Prognostic significance of left atrial volume dilatation in patients with hypertrophic cardiomyopathy.

To evaluate the prognostic role of left atrial (LA) volume in hypertrophic cardiomyopathy (HCM), LA volume was measured at baseline and during follow-up in 140 patients with HCM. Unfavorable outcome, defined as occurrence of sudden death, heart transplantation, or invasive reduction of obstruction, developed in 16 patients. In patients with enlarged LA volume (>27 mL/m(2)), there was an increased risk for unfavorable outcome (P = .0152). Patients with normal LA volume at baseline in whom volume increased more than 3 mL per year (fast dilating LA volume) had a worse prognosis than patients with normal and stable volume (P < .001) and similar to patients with dilated LA volume at baseline (P = not significant). LA volume dilated at baseline, fast dilating LA volume, and New York Heart Association functional class were independent predictors of unfavorable outcome development (odds ratio: 11.453; P = .021, P = 2.019, P = .020, respectively). The assessment of LA volume at baseline and during follow-up adds information regarding prognosis in patients with HCM.