An experimental drug appears to be the first treatment to keep arteries from reclogging after angioplasty, a problem that afflicts 100,000 U.S. heart patients annually at a cost of more than $625 million.

In a study presented Wednesday at a meeting of the American College of Cardiology, doctors report that a medicine called ciprostene can reduce this failure rate from one-third of patients to one-quarter.

In that work, doctors randomly assigned 311 angioplasty patients to get either ciprostene or placebos. Six months later, doctors checked the patients' hearts with X-ray movies called angiograms. They estimated that the angioplasties had failed in 41 percent of the ciprostene patients and 53 percent of the placebo patients.