Abstract 4142703: Characteristics and Transplant Outcomes of Patients with End Stage Hypertrophic Cardiomyopathy Stratified By Genotype

Introduction: Harboring a likely pathogenic/pathogenic (LP/P) sarcomeric genetic variant has been shown to be a predictor of developing hypertrophic cardiomyopathy (HCM) with systolic dysfunction. There are limited data describing the associations between genotype and clinical outcomes of patients with end stage HCM. Methods: All patients with HCM who underwent both genetic testing and heart transplantation (HT) between 2011 and 2023 at a quaternary care center were included. Baseline characteristics, peri-HT management and outcomes were compared between patients with or without LP/P variants for HCM using summary statistics and survival analysis. Results: Between 2011 and 2023, 38 patients with HCM were transplanted. Of these 38, 29 patients underwent genetic testing, and LP/P variants thought to be casual for HCM were identified in 20 (Gene+) (Table 1). Female patients composed 40% of the Gene+ cohort compared to 89% of the gene-negative (Gene-) cohort (p=0.04). The majority of LP/P variants were in MYH7 (7/20) and MYBPC3 (5/20). Pre-transplant cardiometabolic comorbidities were prevalent in both groups. Pre-transplant LVEFs were not significantly different (47% [IQR 34.0, 57.5] in Gene+; 55% [IQR 42.0, 60.0] in Gene-; p=0.23). Pre-transplant medication management and bridge to transplant strategies were similar between the two groups. NYHA Class at time of HT was higher in the Gene+ cohort (p=0.04), though a similar percentage of patients in both cohorts were upgraded to higher UNOS statuses while on the waitlist. Survival at 30, 90 and 180-days after HT (Figure) and incidence of rejection during the year following HT were similar in both cohorts (Table 2). Conclusion: Further investigation is needed to elucidate the impact of genotype on outcomes in end stage HCM.