Improved long-term survival for diabetic patients with surgical versus interventional revascularization

Diabetes is increasing at an alarming rate, affecting nearly 8% of the population. Previous studies have demonstrated a potential benefit for surgical over interventional revascularization in diabetics. However, randomized clinical trials comparing coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) many not accurately reflect current clinical practice. We therefore undertook a prospective registry of coronary revascularization (CR) in diabetic patients with CABG, on-pump and off-pump, and PCI with bare-metal and drug-eluting stents to determine long-term clinical outcomes.

All patients undergoing isolated CR in 8 community hospitals were enrolled. Follow-up was obtained after 5 to 8 years; all mortalities were checked against the Social Security Death Index. The ST-elevation myocardial infarction and salvage patients were excluded. Propensity matching was used to account for differences between PCI and CABG groups. Survival curves were derived using Kaplan-Meier methods, whereas hazard ratios and cumulative hazards were calculated using the Cox proportional hazard model.

Of the 3,156 patients in the registry, there were 1,082 diabetics; 334 CABG and 748 PCI. Due to the differences in baseline characteristics between the 2 groups, propensity score matching was used to achieve clinically comparable groups of 240 patients each. In matched patient groups mortality was more common in the PCI group with an odds ratio (OR) of 0.60 (95% confidence interval [CI] 0.39% to 0.93%; p = 0.023). Similarly, occurrence of any major cardiac adverse event (MACE) (mortality, non-fatal myocardial infarction, or revascularization) was more frequent in the PCI group with an OR of 0.57 (95% CI 0.31% to 0.70%, p < 0.001). Kaplan-Meier event-free survival of matched groups was significantly improved in the CABG versus PCI group (p = 0.001).

In the current era of on-pump and off-pump CABG surgery and bare-metal and drug-eluting stents, this registry which unselectively records all non-ST elevation myocardial infarction patients undergoing coronary revascularization, diabetic patients benefit from improved long-term survival and reduced MACE with CABG versus PCI. These findings corroborate recent evidence from prospective randomized trials and thus provide clinically relevant validation of their broad applicability to diabetics with extensive coronary artery disease in need of revascularization.