Physicians Still Doing Late PCI of Occluded Arteries

July 11, 2011

July 11, 2011 (New York, New York) — The data were straightforward and the guidelines clear, but physicians in the US do not appear to be adopting the results of the Occluded Artery Trial (OAT), [1] a study showing that late stenting of infarct-related arteries in acute MI does not reduce the risk of death, reinfarction, or heart failure when compared with optimal medical therapy.

Even with the 2007 revised clinical guidelines incorporating the OAT results, researchers are reporting that physicians continue to intervene late in the infarct-related artery of stable MI patients.

"Very strong beliefs die hard," senior investigator Dr Judith Hochman (NYU Langone Medical Center, NY) told heartwire . "There is a belief that an open artery is better than a closed artery, and when you couple that belief system with the fact that physicians get reimbursed for the procedure, as well as the expectation on the part of patients that the artery should be open, all of these things make it difficult to change clinical practice."

In an editorial accompanying the study [2], Dr Mauro Moscucci (Miami Miller School of Medicine, Miami, FL) states this new OAT analysis, led by Dr Marc Deyell (University of British Columbia, Vancouver), focuses attention on healthcare procedures that increase costs to the system without showing any clear benefit.

"While the debate on healthcare reform is ongoing, healthcare expenditures in the United States are continuing to escalate," he writes. "Thus, we must heed the call to professional responsibility aimed at the elimination of tests and treatments that do not result in any benefit for our patients and for which the net effects will be added costs, waste, and possible harm."

The results of the new analysis, as well as the editorial, are published online July 11, 2011 in the Archives of Internal Medicine.

Slow Adoption Into Clinical Practice

First presented at the American Heart Association 2006 Scientific Sessions in Chicago, IL, and reported by heartwire at that time, the OAT investigators randomized 2166 stable patients with total occlusions to routine PCI plus stenting and optimal medical therapy (n=1082) or optimal medical therapy alone (n=1082), three to 28 days after their MI. At follow-up, the estimated four-year cumulative primary-event rate--a composite of death, reinfarction, or heart failure--did not differ between the PCI group and the medical group, a finding that held up in intention-to-treat analyses.

The results of OAT were later included in the revised 2007 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for the management of ST-segment elevation myocardial infarction (STEMI) and in the revised PCI guidelines. Late reperfusion, more than 24 hours, with PCI of the infarct-related artery in stable, asymptomatic patients is a class III indication, meaning that it is not indicated and not appropriate.

In the latest analysis, the researchers identified patients undergoing catheterization more than 24 hours after MI with a totally occluded coronary artery and who met the OAT inclusion criteria, analyzing 28 780 patient visits from 896 US hospitals in the CathPCI Registry before the presentation and publication of OAT, after the results were presented and published, and after the 2007 ACC/AHA guideline revisions.

Overall, there was no significant decline in the adjusted monthly rate of PCI for total occlusions after the publication of OAT or after the guideline revisions. Among the hospitals who most consistently reported diagnostic catheterizations to the registry, there was no significant decline in interventions after the OAT publication but there was a trend toward decline after the guideline revisions.

Hochman said she was surprised by the lack of change, as she had expected to see some adoption of OAT and the ACC/AHA guidelines into clinical practice, although she remains optimistic. "I'm hopeful," she told heartwire . "We only looked one to two years after the publication of the Occluded Artery Trial, and these things take time. We're going to publish long-term follow-up shortly, and these results are very robust showing no benefit of PCI, so I think that will help."

Hochman said she does not think that draconian measures, such as insurers and payers not paying for PCI in this setting, are needed to improve compliance, because she does not want to see decision making taken away from clinicians. That said, physicians need to be part of the solution and stop doing procedures that have been shown to have no benefit, said Hochman.

STEMI and Non-STEMI Patients

To heartwire , Dr Harlan Krumholz (Yale University School of Medicine, New Haven, CT), who was not part of the study, called the analysis an interesting one but said that, rather than laying blame on clinicians, it should prompt a "deeper investigation into the pattern of care." He said he would like to know that the data are accurate, noting it would be useful to perform "spot checks" to ensure that the data reflect what is happening in the real world.

Dr Ajay Kirtane (Columbia University Medical Center, New York) took issue with the analysis, however, noting that patients in OAT and the CathPCI registry had little in common. For example, he said that the majority of patients in OAT had a STEMI, but approximately 90% of the registry patients had non-STEMI.

"What this means is that the infarctions were much smaller in NCDR, and that implies that more territory was viable, which is likely why PCI was performed," Kirtane said in an email to heartwire . "When you complete a STEMI, the whole wall of the affected myocardial territory dies, and that's why it doesn't make sense to revascularize it (and which is what OAT showed). The fact that many of these were NSTEMIs, combined with the fact that approximately half had a positive noninvasive test prior, suggests that there might actually have been a reason to intervene."

Similarly, Krumholz said that he would also like to know the indication for the procedure among the NCDR patients and whether there were any extenuating circumstances that might have led to PCI.

Hochman told heartwire , however, that many cardiologists fail to appreciate the consistent lack of effect of PCI across all OAT subsets, including patients with viable myocardium as directly shown by viability testing or indirectly by an increase in ejection fraction. In addition, the lack of benefit was observed in those with proximal left anterior descending (LAD) occlusion, all ejection fractions, and those enrolled within the earliest time window, such as those treated within 24 to 72 hours post-MI.

Krumholz added that he would like to know whether clinicians are unaware of OAT or dismissive of its findings. "This article highlights the importance of following through after publications with efforts to disseminate the new knowledge and assess its appropriate application," he said. "The article raises concern that the national investment in this knowledge has yet to yield returns for patients."

"Persistence of an Established Practice"

In his editorial, Moscucci writes that physicians fail to apply new results and guidelines for numerous reasons, including "lack of awareness, lack of familiarity, and lack of agreement with the evidence supporting the guidelines."

"In addition, in a fee-for-service health system and in an environment in which more and more physicians are being compensated on the basis of relative value unit productivity, it remains to be determined whether personal financial gain might play a role in continuing old practices and in performing procedures shown to be of no benefit," writes Moscucci.

In the setting of stable coronary artery disease, Moscucci notes that previous studies have shown that some physicians are anxious about not intervening on a lesion and feel they have a "mandate" to relieve ischemia. As Hochman noted, patient expectations and anxiety about a blocked coronary are also factors that go into the decision-making process.


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