Prognostic Impact of Left Atrial Minimal Volume on Clinical Outcome in Patients with Non-Obstructive Hypertrophic Cardiomyopathy.

Maximal left atrial volume (LAVmax) has been suggested to be an important indicator of left ventricular (LV) diastolic function and a prognosticator in patients with hypertrophic cardiomyopathy (HCM). However, LAVmax can be influenced by LV longitudinal systolic function, which causes systolic descent of the mitral plane. We investigated the prognostic role of LAVmin in patients with HCM and tested if LAVmin is better than LAVmax in predicting clinical outcome in these patients. A total of 167 consecutive patients with HCM were enrolled (age = 64.7 ± 13.5 years, male: female = 120:47). Clinical parameters and conventional echocardiographic measurement including tissue Doppler measurement were evaluated. Left atrial maximal and minimal volumes were measured just before mitral valve opening and at mitral valve closure respectively using the biplane disk method. The relationship between LAVmin and the clinical outcome of hospitalization for heart failure (HF), stroke or all-cause mortality was evaluated. During a median follow-up of 25.0 ± 17.8 months, the primary end point of HF hospitalization, stroke or death occurred in 35 patients (21%). Indexed LAVmin was predictive of HF, stroke or death after adjustment for age, diabetes, hypertension, atrial fibrillation, LV ejection fraction, and E/e'in a multivariate analysis (P = 0.001). The model including indexed LAVmin was superior to the model including indexed LAVmax in predicting a worse outcome in patients with HCM (P = 0.02). In conclusion, LAVmin was independently associated with increased risk of HF, stroke, or mortality in patients with HCM and was superior to LAVmax in predicting clinical outcome in this population.