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

Study Questions:

What are the predictors of long-term outcomes among symptomatic patients with hypertrophic cardiomyopathy who undergo surgical relief of left ventricular (LV) outflow tract obstruction?

Methods:

The study group was a cohort of 699 consecutive patients with hypertrophic cardiomyopathy and severe symptomatic LV outflow tract obstruction (47 ± 11 years, 63% male) intractable to maximal medical therapy who were referred to a tertiary care hospital between January 1997 and December 2007, for the surgical relief of LV outflow tract obstruction. Exclusion criteria included age <18 years, LV ejection fraction <50%, hypertensive heart disease of the elderly, and more than mild aortic or mitral stenosis. Clinical, echocardiographic, and Holter data were recorded. A composite endpoint was used, defined by death, appropriate implantable cardioverter-defibrillator discharge, resuscitation from sudden death, stroke, and admission for congestive heart failure.

Results:

During a mean follow-up of 6.2 ± 3 years, 86 patients (12%) met the composite endpoint with 30-day, 1-year, and 2-year event rates of 0.7%, 2.8%, and 4.7%, respectively. Rates of the composite of death, defibrillator discharge, and resuscitation from sudden death at 30 days, 1 year, and 2 years were 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 outcomes.

Conclusions:

The authors concluded that symptomatic adult patients with hypertrophic cardiomyopathy undergoing surgery for the relief of LV outflow tract obstruction have low event rates during long-term follow-up; and that worse outcomes are predicted by increasing age and the presence of residual atrial fibrillation during follow-up.

Perspective:

Performed in a large tertiary referral center, this study reported good medium-term (6.2 ± 3 years) outcomes after surgical intervention for symptomatic LV outflow obstruction in patients with hypertrophic cardiomyopathy and symptoms refractory to medical therapy. Symptoms (especially dyspnea) among patients with hypertrophic cardiomyopathy often are due to LV diastolic dysfunction, underscoring the importance of appropriate patient selection. Similarly, expertise is important in determining the nature of surgical intervention, which in this cohort included mitral valve repair or replacement as well as myectomy.

Keywords: Tertiary Care Centers, Stroke, Defibrillators, Follow-Up Studies, Resuscitation, Cardiomyopathy, Hypertrophic, Dyspnea, Incidence, Ventricular Outflow Obstruction, Patient Selection, Heart Failure, Mitral Valve Stenosis, Atrial Fibrillation, Confidence Intervals, Cardiac Surgical Procedures, Death, Sudden, Cardiac, Defibrillators, Implantable, Echocardiography


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