Left ventricular ejection fraction for risk stratification in chronic systolic heart failure

Background: Left ventricular ejection fraction (LVEF) represents the most used measure of cardiac systolic function. Different cut-offs have been proposed to classify patients with systolic dysfunction, and to inform therapy decision-making. Methods: Consecutive outpatients with systolic heart failure (HF; LVEF <50%) were prospectively enrolled and underwent a baseline characterization. The prognostic value of LVEF and LVEF cut-offs was made with regards to the prediction of all-cause and cardiovascular death. Results: Out of 2160 patients, 71% had LVEF <40%, and 61% had ≤35%. Over a 26-month median follow-up (interquartile interval 12–39), patients with LVEF ≤35% (log-rank 31.11 and 59.48, respectively; both p < 0.001) and <40% (log-rank 24.51 and 41.77, respectively; both p < 0.001) had a significantly worse prognosis for all-cause and cardiovascular death. LVEF independently predicted both endpoints in a strong prognostic model including age, sex, ischaemic aetiology, N-terminal fraction of pro-B-type natriuretic peptide, New York Heart Association class III–IV, several comorbidities and therapies. Receiver operating characteristics curves identified LVEF values 32% and 31% as the best cut-offs for the two endpoints. The 40% and lower cut-offs (35%, 32% or 31%) were independent predictors of all-cause and cardiovascular death (p < 0.001 in all cases). The 35% cut-off had a lower Akaike's Information Criterion value than 40%, denoting more accurate risk stratification. Conclusions: LVEF is an independent predictor of all-cause and cardiovascular mortality in chronic systolic HF. The 35% LVEF cut-off displays a better combination of sensitivity and specificity than the 40% cut-off for outcome prediction, although both hold independent prognostic value.