Importance: Prior studies have shown that patients with insulin-treated diabetes mellitus (ITDM) have a higher risk of cardiovascular events. However, this finding is controversial, as other studies have shown that the increased risk of cardiovascular events disappears after risk adjustment. In addition, the choice of a drug-eluting stent (limus- vs taxol-eluting) in ITDM is controversial, with studies showing worse outcomes with an everolimus-eluting stent compared with a paclitaxel-eluting stent.
Objectives: To assess the outcomes of patients with ITDM vs non-ITDM who underwent percutaneous coronary intervention and to assess the efficacy and safety of an everolimus-eluting stent vs a paclitaxel-eluting stent based on insulin use status.
Design, setting, and participants: A prespecified analysis was conducted of the Taxus Element vs Xience Prime in a Diabetic Population (TUXEDO) clinical trial, which enrolled 1830 patients with ITDM and non-ITDM from June 23, 2011, to March 12, 2014. Patients were randomized 1:1 to receive either a paclitaxel-eluting stent or an everolimus-eluting stent.
Main outcomes and measures: The primary end point was target vessel failure, defined as the composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target vessel revascularization at 1 year after the intervention.
Results: Among the 1830 patients (1377 male) in the TUXEDO trial, 747 patients (40.8%) were receiving insulin (ITDM group). Compared with the 1083 patients with non-ITDM, those with ITDM had a significant increase in target vessel failure (42 [5.6%] vs 36 [3.3%]; P = .02), death or myocardial infarction (43 [5.8%] vs 35 [3.2%]; P = .009), death (26 [3.5%] vs 18 [1.7%]; P = .01), and subacute stent thrombosis (8 [1.1%] vs 3 [0.3%]; P = .03). However, in a propensity score-adjusted analysis to account for baseline differences between the 2 groups, the differences in outcomes were no longer significant. In patients with ITDM, 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), myocardial infarction (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) when compared with paclitaxel-eluting stents. The results largely trended in the same direction in patients with non-ITDM (P > .05 for the interaction).
Conclusions and relevance: Patients with ITDM had a significant increase in the risk of cardiovascular events in unadjusted models that was largely attenuated after propensity score adjustment. Everolimus-eluting stents reduced the rate of cardiovascular events, including stent thrombosis, when compared with paclitaxel-eluting stents in patients with ITDM.
Trial registration: ctri.nic.in Identifier: CTRI/2011/06/001830.