“…Most of these studies relied upon single-center populations or public registries, both of which have significant limitations, and utilize analysis methods which may be less accurate when examining a time-varying hazard such as death after transplant (7). While acute right ventricular failure has been proposed as the mechanism of early death in patients with elevated PVRI (11,(14)(15)(16) this relationship is not clear, especially in the modern era of improved treatment of right ventricular failure (4,9,13,14,16,17). Additionally, decreasing the pulmonary vascular resistance pre-transplant, may or may not have an effect upon early mortality (5,18), suggesting that there are more important factors that play a role in early mortality than pulmonary vascular resistance.…”