No mortality or MI benefit in stable CAD patients treated with PCI: New meta-analysis
Stony Brook, NY - A meta-analysis of eight contemporary trials reveals that the implantation of a stent for the treatment of stable coronary artery disease (CAD) does not lower the risk of death, nor does PCI reduce the risk of nonfatal MI, unplanned coronary revascularization, or angina when compared with optimal medical therapy [1]. The findings, say researchers, support recommendations that stable CAD patients should be treated with medical therapy rather than head directly to the cath lab for stent implantation.
"I think the results speak for themselves," lead investigator Dr David Brown (State University of New York—Stony Brook School of Medicine) told heartwire. "I think we need to practice medicine based on the data that we have, and if people are uncomfortable with the data, then we must do the trials that need to be done to change practice. But right now, the data show that patients with stable symptoms should be treated medically."
In an editorial accompanying the study [2], Dr William Boden (VA Medical Center, Albany, NY) echoes similar sentiments, stating that the totality of evidence does not support any demonstrable clinical benefit for PCI in patients with stable CAD for the reduction of death, nonfatal MI, hospitalization for acute coronary syndrome (ACS), need for unplanned revascularizations, and a durable, sustained relief for angina symptoms. Given this lack of benefit on hard clinical outcomes, and the continued importance of identifying the most effective and cost-effective approaches to caring for patients, diverting patients to a program of aggressive medical management instead of PCI first could potentially save the healthcare system billions of dollars, he notes.
The study, with coauthor Dr Kathleen Stergiopoulos (State University of New York-Stony Brook School of Medicine), and the editorial are published in the February 27, 2012 issue of the Archives of Internal Medicine.
Meta-analysis includes COURAGE, OAT
The meta-analysis included eight studies, including such high-profile studies as Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE), Occluded Artery Trial (OAT), and Bypass Angioplasty Revascularization Investigation in Type 2 Diabetes (BARI 2D), among others. In total, 7229 patients were included in the analysis, with five studies enrolling patients with stable angina and/or ischemia following stress testing and three studies enrolling patients with stable CAD following an MI.
After an average follow-up of 4.3 years, 649 deaths occurred, including 322 deaths in the stented patients (8.9%) and 327 deaths in patients who received medical therapy (9.1%), a nonsignificant difference. Nonfatal-MI events were similar in both treatment arms, with events occurring in 8.9% of patients treated with stents and 8.1% of patients treated with medical therapy, also a nonsignificant difference. The rates of unplanned revascularization were similar in the stent and medical-therapy arms, 21.4% vs 30.7% (p=0.11), and there was a nonsignificant trend toward lower rates of persistent angina with optimal medical therapy.
To heartwire, Brown said that medical practice did not appear to change much following the publication of COURAGE. He noted that other meta-analyses have shown that PCI in stable CAD patients reduced the risk of mortality and angina, but their analysis, unlike the others, excluded studies that did not include PCI with coronary stents and is a more up-to-date comparison between optimal medical therapy and coronary interventions.
"The real impact of this meta-analysis is that it makes the medical-therapy arm more contemporary," said Brown. "By this point, medical therapy had largely evolved to something close to its current form, with aspirin, statins, ACE inhibitors, and beta blockers, and when we do this, the meta-analysis suggests there is no benefit [to PCI]. It suggests that the improvement in medicine over time was more significant than the effect of transitioning from balloon angioplasty to stenting."
Bass takes on the Boden editorial
In his editorial, Boden, who was the lead researcher for the COURAGE trial, is critical of physicians who "practice selective evidence-based medicine" by choosing trials to adopt that fit their clinical-practice preferences and ignoring those that don't. At this stage, there is abundant evidence to support a more measured, selective approach for treating stable CAD—that being optimal medical therapy for the majority of patients.
"With such an evidence base derived from multiple randomized controlled trials and meta-analyses, what more will it take to turn the tide of treatment for patients with stable ischemic heart disease and chronic angina from a PCI-first to an [optimal-medical-therapy]-first approach?" asks Boden.
Speaking with heartwire, however, Dr Ted Bass (University of Florida, Jacksonville), the vice president of the Society for Cardiovascular Angiography and Interventions (SCAI), said there is little new information in the meta-analysis, stating that interventionalists already know there is no mortality and MI benefit in treating patients with chronic stable angina and that the robust benefits occur in patients with ST-segment-elevation MI (STEMI) and acute coronary syndrome (ACS).
Bass noted that the interventional community has altered its practices as a result of recent clinical trials, citing data from an assessment of the over 500 000 PCI cases in the National Cardiovascular Data Registry (NCDR) showing that just 11.6% of elective PCIs were classified as inappropriate. He added that Medicare and registry data also suggest a decline in PCIs performed in stable CAD patients.
That said, Bass noted there is a role for PCI in the nonacute setting. For example, an elderly patient with angina who has failed to reduce symptoms with aggressive medical management is still a candidate for stenting, and this type of patient is typically not included in trials. He took exception to the characterization that interventionalists are "not getting it" but said the bottom line remains patient care.
"I think we have spent a great deal of effort to better understand how to best impact quality-of-life issues, and clinical practice has changed as result," Bass told heartwire. "The bottom line is that clinicians want to practice evidence-based medicine and provide the best care to our patients. That's what we care about."
Practice changing slowly
To heartwire, Brown agrees that clinical is practice is changing, but it's changing gradually. A recent study in the Journal of the American Medical Association, which also included an analysis of the NCDR data, showed that, at least among patients ultimately treated with PCI, there was little change in prescribing practice before and after the publication of COURAGE.
"What really concerns me is that we're training a new generation of fellows who come out thinking that intervention is the treatment of choice for patients with any coronary stenosis," said Brown. "If that's what they think, it's because that's what they're seeing."
The major criticism of past stable-ischemia trials is that patients were randomized after the coronary angiography. Once the anatomy is defined and physicians saw stenoses, the patients were not randomized into the trials. To address this, the National Heart, Lung, and Blood Institute is sponsoring an eight-year trial in about 8000 patients, known as the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA), that will require patients to undergo a stress test. Patients with moderate to severe ischemia on the stress test will also undergo a blinded coronary CT angiography to exclude left main disease and to confirm they have obstructive coronary disease.
Until that is done, the evidence to date shows there is no benefit to stenting stable CAD patients, said Brown.
"Except for these issues with before or after angiogram, the data that we have is the data that we have," he told heartwire. "This meta-analysis, Dr Boden's opinions, and the opinions of others just really reflect the data that we have. I agree with [Boden] that we claim to worship at the altar of evidence-based medicine, but it's really only when it fits our preconceived notion of what's the best thing to do."
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