Impact of coronary revascularisation in patients undergoing cardiovascular magnetic resonance for viability assessment

Abstract Background The utility of cardiovascular magnetic resonance (CMR) assessing the myocardial viability to guide revascularisation by percutaneous coronary intervention (PCI) remains controversial. Purpose To assess the prognostic impact of revascularisation by PCI guided by CMR-based myocardial viability to predict death in patients with ischaemic cardiomyopathy (ICM) and reduced left ventricular ejection fraction (LVEF) 50%. Methods From 2008 to 2022, we included all consecutive ICM patients referred for CMR-based myocardial viability assessment in a multicentric study. Eligible patients had ≥70% stenosis in ≥1 epicardial coronary vessel on angiography, a history of myocardial infarction, or prior coronary revascularisation, and LVEF50%. We collected data on PCI within 90 days of the index CMR. The primary outcome was all-cause death using the electronic French National Registry of All-cause mortality (INSEE). Cox regression analysis was performed to determine the prognostic value of myocardial ischaemia and PCI-guided by viability CMR. Myocardial viability was evaluated using ischaemic late gadolinium enhancement (LGE) transmurality, assessed based on maximal scar depth. Myocardial LGE transmurality was categorized into three groups: 50%, 50-74% and ≥75%. Results Among 6,082 patients (mean age 65±12 years; 73% male), 3,591 (59%) exhibited ischaemic-LGE. PCI was performed in 2,773 (46%) patients within 90 days of CMR. PCI was more performed in patients with 50% (89%) and 50-74% (81%) myocardial LGE transmurality than in those with ≥75%. (6%, Figure 1). Over a median follow-up of 9 years (interquartile range 7-12 years), 652 patients (11%) died. Using a multivariable Cox regression analysis, patients with myocardial LGE transmurality 50% who underwent PCI did not have a significantly different risk of mortality compared to those without myocardial LGE (HR: 0.92; 95% CI: 0.66-1.28, p=0.625). However, patients with LGE transmurality 50% who did not undergo PCI had a significantly higher risk of death (HR: 2.42; 95% CI: 1.55-3.80, p0.001). Interestingly, in patients with 50-74% myocardial LGE transmurality, patients who underwent PCI had significantly better survival rates than those without PCI (OR 0.58; 95% CI: 0.43-0.74, p0.001). In patients with ≥75% myocardial LGE transmurality, those who underwent PCI did not have better survival rates than those who did not (OR 0.81; 0.44-1.49, p=0.50). Kaplan Meier curves according to PCI after CMR viability assessment are shown in Figure 2. Conclusion In a large cohort of consecutive ICM patients from a multicentric study, revascularisation by PCI after CMR viability assessment in patients with 50% and 50-74% of CMR myocardial LGE transmurality was beneficial and was associated with improved survival outcomes.