Stent Thrombosis Rates Higher in Diabetics

　　EVASTENT研究显示，糖尿病患者置入支架后血栓发生率达4.2%。E-CYPHER 研究证实，胰岛素依赖型糖尿病患者一年支架内血栓发生率更高。新近Daemen等报道，糖尿病是晚期支架血栓发生的重要预测因子。巴黎Rene Descartes 大学Cochin 医院的Christian Spaulding教授指出，糖尿病多支血管病变患者置入DES比置入BMS具有更高的血栓发生率，但并不增加全因死亡率。

　　Stettler等采用荟萃分析方法发现，无论使用DES和BMS，糖尿病患者PCI术后心肌梗死、死亡以及心肌梗死与死亡总体发生率无区别；使用不同药物支架（Taxus和Cypher支架）的不良事件发生率也没有区别。Spaulding等指出，糖尿病患者置入DES比置入BMS血栓风险增加，但全因死亡率无改变甚至有减少趋势是由于：引起糖尿病患者死亡的原因有多种，而支架血栓仅占一小部分；置入BMS者再狭窄率非常高，再狭窄使心肌梗死和死亡等不良事件发生率增加约10%。

　　（哈尔滨医科大学附属第一医院　李悦 盛力 编译   李为民　审校）

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Stent Thrombosis Rates Higher in Diabetics

No increase in all-cause mortality found among patients with diabetes after stent placement.

Patients with diabetes and multi-vessel disease have a higher rate of stent thrombosis after DES implantation, Christian Spaulding, MD, said Saturday, but this does not translate to an increase in all-cause mortality.

The EVASTENT registry identified a 4.2% rate of stent thrombosis in patients with diabetes, and the E-CYPHER registry showed that insulin dependence is a predictor of stent thrombosis at 1 year. Diabetes was also predictive of late coronary stent thrombosis in a recent trial by Daemen et al (Lancet 2007;369:667-78), said Spaulding, of the Department of Cardiology, Cochin Hospital, Rene Descartes University in Paris.

Stent thrombosis and mortality

A recent collaborative network meta-analysis by Stettler et al (Lancet 2007;370:937-48) examined randomized trials that compared DES with bare-metal stents, and DES with other DES.

“There was no difference in death or MI, and no difference in the com¬bination of death or MI in diabetic patients between bare-metal stents and drug-eluting stents,” Spaulding said. There was also no difference in rates of adverse events between the Taxus (Boston Scientific) and Cypher (Cordis, Johnson & Johnson) stents, he said.
In addition, in another recent study by Spaulding and colleagues (NEJM 2007;356:989-97), DES were found to significantly reduce all-cause mortality in diabetic patients (Figure).

Spaulding listed two reasons for the disparity between increased risk for thrombosis and no increase in all-cause mortality in patients with dia¬betes. First, mortality in patients with diabetes occurs for many reasons. The increased mortality due to stent thrombosis is most likely “just a little drop in the water,” Spaulding said.

Also, patients with bare-metal stents experience restenosis; bare-metal stent-related restenosis is associated with an almost 10% increase in MI, death, or other adverse events and, therefore, likely equalizes the increase of late-stent thrombosis observed with DES, Spaulding said.

PTCA

Diabetes is a risk factor for adverse events after angioplasty, but mortality risk is lower after successful PCI, he said. Ongoing randomized trials comparing CABG and DES (ARTS II, FREEDOM, CARDIA) will hopefully provide answers about when PTCA can be used safely in patients with diabetes, Spaulding said.

Until data are available from ongoing clinical trials, careful selection based on clinical and angiographic evidence is necessary before selecting PCI for a patient with diabetes, he said. ™