A year-long study calls into question the practice of giving patients at high risk of a second stroke a brain stent, a tube that widens a brain artery and help keeps it open. Patients in the study who received a stent were much more likely to die or have a second stroke during the course of the study.

The study (SAMMIS) compared the outcomes of patients who received aggressive medical treatment alone to those who received both this treatment and a stent. Aggressive medical treatment included daily medications to thin the blood (aspirin and clopidogrel), as well as aggressive treatment of high blood pressure and blood cholesterol.

About two and a half times as many patients who received a stent either died or had a second stroke within 30 days than did those who didn't receive a stent (14.5% to 5.8%). Adding in consideration of second strokes that occurred in the originally-affected artery after thirty days but within a year, the number of adverse events was 20.5% in the stent group, compared to 11.5% of those who didn't receive a stent.

New enrollment in the study was stopped in April because there were so many more strokes and deaths in the group that received a stent.

The study concludes that use of a stent is inferior to intensive medical treatment alone for stroke patients at high risk of suffering a second stroke and that this conclusion should immediately be put into clinical practice.

The study is too new for the medical community to have fully evaluated its meaning. And while some doctors have pointed out that stenting has been highly effective in certain stroke patients and still has a place in stroke treatment, so far no one seems to be calling for an increase in the practice.

The study specifically looked at stroke patients with recent symptoms and brain artery blockage of 70% of higher--those at highest risk of suffering a second stroke. These are the patients thought most likely to benefit from a stent. Patients with a lower degree of blockage in a cerebral artery are thought to be even less likely of benefiting from a stent.

Patients enrolled in the study will continue to be followed for two years to evaluate the longer-term effects of both treatments.

An article detailing the study was published online ahead of print by the New England Journal of Medicine (NEJM).