MINNEAPOLIS--A study of 200 heart patients in the United Kingdom shocked the international cardiology community on Thursday when it reported that patients who had stents put in to treat nonemergency chest pain showed about the same improvements as patients who got a "sham" placebo procedure.
The findings from the first-of-its-kind study contradicted widespread assumptions that using the metal mesh tubes to prop open clogged arteries would allow patients to walk longer on a treadmill by hastening blood flow to the muscles that make the heart pump. Cardiologists said the study is likely to cut down on the use of stents, affecting Minnesotans with chest pain and the Minnesota companies that make stents, including Medtronic.
The peer-reviewed study, published Thursday in the medical journal Lancet, found that patients with stable chest pain who got a stent could tolerate running on a treadmill for an extra 28 seconds, on average, six weeks after the procedure. Patients who got a placebo procedure, but no stent, improved their treadmill tolerance by 12 seconds after six weeks. The difference was statistically insignificant.
"I think this is a game-changer," said Dr. Rita Redberg, a researcher and cardiologist at the University of California, San Francisco, who was not involved in the research. "If fewer stents aren't placed, I think we have some real explaining to do."
However, doctors were quick to note that the study doesn't change the thinking about the use of stents in medical emergencies. Most stents are placed in patients with unstable blockages or heart attacks, whereas the Lancet study focused on stent placements in patients with stable blockages but episodic chest pain, or "angina."
"If you're having a heart attack, a stent is lifesaving," said Dr. Michael Miedema, a preventive cardiologist with the Minneapolis Heart Institute at Abbott Northwestern Hospital. "That hasn't changed at all."
The study report noted that some patients may still choose to have a stent placed for nonemergency chest pain, rather than taking prescription drugs to treat their stable angina.
"Companies with major operations in Minnesota are key manufacturers of stents, including Medtronic, Boston Scientific and Abbott Laboratories. Medtronic stock dropped nearly 3 percent Thursday, while Boston Scientific dropped 1.5 percent and Abbott Labs rose up half a percent.
The study report didn't disclose which companies' stents were used in the trial.
A spokesman for Abbott Labs said the study population had "very mild" disease and were not reflective of patients who typically get stents placed. More than 25 percent of the patients who got stents in the trial would not have had one implanted under current medical guidelines.