sábado, 9 de setembro de 2006

Guerra dos stents: perda para os dois lados.

A Boston Cientific e a Johsson & Johnson estão travando há mais de um ano uma guerra para mostrar que tem o melhor stent com medicamento no mercado. Ambas patrocinaram trabalhos que as favorecem, cada uma a seu tempo. Agora, duas apresentações no World Congress of Cardiology recém terminado em Barcelona, Espanha, reduziram as expectativas desse tipo de stent em relação ao tradicional. O melhor texto explicando a confusão é de hoje do The New York Times. Mas, voltaremos ao tema porque essa é uma questão central na organização da assistência ao infartado no Brasil. Interessante, que o estudo citado, o suíco Basket, não nega o uso desses stents, somente limita a sua indicação.
A grosso modo há um aumento considerável no gasto do atendimento ao infartado no mundo todo porque progressivamente os tratamentos mais adequados vão sendo superados por outros mais caros. Muitas aspas em adequados e superados.
Stent Makers Hurt by Reports About Safety
By
BARNABY J. FEDER
Published: September 8, 2006 (copyright NYT)
Shareholder qualms about growth prospects for the $5 billion coronary stunt business yesterday shook the stocks of Boston Scientific and Johnson & Johnson, the two leading stent makers. Shares of Boston Scientific fell 3.3 percent, or 57 cents, to $16.70. The stock of Johnson & Johnson, whose overall business is less dependent on stents, fell 46 ceNts, to $63.46. The declines came after a stream of reports about stent safety from a European medical meeting. Those included the disclosure yesterday that Boston Scientific had quietly told federal regulators this summer that new analysis of the company’s accumulating safety data found that patients using its best-selling Taxus stent had a slightly greater but statistically clear risk of developing potentially deadly blood clots compared with older stent designs. Among the earlier reports at the meeting was a Swiss study suggesting that in some patient groups the Cypher stent of Johnson & Johnson posed even higher long-term clotting risks than Taxus. Stents are metal sleeves inserted in arteries to keep them propped open after medical procedures to clear blockages. Although some are used during heart bypass surgery, most coronary stents are inserted as a follow-up to angioplasty, a less invasive procedure in which the blockage is cleared from inside the artery by inflating a balloon. The balloon and stent are delivered to the heart area via a long catheter inserted into a blood vessel in the patient’s thigh. Stents were first used in the 1990’s. The original designs were bare metal devices. Cypher, introduced in the United States in 2003, and Taxus, which was cleared for sale in 2004, are drug-coated devices. The coatings are meant to combat the tendency of arteries to form new blockages, a process called restenosis. Although the drug-coated devices cost more than $2,000 on average, compared with $800 or so for bare metal devices, they rapidly supplanted the older designs in the United States and now account for 85 percent to 90 percent of the market. Analysts said that the stock market reaction reflected fears that growth in the stent market would slow and that more doctors would prescribe the less profitable bare metal products. Word of Boston Scientific’s report to regulators, whom it met with on Aug. 1, and the news that Food and Drug Administration officials then asked Johnson & Johnson for more data on its Cypher stent, was reported yesterday in The Wall Street Journal.

3 comentários:

Anonymous disse...

DES versus BMS: an evidence-based approache to stent selection in real-world" patients -18 month update of BASKET."
The BASKET study, presented in clinical trial update session I, identifies that to achieve optimal benefit drug eluting stents could be restricted to small vessels less than 3mmm and bypass grafts. Here presenter Christoph Kaiser (Basel, Switzerland) and discussant Jean Marco (Toulouse, France)provide an overview of the results.
Background
In order to define patient subgroups with a particularly high versus no or only minimal clinical benefit from DES compared with BMS use we anlayzed our “real-world” experience from BASKET after 18 months.
Methods
BASKET included 826 consecutive patients with PCI and stenting irrespective of indication. Patients were randomized 2:1 to DES versus BMS and followed up for 18 months for the occurrence of major adverse cardiac events (Cardiac death, non-fatal MI and non-MI related TVR). Based on tests for interaction with the different stent types, patient subgroups with high versus low clinical benefit from DES were identified.
Results
Overall, event rates were low (DES vs. BMS: Death/MI: 8.4% vs. 7.5%; (p=0.63); Non-infarct related TVR: 7.5% vs. 11.6% (p=0.05); MACE: 15.8% vs. 18.9% (p=0.26). Overall, only bypass graft interventions and small vessel stenting < 3.0mm showed significant interactions between stent type and non-infarct related TVR as well as Death/ MI or MACE. Therefore, we analyzed outcomes in patients with versus without these two characteristics. Kaplan-Meier survival curves showed a highly significant benefit of patients with small vessel/stent or bypass graft PCI from DES use (Fig. 1). In contrast, for all other patients there was no benefit of DES compared to BMS.
Conclusion
Based on evidence from this long-term follow-up from BASKET, DES may be restricted to small vessels/stents <3mm and to bypass grafts for optimal and long-term benefit. These findings challenge the notion that today every patient should receive DES irrespective of baseline characteristics

Anonymous disse...

