Cardiac MRI Evaluation of Determinants and Prognostic Implications of Right Ventricular Dysfunction in Aortic Regurgitation

Purpose To investigate the determinants and effect of right ventricular (RV) dysfunction in aortic regurgitation (AR) using cardiac MRI. Materials and Methods This study included patients with moderate or severe AR who were enrolled in the DEBAKEY-CMR registry between January 2009 and June 2020. Patients with previous valve intervention, cardiomyopathy deemed unrelated to AR, severe aortic stenosis, and other confounders were excluded. RV dysfunction (RV ejection fraction <= 40%) was measured at cardiac MRI. Outcomes were all-cause death, cardiovascular death, and perioperative mortality. Factors associated with RV dysfunction and its association with outcomes were assessed using univariable and multivariable Cox regression analyses. Results The study included 395 patients (median age, 62 years [IQR, 51-72 years]; 79% male). Fifty-eight (14.6%) patients had RV dysfunction. Patients with RV dysfunction had higher New York Heart Association class, greater biventricular remodeling, greater coexisting mitral and tricuspid regurgitation, and a higher prevalence of left ventricular dysfunction. In multivariable analysis, factors independently associated with RV dysfunction were coexisting mitral regurgitation (odds ratio per unit of mitral regurgitant fraction, 1.05; P = .001) and reduced left ventricular ejection fraction (odds ratio, 1.14; P < .001). RV dysfunction helped independently predict mortality (hazard ratio [HR], 2.35; 95% CI: 1.07, 5.19; P = .03) and cardiovascular death (HR, 3.29; 95% CI: 1.18, 9.1; P = .02), as well as a higher rate of 90-day perioperative mortality (four of 58 [6.9%]), compared with two of 337 (0.6%) in patients without RV dysfunction; P = .005). Conclusion In patients with chronic AR, the strongest factors associated with RV dysfunction were coexisting mitral regurgitation and left ventricular dysfunction. Patients with RV dysfunction had a higher risk of death from any cause, cardiovascular death, and excess perioperative mortality.