Although bypass surgery and angioplasty have similar effects for heart patients with clogged arteries, the surgical procedure is recommended in more serious cases, according to a new study comparing Boston Scientific Corp.'s (BSX) Taxus Express drug-coated stents with bypass surgery.

The findings, revealed at the European Society of Cardiology meeting in Munich, hinder the progress of stenting, which involves a mesh-metal tube being expanded inside a carotid artery to increase blood flow in areas blocked by plaque. A lack of success in the research would trigger lost sales for stent manufacturers, analysts say.

In the study, funded by Boston Scientific –the makers of heart stents, more than 3,000 European and U.S. patients in 85 hospitals were involved, The Associated Press reported. The health condition of about a third of them called for bypass surgery. The other participants were assigned at random to undergo either surgery or angioplasty, a common medical procedure which implies the use of a stent in order to prop the artery open. The patients were followed for a one-year period of time.

The death rate among the two groups was found almost at a steady level: 7.7% among surgery patients and 7.6% among angioplasty patients. However, an estimated 14% of those who experienced the non-surgical procedure needed another one after 12 months, in contrast with an estimated 6% of patients who received bypass surgery. The stroke risk of this last category of patients was about 2%, compared to approximately 0 for those who had angioplasty.

“Surgeons won't be out of work,'' is the conclusion drawn by Douglas Weaver, president of the American College of Cardiology, who was not involved in the research. "Surgery still comes out as the winner in a head-to-head trial," he said. Bypass surgery remains the most efficient way for treating heart disease for the reason that its effects can persist more than 10 years, the physicians said, Bloomberg reported.

However, in spite of failing to hit its goal, stents remain safe, said Keith Dawkins, Associate Chief Medical Officer at Boston Scientific. The failure is explained by revascularization, not by safety concerns.

Doctors said the current data from the study, which has been called SYNTAX study, is not sufficient in order to establish the real advantages and disadvantages of both medical procedures. Patients should be followed for another four years, they agreed. "This only tells us what happens after one year," said Dr. Heinz Drexel, professor of medicine at the University of Innsbruck in Austria and spokesman for the European Society of Cardiology, who was unconnected to the study. "We need to wait for at least five years to get a good answer about which therapy is really better."

Usually, the period of recovery after bypass surgery is of at least a month. On the other hand, angioplasty patients only need a couple of days to restore their health. As stated by Dr. Tim Gardner, president of the American Heart Association, "you invest more in terms of recuperation with surgery, but the advantage is durability.”