standard median sternotomy. Methods We conducted a prospective, multicenter, single-arm study in patients eligible for HM3 implantation with thoracotomy-based surgical technique (bilateral thoracotomy or partial upper sternotomy with left thoracotomy). The composite primary endpoint was survival free of disabling stroke (Modified Rankin Score > 3), or reoperation to remove or replace a malfunctioning device, or conversion to median sternotomy at 6-months post-implant (elective transplants were treated as a success). The primary end point (non-inferiority, -15% margin) was assessed with >90% power compared to a propensity-matched cohort (ratio 1:2) derived from MOMENTUM 3 Continued Access Protocol (CAP). Results The study enrolled 102 patients between December 2020 and July 2022 in the thoracotomy-based arm at 23 North American Centers. Follow-up concluded in December 2022. In the SWIFT group non-inferiority criteria was met (absolute between-group difference, -1.2%; Farrington Manning lower, one-sided 95%CI: -9.3%, P<0.0025) and event-free survival was not different (85.0% versus 86.2%; HR 1.01, 95%CI 0.58-2.10). Length of stay with thoracotomy-based implant was longer (median 20 versus 17 days, p=0.03). No differences were observed for blood product utilization, adverse events (including right heart failure), functional status, and quality of life between cohorts. Conclusion Thoracotomy-based implantation of the HM3 LVAD is non-inferior to implantation via standard full sternotomy. This study supports thoracotomy-based implantation as an additional standard for surgical implantation of the HM3 LVAD.