Hypertrophic obstructive cardiomyopathy (HOCM) is a complex genetic disorder with unique pathophysiologic characteristics most often caused by mutations in the genes encoding the cardiomyocytes' thick and thin filament proteins [1]. The current estimated prevalence of HOCM ranges from 0.16% to 0.29% in the general adult population [[2], [3], [4], [5]]. However, this condition remains widely underrecognized in women and underserved communities. HOCM is characterized by left ventricular hypertrophy (LVH) of various morphologies that is complicated with dynamic LVOT obstruction and heterogenous clinical presentation in the absence of alternate diagnoses.

While substantial data are available regarding the perioperative evaluation and cardiovascular risk assessment in patients with atherosclerotic coronary artery disease undergoing noncardiac surgery, current evidence regarding such risks and outcomes in patients with confirmed HOCM diagnosis is still lacking [6]. This is primarily due to the relative infrequency of this presentation and its wide array of hemodynamic abnormalities. Even though patients with HOCM have the potential for significant morbidity and mortality and not uncommonly encounter adverse perioperative outcomes. The pathophysiologic determinants of these negative outcomes include left ventricular outflow tract (LVOT) dynamic obstruction, systolic or diastolic dysfunction with impaired filling, impaired coronary vasodilator reserve, myocardial ischemia with poor myocardial function, mitral regurgitation, and supraventricular or ventricular arrhythmias. Predictors of adverse perioperative cardiac events in HOCM patients include the duration of surgery (P < 0.01) and the magnitude of the surgical procedure (major surgery P < 0.05) [7]. This is probably primarily because of inevitable factors leading to hemodynamic fluctuation and the alteration of contractility, preload, afterload, and sympathetic activation during anesthesia induction, laryngoscopy, intubation, the stress of surgery, and blood loss.

Our study aims to interrogate the National Readmission Database (NRD) to determine the perioperative outcomes of the HOCM population compared to non-HOCM all-comers.