Patients who get the leading drug-coated heart stents to prop open coronary arteries rather than bare-metal stents do not run a higher risk of death, according to a new report by a multinational team of doctors.
That finding is consistent with several others reported at recent cardiology meetings, and it may help allay safety concerns set off last year by reports of potentially deadly clots forming in the leading drug-coated stents, namely the Taxus, made by Boston Scientific, and the Cypher, by Johnson & Johnson.
But the analysis, published today in The Lancet, the London-based medical journal, also includes less clear-cut findings that could be troubling for Boston Scientific, which dominates the market. The data suggested that patients who received the Taxus stent were a bit more likely to suffer heart attacks than those who received the Cypher from Johnson & Johnson.
The analysis also confirmed the slightly elevated risk of potentially deadly clots forming in Taxus more than 30 days after implantation, compared with bare-metal stents. The researchers said the data did not show that Cypher patients ran that risk.
Moreover, fewer Cypher patients needed follow-up procedures, either a new stent or bypass surgery, to deal with a recurrence of their coronary blockage.
The study combines and reanalyzes the latest data available from 38 previously reported clinical trials.
Taxus and Cypher are the best-selling drug-coated stents in most overseas markets, and the only such devices approved for sale in the United States, where Taxus controls about 54 percent of the market. Sales of both have tumbled about 40 percent in the last year, because some patients have shifted to bare-metal stents and some patients have decided not to get stents at all.
Still, sales of drug-coated stents will total $5.5 billion of the $6.5 billion worldwide stent market this year, says the Millennium Research Group, a market-research company in Toronto.
Stenting during heart attacks can save lives. But most stents are implanted to provide relief from chest pains, shortness of breath or other symptoms of narrowing heart arteries. Such stenting can vastly improve a patient’s life, yet there is little evidence it helps patients live longer. Results from a clinical trial released in March suggested that most patients could gain such relief over time from taking drugs and adopting healthier lifestyles.
How seriously doctors and patients will take the comparisons between Taxus and Cypher in The Lancet study is unclear.
The 29 doctors who collaborated on the article pooled results from many trials into a meta-analysis, a standard method of dealing with contradictory or inconclusive outcomes from smaller trials. But accounting for differences in the trials is difficult. In this case, the researchers compared Taxus and Cypher mainly by massaging data from more than 18,000 patients in clinical trials where one of the two drug-coated stents was compared with a bare-metal one.
Dr. David E. Kandzari, chief medical officer for Cordis, the Johnson & Johnson subsidiary that makes stents, said in a written statement that the study “significantly enriches the large body of evidence that interventional cardiologists have at their disposal to make the right choice for their patients,” and clarifies the differences between Cypher and Taxus.
In the statement, Cordis also quoted Dr. Peter Juni, a Swiss biostatistics expert who was one of the study’s authors, as saying the data showed Cypher to be clinically superior to both bare-metal stents and Taxus.
But Dr. Donald Baim, chief medical and scientific officer at Boston Scientific, said the Lancet study failed to reflect that Taxus was compared in its major trials with a better-performing bare-metal stent than Johnson & Johnson chose for the Cypher trials.
In addition, Boston Scientific said two of the major comparisons with bare-metal stents in the Boston Scientific trials focused on smaller arteries and longer blockages than those tested in Cypher’s trials — conditions where risks of complications would presumably be higher.
Boston Scientific said other studies directly comparing the two drug-coated stents had not showed big differences in safety or effectiveness. That is also the view among cardiologists.
The study may calm enough fears about drug-coated stents to spur growth in their share of the stent market, said Dr. Gregg Stone, a Columbia University cardiologist who has been a main investigator on Taxus trials and an author of the Lancet study.
“I think this will have a small positive impact,” Dr. Stone said.
A rebounding benefit to Boston Scientific and Johnson & Johnson may be short-lived. Medtronic and Abbott Laboratories are anticipating approval to enter the domestic market next year with drug-coated stents, and Wall Street expects these will take sales from the incumbents.
