Circ: Medical therapy and PCI face off, again

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After patients are diagnosed with stable coronary artery disease (CAD), what treatment strategies do they, and should they, undergo? A new study found that a majority of New Yorkers undergo PCI post-CAD diagnoses, and those who do see better outcomes. Researchers questioned results of the COURAGE trial, which showed that optimal medical therapy (OMT) plus PCI showed no benefit over OMT alone, saying that it may be difficult to achieve OMT in routine practice.

The study, published online March 22 in Circulation, evaluated New Yorkers with stable CAD who underwent cardiac catheterization in New York state between 2003 and 2008 to assess what treatment strategies are most used. The patients were asymptomatic or had stable angina, and at least a 70 percent stenosis in the proximal epicardial coronary artery or its major branch.

“The COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) Trial, in which patients with stable coronary artery disease (CAD) were randomly treated with either 'optimal medical treatment' or percutaneous coronary intervention (PCI) with optimal medical treatment reported that PCI with optimal medical therapy as an initial management strategy did not reduce rates of mortality, myocardial infarction, or other major cardiovascular events in comparison with an initial strategy of optimal medical therapy alone,” wrote Edward L. Hannon, PhD, of the University at Albany, State University of New York in Albany, and colleagues.

The 2007 COURAGE trial, suggested that optimal medical therapy (OMT) plus PCI offers no benefit in terms of mortality or subsequent MI compared with OMT alone (New Engl J Med 2007;356:1503-1316).

"The results of COURAGE indicate that some expensive stenting procedures could be avoided," COURAGE trial principal investigator  William E. Boden, MD, chief of medicine at the Stratton VA Medical Center in Albany, N.Y., and vice chair of the department of medicine at Albany Medical Center., told Cardiovascular Business during a previous interview.

For the current study, the researchers compared PCI outcomes with routine medical therapy (RMT) vs. RMT with usual care (not part of a clinical trial). They used four-year mortality, MI, MI readmissions and revascularizations as the study’s primary endpoint.

A total of 9,586 patients were enrolled. Of the cohort, 88.5 percent underwent PCI and 2 percent underwent CABG. The researchers said that PCI use did not significantly differ before or after COURAGE trial findings (88.4 percent prior to 2008 and 88.7 percent post-COURAGE).

Patients who underwent PCI along with medical therapy were younger, more likely to be white, more likely to hold private health insurance, have a positive stress test and a higher ejection fraction. These patients were also less likely to have peripheral vascular disease or a previous cardiac surgery. Seventy-one percent underwent PCI with drug-eluting stents and 24 percent underwent surgery with bare-metal stents; 5 percent did not receive a stent.

In a propensity matching model, the researchers matched 933 patients with medical therapy to a similar PCI/medical therapy cohort. The two groups were similar in terms of patient characteristics.

At the four-year follow-up, patients who underwent both therapies fared better when compared with those on medical therapy alone in terms of mortality/MI (16.5 percent vs. 21.2 percent), mortality (10.2 percent vs. 14.5 percent), MI (8 percent vs. 11.3 percent) and revascularization (24.1 percent vs. 29.1 percent).  

The authors noted that both RMT and PCI/RMT rates were higher in the current study when compared with the COURAGE trial rates. The researchers speculated that the PCI/RMT rates were more similar to COURAGE due to the fact that DES was used in more than 70 percent of the population. "DES have been shown to be associated with lower mortality rates than BMS in observational studies, although not in randomized controlled trials (RCTs),” the authors wrote.

The authors speculated that reasons why routine medical therapy rates were higher in the current study compared with COURAGE were because the current medical therapy population was at higher risk and less selected or because patients received RMT rather than OMT.

But due to the fact that the study was observational, the researchers said it could be subject to selection bias.

Additionally, the authors said, “The nature of the medical therapy provided to the 'RMT' patients in our study is completely unknown, and undoubtedly many RMT patients received non-optimal medical therapy.” While the authors said that OMT may be as effective as PCI/OMT in tightly controlled settings where lifestyle changes and adherence were “excellent,” real-world situations may show different results.

The authors summed with two key findings:
  • With standard medical care, a large majority of N.Y. catheterization patients were treated with PCI rather than medical therapy alone; and
  • CAD patients treated with PCI saw improved outcomes compared with patients who did not undergo PCI.

"The reasons for these findings need to be better understood, including the role of the inability to achieve optimal medical therapy in routine medical practice," the authors summed. “A RCT [randomized controlled trial] in which patients are randomized to PCI and MT [medical therapy] without efforts to guarantee optimal MT would serve as a definitive test of how patients in routine medical practice fare with each of the interventions."