quarta-feira, 28 de março de 2007

Coragem para contestar os stents e sua indústria.

Na sessão da American College of Cardiology, que se encerra hoje, houve a apresentação de vários estudos novos, um deles chamado COURAGE. Esse estudo avaliou 2287 pacientes com angina do peito para comparar se angioplastia com stent não farmacológicos é superior ao tratamento convencional com medicamentos. Houve uma leve vantagem para o tratamento clínico, ou seja não há porque indicar angioplastia nessa situação. O texto completo está em http://www.nejm.org Abaixo segue um reportagem muito esclarecedora do The New York Times com a repercussão do estudo. Um pouco antes, a Boston Scientific que produz o Taxus - stent farmacológico - aproveitou-se da situação para lançar a idéia que o problema do estudo foi que somente 3% dos participantes teriam usado o seu produto.
By BARNABY J. FEDER Published: March 28, 2007 NEW ORLEANS, March 27 — Is today the first in a new era for angioplasty and stenting, the artery-clearing technology that enchanted doctors while giving birth to a multibillion-dollar industry? Many heart specialists at the annual scientific meeting here of the American College of Cardiology said it ought to be, based on a report Monday that found little additional value in giving stents to most heart patients as long as they received the right medicines. “We were amazed at how well people did with medical therapy,” said Dr. William Weintraub, chief of cardiology at the Christiana Care Health System in Newark, Del., who is leading the analysis of the economic and quality of life data from the trial. The trial focused on patients with severe constrictions in their arteries that were causing angina chest pains or other symptoms but were not immediately life-threatening. Device makers and some doctors, however, doubted that the trial would have broad impact. They noted several reasons to question the results, starting with the fact that only 3 percent of the stented patients in the trial received the latest drug-coated models. Those models were just reaching the market when enrollment in the study ended in 2004.
Whether the trial results lead to a change in the use of stents depends on how the doctors and patients react. In any event, the research comes as sales have already been dropping because of safety concerns.
Estimates from doctors and analysts of the number of stent patients whose conditions resembled those in the trial ranged from 20 percent to as much as 80 percent. Marshall Gordon, who follows device makers for
Credit Suisse Securities in New York, said that in conversations with cardiologists, 30 percent to 40 percent of them said they would recommend less angioplasty. But, he cautioned, it was too soon to know how the practice would unfold. Dr. Salim Yusuf, a Canadian cardiologist who has argued that stents are overused, questioned how much impact the study would have. “We’re going to have a hell of a time putting the genie back in the bottle,” Dr. Yusuf said to the researchers gathered Tuesday. “It’s a $15 billion to $20 billion industry. You have huge vested interests that are going to push you back.” Dr. Yusuf was referring not just to device makers but also to interventional cardiologists, the specialists who do angioplasty and stenting. The technology was born 30 years ago when Dr. Andreas Gruentzig first used a catheter threaded into a coronary artery to inflate a tiny balloon inside a developing blockage. The arrival of a minimally invasive alternative to bypass surgery for restoring blood flow to ailing hearts led to a rush of investment in device companies. Small fortunes were made in the mid-1990s when stents were invented in response to angioplasty’s biggest shortcoming — the tendency of arteries to quickly reclose. Those fortunes became giant ones when drug-coated stents were introduced in the United States in 2003, sending the number of patients returning for repeat procedures below 10 percent. The Taxus stent from Boston Scientific, which arrived in 2004, achieved more sales in its first year than any health care product in history. By last year, more than 60 percent of the patients getting stents had more complex blockages than those the drug-coated stents had been tested on in clinical trials, according to federal regulatory officials. Then reports began emerging that deadly clots could form in the drug-coated stents long after implantation. Sales began dropping on uncertainty about the stents’ safety even though the data showed that the problem affected only a handful of patients out of every thousand. The available data, which some doctors say is inadequate, suggests that the clotting is not frequent enough to make the new stents less safe than the older bare-metal devices they have largely supplanted. A decline in sales last year reflected some switching to the cheaper bare-metal stents, but by the end of the year, the total number of procedures was falling for the first time. Now the question is whether the new trial data will accelerate the decline and make it harder for the companies to reverse with new products that might be safer. Medical therapy — which to cardiologists means a combination of modern drugs, exercise, healthy diets and almost anything else that does not break the patient’s skin — was so successful at relieving angina that Dr. Weintraub and others said angioplasty should be used as a fallback, after the drug treatments failed in patients like those in the trial. In common practice, many such patients get angioplasty and stents because they are sent to interventional cardiologists for angiograms — X-rays of the blood vessels sustaining the heart muscle. The angiogram requires inserting a thin catheter to deliver a dye to the arteries being pictured. Because the same system is used to deploy the tiny angioplasty balloons that create channels through blockages and then to implant stents to prop the vessel open, interventional cardiologists often do such procedures immediately after a major blockage is identified. “It’s very difficult to turn your back on the angiogram and not fix what’s there,” Dr. William Boden, a lead investigator in the trial, said. Yet that is exactly what the trial results suggest that doctors could safely do in patients like those studied. Two-thirds ended up not needing angioplasty and stents. The one-third whose symptoms worsened to the point that they underwent stenting or bypass surgery did not suffer higher rates of death, heart attacks or hospitalization if stenting was delayed to try aggressive medical therapy first, the trial found. In the trial, patients who received angioplasty and stents got quicker and more complete relief initially. By the end of five years, 74 percent of that group and 72 percent of the patients assigned to the medical therapy group had no symptoms of the chest pains — in essence, statistically speaking, an identical outcome. Dr. Weintraub said on Monday that the trial data suggested that the cost of gaining an additional year of improved quality of life from stenting came out to $217,000 a patient, because so many patients gained nothing. That data, however, covered such a broad range of individual outcomes that he cautioned against relying too much on it. More notably, he said, the data suggested that 1 percent of stenting patients gained an additional year of improved quality of life for less than $50,000, a commonly used standard for whether medical resources were being used wisely. But all of the researchers stressed that angioplasty with stenting was still the preferred therapy for many less-stable patients. Some doctors said they were worried that patients reading about Courage, as the new study is called, might get the wrong impression. “If someone comes in with a heart attack, you could lose vital time having to convince a patient or family member it’s appropriate,” Dr. Ralph Brindis, a cardiologist in San Francisco, said

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