Right Ventricular Systolic Dysfunction Assessed by Cardiac Magnetic Resonance Is a Strong Predictor of Cardiovascular Death After Coronary Bypass Grafting

Abstract

Limited data are available regarding the prognostic value of right ventricular (RV) systolic dysfunction (RVSD) in patients with coronary artery disease. Our objective was to evaluate the effect of RVSD assessed by cardiac magnetic resonance on survival of patients with low left ventricular (LV) ejection fraction (EF) undergoing coronary bypass grafting (CABG). We prospectively assessed overall and cardiovascular death of 107 consecutive patients (94 men; age, 66 ± 10 years) undergoing CABG who had a LVEF of 0.35 or less by cardiac magnetic resonance before CABG. Mean LVEF was 0.25 ± 0.07, and mean RVEF was 0.46 ± 0.16. RVSD, defined by RVEF of 0.35 or less, was present in 32 patients (30%). In-hospital mortality rate (n= 8) was significantly higher in patients with RVSD (18.7% vs 2.7%, p= 0.004). Over a median follow-up of 4.7 years, 44 patients died, 33 of a cardiovascular cause. The primary end point of cardiovascular death was reached by 15 of 32 patients with RVSD and 18 of 75 patients without RVSD (47% vs 24%, p= 0.019). Univariate survival analysis showed that age, New York Heart Association Functional Classification, diabetes, estimated glomerular filtration rate, LVEF, LV indexed end-diastolic volume, RVEF, RV indexed end-diastolic volume, RV systolic function, and The Society of Thoracic Surgeons risk score were independent predictors of the primary end point of cardiovascular death. By multivariable analysis, the Society of Thoracic Surgeons risk score (hazard ratio, 1.32; 95% confidence interval, 1.13 to 1.55; p= 0.001) and RVSD (hazard ratio, 2.14; 95% confidence interval, 1.06 to 4.31; p= 0.034) remained significant independent predictors of cardiovascular death. RVSD strongly and independently predicts cardiovascular death in patients with coronary artery disease and low EF undergoing CABG. Evaluation of RV function should thus be part of preoperative evaluation of such patients.