Left Atrial Volume Index: A Predictor of Adverse Outcome in Patients With Hypertrophic Cardiomyopathy

To the Editor:

I read with great interest the report by Yang et al1 on the value of the left atrial (LA) volume index for predicting adverse outcome in patients with hypertrophic cardiomyopathy. The article raises the following concerns.

Mitral regurgitation grade > 2 was present in 8 patients, and 23 patients (28%) had left ventricular (LV) outflow tract obstructions. In patients with hypertrophic cardiomyopathy, the dilation of the left atrium is associated with the degree of the LV outflow tract obstruction and the severity of mitral regurgitation.2 Did the LA volume index remain a predictor of adverse outcomes in patients without mitral regurgitation and without LV outflow tract obstructions?

An improvement in LV diastolic function and a decrease in LA volume after surgical septal myectomy in patients with hypertrophic cardiomyopathy have been reported.3 Also, alcohol septal ablation leads to a decrease in LA volume in patients with this disease.4 Considering that alcohol septal ablation and myectomy influence outcomes, did the LA volume index remain a predictor of adverse outcome in patients who benefited from these procedures compared with patients who did not undergo septal intervention?