NEW YORK (Reuters Health) – Although spontaneous reperfusion during percutaneous angiography for treatment of ST-segment myocardial infarction (STEMI) occurs less often in patients with diabetes than in nondiabetics, diabetics reap as much benefit from the phenomenon, according to a new study.

“Spontaneous resolution before mechanical reperfusion is associated with greater myocardial salvage, and such patients are less likely to develop left ventricular dysfunction, and have better early and late survival,” Dr. Paul W. Armstrong and co-authors explain in the August 15 issue of Heart.

Whether or not diabetics also have a better prognosis after spontaneous resolution has remained unclear, they add.

The researchers analyzed the effects of spontaneous reperfusion in a large primary percutaneous coronary intervention (PCI) among 4944 patients with STEMI, among whom 15.5% were diabetic. They defined spontaneous reperfusion as pre-PCI Thrombolysis in Myocardial Infarction (TIMI) 3 flow.

Spontaneous reperfusion was more common among nondiabetics than among diabetics (11.9% vs 9.2%, p = 0.028), Dr. Armstrong, from the University of Alberta in Edmonton, Canada, and associates report.

Patients with spontaneous reperfusion had improved post-PCI TIMI 3 flow (among nondiabetics, 99.8% vs 90.3%, p < 0.001; among diabetics 98.6% vs 84.9%, p 50%, p = 0.005).

The 90-day composite outcome of death/shock/congestive heart failure was significantly reduced in nondiabetic patients with spontaneous reperfusion (4.4% vs 8.9%). A similar, though nonsignificant trend was observed among diabetic patients (10.0% vs 14.9%, p = 0.270).

Moreover, both nondiabetics and diabetics with normoglycemia showed higher rates of spontaneous reperfusion and ST resolution, and significant improvement in the 90-day composite outcome.

“Identifying the diabetic patient without spontaneous reperfusion signals a high-risk patient population who deserve particular attention,” Dr. Armstrong’s team concludes. “New approaches such as mechanical devices and/or pharmacological reperfusion therapies may prove to be particularly successful in such patients with poor clinical outcomes.”

This study was jointly funded by Procter and Gamble Pharmaceuticals and Alexion Pharmaceuticals, both of whom market, or are testing, treatments for cardiovascular disease.

Reference:
Heart 2009;95:1331-1336.