The Impact Of Preexisting Hematologic Disorders On Morbidity And Mortality Following Heart Transplantation

Introduction Bleeding and thrombotic morbidity is common and impacts outcomes following heart transplantation (HT). HT candidates with pre-existing primary bleeding and clotting disorders (“hematology cohort-HC”) may represent a higher risk population. We aim to assess the short- and long-term outcomes of patients with preexisting bleeding or clotting disorders undergoing HT. Hypothesis : We hypothesize that HC will have higher rates of post-operative bleeding (requiring recurrent operative procedures), thrombotic complications, primary graft failure, and longer length of stay (LOS), as well as increased mortality, when compared to those without such hematologic conditions undergoing HT. Methods Patients who received HT from January 2010 to December 2019 were retrospectively reviewed, excluding re-transplantation and multi-organ recipients. HC was identified via chart review and adjudicated by a dedicated hematologist. Basic demographics and outcome variables were abstracted. Inverse probability weighting and multivariable logistic, negative binomial, and Cox proportional hazards models were used to adjust for potential pretransplant confounders. Results 494 HT patients were eligible for inclusion, of whom 29 were included in the HC (Table 1). HC consisted of heparin-induced thrombocytopenia (4 patients), immune thrombocytopenia purpura (4), possible antiphospholipid antibody syndrome (2), thrombocytosis (2), antithrombin III deficiency (1), Factor V Leiden (1), polycythemia vera (1), clinically relevant hypercoagulable state not otherwise specified (14). HC was associated with severe primary graft failure requiring ECMO (aOR 3.50 [1.31-9.33]; p=0.01) and longer post-transplant LOS (adjusted mean LOS 30.0 days for HC vs. 25.2 for control, p=0.04). There was no difference in mortality between the two groups, both in-hospital (aHR 0.83 [0.06-12.0], p=0.89) and at 5-year follow up (aHR 1.42 [0.53-3.84], p=0.49). Conclusions HT in patients with primary bleeding or clotting disorders is associated with increased risk of severe primary graft failure and longer LOS. Larger prospective studies are needed to assess the impact on mortality and determine the degree to which pre-existing hematologic conditions directly lead to post-transplant adverse outcomes.