Inpatient outcomes of mechanical circulatory support devices and heart transplantation in hypertrophic cardiomyopathy

Introduction: The pathophysiology of HCM presents unique challenges for the management of cardiogenic shock and the use of mechanical circulatory support devices (MCSD). However, outcomes investigations for MCSD and HT in HCM patients is limited to case reports. The present study investigated MCSD and HT outcomes in HCM patients in a large retrospective cohort. Methods: The National Inpatient Sample (2016-2019) was used for the retrospective analysis of patients hospitalized for MCSD and HT using ICD-10 codes. Patients with implantation of more than one device category were excluded. These patients were divided into two cohorts, with and without HCM, and compared in terms of in-hospital mortality, trends in mortality rates, hospitalization costs and mean length of stay. Results: Among 267,780 patients hospitalized for MCSD and HT, 1155 patients had underlying HCM. Underlying HCM was associated with increased odds of mortality in patients receiving left ventricular assist devices (LVAD) (OR 3.4, 95% CI 1.03-11.2, p = 0.04) and temporary MCSD (OR 2.5, CI 1.8-3.6, p < 0.001). HCM was not associated with increased mortality in patients hospitalized for HT (OR 0.67, CI 0.15-2.85, p = 0.6). Patients with HCM undergoing MCSD and HT had a longer mean length of stay (22.1 vs 13.2 days, p = 0.004), and higher mean hospitalization charges ($830,103 vs $460,383, p < 0.0001) as compared to non-HCM patients. Conclusion: Underlying HCM is associated with increased in-hospital mortality in patients undergoing LVAD and temporary MCSD placement. Further prospective studies are required to expand our understanding of prognosis among HCM patients undergoing MCSD and establish management guidelines.