Prognostic significance of echocardiographically estimated right ventricular shortening in advanced heart failure

Abstract

Little is known about the association of echocardiographic estimates of right ventricular (RV) function with survival, in relation to hemodynamic and exercise-derived predictors of outcome in congestive heart failure. We prospectively studied 40 patients (age 55+/-10 years, in New York Heart Association functional class III [70%] and IV [30%]), with left ventricular (LV) ejection fraction <30%. At enrollment, all patients underwent echocardiographic evaluation of LV dimensions and function. RV shortening was measured as the difference of the end-diastolic distance - the end-systolic distance between the tricuspid annulus and the RV apex. Thirty-five patients (88%) were able to perform a maximal symptom-limited exercise test. Peak oxygen consumption (peak VO2) and percent peak age- and gender-adjusted predicted oxygen consumption (%peak VO2) were calculated. Of 40 patients, 10 died during a mean follow-up period of 14+/-10 months. On univariate analysis, nonsurvivors had lower RV shortening (p=0.0001), higher pulmonary artery wedge pressure (p=0.009), higher pulmonary vascular resistance (p=0.02), and lower mean aortic pressure (p=0.05). Cox proportional-hazards model revealed that the only independent associate of survival was RV shortening (p=0.0005), with a trend toward significance for mean aortic pressure (p=0.08). The best cutoff point of RV shortening identified by the receiver-operating curve was 1.25 cm. This value had a sensitivity of 90%, specificity of 80%, and overall predictive accuracy of 83% to distinguish survivors from nonsurvivors. In patients with advanced heart failure, preserved RV function as indicated by an echocardiographically derived RV shortening > 1.25 cm is a strong predictor of survival.