The importance of thorough reading of cardiac computed tomographic angiography after bypass surgery was reinforced simply by reviewing reports for a large series of patients who underwent postoperative evaluation, according to an article in the August issue of the American Journal of Roentgenology.

Researchers at the University of Maryland School of Medicine, Baltimore, MD, reviewed reports for 259 patients who underwent postoperative evaluation at a single large heart center. Of the total, 51 (19.6 percent) had at least one unsuspected but potentially significant finding, including 24 who had a cardiac finding such as intracardiac thrombus and 34 who had a noncardiac finding such as pulmonary embolism, lung cancer, or pneumonia.

“Our interest in this topic developed because we were performing many cardiac CT angiography examinations, including those for bypass grafting, and we wondered how often we would find unrelated but clinically significant findings in the heart and lungs,” said Charles White, MD, senior author of the study. “We wanted to know the effect of using intravenous contrast and thinner slices on the prevalence of these findings,” he added.

“There was a fairly high rate of abnormalities that are found incidentally outside the coronary arteries and bypass grafts,” said Dr. White. “The take home message is that these examinations require physician interpreters who are trained to read the entire CT, not just the coronary vessels,” he said.

“One of the issues that we found somewhat surprising is the number of patients with pulmonary embolism who had undergone recent bypass grafting,” he said. “It is reasonable to suspect that cardiac surgery patients who are often immobilized after their procedure might have these problems; but this connection is certainly not well known in the radiology community,” he said.