More heart victims die when clot-buster drug is used before angioplasty

Sep 7 2005

Currently it is fairly common practice to give heart attack patients a clot-busting drug a few hours before planned angioplasty.

But now a major study has found that the practice could be dangerous.

Doctors often give the clot-dissolver in the hope that it will make the artery-widening operation more successful.

The researchers found that more patients died in the month following the procedure if they were given the drug.

Their findings are expected to prompt many doctors around the world to stop using the strategy, at least for now.

Apparently there are two main options for treating heart attack victims, a clot dissolving drug or angioplasty; this is a procedure where doctors thread a wire through the blood vessels to get at the blood clot that caused the heart attack.

The wire mechanically breaks up the clot, then doctors inflate a balloon to squash plaque against the wall of the artery and implant a tiny mesh tube at the site of a blockage which permanently props the artery open.

Angioplasty is widely considered the more effective option, but only as long as it is done by experienced doctors in well-equipped hospitals.

However, as most community hospitals do not have such expertise, patients are either treated with a clot-busting drug or transferred to a nearby hospital that can perform the angioplasty within three hours.

It apparently is unclear whether angioplasty would work better if the clot was dissolved before the procedure.

In cases where angioplasty cannot be performed immediately but can be done some time between one and three hours after the heart attack, doctors have been giving the clot-buster to patients in this situation anyway, in the hope it might help.

In this latest study, led by Dr Frans Van de Werf of the Catholic University of Leuven in Belgium, the strategies were compared among 1,667 patients in hospitals.

Half were given the clot-buster while en route to angioplasty, while the other half were given a fake pill.

The researchers found that 6% of patients who got the drug, TNKase, died within 30 days of the angioplasty, compared with only 3.8% of those in the angioplasty alone group.

The study, which was supposed to enroll 4,000 patients, was stopped prematurely once the difference in death rates between the two groups became apparent.

The findings were presented at the annual conference of the European Society of Cardiology in Sweden.