Clinical Outcomes of Concomitant Coronary Artery Bypass Grafting During Ventricular Septal Myectomy.

Background: The clinical characteristics and survival outcomes of patients who underwent concomitant coronary artery bypass grafting during septal myectomy have not been well studied.
Methods and Results: We reviewed patients who underwent both septal myectomy and coronary artery bypass grafting from 2009 to 2020. Causes of concomitant grafting and their impact on survival were analyzed. The median follow-up period was 5.1 years. A total of 320 patients underwent both grafting and myectomy. Of these, 69.7% and 28.1% underwent grafting attributed to atherosclerotic coronary artery disease and myocardial bridging, respectively. Patients who underwent grafting for coronary artery disease tended to be older, had a longer bypass time, and required more grafts compared with patients undergoing procedures because of myocardial bridging (all P <0.05). Postoperatively, the left ventricular outflow gradient significantly decreased from 85.4 mm Hg to 12.8 mm Hg ( P <0.001) without perioperative death. The cumulative survival rates were 96.2% and 97.6% at 5 years in the coronary artery disease and myocardial bridging groups, respectively, and they were comparable to that of general myectomy cohort (hazard ratio [HR], 1.06 [95% CI, 0.47-2.36], P =0.895 and HR 0.75 [95% CI, 0.23-2.46], P =0.636, respectively). Sudden death accounted for 45.5% (5 of 11) of postoperative mortality. Analysis of composite end point events showed decreased morbidity with at least one arterial graft in the overall cohort (HR, 0.47 [95% CI, 0.23-0.94], P =0.034).
Conclusions: Concomitant grafting in septal myectomy was found to be a safe procedure. Patients who underwent such surgery experienced favorable postoperative outcomes comparable to those who underwent septal myectomy alone, with a 5-year survival rate of >95% and improved functional class of >90%.