Study Finds Use of PCI After MI Not Meeting Standards of Updated Guidelines

July 11, 2011—Guideline recommendations for the appropriate use of percutaneous coronary intervention (PCI) for patients who have an occluded coronary artery after having a myocardial infarction (MI) appear not to have been fully incorporated in clinical practice, according to a study by Marc W. Deyell, MD, et al published online ahead of print in the Archives of Internal Medicine.

The investigators concluded, “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 background of the study is the results of the Occluded Artery Trial (OAT) that were published by Judith S. Hochman, MD, et al in December 2006 in the New England Journal of Medicine (2006;355:2395–2407). The US National Heart, Lung, and Blood Institute sponsored the OAT study. Dr. Hochman and other OAT investigators are also co-authors of the current study.

As the investigators recounted in the Archives of Internal Medicine, the OAT study examined the effect of PCI on completely blocked arteries that were identified a minimum of 24 hours (on calendar days 3–28) after MI in stable patients. 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. The investigators noted that because PCI was more costly than optimal medical therapy alone, the OAT findings should have discouraged routine PCI in this setting and, accordingly, the American College of Cardiology (ACC) and the American Heart Association (AHA) updated their guidelines after the OAT trial results were published. ACC/AHA Writing Committee Chair Jeffrey L. Anderson, MD, et al published the revised guidelines in August 2007 in the Journal of American College of Cardiology (2007;50:1–157).

In the current study, Dr. Deyell and colleagues sought to determine whether clinical practice had changed after the revised guidelines were issued. The investigators examined data from the CathPCI Registry, which collects information from hospitals in the United States that perform cardiac catheterization. The registry is part of the ACC's National Cardiovascular Data Registry.

The investigators compared PCI rates before and after the OAT trial results were published and before and after the guidelines were updated, from 2005 to 2008. They studied trends in hospitals in the highest quartile for reporting diagnostic procedures because institutions are not required to report diagnostic catheterization.
 


As detailed in the Archives of Internal Medicine, the study included data from 896 hospitals and 28,780 patient visits. PCI was performed in 11,083 patients before the OAT results were published, in 7,838 patients between publication and guideline changes, and in 9,859 patients after the guidelines were revised. After adjusting for other variables, the investigators found no overall significant decrease in the monthly rate of PCI performed for blockages either after the OAT results were published (odds ratio [OR], 0.997; 95% confidence interval [CI], 0.989–1.006) or after the guidelines were changed (OR, 1.007; 95% CI, 0.992–1.022). Among hospitals that consistently reported procedures done for diagnostic purposes, PCI rates did not diminish after publication of OAT (OR, 1.018; 95% CI, 0.995–1.042), but did appear to trend downward with a small decrease after the guidelines were revised (OR, 0.963; 95% CI, 0.92–1.0).

The investigators stated that these findings suggest that the results of the OAT study and consequent ACC/AHA guideline revisions have not, to date, been fully incorporated into clinical practice in a large cross-section of hospitals in the United States and that there was only modest evidence that the OAT results and guideline revisions influenced cardiology and interventional cardiology practice over the subsequent 1 to 2 years.

“The results of this study are a cause for concern on two levels,” the investigators advised. “First, they imply that many stable patients with recent MI and persistent infarct artery occlusion continue to undergo a costly and ineffective procedure. Second, a large public, scientific, and human patient investment in the generation of robust clinical evidence has yet to broadly influence US practice. The factors accounting for this incomplete knowledge transfer over this time period remain uncertain.”

In an accompanying commentary, Mauro Moscucci, MD, remarked that the reasons for the observed failure of reversal in practice may include barriers to changing physicians' and patients' beliefs and behaviors. He added, “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.”