Bridge-to-Bridge Left Ventricular Assist Device Implantation Strategy vs. Primary Left Ventricular Assist Device Implantation Strategy

Background: The bridge-to-bridge (BTB) strategy, a conversion to durable left ventricular assist device (LVAD) after stabilization using surgical temporary mechanical circulatory supports for a couple of months, is not uncommon in Japan. However, its effect on clinical outcomes in comparison with a primary durable LVAD implantation strategy remains unknown. Methods and Results: Data of 837 consecutive patients (median age 45, 73% males) who underwent durable LVAD implantation as BTB (n=168) or primary implant (n=669) between April 2011 and April 2019 were retrospectively reviewed from the prospective multicenter Japanese mechanically assisted circulatory support registry. The BTB group was younger and had comparable end-organ function, better hemodynamic profile, and longer operative time compared with the primary implant group at baseline. The 3-year survival was 80% vs. 87% (P=0.007) for the BTB and primary implant groups respectively, with greater observed rates of stroke and infection as the predominant causes of death. The BTB strategy was independently associated with increased 3-year mortality (hazard ratio 2.69 [1.43–5.07], P=0.002) in addition to other significant risk factors. Conclusions: The BTB cohort had comparable baseline characteristics to the primary implant cohort at the time of durable LVAD conversion, but had lower 3-year survival. Detailed analysis clarifying the causality of this finding should improve outcomes with the BTB strategy.