Risk marker profiles in patients treated with percutaneous septal ablation for symptomatic hypertrophic obstructive cardiomyopathy.

Background And Study Objective: Different studies have shown a good long-term survival with improvement of symptoms and hemodynamics after percutaneous septal ablation (PTSMA), similar to myectomy considered to be the therapeutic "gold standard" for symptomatic hypertrophic obstructive cardiomyopathy (HOCM). Furthermore, desobliteration of left ventricular (LV) outflow may modify features of the disease considered to be risk-relevant, such as magnitude of LV hypertrophy, outflow gradient, and left atrial (LA) size. The aim oft this study was to examine predictors of long-term mortality in a large cohort of patients with HOCM treated with PTSMA.

Methods And Results: 497 consecutive patients with symptomatic HOCM (mean age 55.4 ± 14.4 years, NYHA class: 2.9 ± 0.4) who underwent PTSMA between 1996 and 2014 were studied. Periprocedural mortality was 1% (five patients). During a follow-up time of 64.5 ± 53.2 months (range 0.1-207), 51 patients died, of these 25 due to cardiovascular problems, while 26 deaths were attributed to non-cardiac causes. Overall survival rates were 89.4% (± 1.7) after 5 and 80.6% (± 2.7) after 10 years. Among the baseline variables, advanced age, recurrent syncope, and magnitude of LV thickening were risk markers correlated to long-term post-procedural survival. The only mortality predictor that could be identified during follow-up was post-procedural NYHA class. Neither the other classical HCM risk markers nor other clinical or echocardiographic parameters predicted cardiac or all-cause mortality in this cohort.

Conclusions: Our findings suggest that the risk profile after septal ablation may differ from that of HOCM patients without an outflow desobliteration.