Global Risk Classification Predicts the Clinical Outcomes of Patients with Significant Left Main Coronary Artery Disease Undergoing Coronary Bypass Surgery

Background: The use of combined SYNTAX score and EuroSCORE to predict two-year cardiac mortality in de-novo left main coronary artery (LMCA) disease patients undergoing percutaneous coronary intervention (PCI) has been discussed. Whether the combination of these two parameters could also predict the clinical outcomes in de-novo LMCA patients undergoing bypass surgery remains unknown. Method: From April 2003 to June 2008, 86 patients with de-novo LMCA disease undergoing coronary artery bypass surgery (CABG) were studied. Patients were divided into three subgroups of global risk classification (GRC), low-risk group (n = 44), intermediate-risk group (n = 28), and high-risk group (n = 14) according to their SYNTAX score and EuroSCORE. The baseline characteristics were compared between different risk subgroups of GRC. The differences of clinical outcomes in terms of major cardiovascular and cerebrovascular events (MACCEs) between different risk subgroups of GRC were compared. Results: Compared with the low-risk group, the high-risk group showed a significantly higher proportion of myocardial infarction (50.0% vs. 18.2%), congestive heart failure (21.4% vs. 2.3%), and cardiogenic shock (7.1% vs. 0.0%; p = 0.02), higher SYNTAX score (48.7 5.6 vs. 27.5 6.8; p < 0.01), higher EuroSCORE (7.7 1.9 vs. 2.7 1.5; p < 0.01), a higher proportion of diabetes mellitus (85.7% vs. 43.2%; p = 0.02), prior stroke (28.6% vs. 4.6%; p = 0.03), and peripheral arterial occlusive disease (28.6% vs. 2.3%; p < 0.01), and lower ejection fraction (50.8 17.4 vs. 66.5 14.1, p < 0.01). Using multivariable Cox-regression proportional regression with the forward conditional method, the global risk classification (GRC) predicted long-term cumulative MACCEs (p < 0.01, HR: 4.45, 95% CI: 2.48-7.99). The Kaplan-Meier Curve with log-rank test displayed significant differences of long-term MACCEs (p < 0.01; 2 = 39.08) between different subgroups of GRC. Conclusion: The new GRC system effectively predicts long-term MACCEs of de-novo LMCA disease patients undergoing CABG.