Abstract

not-yet-known not-yet-known not-yet-known unknown Background and aims: The assessment of left ventricular (LV) outflow velocity time integral (LVOT-VTI) has gained favor in the stratification of patients with heart failure (HF). We evaluated the prognostic significance of LVOT-VTI compared with the commonly used indices of LV outflow: cardiac index (CI) and stroke volume index (SVI), their reproducibility and cut-off values. Methods and results: 424 outpatients diagnosed with HF and LV systolic dysfunction (LV ejection fraction <50%) underwent a Doppler echocardiographic examination, including the assessment of CI, SVI and LVOT-VTI. The Bland-Altman analysis showed LVOT-VTI the most reproducible outflow index. The study follow-up duration was 3.5 years (interquartile range 1.6 to 6.5), at the end of which there were 94 cardiovascular deaths (29%). Cox regression univariate analysis showed that LVOT-VTI was the most predictive of the study end-point. The ratio of tricuspid annular displacement-to-pulmonary artery systolic pressure (TAPSE/PASP) (p<0.0001), LVOT-VTI (p=0.0001) and end-systolic volume index (p=0.0006) independently predicted the study end-point. At Receiver-operating characteristic (ROC) analysis, LVOT-VTI <12.0 cm had the best sensitivity and specificity for predicting cardiovascular mortality. Reduced LV EF (p=0.0011), raised BNP levels (p=0.0053) and high LV filling pressure (p=0.044) were associated with low LVOT-VTI in multivariate logistic regression analysis. Patients with low LVOT-VTI and TAPSE/PASP<0.32 mm/mmHg exhibited the worst prognosis on Kaplan-Meier survival curves (p<0.0001). Conclusions. A LVOT-VTI < 12.0 cm represents the best predictor of the cardiovascular outcome and proved the most reproducible index of LV forward flow in patients with chronic HF and systolic dysfunction.