Dr. Michael N. Zairis and colleagues at Tzanio Hospital in Piraeus note in the medical journal Diabetes Care that there is evidence that diabetics treated with clot-dissolving drugs after a heart attack fare more poorly than those without diabetes.

To help determine why this might be, the researchers followed 726 survivors of a heart attack, 214 of whom had type 2 diabetes, for up to 3.5 years.

All had had been given clot-dissolving drugs within six hours of first experiencing chest pain.

Fewer diabetics than nondiabetics showed full normalization of their echocardiogram (indicating clot clearance) after treatment, and both diabetic and nondiabetic patients who failed to show recovery had a significantly elevated risk of dying.

Moreover, those patients with diabetes whose electrocardiogram did show more complete recovery took significantly longer to do so than did the nondiabetic patients.

In addition, diabetics who took 60 minutes or more after the start of clot-buster treatment to achieve a normal electrocardiogram reading were at significantly increased risk of death. This was not true for nondiabetic patients.

The investigators conclude that "more appropriate therapeutic approaches" may improve the outlook for diabetic patients when they suffer a heart attack. An alternative to clot-dissolving drugs is to treat patients immediately with balloon angioplasty and/or a stent to open coronary arteries.