AHA - 2007: MASS Stent

Study looks at differences in drug-eluting vs. bare metal stents


American Heart Association Scientific Sessions Late-Breaking News:


ORLANDO, Nov. 4 – Drug-eluting stents to open blocked coronary arteries caused no more risks for death or heart attack than bare metal stents, according to a late-breaking outcomes trial presented at the American Heart Association’s Scientific Sessions 2007.


The Massachusetts stent (MASS Stent) trial compared death rates between patients who received drug-eluting stents (stents coated with a drug to reduce restenosis or re-narrowing of the artery) and those who received bare metal stents (stents not coated with a drug). They reviewed records of all adults undergoing percutaneous coronary intervention (PCI) with stenting between April 1, 2003 and December 31, 2004 at all acute care non-U.S. governmental hospitals in Massachusetts. Using this criterion, they identified 20,654 patients from a state database with mandatory follow-up after PCI.


“This is the largest study of patients comparing drug-eluting stents and bare metal stents for long-term outcomes in the U.S.,” said Laura Mauri, M.D., principal investigator of the trial and assistant professor of medicine at Harvard Medical School and Brigham and Women’s Hospital in Boston, Mass.


PCI, also called angioplasty, is done in patients who have blocked or narrowed heart arteries. During the procedure, a thin tube called a catheter is inserted into a blood vessel in the groin or leg, and then threaded through to the blocked coronary artery. A small balloon at the tip of the wire is then inflated to push back the blockage and allow more blood flow to the heart. Often, a tiny wire mesh tube called a stent is put in place to hold the vessel open and prevent restenosis (reclosing of the artery). However, stent thrombosis (blood clots forming inside the stent) is possible. Patients are prescribed anti-clotting drugs after the procedure to lessen the chance of stent thrombosis.


“It was previously established that drug-eluting stents make it less likely that patients will need repeat procedures within the first year after a stent procedure,” Mauri said. “What we were less certain about before this study was the long-term safety of drug-eluting stents compared to bare metal.”


Mauri adds that this trial has several benefits for addressing this issue. “It is a very large study with long-term follow up, it reflects contemporary U.S. practice – where most patients receive drug-eluting stents – and it includes all patients who were undergoing PCI – not just those who would have qualified for a randomized trial.”


Patients were followed up for at least two years after receiving a stent. Researchers compared the number of deaths, heart attacks, and revascularization procedures (either bypass surgery or another PCI) between the two groups. The adjusted incidence of mortality at two years was 9.4 percent for those with drug-eluting stents and 11.9 percent for those with bare metal stents.


Statements and conclusions of study authors that are presented at American Heart Association scientific meetings are solely those of the study authors and do not necessarily reflect association policy or position. The American Heart Association makes no representation or warranty as to their accuracy or reliability.

Use caution with drug-eluting stents in patients with STEMI

Use caution with drug-eluting stents in patients with STEMI

VIENNA, Austria — Results from the GRACE registry suggest caution when considering drug-eluting stents in patients with ST-elevated myocardial infarction.

The Global Registry of Acute Coronary Events (GRACE) trial results, presented at the European Society of Cardiology Congress 2007, demonstrated that patients with STEMI were at an increased risk for mortality. More patients with STEMI had reinfarction than patients with bare metal stents.

“Personally, I never implant drug-eluting stents in patients with STEMI undergoing primary PCI nowadays,” said Philippe Gabriel Steg, MD, professor of cardiology at Hopital Bichat-Claude Bernard, Paris.

In other registry trial results presented at the congress, Stefan James, MD, said updated data from the SCAAR (Swedish Coronary Angiography and Angioplasty Registry) no longer indicated increased mortality in patients treated with drug-eluting stents vs. bare metal stents.

For more on GRACE, click here. For more on SCAAR, click here.

Coronary artery bypass graft vs. percutaneous coronary angioplasty: CABG on the rebound?.

Coronary artery bypass graft vs. percutaneous coronary angioplasty: CABG on the rebound?.


Department of Cardiac Surgery, John Radcliffe Hospital, Oxford, UK


Current Opinion in Cardiology. 22(6):517-523, November 2007.


