Outcomes In Guideline-Based Class I Indication Versus Earlier Referral For Surgical Myectomy In Hypertrophic Obstructive Cardiomyopathy

BackgroundIn patients with obstructive hypertrophic cardiomyopathy, surgical myectomy (SM) is indicated for severe symptoms. We sought to compare long-term outcomes of patients with obstructive hypertrophic cardiomyopathy where SM was based on guideline-recommended Class I indication (Functional Class or FC >= 3 or angina/exertional syncope despite maximal medical therapy) versus earlier (FC 2 and/or impaired exercise capacity on exercise echocardiography with severe obstruction).Methods and ResultsWe studied 2268 consecutive patients (excluding <18 years, >= moderate aortic stenosis and subaortic membrane, 56 +/- 14 years, 55% men), who underwent SM at our center between June 2002 and March 2018. Clinical data, including left ventricular outflow tract gradient, were recorded. Death and/or appropriate internal defibrillator discharge were primary composite end points. One thousand three hundred eighteen (58%) patients met Class I indication and 950 (42%) underwent earlier surgery; 222 (10%) had a history of obstructive coronary artery disease. Basal septal thickness, and resting and maximal left ventricular outflow tract gradient were 2.0 +/- 0.3 cm, 61 +/- 44 mm Hg, and 100 +/- 31 mm Hg, respectively. At 6.2 +/- 4 years after SM, 248 (11%) had composite events (13 [0.6%] in-hospital deaths). Age (hazard ratio [HR], 1.61; 95% CI, 1.26-1.91), obstructive coronary artery disease (HR, 1.46; 95% CI, 1.06-1.91), and Class I versus earlier SM (HR, 1.61; 95% CI, 1.14-2.12) were associated with higher primary composite events (all P<0.001). Earlier surgery had better longer-term survival (similar to age-sex-matched normal population) versus surgery for Class I indication (76 [8%] versus 193 [15%], P<0.001).ConclusionsIn patients with obstructive hypertrophic cardiomyopathy, earlier versus surgery for Class I indication had a better long-term survival, similar to the age-sex-matched US population.