Drug-eluting stents may not confer advantage in diabetic patients

An editorial noted that drug-eluting stents may work for noncomplex lesions in patients with diabetes, but complex disease states incurred high rates of myocardial infarction and revascularization.

Diabetic patients had worse angiographic and clinical outcomes compared with nondiabetic patients receiving percutaneous coronary intervention (PCI) despite advances in interventional therapies and the implementation of new-generation drug-eluting stents, a study found.

Researchers conducted a prospective, multicenter, randomized, noninferiority trial to evaluate the safety and efficacy of ridaforolimus-eluting stents versus zotarolimus-eluting stents among 1,919 patients undergoing PCI in the BIONICS (BioNIR Ridaforolimus Eluting Coronary Stent System in Coronary Stenosis) trial. Randomization was stratified by medically treated diabetes, and a prespecified analysis compared outcomes by the presence or absence of diabetes up to two years. Results were published Dec. 24, 2018, by JACC: Cardiovascular Interventions.

The overall prevalence of diabetes was 29.1% (559 of 1,919 patients). These patients had higher body mass index, greater prevalence of hyperlipidemia and hypertension, and smaller reference vessel diameter. The rate of one-year target lesion failure, defined as cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization, was significantly higher among diabetic patients (7.8% vs. 4.2%; P=0.002), mainly due to higher rates of target lesion revascularization (4.5% vs. 2.0%; P=0.002). Rates of cardiac death, myocardial infarction, and stent thrombosis did not significantly vary.

Among 158 patients undergoing 13-month angiographic follow-up, restenosis rates were three times higher in diabetic patients than in nondiabetic patients (15.2% vs. 4.7%; P=0.01). Clinical and angiographic outcomes were similar between patients treated with the ridaforolimus-eluting stent and zotarolimus-eluting stent. At one year, insulin-treated patients had significantly higher rates of target lesion failure, major adverse cardiac events, stent thrombosis, and target vessel revascularization than those not receiving insulin.

The authors wrote, “In our study, the increased rate of [target lesion failure] and [stent thrombosis] among insulin-treated diabetic patients, especially during the first year following [drug-eluting stent] implantation, probably indicates a more accelerated intimal hyperplasia, greater degree of vascular inflammation and/or endothelial dysfunction, and increased plaque vulnerability in insulin-treated diabetic patients, and highlights the need for [drug-eluting stents] with even more potent antirestenosis efficacy.”

An accompanying editorial added that the findings should also motivate a “reappraisal and consideration of novel approaches to lower the substantial burden of cardiovascular risk” after PCI in patients with diabetes, especially those with complex lesions and those taking insulin, who continue to have very high rates of myocardial infarction and subsequent revascularization. The editorialists noted a relatively high adherence to guideline-directed therapy by the trial participants and contrasted that with how less than half of U.S. adults with diabetes meet care goals. The excess risk associated with diabetes may have been magnified in this study, they added. The editorial called on cardiologists to “to move out of our device-oriented comfort zones, recognize the need for systemic, risk-appropriate therapies, and elicit the support of our colleagues to improve outcomes in these high-risk patients.”