Heart Disease :: PCI for occlusion after MI not always beneficial

Logic would hold that an occluded infarct-related artery should be open before the patient is discharged. But the chair of the Occluded Artery Trial (OAT) presented data here showing that stable patients undergoing routine PCI for occluded arteries three to 28 days after MI had virtually the same number of major cardiovascular events as similar patients receiving medication alone.

?It?s logical that open arteries would be better, but logic isn?t always right,? said Judith S. Hochman, M.D., clinical chief of cardiology, director of cardiovascular clinical research and a professor of cardiology at New York University School of Medicine. ?We didn?t know patients don?t always need PCI until we did the trial.?

PCI failed to reduce major cardiovascular events compared with medical treatment, and the study also showed a trend toward an excess of nonfatal recurrent MI with PCI, Dr. Hochman said during a news conference Monday.

The OAT authors said the trial results should lead to lower rates of unnecessary coronary interventions in the population studied and to substantial healthcare cost savings.

OAT followed 2,166 patients, 1,082 randomly assigned to PCI plus medication and 1,084 to medication alone.

Patients were clinically stable, with persistent total occlusion of the infarct-related artery and some high-risk characteristics.

The researchers had estimated beforehand that late PCI of an occluded infarct artery after MI would reduce the occurrenc

e of a composite of death, reinfarction or NYHA class IV heart failure by 25 percent. The actual results were quite different.

At five years, 17.2 percent of the PCI group had had a major event (death, MI, CHF class IV), compared with 15.6 percent for the medical treatment patients, for a nonsignificant hazard ratio of 1.16.

Major funding for OAT was from the National Heart, Lung, and Blood Institute. ?It?s a very important study but challenging results, challenging to completely understand and put into proper context,? said news conference moderator Timothy Gardner, M.D., chair of the 2006 Scientific Sessions program and medical director of the Center for Heart and Vascular Health at Christiana Care Health Services, Wilmington, Del.

Dr. Hochman clarified an important point. ?We know early reperfusion improves LVEF and survival in ST elevation MI, and no one should be confused by the results of OAT and think that that has changed,? Dr. Hochman said. ?People need to seek early reperfusion.

?However, [until now] it was unknown and controversial whether to reperfuse or recanalize the artery late if you find it to be totally occluded days to weeks after the MI.?

One reason the question is controversial, she said, is that a strong bias exists in favor of PCI, especially in the U.S. more than in Europe.

Dr. Hochman said about 100,000 people in the U.S. who have had an MI meet the eligibility criteria for OAT, and that about 50,000 of them undergo PCI.

?Considering OAT?s results, that suggests patients are receiving PCI when they may not need it,? she said.

To illustrate, she said the OAT protocol called for 320 study sites but only 217 were recruited.

?Physicians at so many institutions said they wouldn?t participate because they thought it unethical to leave the artery closed,? Dr. Hochman said.

The chair of an OAT ancillary study conducted in Canada, TOSCA-2, said he encountered the same reluctance among physicians there.

TOSCA-2 (Total Occlusion Study of Canada) compared left ventricular function and late vessel patency after PCI and stenting in occluded infarct-related arteries, versus medication alone, said study chair Vladimir Dzavik, M.D., professor in Interventional Cardiology at the University of Toronto and director of the Cardiac Catheterization Laboratory, University Health Network, Toronto.

Among 286 patients whose repeat left ventricle angiograms could be analyzed, 83 percent in the PCI group still had an open artery; in the medication-only group, 25 percent of patients had the blocked artery open spontaneously.

There was no difference between the two groups in ejection fraction, although a trend was seen for the heart cavity to enlarge over one year in medication-only patients.

Because PCI for post-MI occlusion has competing effects ? reducing enlargement of the heart but increasing the risk of another major adverse event ? the authors concluded there is no role for routine PCI in stable patients with post-MI occlusion.


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