Spontaneous restoration of sinus rhythm during heart transplantation is associated with a reduced incidence of primary graft dysfunction and early mortality

Background: Insults to the donor heart during heart transplantation (HT) include ischemia and reperfusion injury after release of the aortic cross-clamp in the recipient. Restoration of heart beat after aortic unclamping can be by spontaneous resumption of sinus rhythm, pacing for atrioventricular (AV) block, or direct-current (DC) cardioversion for ventricular fibrillation. We investigated the association between mode of heart beat restoration and primary graft dysfunction (PGD).

Methods: HT recipients between 1997-2017 were grouped by mode of heart beat restoration after aortic unclamping into: spontaneous (S; 126 pts), pacing (P; 17 pts), or DC (58 pts) groups. Endpoints were 30-day mortality and PGD (defined by the ISHLT consensus statement).

Results: Baseline characteristics differing among the groups included proportion of women, pre-HT amiodarone and gender mismatch (Table). PGD was significantly higher for the P-group (71%) > DC-group (59%) >S-group (21%, p<0.001). Multivariable analysis consistently showed that restoration of sinus by DC, and pacing for AV block, were independently associated with significant ~5-fold and ~10-fold increased risk for PGD, respectively (Figure) compared to spontaneous sinus restoration. Consistently, 30-day mortality was significantly lower for S- (6%) than for DC- (17%) patients and highest for the P group (22%, p<0.001).

Conclusion: Spontaneous restoration of sinus after aortic unclamping at HT is associated with a reduced risk for PGD and early mortality, whereas pacing for AV block and DC are associated with an increased risk.