‘Appropriate’ Use of Revascularization Varies in Stable CAD Patients

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Key Points:
  • Canadian study assesses agreement between clinical practice, appropriate use criteria for revascularization procedures
  • In patients with stable CAD, 69% of those deemed appropriate underwent revascularization vs. 45% of those judged inappropriate
  • Treatment of appropriate candidates reduced 3-year risk of death or recurrent ACS

By Caitlin E. Cox
Wednesday, October 10, 2012

More than a quarter of patients with stable coronary artery disease (CAD) who are candidates for revascularization do not receive the treatment, reports a Canadian study that looked at how well real-world practice reflects appropriate use criteria. Meanwhile, a substantial proportion of patients receive invasive treatment for inappropriate indications. The findings were published online October 10, 2012, ahead of print in the Journal of the American College of Cardiology.

Dennis T. Ko, MD, MSc, of the University of Toronto (Toronto, Canada), and colleagues examined 1,625 patients with CAD treated between April 2006 and March 2007 in Ontario, Canada. In addition to retrospectively assessing how closely revascularization adhered to the 2009 appropriate use criteria co-developed by the American College of Cardiology, American Heart Association, and 4 other professional societies, the researchers evaluated the effect of invasive treatment on long-term outcomes.

Appropriate Care Reduces Adverse Events

At the time of angiography, 61% of the cohort had indications qualifying as appropriate for revascularization, 20% qualifying as uncertain, and 19% as inappropriate.

In all, 997 revascularization procedures—either PCI or CABG—were performed, of which 68% were considered appropriate, 18% uncertain, and 14% inappropriate. Looking specifically at PCI, 61% of cases were appropriate, 23% uncertain, and 18% inappropriate. CABG, however, was more likely than PCI to be consistent with the criteria: 85% of surgeries were appropriate, 8% uncertain, and 7% inappropriate.

Yet only 69% of the patients who had an appropriate indication actually underwent revascularization, compared with 54% of those with uncertain indications and 45% of those with inappropriate indications. Patients who appropriately received revascularization were slightly younger, had lower cardiac risk, and had no prior history of CAD. In the uncertain category, patients who proceeded to revascularization were much more likely to have received diagnostic catheterization at the hands of an interventional cardiologist (42%) than those who did not (26%; P = 0.002).

At 3-year follow-up, revascularization for appropriate candidates was associated with reduced risk of death or recurrent ACS. There also was a trend toward benefit in uncertain candidates (table 1).

Table 1. Likelihood of Death or Recurrent ACS at 3 Years

 

No Revascularization

Revascularization

Adjusted HR (95% CI)

P Value

Inappropriate

9.4%

14.2%

0.99 (0.48-2.02)

0.97

Uncertain

15.3%

8.0%

0.57 (0.28-1.16)

0.12

Appropriate

16.1%

11.8%

0.61 (0.42-0.88)

0.0087


The findings help validate appropriate use criteria in patients with stable CAD and provide evidence of both “underutilization and overutilization of coronary revascularization in clinical practice,” the investigators conclude.

Better Tools for Better Practice

In an editorial accompanying the paper, Manesh R. Patel, MD, of Duke University Medical Center (Durham, NC), argues that the most important finding by Ko et al is not related to overuse but rather to “the potential underuse of coronary revascularization.”

To encourage appropriate treatment on both sides of the coin, “the American College of Cardiology, along with other stakeholders, should continue to encourage innovation and ensure systems are put into place to inform patients and physicians about coronary revascularization,” he advises. “Ideally, real-time clinical decision support tools with outcomes that include [appropriate use criteria] and patient-specific risk scores would be embedded in portable electronic health records that eventually become parts of the structured reports at the end of the revascularization procedure. In the interim, simple paper and web checklists should be used.”

Such tools can guide treatment decisions and improve outcomes, Dr. Patel concludes. “It is with these types of tools that cardiovascular physicians can continue to have the discipline and daily habits to ensure [efficiency] and excellence in cardiac care.”

Getting Past the Paradox

In a telephone interview with TCTMD, Dr. Ko observed that the specific reasons for underutilization are unclear but likely stem from the ‘treatment-risk paradox.’

“Despite having an appropriate indication, if patients have more comorbidities, they tend to get less therapy,” he said.

Steven M. Bradley, MD, MPH, of the University of Colorado Denver (Denver, CO), told TCTMD in an e-mail communication that this pattern suggests “physicians need greater support, especially among patients with multiple comorbidities, to integrate patient risk in treatment decisions at the point-of-care. In addition, there is significant potential for underuse of coronary revascularization related to failure to refer or inadequate patient access to invasive coronary procedures—patients that are not captured in the current or prior studies of appropriate use.”

While cath lab practices are important, he said, efforts toward appropriate use ideally “should begin earlier in the evaluation and care of a patient to ensure the right patient arrives at the cath lab for consideration of revascularization at the right time.”

Dr. Bradley also confirmed that the current findings extend beyond the Canadian context.

“A persistent concern regarding the [appropriate use criteria] for coronary revascularization is the validity of the criteria themselves, given that ratings for many clinical scenarios were based on expert opinion in the context of available evidence. This study supports the validity of the criteria for stable coronary disease,” he said. “Given that the major benefit of PCI in stable coronary disease is the improvement of symptoms, future work will need to incorporate health status and patient symptoms to further clarify [these findings].”

Dr. Ko added that the study results should encourage greater awareness of the criteria. While the potential for overtreatment still exists, “there are also patients who would benefit from revascularization and are not getting it,” he stressed.

 


Sources:
1. Ko DT, Guo H, Wijeysundera HC, et al. Assessing the association of appropriateness of coronary revascularization and clinical outcomes for patients with stable coronary artery disease. J Am Coll Cardiol. 2012;Epub ahead of print.

2. Patel MR. Appropriate use criteria to reduce underuse and overuse: Striking the right balance. J Am Coll Cardiol. 2012;Epub ahead of print.

 

Disclosures:

  • Dr. Ko reports being supported by a Canadian Institutes of Health Research New Investigator Award.
  • Dr. Patel reports receiving research grants from the Agency for Healthcare Research and Quality, AstraZeneca, Johnson & Johnson, and the National Heart, Lung, and Blood Institute as well as serving as a consultant to or advisory board member of Baxter, Bayer, Genzyme, Jansen, and Otsuka.
  • Dr. Bradley reports receiving the VA Career Development Award 10-199 for “Appropriateness of Percutaneous Coronary Intervention.”

 

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