Aims: Impaired diastolic function is responsible for many of the clinical features of hypertrophic cardiomyopathy. In patients with hypertrophic obstructive cardiomyopathy (HOCM) whose symptoms are refractory to medical therapy, alcohol septal ablation (ASA) reduces left ventricular (LV) outflow tract gradient, with short-term improvement in LV diastolic function. Little is known about the longer term impact of ASA on diastolic function.
Methods and results: We evaluated LV diastolic function at baseline and 1- and 2-year follow-up after successful ASA. In 30 patients (58+/-15 years, 22 men) who underwent successful ASA, New York Heart Association class was lower at 1-year follow-up compared with baseline (3.0+/-0.5 to 1.5+/-0.7; P<0.0001). LV outflow tract gradient (76+/-37 to 19+/-12; P<0.0001), interventricular septal thickness (19+/-2 to 14+/-2; P<0.0001), and left atrial volume (26+/-5 to 20+/-4; P<0.0001) were decreased. Significant improvement in E-wave deceleration time, isovolumic relaxation time, early diastolic mitral lateral annular velocity (E'), mitral inflow propagation velocity (V(p)), ratio of transmitral early LV filling velocity (E) to early diastolic Doppler tissue imaging of the mitral annulus (E/E'), and E/V(p) were observed at 1 year following successful ASA. These changes persisted in the subset cohort (n=21) for whom 2-year data were available.
Conclusion: Successful ASA for HOCM leads to significant and sustained improvement in echocardiographic measures of diastolic function, which may contribute to improved functional status after successful ASA.