Predictors of Long-Term Outcomes in Symptomatic Hypertrophic Obstructive Cardiomyopathy Patients Undergoing Surgical Relief of Left Ventricular Outflow Tract Obstruction

Background We report the predictors of long-term outcomes of symptomatic hypertrophic cardiomyopathy patients undergoing surgical relief of left ventricular outflow tract obstruction. Methods and Results We studied 699 consecutive patients who have hypertrophic cardiomyopathy with severe symptomatic left ventricular outflow tract obstruction (47 +/- 11 years, 63% male) intractable to maximal medical therapy, who were referred to a tertiary hospital between January 1997 and December 2007 for the surgical relief of left ventricular outflow tract obstruction. We excluded patients <18 years of age, those with an ejection fraction <50%, those with hypertensive heart disease of the elderly, and those with more than mild aortic or mitral stenosis. Clinical, echocardiographic, and Holter data were recorded. A composite end point of death, appropriate internal cardioverter defibrillator discharges, resuscitated from sudden death, documented stroke, and admission for congestive heart failure was recorded. During a mean follow-up of 6.2 +/- 3 years, 86 patients (12%) met the composite end point with 30-day, 1-year, and 2-year event rates of 0.7%, 2.8%, and 4.7%, respectively. The hard event rate (death, defibrillator discharge, and resuscitated from sudden death) at 30 days, 1 year, and 2 years was 0%, 1.5%, and 3%, respectively. Stepwise multivariable analysis identified residual postoperative atrial fibrillation (hazard ratio, 2.12; confidence interval, 1.37-3.34; P=0.001) and increasing age (hazard ratio, 1.49; confidence interval, 1.22-1.82; P=0.001) as independent predictors of long-term composite outcomes. Conclusions Symptomatic adult hypertrophic cardiomyopathy patients undergoing surgery for the relief of left ventricular outflow tract obstruction have low event rates during long-term follow-up; worse outcomes are predicted by increasing age and the presence of residual atrial fibrillation during follow-up.