Safety of drug-eluting stents: insights from meta analysis.
A meta-analysis of first generation drug eluting stents - including both first generation drug eluting stent extent of both mortality and Q-wave Myocardial Infarction in comparison to bare metal stents. Here the presenter Edoardo Camenzind (Geneva, Switzerland) and the discussant Alain Nordmann (Basel, Switzerland) provide an overview of the results.
Introduction
First generation drug eluting stents (1stg-DES: sirolimus eluting stent [SES] have been widely accepted and are used for a large spectrum of clinical indications.
Recently case reports and autopsy reports have been published on single cases as well as on series of cases which experienced stent thrombosis more than 30 days after stent deployment, so called late stent thrombosis. Delayed healing and diminished antiplatelet therapy could be demonstrated as relevant precipitating factor.
The global incidence of ‘in-1st g-DES’ thrombosis according to the literature remains uncertain. According to some single center registries and post-marketing surveillance registries as well as meta-analysis the incidence of late angiographic stent thrombosis does not seem to be higher in 1st g-DES as compared to bare metal stents (BMS). However according to the recently presented BASKET-Late trial, a small randomized trial designed to evaluate cost effectiveness of 1st g-DES versus BMS, severe cardio-vascular events were significantly higher in patients with 1st g-DES as compared to BMS in the year following the interruption of dual antiplatelet therapy.
Methods
The current analysis embraced both 1st g-DES clinical programs (SES and PES) and included all available data concerning company supported randomized double-blind clinical trials comparing 1st g-DES to the respective BMS control. Of the SES program the following trials were included: RAVEL, SIRIUS, E-SIRIUS and C-SIRIUS and for the PES program: TAXUS II, IV, V and VI accounting for a total of n=878 SES vs n=870 BMS and n=1685 PES vs n=1675 BMS. Available randomized trials’ data within a specific study program (SES or PES) were stratified by trials and data of the same time-periods of follow-up were pooled as well as data of the latest available follow-up.
The clinically oriented analysis focuses on death, Q-wave MI and death and Q-wave MI combined thought to reflect the incidence of stent thrombosis best instead of using restrictive thrombosis definitions (e.g. late angiographic stent thrombosis).
Results
The incidence - up to the latest available follow-up - of total mortality and Q-wave MI combined were 38% (SES) and 16% (PES) higher in 1st g-DES as compared to control BMS (p-value: SES vs BMS: 0.03 ; PES vs BMS. 0.68).
Conclusion
eath and Q-wave myocardial infarction have a higher incidence in 1st generation drug eluting stents as compared to the bare metal control stents.
Thus the indiscriminated use of 1st g-DES should be avoided and the use of bare metal stent may still be maintained awaiting for safer 2nd g-DES

Anonymous disse...

Top U.S. cardiologist calls for sweeping stent study
Mon Sep 11, 2006 8:22am ET
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CHICAGO (Reuters) - One of the nation's leading cardiologists is calling for a sweeping study that evaluates the risks of potentially fatal blood clots related to widely used heart devices that treat blocked heart arteries.

Nearly 6 million heart patients worldwide have received a so-called drug-eluting stent, a tiny wire mesh tube that is covered with a drug that reduces scar formation and keeps vessels from reclosing.

But there has been a growing body of evidence that this newer generation of stents, compared with the bare metal variety, may cause blood clots to form long after implantation. Known as late-stent thrombosis, the risks were the center of debate at a cardiology meeting earlier this week in Barcelona.

"This really shakes up the whole cardiology community," Dr. Stephen Nissen, head of cardiovascular medicine at the Cleveland Clinic, said in a telephone interview.

"No one has done the right kind of long-term study," he said, adding that patients should be followed for three or four years instead 9 months. "We need a prospective, randomized trial. That's the gold standard and I'm hoping regulators will mandate it."

He said he will take an active role in initiating such a study. "How else will we answer the question?" Nissen added.