Diabetes Drug-Eluting Stents: Second Generation Safer Than First

For patients with diabetes mellitus (DM), the second-generation everolimus-eluting stent (EES) appears to be safer than two first-generation stents, the sirolimus-eluting stent (SES) and the paclitaxel-eluting stent (PES). This safety profile correlates with lower observed risk of stent thrombosis, according to an analysis of insights from a nationwide coronary intervention registry.

The EES has shown outstanding safety properties when compared with the first-generation drug-eluting stents. Therefore, my colleagues and I thought it important to study whether the safety advantage of the EES as previously shown in other studies could be observed in a large all-comer registry.

We used the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) to compare the safety of the EES with that of the SES and PES using a primary composite end point of clinically driven detected restenosis, definite stent thrombosis, and all-cause mortality. Our study results were published recently in the journal JACC Cardiovascular Interventions.Percutaneous Coronary Intervention
Some 4751 percutaneous coronary intervention (PCI)–treated patients with DM were included in the SCAAR from January 18, 2007, to July 29, 2011; 8134 stents were implanted (EES, 3928; PES, 2836; and SES, 1370). The EES was associated with a significantly lower risk of the composite primary end point compared with the SES (hazard ratio [HR] = 1.99; 95% confidence interval [CI], 1.19-3.08) and a strong trend toward lower risk compared with the PES (HR = 1.33; 95% CI, 0.93-1.91).

These results were driven mainly by a lower incidence of stent thrombosis and mortality. No significant differences in restenosis rates were observed between the EES and the SES or PES.

The results are clear: EES is associated with significant lower mortality, and this correlates with lower observed risk of stent thrombosis compared with the SES or PES. This is the first study to show such results, even in high-risk patients such as those with DM.

On the other hand, there was no difference between the EES device and the first-generation drug-eluting stent devices in terms of efficacy. Earlier reports showed that the worse outcomes after PCI with drug-eluting stents in patients who have DM than in those who do not are driven mainly by higher rates of death, cardiac death, and myocardial infarction (ie, safety end points), but the efficacy end points do not differ significantly between these two groups in the drug-eluting stent era.^1,2 Therefore, the EES-by improving safety, including mortality-takes a step forward in the PCI treatment of patients with DM.

A Message of Hope
The message for primary care physicians is one of hope. Until now, new devices have not shown any progress in treatment of patients with DM. In addition, reports from large randomized studies have shown that atherosclerotic disease in patients with DM is better managed surgically (eg, with a coronary artery bypass graft³) mainly because of better results in terms of safety, including mortality. However, the devices used in these trials were first-generation drug-eluting stents. As shown in this study, the new-generation thin-strut, durable, polymer drug-eluting stents, such as the EES, can improve safety outcomes in patients with DM.

Larger, dedicated trials are still needed to elucidate the role of newer-generation drug-eluting stents to further shape treatment indications and strategies for patients with DM.

References
1. Billinger M, Rber L, Hitz S, et al. Long-term clinical and angiographic outcomes of diabetic patients after revascularization with early generation drug-eluting stents. Am Heart J. 2012;163:876-886.
2. Iijima R, Ndrepepa G, Mehilli J, et al. Impact of diabetes mellitus on long-term outcomes in the drug-eluting stent era. Am Heart J. 2007;154:688-693.
3. Farkouh ME, Domanski M, Sleeper LA, et al. Strategies for multivessel revascularization in patients with diabetes. N Engl J Med. 2012;367:2375-2384.