About 25 percent of a sample of patients with coronary artery disease (CAD) in New York who underwent diagnostic catheterization (DC) were not appropriate candidates for the procedures, according to a study published online Jan. 28 in Circulation: Cardiovascular Interventions.

Using data from the state’s Cardiac Diagnostic Catheterization Database, investigators led by Edward L. Hannan, PhD, of the State University of New York’s University at Albany identified patients with suspected CAD who underwent DC between 2010 and 2011. Based on appropriate use criteria, they rated patients as appropriate, uncertain and inappropriate for DC.

AUC ratings were determined by combining a global risk score; pretest probability of CAD; stress test results; symptoms; and if there were intermediate-risk stress test results, whether the stress test was an electrocardiogram or imaging.

The researchers also examined relationships between patient risk factors and the appropriateness rating and also evaluated the relationship between appropriateness ratings and hospital variables.  

They were able to rate 8,896 patients for appropriateness, and rated only 35.3 percent as appropriate for DC. They rated 39.8 percent as uncertain and 24.9 percent as inappropriate. Of the patients rated as inappropriate, more than half were asymptomatic, had no previous stress test or had low or intermediate risk for CAD.

The average rate of hospitals’ inappropriateness was 28.5 percent and was not associated with hospital volume or whether PCI was inappropriate.

The authors noted that the appropriateness criteria for DC were only recently published, and there have not yet been large-scale studies of patients undergoing DC.

“It should also be noted that AUC for DC and PCI are an evolving process, and a new nomenclature change has been approved, but not yet published,” they wrote. “This could have a bearing on how the AUC should be interpreted and used.”