Patients with insulin-treated diabetes who underwent percutaneous coronary intervention (PCI) with an everolimus-eluting stent had a reduced rate of cardiovascular (CV) events compared with paclitaxel-eluting stents.
Results from this prespecified analysis of the TUXEDO (Taxus Element vs Xience Prime in a Diabetic Population) trial were published in JAMA Cardiology.
Researchers noted that among patients with diabetes who undergo revascularization, those treated with insulin have shown worse outcomes compared with those who are not, but this finding has been considered controversial. Other studies have demonstrated that this increased possibility of adverse CV outcomes in patients with insulin-treated diabetes disappears after risk adjustment.
A total of 1830 patients with either insulin-treated diabetes (n=747; 40.8%) or non-insulin-treated diabetes (n=1083; 59.2%) were enrolled from June 2011 to March 2014 and were randomized 1:1 to receive either a paclitaxel-eluting or an everolimus-eluting stent.
Among the patients with insulin-treated diabetes, more were women, had higher BMIs, had a longer duration of diabetes, had a higher hemoglobin A1C, were more likely to have had prior PCI, and were more likely to have chronic kidney disease. They were also more likely to be asymptomatic but less likely to have had a prior myocardial infarction (MI), currently smoke, or have lower left ventricular ejection fraction.
The primary end point was target vessel failure at 1 year after the intervention (defined as composite of cardiac death, target vessel MI, or ischemia-driven target vessel revascularization).
Everolimus-eluting stents reduced the rate of target vessel failure (13 of 382 [3.4%] vs 29 of 365 [7.9%]; P=.007), major adverse cardiac events (15 of 382 [3.9%] vs 30 of 365 [8.2%]; P=.01), MI (5 of 382 [1.3%] vs 16 of 365 [4.4%]; P=.01), stent thrombosis (2 of 382 [0.5%] vs 11 of 365 [3.0%]; P=.009), target lesion revascularization (4 of 382 [1.0%] vs 19 of 365 [5.2%]; P=.001), and target vessel revascularization (4 of 382 [1.0%] vs 19 of 365 [5.2%]; P=.001) compared with paclitaxel-eluting stents in patients with insulin-treated diabetes.
For patients with non-insulin-treated diabetes, results largely trended in the same direction (P>.05 for interaction). “However, the absolute risk reduction for target vessel failure with everolimus-eluting stents was greater in those with ITDM [insulin-treated diabetes mellitus] compared with patients with non-ITDM (4.5% vs 1.4%),” researchers noted.
When compared with patients not treated with insulin, patients with insulin-treated diabetes had significantly higher rates of target vessel failure (5.6% vs 3.3%; P=.02), major adverse CV events (6.0% vs 3.7%; P=.02), death or MI (5.8% vs 3.2%; P=.009), and cardiac death or MI (4.7% vs 2.9%; P=.04). Higher rates of subacute stent thrombosis, Q-wave MI, and death were also observed in patients with insulin-treated diabetes.
These significantly worse outcomes in the patients with insulin-treated diabetes were “largely attenuated in the propensity score-adjusted analysis,” according to the study authors. This suggests that the increased possibility of adverse CV events in the patients with insulin-treated diabetes is accounted for by the differences in baseline risk factors, diabetes duration, and diabetes control.
Although debate may continue regarding stent choice, the TUXEDO trial—the only well-powered, head-to-head randomized trial of the 2 drug-eluting stents—showed superiority of the everolimus-eluting stent vs paclitaxel-eluting stent in patients with diabetes, according to the researchers. This subanalysis extends this finding specifically to patients with insulin-treated diabetes, and that everolimus-eluting stents reduced CV events risk, including stent thrombosis.
Bangalore S, Bhagwat A, Pinto B, et al. Percutaneous coronary intervention in patients with insulin-treated and non-insulin-treated diabetes mellitus. Secondary analysis of the TUXEDO trial. JAMA Cardiol. 2016. doi:10.1001/jamacardio.2016.0305.