Prognostic value of vasodilator stress perfusion cardiovascular magnetic resonance (CMR) in patients with previous coronary artery bypass graft (CABG)

Abstract

The accuracy and prognostic value of stress perfusion cardiac magnetic resonance (CMR) are well established in patients with suspected or proven coronary artery disease (CAD). Because myocardial contrast kinetics may be altered in patients with previous coronary artery bypass graft (CABG), most studies have excluded those patients in whom prognostic data are missing. To assess the prognostic value of vasodilator stress perfusion CMR in patients with previous CABG. Between 2008 and 2018, we prospectively included consecutive patients with CABG referred for vasodilator stress perfusion CMR with dipyridamole. They were followed for the occurrence of major adverse cardiovascular events (MACE) defined by cardiovascular death, non-fatal myocardial infarction or late coronary revascularisation > 90 days. Univariable and multivariable Cox regressions were performed to determine the prognostic association of inducible ischemia and late gadolinium enhancement (LGE). Of 866 CABG patients (70 ± 9 years, 89% men), 852 (98%) completed the CMR protocol and 771 (89%) completed the follow-up (median 4.2 ± 2.7 years). Stress CMR was well tolerated without severe adverse event. Overall, 531 (61%) patients had a myocardial infarction defined by the presence of LGE with ischemic patterns. Using Kaplan–Meier analyses, the presence of myocardial ischemia was correlated with the occurrence of MACE and cardiac mortality (both P < 0.0001) ( Fig. 1 ). In multivariable stepwise Cox regression, the absence of inducible ischemia was an independent predictor of a lower incidence of MACE (HR: 2.17, 95% CI: 1.56–3.13; P < 0.001) and cardiovascular mortality (HR: 2.38; 95% CI: 0.25–4.03; P = 0.001). Stress CMR is feasible, safe and has a good discriminative prognostic value to predict the occurrence of MACE and cardiovascular mortality in patients with CABG.