Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Coronary stents do not improve long-term survival

08.11.2004


While the placement of stents in newly reopened coronary arteries has been shown to reduce the need for repeat angioplasty procedures, researchers from the Duke Clinical Research Institute have found that stents have no impact on mortality over the long term.



In the largest such analysis of its kind, the Duke researchers said their findings have important economic and clinical implications for physicians who are deciding whether their heart patients should receive coronary artery bypass surgery, or less-invasive angioplasty, which includes the placement of a stent.

Stents, which were introduced in the U.S. in 1994, are tiny mesh tubes that are inserted at the site of a blockage in a coronary artery that has been opened during balloon angioplasty. The procedure seeks to prevent the artery from becoming blocked again, a process known as restenosis. These blockages, caused by atherosclerotic plaque, can starve the heart of oxygen-rich blood and lead to a heart attack.


Duke cardiologist David Kandzari, M.D., who presented the results of the Duke analysis Nov.7, 2004, at the American Heart Association’s annual scientific sessions in New Orleans, said the findings on mortality rates should also be expected to hold true for the latest generation of drug-eluting stents. These stents, which were introduced in 2003, are coated with a drug that keeps blood clots from forming inside them. "We have found in our long-term analysis that stents do provide a significant early and sustained reduction in the need for subsequent procedures to re-open the treated artery," Kandzari said. "However, we also found that stents do not have any influence on long-term survival.

"Since earlier studies have shown that new drug-eluting stents can lessen the incidence of restenosis, we would expect the need for repeat procedures to decline even more as these stents become more widely used," Kandzari continued. "While earlier trials of drug-eluting stents have demonstrated a significant reduction in repeat procedures, they still have shown no differences in mortality compared with more conventional stents."

Specifically, the researchers found that over the average seven-year follow-up period of their study, 19 percent of patients who received a stent needed another revascularization procedure in the treated artery, compared to 27 percent for those who did not receive a stent. However, the long-term mortality rate for those receiving a stent was 19.9 percent vs. 20.4 percent for those who did not, a disparity which did not statistically differ.

For their analysis, the researchers consulted the Duke Database for Cardiovascular Disease, which keeps detailed clinical data on all heart patients receiving treatment at Duke. The researchers identified 1,288 matched pairs of patients who underwent either balloon angioplasty alone or stenting -- yet all had a similar likelihood of receiving a stent based on their clinical and demographic characteristics.

The patients, 63 percent of whom were male and who had an average age of 59 years, were treated between 1994 and 2002. One in four was diabetic, and one in four had suffered a previous heart attack. "This study, based as it is on a real-world population of patients, tells us that stents do not save lives, though they do have a profound effect on avoiding repeat procedures," Kandzari said. "We’ve know that restenosis has never been scientifically associated with increased mortality, but it has been associated with an increased need for revascularization and with a reduction in symptoms such as chest pain."

Given these findings, Kandzari said physicians treating their heart patients should not automatically assume that placing a stent, whether the original bare-metal type or the newer drug-eluting version, will be the end of treatment. "Many physicians will successfully place a stent and think that’s it," Kandzari continued. "The bigger issue is that many of these physicians should also then be prescribing drugs that have a clearly demonstrated beneficial effect on long-term mortality."

Kandzari plans to follow up this study with a similar analysis of the effects of the drug-eluting stents on mortality. Also, the team plans to measure any differences in the quality of life of these patients. "As we take on more and more difficult and complicated cases in the catheterization lab, we should take a step back to see if there are certain instances when bypass surgery may be the best option," Kandzari said. "There is the temptation out there to just place stents in all patients, no matter what. In some prior trials, the difference in outcome between angioplasty and surgery patients was driven by restenosis, not by differences in mortality.

"However, in the era of conventional stenting, we knew that there we still some instances in which bypass surgery might provide an incremental survival benefit," Kandzari said. "Before routinely placing drug-eluting stents in similar patients, these findings underscore the need for systematic evaluation of drug-eluting stents in these types of patients." Patients with left main coronary artery disease, for example, appear to fare better with bypass surgery than with angioplasty and stents. Previous study has also suggested this may be true for diabetic heart patients with extensive disease, who appear to benefit the most from bypass surgery, Kandzari said. "Appropriately, a trial is forthcoming to compare treatment with drug-eluting stents with bypass surgery in diabetic patients," he said.

The study was supported by the Cordis Corp., Miami Lakes, Fla., which develops stents. Kandzari has no financial interest in Cordis. Other members of the Duke team were Robert Tuttle, M.D., James Zidar, M.D., and James Jollis, M.D.

Richard Merritt | EurekAlert!
Further information:
http://www.mc.duke.edu

More articles from Health and Medicine:

nachricht New 3-D imaging reveals how human cell nucleus organizes DNA and chromatin of its genome
28.07.2017 | University of California - San Diego

nachricht Malaria Already Endemic in the Mediterranean by the Roman Period
27.07.2017 | Universität Zürich

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Abrupt motion sharpens x-ray pulses

Spectrally narrow x-ray pulses may be “sharpened” by purely mechanical means. This sounds surprisingly, but a team of theoretical and experimental physicists developed and realized such a method. It is based on fast motions, precisely synchronized with the pulses, of a target interacting with the x-ray light. Thereby, photons are redistributed within the x-ray pulse to the desired spectral region.

A team of theoretical physicists from the MPI for Nuclear Physics (MPIK) in Heidelberg has developed a novel method to intensify the spectrally broad x-ray...

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

New 3-D imaging reveals how human cell nucleus organizes DNA and chromatin of its genome

28.07.2017 | Health and Medicine

Heavy metals in water meet their match

28.07.2017 | Power and Electrical Engineering

Oestrogen regulates pathological changes of bones via bone lining cells

28.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>