Stents farmacológicos: Folha de S.Paulo e NY Times noticiam a mesma conferência, mas com conclusão diferente.

Esse blog tem acompanhado a questão dos stents farmacológicos há meses. Na semana passada, o FDA reuniu especialistas para debater o assunto. A posição da maioria foi por limitar as indicações do stent farmacológico. As duas empresas fabricantes publicaram sua defesa no site

http://theheart.org que por sua vez disponibiliza a seqüência do debate. O acesso ao site é gratuito, mas necessita inscrição. Aqui, a Folha de S. Paulo repercutiu somente uma parte das conclusões, o The New York Times mostrou os riscos inerentes ao procedimento.
Folha de S. Paulo: 12/12/06

FDA deve descartar risco cardíaco de prótese
Stents farmacológicos, utilizados contra obstruções, estavam sob suspeita de aumentar risco de infarto
Os stents farmacológicos -próteses de aço que liberam remédios, colocadas dentro das artérias do coração para evitar obstruções- devem sair incólumes de uma avaliação que vem sendo realizada pela FDA, a agência regulatória de medicamentos dos Estados Unidos.Eles se tornaram suspeitos de trazer um maior risco de mortes por infarto a longo prazo em estudos divulgados em setembro passado.Estima-se que, no mundo, 2 milhões de pessoas já tenham recebido stents farmacológicos para evitar "entupimentos".O procedimento, testado pela primeira vez no mundo em 1999, em um tratamento feito no Brasil, é menos invasivo do que cirurgias e em apenas 5% dos casos as obstruções nas artérias reaparecem.Na última semana, especialistas reunidos na sede da FDA, na Virgínia (EUA), apontaram que os stents farmacológicos não causam mortes se forem usados nos casos corretos. "Senão é como colocar uma peça errada no carro", diz Luiz Alberto Matos, presidente da Sociedade Brasileira de Hemodinâmica e Cardiologia. O parecer final da agência deve sair ainda neste mês. Os especialistas entendem que o uso sem critérios do stent farmacológico possa ser a explicação para os problemas relatados.Diabéticos, pessoas com vasos de pequeno e médio calibre e entupimentos de média a longa extensão e que não tiveram sucesso com stents comuns são os principais candidatos à prótese com remédios.Segundo Matos, os stents farmacológicos trazem os mesmos riscos da "geração" anterior, a dos stents que não continham remédios."Na evolução de quatro anos, o risco de trombose [formação de coágulos que podem levar a morte por infarto] é de 0,6% a 1% ao ano tanto no uso de stents com remédios quanto no de convencionais", disse o presidente da entidade.Ainda de acordo com o dirigente, não podem utilizar stents farmacológicos principalmente pessoas que estejam utilizando remédios anticoagulantes a médio e longo prazo. Também estão vetados para casos de alta complexidade, explica. Por exemplo, uma pessoa com indicação de ponte de safena não pode se arriscar a implantar o stent com remédio.Os stents farmacológicos ainda não estão acessíveis à maior parte da população no Brasil, pois o SUS (Sistema Único de Saúde) não paga as próteses, afirma Matos. Somente a rede privada as oferta.

The New York Times 08/12/06

Panel Urges Caution on Coated Stents
By BARNABY J. FEDER
Published: December 9, 2006
GAITHERSBURG, Md., Dec. 8 — A panel of experts recommended Friday that doctors and patients be given stronger warnings about the dangers associated with the use of drug-coated stents in high-risk patients. The panelists also recommended that the Food and Drug Administration warn doctors that if possible, such patients should remain on aspirin and Plavix, an anticlotting drug, for at least a year after a drug-coated stent implant. The label on the Cypher stent, from Johnson & Johnson, approved for sale in the United States in 2003, calls for the anticlotting therapy for just three months. The label on the Taxus stent, from Boston Scientific, approved the next year, calls for six months on the drug.
At the end of the two-day hearing here, the panelists struggled to reach a consensus on most of the questions posed to it by the F.D.A. about whether it should restrict the use of the tiny devices, which are implanted to prop open heart arteries.
As the session ended, Daniel Schult, head of the drug agency’s Center for Devices and Radiological Health, said it was too soon to discuss what specific actions the F.D.A. might take. “What I heard loud and clear is that we need to do a better job communicating to doctors and patients the best and latest information,” Dr. Schult said.
The challenge the agency faces is that most of the stents — over 60 percent by the F.D.A.’s estimates — are being implanted in patients with more complex cardiovascular problems than those of the patients the devices were tested on.
The experts told F.D.A. officials that there was little reliable research comparing the risks associated with such “off label” use to the outcomes with drug treatment or surgery. And what research there is suggests that the risks of clotting, heart attack and death are higher for such high-risk patients than for those who were in clinical trial groups.
The stent market grew so explosively after the drug-coated devices were introduced in 2003 that regulators and consumers were caught with too little data. About one million Americans annually get stents — often more than one. Stents are implanted after tiny balloons have been inflated in clogged arteries to reopen blood flow, a procedure known as angioplasty.
The first stents were bare metal devices. The drug-coated products sharply reduced the frequency with which new blockages formed at the implant site, thus reducing the number of follow-up procedures. In the last year, though, it was discovered that the formation of potentially deadly clots long after implantation was slightly more common with the drug-coated stents than with bare-metal stents.
Doctors today commonly give the drug-coated stents without F.D.A. clearance to diabetics, people with weakened hearts or kidneys, and those with plaque blockages in three or more coronary arteries who hope the stenting will allow them to avoid bypass surgery.
Three medical societies, including the American Heart Association, have recommended that patients stay on anticlotting drugs for a year.
How the F.D.A. may address the issue is unclear. It cannot require the companies to recommend a drug program on their labels for an unapproved use of the device. And Bristol-Myers, which makes Plavix, is not allowed to market the drug for off-label stent use.
Many doctors are already recommending extended or even indefinite use of anticlotting drugs for stent patients. But the panelists pointed out Friday that no one knows the optimal length of time to take the drugs.
The anticlotting drugs can lead to excessive bleeding when a patient is in an accident and must be stopped if surgery or dental work is needed. Doctors also worry about whether patients will remember to take them every day and whether poorer patients can afford Plavix, which costs $1,400 annually for a daily dose.
“I haven’t heard anything today that’s going to change my practice when I go back to it Monday,” said Dr. Christopher J. White, a cardiologist on the panel from the Ochsner Medical Center in New Orleans. After a moment’s thought, though, he said he might cut back on the use of drug-coated stents where arteries branch since data showed clotting rates were higher where patients had overlapping stents.
Surgeons told the panel that a way to reduce risks was to cut back on the use of stents in most patients with blockages in three or more vessels or in the left main coronary artery — both cases in which data indicates survival rates are better for patients who undergo bypass surgery.