부산대학교 도서관

Introduction: Left ventricular outflow tract velocity time integral (LVOT VTI) correlates with stroke volume, reflecting cardiac pump systolic function. In patients with heart failure, lower LVOT VTI was hypothesized to predict increased mortality and need for left ventricular assist device (LVAD) therapy.Methods: All patients admitted with a primary diagnosis of heart failure at a midsize health system during 2011 and 2012 were included in an initial data query and the resulting list was cross indexed with the institution’s echocardiogram database to identify subjects with an echocardiogram performed within one year of index hospitalization. Baseline echocardiographic parameters including ejection fraction, left ventricular (LV) mass index, LV end systolic volume, right ventricular systolic pressure and LVOT VTI and baseline laboratory and clinical data were obtained. Mortality data from the Center for Health Statistics National Death Index was obtained after protocol approval. Deaths at 6 months from the time of hospitalization were recorded and confirmed using our center’s electronic medical record. The study population was stratified into quartiles by LVOT VTI and univariate and multivariate analyses conducted by cox proportional hazards model.Results: Seven hundred and forty seven eligible subjects were identified. There was a nearly even representation of male and female subjects (56.1% male), and close to 1/3 of subjects had diabetes. The average ejection fraction was 48.4% and 47% of subjects had systolic heart failure with EF less than 40%. The average LVOT VTI was 18.8 cm. LVOT VTI quartile was found to be predictive of death and LVAD placement (HR 0.79, 95% CI 0.65-0.94, p-value 0.009) while ejection fraction (HR 0.995, 95% CI 0.98-1.01, p-value 0.36) and doppler derived cardiac output (HR 1, p-value 0.97) were not predictive. In the multivariate analysis, LVOT VTI quartile remained predictive when adjusted for age, right ventricular systolic pressure by echo, anemia and ESRD (HR 0.739, 95% CI 0.612-0.893, p-value 0.003)Conclusions: LVOT VTI is a robust echocardiographic predictor of important clinical outcomes in heart failure and may be useful for identifying patients at higher risk for poor outcomes.