Although guidelines are available for the appropriate use of percutaneous coronary intervention (PCI) in patients with a blocked coronary artery post myocardial infarction (heart attack), their adoption in clinical practice is still questionable. This was revealed in a report published recently in one of the Less is More series of the Archives of Internal Medicine, one of the JAMA/Archives journals.

The background information in the article has mention of a study entitled 'Occluded Artery Trial' (OAT) which was sponsored by the National Heart, Lung, and Blood Institute and was published in 2006. In this study, completely blocked coronary arteries that were identified in stable patients after a minimum of 24 hours post myocardial infarction (MI) (on calendar days 3 to 28), were examined for the effects of PCI, such as the use of balloon angioplasty and stenting.

The authors state:

"The OAT results provided objective evidence that the use of PCI did not lead to a reduction in clinical events and that the beneficial effect on angina and quality of life was small and not durable. Percutaneous coronary intervention was more costly than optimal medical therapy alone; hence, these findings should have discouraged routine PCI in this setting."

The American College of Cardiology and the American Heart Association updated their guidelines after the results of this study were made available to the public.

Researcher Marc W. Deyell, (M.D) from the University of British Columbia in Vancouver, Canada and his team studied whether any changes to clinical practice had taken place after the revision of guidelines. Data between 2005 and 2008 were collected by the researchers from the CathPCI Registry. The CathPCI Registry is a database with information from all U.S. hospitals that perform cardiac catheterization. A comparison of PCI rates, before and after the OAT results were published and guidelines updated, was made, and the trends in hospitals in the highest quartile for reporting diagnostic procedures were studied.

A cohort of 28,780 patient visits from 896 hospitals was included in the current study. Before the OAT results were published 11,083 percutaneous coronary interventions were performed; while 7,838 were performed between publication and guideline changes; and another 9,859 after the revised guidelines were in place. After adjusting for other variables, researchers did not report any significant decrease in the monthly rate of PCI performed for occlusion, both after the OAT results were published and after the guidelines were updated. PCI rates did not decline after OAT publication even in hospitals that were regularly reporting procedures done for diagnostic purposes to the CathPCI registry; however in these hospitals a small gradual decline was observed after the guidelines were updated.

The authors stated:

"In conclusion, among this large cross-section of hospitals in the United States we found only modest evidence that the results of the OAT and its incorporation into major guideline revisions have influenced cardiology and interventional cardiology practice over the subsequent 1 to 2 years." "Percutaneous coronary intervention of total occlusions identified greater than 24 hours after MI remains commonplace despite little evidence to support its use in stable patients and new clinical practice guidelines recommending against it."

The researchers highlighted that many patients may be receiving an expensive intervention that may not be of any use to them and that the huge amount of time and effort devoted to the research did not translate into effective clinical practice for such patients in the U.S. Commentary: The OAT Results, Guideline Revisions and Clinical Practice A Commentary accompanying the article, Mauro Moscucci, M.D., M.B.A., from the University of Miami's Miller School of Medicine, considers the current view of a lack of PCI usage by physicians. He writes:

"The reason for the observed failure of reversal is multifactorial.

The study by Deyell et al adds an important chapter to the evaluation of appropriate use of PCI and further focuses our attention on procedures that certainly increase health care expenditures without clear benefit, while the debate on health care reform is ongoing, health care expenditures in the United States are continuing to escalate. 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."

"Impact of National Clinical Guideline Recommendations for Revascularization of Persistently Occluded Infarct-Related Arteries on Clinical Practice in the United States"
Marc W. Deyell, MD; Christopher E. Buller, MD; Louis H. Miller, MD; Tracy Y. Wang, MD; David Dai, MS; Gervasio A. Lamas, MD; Vankeepuram S. Srinivas, MD; Judith S. Hochman, MD
Arch Intern Med. Published online July 11, 2011. doi:10.1001/archinternmed.2011.315

Anne Hudsmith