Coronary plaque burden as a determinant of cardiovascular outcomes in patients undergoing percutaneous coronary intervention versus coronary artery bypass grafting: The Western Denmark Heart Registry

Aims: Benefits of coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) for patients with stable coronary artery disease (CAD) may be determined by total plaque burden alongside number of stenoses. We aimed to determine whether coronary artery calcification (CAC), reflecting overall plaque burden, predicts CABG versus PCI benefits. Methods: Among 85,512 symptomatic patients undergoing computed tomography angiography, we conducted propensity-matched analyses. CABG-treated patients (n = 1,479) were 1:1:1 matched with PCI-treated patients and non-obstructive CAD patients. Cox proportional hazard models assessed risk for the primary endpoint (death, myocardial infarction, stroke), stratified by CAC1000. Results: Over 5.3 years, 710 primary endpoints occurred. CABG patients had higher prevalence of three-vessel obstructive CAD compared to PCI-treated patients (30 %vs.18 %). Event rates rose with increasing CAC scores; CAC1000 indicated very-high risk. Patients with non-obstructive CAD had similar risk to PCI-revascularized patients across CAC groups. Compared to PCI, risk for the primary endpoint were lower at higher plaque burden in CABG-treated patients with hazard ratios of 1.12 (95 %CI 0.70-1.80), 0.82 (95 %CI 0.55-1.20), and 0.75 (95 %CI 0.58-0.94) for CAC1000, respectively. The lower CABG-associated risk was driven by reduced myocardial infarction risk (HR 0.44 (95 %CI 0.26-0.73)). Conclusions: Among patients with high, but not low, coronary plaque burden, CABG yielded lower long-term risk than PCI, despite more multivessel obstructive CAD. This suggest that the benefit of CABG over PCI for patients with extensive CAD can, at least partly, be attributed to the bypassing of a larger plaque burden.