Taggart, David P



Purpose of review: To examine the benefits of coronary artery bypass grafting (CABG) against percutaneous coronary intervention (PCI) and particularly the use of drug-eluting stents (DES) in situations where CABG has traditionally been considered the most effective therapy on clinical and economic grounds.


Recent findings: Current studies reconfirm that CABG is still the best therapy in terms of improved survival and freedom from reintervention for most patients with proximal left anterior descending, multivessel and left main-stem coronary artery disease (CAD) and that these benefits are even greater in diabetic patients. Health economic analyses also confirm the cost-effectiveness of medical therapy and CABG but not PCI. Furthermore, several meta-analyses have shown that DES do not improve survival or freedom from myocardial infarction compared with bare metal stents, but increase the risk of stent thrombosis, with associated medical and financial implications for prolonged dual antiplatelet medication.


Summary: In view of the evidence in favour of CABG, this article questions the justifiability of some trials of PCI vs. CABG, especially in diabetic patients and those with left main-stem CAD, and exhorts the need for a multidisciplinary team approach to the management of CAD as a minimum standard of care.

The conundrum of late and very late stent thrombosis following drug-eluting stent implantation

The conundrum of late and very late stent thrombosis following drug-eluting stent implantation


Division of Clinical Biometrics, Brigham and Women's Hospital, Harvard Medical School and Harvard Clinical Research Institute, Boston, Massachusetts, USA


Current Opinion in Cardiology. 22(6):565-571, November 2007.


Garg, Pallav; Mauri, Laura



Purpose of review: Drug-eluting stents reduce restenosis compared with bare metal stents, but there is growing concern that drug-eluting stents may lead to higher rates of late stent thrombosis, a rare and potentially catastrophic complication following stenting.


Recent findings: While the data on the risk of late stent thrombosis are not definitive, several general conclusions may be drawn from the available data. Late thrombosis, while associated with high mortality and morbidity, is an uncommon complication of both drug-eluting stents and bare metal stents. Randomized trials of approved drug-eluting stents versus bare metal stents have shown additional cases of late stent thrombosis in drug-eluting stents, but no significant difference in the cumulative incidence of stent thrombosis, myocardial infarction, or cardiac death at 4 years of follow-up. Observational studies suggest higher very late stent thrombosis incidence, but the relative risks of drug-eluting stents versus bare metal stents in specific high-risk groups require further study. Although the etiology of late stent thrombosis is multifactorial, premature discontinuation of clopidogrel appears to be the most important risk factor.


Summary: Long-term follow-up of patients after coronary stenting has identified stent thrombosis as a rare but serious event. Ongoing clinical trials in broader patient populations will be helpful to understand the risk of late stent thrombosis with greater certainty.

Are Different Stents Better for Different Vessels?

Wall Street Journal

Are Different Stents Better for Different Vessels?

More stent data out of Vienna: A doctor who autopsied 83 patients with drug-coated stents says the diameter of the artery to be treated makes all the difference. She recommends against using the devices in patients with small blood vessels, Dow Jones target

Yet the author, Renu Virmani of the CVPath Institute in Maryland, also says that “large vessels don’t need drug-coated stents” to reduce the risk of re-blockage.

Her study, described here, looked at U.S. patients who had received stents made by both Johnson & Johnson and Boston Scientific. Besides the issues specific to stents, she found the deviced had been imperfectly inserted in about 10% of the patients, and that about 5% of the patients had overlapping stents. She also noted that 10% of the patients had died of a heart attack.


ESC Congress 2007 Press Releases

DES: Friend or Foe?

Author: Renu Virmani, MD

One can conclude from these histologic studies that because of underlying atherosclerotic plaque morphology differences, variability in healing from patient to patient, and a hypersensitivity in some patients; DES technology may have to be tailored to individual patient characteristics, rather than one stent fits all.

ESC Congress - News - Long term mortality after drug eluting stents in Sweden - one additional year of follow-up

Hotlines and Clinical Trial Updates - Long term mortality after drug eluting stents in Sweden - one additional year of follow-up


Conclusion:

With inclusion of one additional year, thereby doubling the number of DES treated patients and outcome events, the previously reported increase in mortality with drug eluting stents can no longer be observed. Still there remains a slightly raised risk of late stent thrombosis and reinfarction after 6 months, which is however compensated by a lower event rate during the first 6 months. The reduction of clinically relevant restenosis is lower than in randomized trials with mandated angiography at follow-up and amounts only to 4%.

