Study stirs debate on PCI for stable coronary artery disease

Medical Tribune November 2008 SFXI
David Brill

A recent meta-analysis has reignited the debate over whether to employ an invasive strategy for patients with stable coronary artery disease (CAD).

The study by Professor Albert Schömig and colleagues concluded that percutaneous coronary intervention (PCI) reduced the risk of all-cause death by 20 percent compared with medical therapy alone.

The findings appear at odds with the pivotal COURAGE* trial which, to the consternation of interventional cardiologists the world over, found that PCI offered no benefits on a composite endpoint of death, myocardial infarction and stroke.

"The take-home message of this metaanalysis is that patients with stable CAD might benefit from PCI not only in terms of symptom alleviation but also of prognosis," said Schömig, who is based at the German Heart Centre Munich, Germany.

"PCI should not be seen as a substitute for effective pharmacological therapies that are available for patients with atherosclerotic CAD but as a treatment option on top of those therapies," he said.

The study comprised 7,513 patients with symptoms of myocardial ischemia but no acute coronary syndrome, drawn from 17 trials, including COURAGE. After an average of 51 months of follow up 335 patients died in the medical therapy group compared to 271 in the PCI group. [J Am Coll Cardiol 2008 Sep 9;52(11):894-904]

Schömig added that despite the apparently different conclusions, the results of the meta-analysis should not be seen as contradicting those of COURAGE since the trial alone was underpowered to assess mortality. He noted that COURAGE reported a 13 percent reduction in overall mortality with PCI but this did not reach significance.

Dr. Paul Chiam, a consultant cardiologist at the National Heart Centre, Singapore, said that the meta-analysis would be useful for informing treatment decisions in future.

"Cardiologists may be able to advise patients that PCI is more effective than medical therapy in relieving symptoms and may reduce events in those with moderate to severe ischemia on functional testing. In addition PCI may even reduce all cause mortality, or at the very least does not worsen mortality outcomes," he said.

Chiam noted, however, that the methodological limitations inherent to meta-analyses mean that the study does not carry the same weight as a large-scale trial.

COURAGE randomized 2,287 patients at 50 centers to PCI or optimal medical therapy. After a median of 4.6 years the rates of the composite end point were 20 percent and 19.5 percent, respectively, in the two groups (hazard ratio 1.05; P=0.62). [N Engl J Med 2007;356(15):1503-16]

One of the co-principal investigators for COURAGE, writing in a commentary accompanying the meta-analysis, said that the study had several limitations, such as the fact that some trials included patients with recent myocardial infarction whereas others did not.

"The difference between the findings of the meta-analysis and the COURAGE trial may be attributable to a difference in the accuracy of the data being analyzed, with pa-tient-level data from a large randomized controlled trial being superior," wrote Dr. Robert O’Rourke of the University of Texas Health Science Center at San Antonio, US. [J Am Coll Cardiol 2008 Sep 9;52(11):905-7] – DB