Combining blood flow and tissue Doppler imaging with N-terminal pro-type B natriuretic peptide for risk stratification of clinically stable patients with systolic heart failure

AIMS: This study was designed to ascertain whether the combination of Doppler assessment of the ratio of mitral blood flow to myocardial early diastolic velocities (E/E(m) ratio) and plasma N-terminal pro-type B natriuretic peptide (NT-proBNP) testing is useful to better stratify patients with stable systolic heart failure (HF). METHODS AND RESULTS: A total of 362 outpatients with chronic systolic HF (left ventricular ejection fraction <or=45%) underwent clinical assessment, NT-proBNP testing, and comprehensive echo-Doppler study. The endpoint was all-cause mortality or HF-related hospital admissions (i.e. hospitalization for worsening HF, biventricular pacemaker implantation, or mitral valve surgery). Median follow-up duration was 25 months. Two hundred and fifty-nine patients were judged clinically stable by a Framingham's criteria-based HF score. In multivariate Cox's proportional hazards analysis, plasma NT-proBNP (P< 0.0001) and E/E(m) ratio (P= 0.04) were among the significant predictors of the combined endpoint. Survival free from cardiac mortality and HF-related hospitalization was 55% in patients with the E/E(m) ratio in the higher third (>or=12), 77% in those with the E/E(m) ratio in the intermediate third, and 86% in those with the E/E(m) ratio in the lower third (<or=7) (P< 0.0001). By stratifying patients according to NT-proBNP above the median, patients' outcome was predicted in 13 out of 17 in the intermediate third (P = 0.002) and in 9 out of 10 in the lower third of E/E(m) ratio (P= 0.005). CONCLUSION: In patients with stable HF categorized according to the E/E(m) ratio, NT-proBNP testing improves risk stratification, particularly in those with minor degrees of diastolic dysfunction.