Stop Paying for Drug-Coated Stents

Wall Street Journal (Health Blog)
August 27, 2007

UK Gov’t Could Stop Paying for Drug-Coated Stents

Posted by Jacob Goldstein


This week’s installment in drug-coated stents’ never-ending tale of woe comes from Britain, where the National Health Service could soon stop paying for the devices altogether.


A recent report (available here) commissioned by the government found that drug-coated stents, which cost about $2,300, aren’t worth the extra money compared to older bare metal stents, which cost about $700.


Tomorrow is the last day for the public to comment on the report, and the country’s National Institute for Health and Clinical Excellence will meet next week to review the evidence, the Associated Press reports.


“We are seeing the pendulum swing too far the other way,” a cardiologist and spokesman for the European Society of Cardiology told the AP. The British Cardiovascular Society said it was “surprised, disappointed and very concerned” by the proposal.


The British will likely will stop short of denying reimbursement altogether, Morgan Stanley analyst Glenn Reicin argues in a note to investors. But Reicin, who puts the U.K.’s drug-coated stent market at $80 million to $100 million, adds that “one cannot totally rule out something more dramatic.”


Clogged arteries propped open with drug-coated stents are less likely to re-clog than those supported by bare-metal stents. But the drug-coated devices may carry a slightly higher risk of causing blood clots long after being inserted. And one recent study found that many patients who receive stents might do just as well receiving only drug treatment.


Those findings have sent sales of drug-coated stents way down for Johnson & Johnson and Boston Scientific. So far, though, there’s no sign that insurers in this country plan to stop paying for the devices.

Drug-eluting stent controversy

Drug-eluting stent controversy explored in the American Heart Hospital Journal

Shelton, Conn. - August 08, 2007 – The Summer 2007 issue of The American Heart Hospital Journal explores one of the pivotal issues in cardiology today, the drug-eluting stent (DES). Through commentaries from ten leading national and international specialists, the issue presents a comprehensive discussion on the explosive growth and the potential risks of DESs.
The issue reports on the initial enthusiasm for drug-eluting stents, the great advances made possible by their use, and explores the significance of the benefits and disadvantages revealed through their high-volume adoption.

Dr. Ulrich Sigwart of University Hospital in Geneva, Switzerland, author of one of the studies, examines the sobering current appraisal of DES use, in contrast to the triumphs of their early success. “Subacute stent thrombosis due to incomplete intimal coverage, the formation of blood clots that can occur when the inner layers of blood vessels are not fully treated, remains the Achilles’ heel of DES use,” says Dr. Sigwart. “The polymer matrix used for the delivery of drugs, which clearly induces inflammatory responses, may, in part, be responsible for very late thrombosis.”

Dr. Renu Virmani and colleagues at the CVPath Institute of Gaithersburg, Maryland base the judgments in their article on the evidence obtained through pathologic studies of patients dying after stent implantation. “These data indicate that DESs cause both substantial impairment in arterial healing characterized by lack of complete re-endothlialization (the re-healing of the inner surfaces of vessels after stenting) and persistence of fibrin, a protein that indicates blood clotting, when compared with bare metal stents. This delayed healing is the primary substrate underlying all cases of late DES thrombosis at autopsy.”

In contrast, Drs. Williams and Abbott, of Brown Medical School and affiliated with Rhode Island Hospital, note, “DESs are a revolutionary advancement in interventional cardiology and are here to stay. Recognizing that they are different from bare metal stents, it is prudent to exercise caution with these devices and avoid using them in patients in whom dual antiplatelet therapy, a common practice used to reduce blood clotting, is unlikely or impossible.”

Dr. Peter Fitzgerald of Stanford University Medical Center, who writes with his colleagues, Drs. Shimohama and Honda of the Center for Cardiovascular Technology, offers his view of the future of DESs. “While first generation DESs place great emphasis on efficacy, long-term safety issues have arisen, making DESs stand in an exquisite balance among occasionally conflicting effects. Careful reexamination of research findings, as well as redefinition of safe and effective outcomes, will lead future stent technology in the optimal direction.”

