Most patients referred for catheterization before noncardiac surgery are asymptomatic

More than 60 percent of clinically stable patients undergoing cardiac catheterization and/or PCI before noncardiac surgery were asymptomatic, according to a retrospective, descriptive analysis of a large national registry.

In addition, more than 86 percent of patients who underwent prior noninvasive stress testing had positive stress data. Further, more than 48 percent had obstructive coronary artery disease.

Lead researcher Joshua Schulman-Marcus, MD, of Weill Cornell Medical College in New York, and colleagues published their results online in JAMA Internal Medicine on March 28.

“Although randomized clinical trials have not found a benefit, revascularization is recommended in nearly half of these patients,” the researchers wrote. “Treatment recommendations in those with obstructive [coronary artery disease] are split nearly evenly between medical or conservative therapy and revascularization. These data highlight the dilemmas of management in this population and the need for better evidence- based guidelines and practices.”

The researchers analyzed data on 194,444 patients from 1,046 sites who underwent diagnostic cardiac catheterization and/or PCI and were enrolled in the National Cardiac Data Registry CathPCI Registry, which is cosponsored by the American College of Cardiology and the Society for Cardiovascular Angiography. They used version 4.0 of the registry, which had data for July 1, 2009 through Dec. 31, 2014.

They excluded patients who underwent catheterization who had suspected acute coronary syndrome or unstable angina symptoms and those who underwent catheterization as part of a cardiac transplant evaluation.

Patients were defined as having obstructive coronary artery disease if they had at least one vessel with obstructive disease. The researchers defined a vessel as having obstructive disease if there was more than 50 percent luminal stenosis in the left main artery and more than 70 percent stenosis for all other arteries or grafts.

The median age of patients was 65 years old, while 58.4 percent were male, 83.6 percent were white, 78.6 percent were clinically obese and 40.6 percent had diabetes.

Further, 60.6 percent of patients were asymptomatic, 57.8 percent took antianginal medications within two weeks of the procedure, 65.2 percent had prior noninvasive testing and 48.1 percent had obstructive disease.

After diagnostic angiography, 23.8 percent of the overall patient population, 23.1 percent of asymptomatic patients and 48.3 percent of patients with obstructive disease were recommended to undergo revascularization with PCI or bypass surgery.

Of the patients who underwent PCI, 1.3 percent of treated lesions were in left main artery, 13.8 percent of treated lesions were in the proximal left anterior descending artery and 40.8 percent of patients received drug-eluting stents. The catheterization-related mortality rate was 0.05 percent.

The researchers cited a few limitations of the study, including that they did not know the surgical procedures that prompted cardiac evaluation, their urgency or their surgical risk and did not know the timing, performance or outcome of surgery after the catheterization and/or PCI. They also did not know the occurrence or timing of any PCI after surgery.

In addition, they mentioned that some centers might not have reported all of the catheterizations performed. The registry also does not include complete data on the presence or timing of CABG procedures and does not collect the recommended duration of post-PCI antiplatelet therapy.