"A procedure used to relieve chest pain in hundreds of thousands of heart patients each year is useless for many of them researchers reported on Wednesday. Their study focused on the insertion of stents tiny wire cages to open blocked arteries. The devices are lifesaving when used to open arteries in patients in the throes of a heart attack. But they are most often used in patients who have a blocked artery and chest pain that occurs for example walking up a hill or going up stairs. Sometimes patients get stents when they have no pain at all just blockages. Heart disease is still the leading killer of Americans   people have heart attacks each year  and stenting is a mainstay treatment in virtually every hospital. More than  heart patients worldwide have stents inserted each year to relieve chest pain according to the researchers. Other estimates are far higher. Several companies  including Boston Scientific Medtronic and Abbott Laboratories  sell the devices and inserting them costs from  to  httphealth.costhelper.comstents.html at hospitals in the United States. The new study http published in the Lancet stunned leading cardiologists by countering decades of clinical experience. The findings raise questions about whether stents should be used so often  or at all  to treat chest pain. Its a very humbling study for someone who puts in stents said Dr. Brahmajee K. Nallamothu an interventional cardiologist at the University of Michigan. Dr. William E. Boden a cardiologist and professor of medicine at Boston University School of Medicine called the results unbelievable. Dr. David Maron a cardiologist at Stanford University praised the new study as very well conducted but said that it left some questions unanswered. The participants had a profound blockage but only in one artery he noted and they were assessed after just six weeks. Editors Picks   https_idWe dont know if the conclusions apply to people with more severe disease Dr. Maron said. And we dont know if the conclusions apply for a longer period of observation. For the study Dr. Justin E. Davies a cardiologist at Imperial College London and his colleagues recruited  patients with a profoundly blocked coronary artery and chest pain severe enough to limit physical activity common reasons for inserting a stent. All were treated  httpswe.tlxMlsGYBfor six weeks with drugs to reduce the risk of a heart attack like aspirin a statin and a blood pressure drug as well as medications that relieve chest pain by slowing the heart or opening blood vessels. Then the subjects had a procedure a real or fake insertion of a stent. This is one of the few studies in cardiology in which a sham procedure was given to controls who were then compared to patients receiving the actual treatment. In both groups doctors threaded a catheter through the groin or wrist of the patient and with Xray guidance up to the blocked artery. Once the catheter reached the blockage the doctor inserted a stent or if the patient was getting the sham procedure simply pulled the catheter out. Sign up for Science Times Well bring you stories that capture the wonders of the human body nature and the cosmos. Jim Stevens a lawyer in Troy Mich. was about to have a stent put in but the new study gave his cardiologist pause. He advised against inserting the stent and Mr. Stevens concurred.CreditSean Proctor for The New York Times  Jim Stevens a lawyer in Troy Mich. was about to have a stent put in but the new study gave his cardiologist pause. He advised against inserting the stent and Mr. Stevens concurred.CreditSean Proctor for The New York Times Neither the patients nor the researchers assessing them afterward knew who had received a stent. Following the procedure both groups of patients took powerful drugs to prevent blood clots. The stents did what they were supposed to do in patients who received them. Blood flow through the previously blocked artery was greatly improved. When the researchers tested the patients six weeks later both groups said they had less chest pain and they did better than before on treadmill tests. But there was no real difference between the patients the researchers found. Those who got the sham procedure did just as well as those who got stents. Cardiologists said one reason might be that atherosclerosis affects many blood vessels and stenting only the largest blockage may not make much difference in a patients discomfort. Those who report feeling better may only be experiencing a placebo effect from the procedure. All cardiology guidelines should be revised Dr. David L. Brown of Washington University School of Medicine and Dr. Rita F. Redberg of the University of California San Francisco wrote in an editorial published with the new study. Clinical guidelines in the United States say stenting is appropriate for patients with a blocked artery and chest pain who have tried optimal medical therapy meaning medications like those given to the study patients. But those guidelines were based on studies in which patients simply said they felt better after having stents inserted. It was impressive how negative it was Dr. Redberg said of the new study. Since the procedure carries some risks including death stents should be used only for people who are having heart attacks she added. Stents came into wide use in the s and became the treatment of choice because they were less invasive than bypass surgery. But there have long been questions about their effectiveness. A large federally funded study https with Dr. Maron as a coprincipal investigator which does not have an untreated control group is now underway to determine whether medications can be just as effective as stenting or coronary bypass in preventing heart attacks. In  another large study http led by Dr. Boden  also without an untreated control group  found stents did not prevent heart attacks or deaths from heart disease. The explanation researchers said was that atherosclerosis is a diffuse disease. A few arteries might be blocked today and then reopened with stents. But tomorrow a blockage might arise in another artery and cause a heart attack. Relieving chest pain though seemed a different goal to many cardiologists. After all the heart is a muscle and if a muscle is starved for blood it aches. Many patients have coronary arteries that are  to  percent blocked. Surely opening those vessels should make the patients feel better. Mr. Stevens was on the operating table to receive a stent through his wrist when his cardiologist Dr. Brahmajee K. Nallamothu had second thoughts and ended the procedure.CreditSean Proctor for The New York Times  Mr. Stevens was on the operating table to receive a stent through his wrist when his cardiologist Dr. Brahmajee K. Nallamothu had second thoughts and ended the procedure.CreditSean Proctor for The New York Times The idea that stenting relieves chest pain is so ingrained that some experts said they expect most doctors will continue with stenting reasoning that the new research is just one study. Even Dr. Davies hesitated to say patients like those he tested should not get stents. Some dont want drugs or cant take them he said. Stenting is so accepted that American cardiologists said they were amazed ethics boards agreed to a study with a sham control group. But in the United Kingdom said Dr. Davies getting approval for the study was not so difficult. Neither was it difficult to find patients. There are many people who are open to research and if you tell them you are exploring a question people agree he said. Nonetheless it took him three and a half years to find the subjects for his study. Ethics boards at many American hospitals probably would resist since giving such patients fake procedures flies in the face of guidelines Dr. Boden said. Placebo effects can be surprisingly powerful said Dr. Neal Dickert Jr. a cardiologist and ethicist at Emory University. A few years ago researchers  at the insistence of the Food and Drug Administration  did a study http to test an invasive procedure to treat high blood pressure. The control group got a sham procedure. The method was becoming popular in Europe but the study found that blood pressure dropped just as much in those who had the fake treatment. Dr. Dickert said he hoped the new stent study will show cardiologists that they need to do more studies with sham procedures. This may turn out to be an important moment he said. But getting them underway in the United States may not be easy. Ethics boards at hospitals and universities are likely to resist as are patients. Its not just up to us said Dr. David Goff director of cardiovascular sciences at the National Heart Lung and Blood Institute. Still the results of the new research have at least one heart specialist rethinking his practice. Dr. Nallamothu got an advance look at the new paper on Tuesday. Coincidentally he had a patient Jim Stevens  a lawyer in Troy Mich. scheduled to receive a stent that day. Mr. Stevens had a blocked artery but the new report gave Dr. Nallamothu second thoughts. I took him off the table he said. He explained to Mr. Stevens and his wife that he did not need a stent. I was surprised Mr. Stevens said. But I feel better not needing it."