Assessing the Role of Primary Heart Failure Etiology on Cardiac Transplant Outcomes

Background: There are diverse indications for heart transplantation (HTx), often categorized into ischemic (ICM) and nonischemic (NICM) cardiomyopathy. Although there is extensive research comparing the outcomes for these disease processes following certain therapeutic interventions, there are limited data on how recipient etiology impacts post-HTx survival. Our investigation seeks to identify this relationship. Methods: We conducted a retrospective analysis using adult HTx patients from the United Network for Organ Sharing database between 2000 and 2021. Patients with a combined heart-lung transplant or previous HTx were excluded. ICM included coronary artery disease (CAD) and ischemic dilated cardiomyopathy. NICM included nonischemic dilated (NIDCM), hypertrophic (HCM), and restrictive (RCM) cardiomyopathy. Overall survival was analyzed using Kaplan-Meier curves, log-rank tests, and multivariable Cox regression models. Results: A total of 42 268 patients were included in our study. Recipients with ICM were older and more likely to be males, obese, diabetics, and smokers. We found that patients with ICM had an increased incidence of transplant CAD (OR = 1.23, p < 0.001) and risk of mortality (hazard ratio [HR] = 1.22, p < 0.001) compared to NICM. When NICM was expanded, RCM had a similar hazard risk compared to ICM (HR = 1.03, p = 0.650), whereas both NIDCM (HR = 0.81, p < 0.001) and HCM (HR = 0.70, p < 0.001) had improved survival. Conclusion: Our study provides evidence to suggest that ICM has decreased survival when compared to NICM. When NICM was expanded, RCM was found to have an increased mortality risk similar to ICM, whereas NIDCM and HCM both had superior outcomes. The clinical implication of this investigation will allow clinicians to better understand the prognosis of certain patient groups.