These articles are published in the Summer 2007 issue of The American Heart Hospital Journal. Media wishing to receive PDFs of any of these articles may contact medicalnews@bos.blackwellpublishing.net.

The EVASTENT Matched-Cohort Registry

Risk Factors for Stent Thrombosis After Implantation of Sirolimus-Eluting Stents in Diabetic and Nondiabetic Patients

The EVASTENT Matched-Cohort Registry

Objectives: We sought to assess the frequency and causes of stent thrombosis in diabetic and nondiabetic patients after implantation of sirolimus-eluting stents.

Background: Safety concerns about late stent thrombosis have been raised, particularly when drug-eluting stents are used in less highly selected patients than in randomized trials.

Methods: The EVASTENT study is a matched multicenter cohort registry of 1,731 patients undergoing revascularization exclusively with sirolimus stents; for each diabetic patient included (stratified as single- or multiple-vessel disease), a nondiabetic patient was subsequently included. Patients were treated with aspirin + clopidogrel for at least 3 months and were followed for 465 (range 0 to 1,062) days (1-year follow-up in 98.5%). The primary end point was a composite of stent thrombosis (according to Academic Research Consortium definitions), cardiovascular death, and nonfatal myocardial infarction (major adverse cardiac events [MACE]).

Results: During follow-up, MACE occurred in 78 patients (4.5%), cardiac death in 35 (2.1%), and stent thrombosis in 45 (2.6%): 30 definite, 23 subacute, and 22 late, including 9 at >6 months. In univariate analysis, the 1-year stent thrombosis rate was 1.8 times higher in diabetic than in nondiabetic patients (3.2% vs. 1.7%; log rank p = 0.03), with diabetic patients with multiple-vessel disease experiencing the highest rate and nondiabetic single-vessel disease patients the lowest (4.3% vs. 0.8%; p < 0.001). In multivariate analysis, in addition to the interruption of antithrombotic treatment, independent stent thrombosis predictors were previous stroke, renal failure, lower ejection fraction, calcified lesion, length stented, and insulin-requiring diabetes.

Conclusions: The risk of sirolimus stent thrombosis is higher for multiple-vessel disease diabetic patients.

Fewer Stents Implanted

Wall Street Journal

July 20, 2007

Fewer Stents Implanted in June,Signaling Impact of New Studies

By KEITH J. WINSTEINJuly 20, 2007; Page B2

U.S. doctors implanted fewer coronary stents in June than any other month in the last year, according to a market researcher, indicating that medical studies critical of the devices appear to be having a sustained impact.

Stents are tiny scaffolds that prop open clogged arteries. Doctors flocked to them until late last year because they quickly relieve the chest pains and shortness of breath caused by a blocked artery. Last year, Americans spent more than $14 billion on stent procedures, with doctors implanting about 130,000 stents a month, according to various estimates.

But data from Goodroe Healthcare Solutions LLC, of Norcross, Ga., which surveys 75 U.S. hospitals with catheterization facilities for stenting, indicated that rate has significantly slowed.

According to Goodroe, doctors in June performed fewer artery-inflating angioplasties -- 11% below January levels. Fewer of those procedures involve a stent -- 92%, down from 94% in January. And doctors in June used about 1.48 stents per procedure, down 4% from January.

Those numbers indicate stent usage, in total, fell about 16%. (See more data from Goodroe1.)
Goodroe didn't provide usage numbers in units of stents. In the past, its numbers have largely agreed with figures released by manufacturers and market researchers.

In late March, the New England Journal of Medicine published a study indicating that patients with mild chest pains could safely delay stenting in favor of treatment with drugs. Some of those patients may return for stenting later in the year if their pain persists.

Stent use has also been hurt by studies linking the most popular and expensive kind -- those coated with drugs to prevent reclogging -- with blood clots more than a year after implantation. In response, doctors have shifted back to older, bare-metal stents.

That has been good news for Abbott Laboratories, whose U.S. sales of bare-metal stents were up 179% in the last year. But the makers of drug-coated stents -- Johnson & Johnson, whose U.S. stent sales fell 41%, and Boston Scientific Corp., which reports its quarterly results today -- have been hit hard. Boston Scientific and Abbott said they predicted an eventual recovery in the market. J&J declined to comment.