Drug coated heart stents more likely to cause blood clots

Dec 4 2006

A review and analysis of studies on drug-coated heart devices known as stents, has found that patients with them are four to five times more likely to get blood clots when compared to the older bare-metal variety.

The analysis by Cleveland Clinic researchers covered 14 studies and 6,675 patients; it found the drug-coated stents, tiny wire-mesh devices used to prop open surgically cleared arteries, unless used with anti-clotting drugs, present a real hazard of thrombosis.

Thrombosis, or blood clots, can lead to heart attacks.

In the procedure a miniscule deflated balloon is positioned next to a clog, it is then inflated, thus flattening the clog, a tiny mesh scaffolding (stent) is placed in the area to keep the artery open.

But it seems that if a patient does not stay on Plavix, an anti-clotting medication, the chances of developing dangerous blood clots are significantly raised.

However the safety of the long-term use of Plavix for stent patients is at present unknown.

Dr. Deepak Bhatt, an associate director of the Cleveland Clinic Cardiovascular Coordinating Center and one of the study's authors, says this does not mean they should not be used as they significantly reduce the need for repeat procedures compared with bare metal stents.

Some doctors say the raised risk is not significant, about five clots are found in every 1,000 drug-coated stent patients, and are concerned that an overreaction to the risk could undermine patients' long term options.

The analysis preempts a meeting of a Food and Drug Administration panel of experts which is about to discuss the issue.

Over six million people around the world have received the drug coated stents which are inserted during an angioplasty.

The study is published in the current issue of American Journal of Medicine.