Revascularization in Diabetics With ACS

Study Questions:

What is the optimal revascularization strategy for multivessel coronary artery disease (CAD) in patients with diabetes and acute coronary syndromes (ACS)?

Methods:

The authors used a large population-based database from British Columbia, Canada, to evaluate major cardiovascular outcomes in all diabetic patients who underwent coronary revascularization between 2007 and 2014. The primary endpoint (major adverse cardiac or cerebrovascular events [MACCE]) was a composite of all-cause death, nonfatal myocardial infarction, and nonfatal stroke. The risk of MACCE with coronary artery bypass grafting (CABG) surgery or percutaneous coronary intervention (PCI) was compared using multivariable adjustment and a propensity score model.

Results:

The study cohort was comprised of 4,661 patients, of whom 2,947 presented with ACS. PCI was performed in 2,888 and CABG in 1,931 diabetic patients (ACS subgroup, 1,966 with PCI vs. 1,051 with CABG). Patients treated with PCI were older, had lower ejection fraction, and were more likely to have renal and pulmonary disease. At 30 days post-revascularization, for ACS patients with diabetes, the odds ratio (OR) for MACCE favored CABG (OR, 0.49; 95% confidence interval [CI], 0.34-0.71), while among those with stable disease, MACCE was not affected by revascularization strategy (OR, 1.46; 95% CI, 0.71-3.01; p interaction < 0.01). Over a median follow-up of 3.3 years, the late (31 days to 5 years) benefit of CABG over PCI was preserved in both patients with ACS (hazard ratio [HR], 0.67; 95% CI, 0.55-0.81), and for those with stable CAD (HR, 0.55; 95% CI, 0.40-0.74; p interaction = 0.28).

Conclusions:

Patients with diabetes and multivessel CAD who present with ACS derive greater benefit from CABG.

Perspective:

This study adds to the data evaluating the comparative effectiveness of CABG versus PCI in patients with diabetes who present with ACS. The challenge with this paper is that the observed difference in outcome between CABG and PCI is so large that it belies biological plausibility and is most likely related to unmeasured confounding. The choice of revascularization in these patients should continue to be guided by the randomized data (albeit derived from patients with stable CAD), angiographic anatomy, and patient preference.

Keywords: Acute Coronary Syndrome, Cardiac Surgical Procedures, Coronary Artery Bypass, Coronary Artery Disease, Diabetes Mellitus, Myocardial Infarction, Myocardial Revascularization, Percutaneous Coronary Intervention, Stroke, Stroke Volume


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