The Prevalence, Correlates, and Impact on Cardiac Mortality of Right Ventricular Dysfunction in Nonischemic Cardiomyopathy

Objectives This study sought to determine the prevalence, correlates, and impact on cardiac mortality of right ventricular (RV) dysfunction in nonischemic cardiomyopathy. Background Current heart failure guidelines place little emphasis on RV assessment due to limited available data on determinants of RV function, mechanisms leading to its failure, and relation to outcomes. Methods We prospectively studied 423 patients with cardiac magnetic resonance (CMR). The pre-specified study endpoint was cardiac mortality. In 100 patients, right heart catheterization was performed as clinically indicated. Results During a median follow-up time of 6.2 years (interquartile range: 2.9 to 7.6 years), 101 patients (24%) died of cardiac causes. CMR right ventricular ejection fraction (RVEF) was a strong independent predictor of cardiac mortality after adjustment for age, heart failure–functional class, blood pressure, heart rate, serum sodium, serum creatinine, myocardial scar, and left ventricular ejection fraction (LVEF). Patients with the lowest quintile of RVEF had a nearly 5-fold higher cardiac mortality risk than did patients with the highest quintile (hazard ratio: 4.68; 95% confidence interval [CI]: 2.43 to 9.02; p < 0.0001). RVEF was positively correlated with LVEF (r = 0.60; p < 0.0001), and inversely correlated with right atrial pressure (r = −0.32; p = 0.001), pulmonary artery pressure (r = −0.34; p = 0.0005), transpulmonary gradient (r = −0.28; p = 0.006) but not with pulmonary wedge pressure (r = −0.15; p = 0.13). In multivariable logistic regression analysis of CMR, clinical, and hemodynamic data the strongest predictors of right ventricular dysfunction were LVEF (odds ratio [OR]: 0.85; 95% CI: 0.78 to 0.92; p < 0.0001), transpulmonary gradient (OR: 1.20; 95% CI: 1.09 to 1.32; p = 0.0003), and systolic blood pressure (OR: 0.97; 95% CI: 0.94 to 0.99; p = 0.02). Conclusions CMR assessment of RVEF provides important prognostic information independent of established risk factors and LVEF in heart failure patients with nonischemic cardiomyopathy. Right ventricular dysfunction is strongly associated with both indices of intrinsic myocardial contractility and increased afterload from pulmonary vascular dysfunction.