Impact of combined heart and lung transplantation on bronchiolitis obliterans syndrome, cardiac allograft vasculopathy, and long-term survival.

Background: Evidence from animal studies and small case series suggests that primary graft dysfunction occurs less often following combined organ transplantation than following isolated organ transplantation. In this large-scale national registry study, we aimed to investigate whether survival and the rates of bronchiolitis obliterans syndrome (BOS) and coronary allograft vasculopathy (CAV) are affected by simultaneous heart and/or lung transplantation (HLTx).

Methods: Clinical data from the United Network of Organ Sharing database were retrospectively reviewed to identify transplant-naive patients who had undergone heart and/or lung transplantation between 1987 and 2016. The comparisons were conducted for isolated vs combined organ transplant. The outcomes included all-cause mortality, as well as the incidence of BOS and CAV RESULTS: Of the 98,310 patients reviewed, 63,976, 1,189, and 33,145 had received isolated heart transplantation (iHTx) (65%), HLTx (1%), and isolated lung transplantation (iLTx) (34%), respectively. In the early post-operative period, the mortality rates were higher after HLTx than after iHTx or iLTx (on crude and propensity score-matched analyses). However, the adjusted hazard risk for mortality associated with HLTx was significantly lower relative to the iLTx-associated risk beyond 3 years postoperatively, and similar relative to the iHTx-associated risk beyond 7 years postoperatively. On both crude and adjusted analyses, the incidence of BOS and CAV was significantly lower after HLTx than after iHTx or iLTx (p < 0.001 for all comparisons).

Conclusions: Combined (rather than single) organ transplantation may provide immunoprotective benefits enhancing long-term survival and attenuating the risk of BOS and CAV.