330 patients who survived 鈮?#xA0;6 months after CRT (males 80%, age 62 卤 11 years) were grouped according to 1-year LVEF 鈮?#xA0;35% (Group 1, n = 187, 57%) or > 35% (Group 2, n = 143, 43%). According to changes vs. baseline (reduction of left end-systolic volume [LVESV] 鈮?#xA0;10% or increase of LVEF% > 10 units), patients were also classified as echocardiographic (Echo) non-responders (Group A, n = 152, 46%) or responders (Group B, n = 178, 54%).
At baseline, LVESV volume was larger and LVEF was lower in Group 1 vs. Group 2 (p < 0.001). After 1 year, echocardiographic improvement was greater in Group 2 vs. Group 1 (p < 0.001 for changes in both LVESV and LVEF). Over a median follow-up of 49 months, 47 patients (14%) died, 36 in Group 1 vs. 11 in Group 2 (19% vs. 8%, p = 0.004). A significantly higher rate of freedom from all-cause mortality (p = 0.002), cardiovascular mortality (p < 0.001) and SCD (p < 0.001) was observed in Group 2. Multivariate analysis demonstrated that only 1-year LVEF > 35% was associated with freedom from SCD/VF.
LVEF > 35% after 1 year of CRT characterizes a favorable long-term outcome, with a very low risk for SCD.