According to a study presented at the annual meeting of the Radiological Society of North America (RSNA), people with obstructive sleep apnea (OSA) may have more non-calcified or "bad" plaque in their coronary arteries. "Our study reveals that individuals with obstructive sleep apnea are prone to developing an aggressive form of atherosclerosis that puts them at risk for impaired blood flow and cardiovascular events," said U. Joseph Schoepf, M.D., professor of radiology and medicine and director of cardiovascular imaging at the Medical University of South Carolina in Charleston, S.C. "Compared to the non-OSA group, the patients with OSA had a significantly higher prevalence of non-calcified and mixed plaque," Dr. Schoepf said. OSA is caused by obstruction of the upper airway during sleep and is characterized by periodic pauses in breathing, which last for 10 or more seconds. OSA is also commonly associated with snoring. 95 obese patients participated in the study. Participants underwent coronary CT angiography (cCTA), which provides detailed pictures and information on plaque buildup and narrowing in the vessels. "Coronary CT angiography is an effective way to noninvasively diagnose non-calcified and mixed plaque," Dr. Schoepf said. "With technological advancements that are lowering the radiation dose required for cCTA, this exam could become a screening tool for obese individuals at increased risk for cardiovascular disease." The OSA group included 26 men and 23 women, and the matched control group included 22 men and 24 women. The imaging revealed that the amount of calcified plaque in the coronary arteries was not significantly different between the two groups, but the overall composition of vessel plaque was notably different. Non-calcified plaque is considered bad plaque, because it is more vulnerable to rupturing and causing a blood clot, which could lead to a heart attack or other cardiovascular event. Patients with OSA also had a significantly higher prevalence of vessel narrowing and more extensive vessel involvement. Eighty-eight percent of OSA patients had narrowing in at least one vessel, compared to 59 percent of non-OSA patients. One-third of OSA patients had narrowing in four vessels. Learn more about obstructive sleep apnea (OSA).