Effects of surgical septal myectomy on survival in patients with hypertrophic obstructive cardiomyopathy

Özet

Objective: The purpose of this study was to determine the effects of surgical resection of muscle layer on the long-term survival of patients withhypertrophic obstructive cardiomyopathy (HOCM).Methods: The original study cohort consisted of 552 patients with hypertrophic cardiomyopathy (HCM), including 380 patients with HOCM and172 patients with nonobstructive HCM. All these patients had a definite diagnosis in our center from October 1, 2009, to December 31, 2012. Theywere divided into three groups, viz., HOCM with myectomy group (n=194), nonoperated HOCM group (n=186), and nonobstructive HCM group(n=172). Median follow-up duration was 57.57±13.71 months, and the primary end point was a combination of mortality from all causes.Results: In this survival study, we compared the prognoses of patients with HOCM after myectomy, patients with nonoperated HOCM, andpatients with nonobstructive HCM. Among the three groups, the myectomy group showed a lower rate of reaching the all-cause mortality withstatistically indistinguishable overall survival compared with patients with nonobstructive HCM (p=0.514). Among patients with left ventricularoutflow tract (LVOT) obstruction, the overall survival in the myectomy group was noticeably better than that in the nonoperated HOCM group(log-rank p<0.001). Parameters that showed a significant univariate correlation with survival included age, previous atrial fibrillation (AF), NTproBNP, Cr, myectomy, and LV ejection fraction. When these variables were entered in the multivariate model, the only independent predictorsof survival were myotomy [hazard ratio (HR): 0.109; 95% CI: 0.013–0.877, p<0.037], age (HR: 1.047; 95% CI: 1.007–1.088, p=0.021), and previous AF(HR: 2.659; 95% CI: 1.022–6.919, p=0.021).Conclusion: Patients with HOCM undergoing myectomy appeared to suffer from a lower risk of reaching the all-cause mortality and demonstrated statistically indistinguishable overall survival compared with patients with nonobstructive HCM. Multivariate analysis clearly demonstratedmyectomy as a powerful, independent factor of survival, confirming that the differences in long-term survival recorded in this study may be dueto surgical improvement in the LVOT gradient. (Anatol J Cardiol 2020; 23: 342-8)