Feb. 7 (HealthDay News) -- Vacuuming out loose pieces of clots in blocked heart vessels improved the results of artery-opening angioplasty in a Dutch trial.

The technique, called thrombus aspiration, has been available for several years, said Dr. Felix Zijlstra, a professor of cardiology at the University of Groningen and senior author of the report in the Feb. 7 issue of the New England Journal of Medicine.

The trial included 1,071 persons who were assigned to get either conventional angioplasty or thrombus aspiration as part of their regimen. A major measure used by the Dutch researchers was blush grade, in which X-rays determine how well blood flow resumes to heart muscle after injury. A higher blush grade indicates better blood flow.

The lowest score, blush grade 0 to 1, was recorded for 26.3 percent of those getting conventional treatment and 17.1 percent of those who also had thrombus aspiration, the researchers reported. Thirty days after treatment, 5.2 percent of those with blush grades of 0 or 1 had died, compared to 1 percent of those with blush grades of 3.

Adverse affects such as second heart attacks occurred in 14.1 percent of those with the lowest blush grades, compared to 4.2 percent of those with the highest blush grades.

"In our practice, after we finished this trial, we adopted it [thrombus aspiration] for all patients, at least 80 to 90 percent of them," Zijlstra said.

When the trial results are publicized, "I think it will be adopted on a large scale very quickly," he said. The technique is easily learned, Zijlstra added: "I can teach it in an afternoon to every experienced cardiologist."

However, Dr. Gregg W. Stone, a professor of medicine at Columbia University and an expert in the field, had some cautionary words.

"There have been many prior trials, probably between 16 and 20," Stone said. "Everyone in the field has been interested for many years in the concept of removing thrombus. I, along with others, originated it and ran the first big trial."

Studies using two kinds of devices that actively break up clots and suck out the fragments have shown "no benefit and some harm," Stone said. The new study uses a more passive suction device, which smaller trials have shown gives results that are "mixed to slightly positive," he said.

"This trial is significant, because it is the largest study ever done," Stone said. "It pretty much showed what the other trials have shown. It showed trends in the right direction, although they were not statistically significant."

Because the study had some weaknesses, notably lacking a measure of the size of coronary muscle affected by the heart attacks, "I don't think it will have a major impact on how people practice," Stone said. "People who were on the fence may start using it in selected cases. But, unfortunately, it is not a definitive study."

SOURCES: Felix Zijlstra, M.D., Ph.D., professor, cardiology, University of Gronigen, Netherlands; Gregg W. Stone, M.D., professor, medicine, Columbia University, New York City; Feb. 7, 2008, New England Journal of Medicine