In isolation, AUCs for diagnostic caths may miss mark

Appropriate use criteria (AUC) can be useful for decision-making, but is it a hard and fast answer? A prospective study found approximately one-third of patients diagnosed with blocked arteries would have been deemed inappropriate for angiography with 2012 AUCs.

To validate 2012 angiography AUC, Michael M. Mohareb, MD, of the Sunnybrook Health Sciences Centre in Toronto, and colleagues called on angiography data from the Cardiac Care Network (CCN) of Ontario between 2008 and 2011. They analyzed data from 48,336 patients with suspected stable ischemic heart disease, defining them by use of score as appropriate (seven to nine), uncertain (four through six), or inappropriate (one through three). They classified 58.2 percent as appropriate, 10.8 percent as inappropriate and 31 percent as uncertain.

While angiography found a total of 45.5 percent of patients had obstructive coronary artery disease (CAD), a significant number of these were also part of the uncertain and inappropriate groups. Over half of AUC appropriate patients had obstructive CAD and 40 percent were revascularized. Angiography diagnosed 30.9 percent of inappropriate and 36.7 percent of uncertain patients with obstructive CAD and revascularization occurred in 18.9 percent and 25.9 percent, respectively.

Left main or triple-vessel disease was found in 13.1 percent of patients overall. Among appropriate, inappropriate and uncertain angiography use, left main or triple-vessel disease was found in 16.5 percent, 7.1 percent and 8.7 percent, respectively.

Due to the “substantial proportion of patients with inappropriate or uncertain indications” with significant CAD, Mohareb et al cautioned using AUC in isolation. However, they wrote that angiography is more meaningful when normal arteries are found in patients “who would otherwise have been subjected to primary prevention medications and whose actual cause of symptoms would have been misdiagnosed.”

In an editorial, Jacob A. Doll, MD, and Manesh R. Patel, MD, both of Duke University Medical Center in Durham, N.C, wrote that “[t]hese findings highlight the need for ongoing maintenance of AUC with an iterative process that incorporates new evidence from clinical trials and quality improvement initiatives.” Since procedures may be prompted by “unique clinical scenario not captured by the AUC or influenced by patient preference,” Doll et al wrote, determining whether the AUC response is appropriate for the case at hand is an important part of considering a patient’s next steps.

“Physicians must embrace the opportunity for self-regulation that AUC offer to ensure that we remain advocates for our patients and stewards of our health system,” Doll et al wrote.

The study was published online March 10 in Annals of Internal Medicine.