JUAN A. CRESTANELLO: Welcome to the Cardiovascular Surgery Series. I am Dr. Juan Crestanello from the Mayo Clinic. I will discuss today mitral annular calcification in obstructive hypertrophic cardiomyopathy, prevalence and outcomes.

Echocardiograms of more than 2,100 patients who underwent septal myectomimes for hypertrophic obstructive cardiomyopathy were reviewed to identify the prevalence of mitral annular calcification. Mitral annular calcification was present in 18% of these patients. Patients with MAC were older, more often female, and had many cardiovascular risk factors, such as hypertension, diabetes, atrial fibrillation, cerebrovascular disease, peripheral vascular disease, and coronary artery disease.

Preoperative echocardiogram demonstrated that they had worse preoperative mitral regurgitation, higher left ventricular outflow tract gradients and a higher rate of pulmonary hypertension. During myectomy, patients with MAC were more likely to have mitral valve surgery. And among those patients, mitral valve replacement was more commonly performed. MAC patients also had aortic and coronary artery bypass procedures performed during the myectomy.

The operative mortality was 0.4% and similar among patients with MAC and those without MAC. LVOT of structural reduction was achieved similarly in both groups. Patients with MAC had a higher rate of residual moderate or severe mitral regurgitation. The adjusted long-term survival was worse for patients with MAC with an increased rate of cardiovascular mortality.

We conclude that MAC is common in patients presenting for septal myectomy. Patients with MAC tend to have a higher prevalence of comorbidities. Mitral valve dysfunction is common and more likely to undergo concomitant mitral valve procedures during the septal myectomy. Despite a satisfactory relief of the left ventricular outflow tract obstruction, patients with MAC have reduced overall survival and greater frequency of residual mitral regurgitation.

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