Incremental value of left atrial active function measured by speckle tracking echocardiography in patients with hypertrophic cardiomyopathy

PURPOSE Hypertrophic cardiomyopathy (HCM) impairs left ventricular (LV) diastolic function leading to left atrial (LA) dilatation. Because Doppler echocardiography cannot accurately assess LV diastolic function in hearts with heterogeneous hypertrophy, assessment of LA function might be useful for risk stratification of patients with HCM. This study aimed to elucidate the impact of LA function on outcome in patients with patients. METHODS Seventy-six patients with HCM who underwent echocardiographic and cardiac magnetic resonance imaging were retrospectively enrolled. Twenty-six control subjects were also included. Using speckle tracking echocardiography, LA function was divided into active and passive strain indices based on the timing of the second positive peak of LA strain rate that occurred during LV systole. RESULTS Left atrial strain indices of active and passive function were significantly impaired concomitantly with increased LA volume index in HCM patients compared with controls. During follow-up (2.6 ± 1.7 years), 14 patients with HCM developed cardiac events (heart failure hospitalization or atrial fibrillation). The association of LA active strain with cardiac events was independent of and incremental to clinical and echocardiographic parameters (age, gender, E/e', LV global longitudinal strain, and LA volume index) in sequential models. Cardiac events were more frequent in HCM patients with LA active strain