The outcome of restrictive cardiac allograft physiology in severe coronary allograft vasculopathy.

Background: Microvascular dysfunction after heart transplantation leads to restrictive cardiac allograft physiology (RCP), which is classified as severe coronary allograft vasculopathy (CAV); however, the prognosis of RCP remains unclear. Therefore, in this study, we aimed to elucidate the prognosis of RCP in comparison with that of severe angiographic CAV.

Methods: We assessed 116 patients with severe CAV who underwent heart transplantation between 2004 and 2023. RCP was defined as symptomatic heart failure with restrictive hemodynamic values (mean right atrial pressure >12 mm Hg, pulmonary capillary wedge pressure >25 mm Hg, and cardiac index <2.0 liter/min/m²). The primary outcome was death or retransplantation.

Results: Of the 116 patients with severe CAV, 42 had RCP (RCP-CAV group) and 74 had severe angiographic CAV without RCP (Angio-CAV group). A significantly shorter time from heart transplantation to diagnosis and lower subsequent percutaneous catheter intervention after diagnosis were seen in the RCP-CAV group than in the Angio-CAV group (both p < 0.001). Freedom from death or retransplantation at 5 years was significantly worse in the RCP-CAV group compared to the Angio-CAV group (18.4% vs 35.4%, p = 0.001). In the Cox proportional hazard model, RCP was independently associated with an increased risk of death or retransplantation (hazard ratio 2.08, 95% confidence intervals 1.26-3.44, p = 0.004).

Conclusions: The prognosis of patients with RCP was significantly worse than that of patients with severe angiographic CAV. The early detection of microvascular dysfunction and retransplantation listing may improve the prognosis of patients with RCP.