Characteristics And Procedural Complications Of Septal Myectomy For Obstructive Hypertrophic Cardiomyopathy In The United States.

Septal myectomy (SM) outcomes in patients with obstructive hypertrophic cardiomyopathy (oHCM) are derived from experienced centers' reports or survey data. In this study, we report the characteristics and procedural outcomes of SM in an all-payer oHCM cohort. An observational study using individual-level healthcare claims data (Symphony Health, covers ˃280 million enrollees). Adult patients with oHCM diagnosis who underwent SM (2016-2021) were included. Patients had to have ≥ 1 diagnosis claim (continuous enrollment) in the 120 days prior to SM. Baseline characteristics were derived from claims codes in the 90 days prior to SM. Inpatient complications (within 30 days post-SM) included a composite of: repeat SM, cardiac arrest, CPR, TIA/stroke, anoxic brain damage, hemothorax, tracheotomy, emergency intubation, ECMO, new dialysis, and ventricular septal defect. We identified 5,324 patients who underwent SM for oHCM (median age 62.0, 53.5% female, 70% with commercial insurance). Baseline characteristics are shown (Table 1). Concomitant mitral valve repair occurred in 33.4%, mitral valve replacement in 13.2%, papillary muscle intervention in 11.8%, and left atrial appendage clipping/excision in 11.8%. There were 48 (0.9%) patients without claims following SM. Inpatients events occurred in 627 (11.8%) patients. New atrial fibrillation/flutter occurred in 1498 (28.1%) patients and heart block requiring pacemaker implantation occurred in 526 (9.9%) patients. Repeat septal myectomy within 30 days was required in 43 (0.8%) patients. Predictors of inpatients complications are shown in Table 2. In a large cohort of patients with oHCM undergoing SM, morbidity resulting from SM complications was substantial. Further representative nationwide studies are needed to understand the long-term non-fatal outcomes of HCM patients post-SM. [ABSTRACT FROM AUTHOR]