Septal Myectomy and Concomitant Coronary Artery Bypass Grafting for Patients With Hypertrophic Cardiomyopathy and Coronary Artery Disease

Severe coronary artery disease is associated with disproportionately increased risks of death in patients with hypertrophic cardiomyopathy. There is a paucity of data on the long-term effect of coronary revascularization at the time of myectomy. Between January 1, 1961, and October 31, 2017, 2913 adult patients underwent transaortic septal myectomy at Mayo Clinic. Concomitant coronary artery bypass grafting (CABG) was performed in 246 (8.4%). We compared baseline characteristics of patients who underwent septal myectomy with and without CABG and assessed the effect of surgical revascularization on the risk of all-cause mortality. Patients who underwent concomitant CABG were older (median [interquartile range], 66.3 [59.8-72.1] years vs 54.4 [43.5-64.8] years; P<.0001) and more likely to be male (63.0% vs 54.2%; P=.008) than those who did not undergo coronary revascularization at operation. There was no significant difference in preoperative left ventricular outflow tract gradients (55 [25-81] mm Hg vs 58 [25-88] mm Hg; P=.116). Overall operative mortality (≤30 days after surgery) was 1.0% and higher in patients who underwent concomitant CABG (2.2% vs 0.8%; P=.048). In multivariable analysis (n=2641), factors independently associated with mortality included concomitant CABG (hazard ratio [95% CI], 1.89 [1.39-2.58]; P<.0001), older age at operation (per interquartile range increase, 2.79 [1.95-3.98]; P<.0001), atrial fibrillation (1.46 [1.11-1.92]; P=.006), diabetes (1.45 [1.04-2.04]; P=.031), higher body mass index (change from 0.95 to 0.5 quantile, 1.95 [1.46-2.59]; P<.0001), and surgery performed earlier in the study period (2.02 [1.31-3.11]; P=.001). In conclusion, obstructive coronary artery disease severe enough to prompt concomitant CABG at the time of septal myectomy is an important risk factor for late mortality.