Right ventricular function predicts transplant-free survival in idiopathic dilated cardiomyopathy

Abstract

Right ventricular function may be reduced in patients with idiopathic dilated cardiomyopathy (IDC). The prognostic implications of right ventricular dysfunction have not been investigated in this group of patients. In a series of 120 consecutive patients with IDC [defined as a left ventricular ejection fraction (LVEF) < 55%, normal coronary arteries and no other causes for left ventricular dysfunction], right ventricular function was prospectively evaluated by means of angiocardiography at the time of catheterization. A head-to-head comparison of ventricular volumes, ejection fraction, end-diastolic pressure, stroke work index and end-systolic pressure/volume ratio of the left and right ventricle was performed according to the Cox's proportional hazard method for the pre-defined end-point of transplant-free survival. In the study population, LVEF was 31 +/- 11% and right ventricular ejection fraction (RVEF) was 34 +/- 10%. After a mean follow-up of 30 months (range 12-120 months), 26 patients died (22%) and 14 (12%) underwent heart transplantation. At univariate analysis, all the above mentioned parameters were significantly (P < 0.0001) associated with outcome except left and right ventricular end-systolic pressure/volume ratio. At multivariate analysis, independent predictors of transplant-free survival were RVEF (P = 0.001), right ventricular stroke work index (P = 0.015), right ventricular end-diastolic volume (P = 0.034) and left ventricular end-diastolic volume (P = 0.048), but not LVEF. The same relation holds true considering the end point of total mortality. Parameters of right ventricular function are strong predictors of survival in IDC, even in patients enrolled over a wide range of LVEFs. The present study suggests that right ventricular function should be evaluated in patients with IDC. A large non-invasive based study on right ventricular function in IDC appears to be warranted.