Abstract 5772: The Impact of Aortic Plaque Morphology on Survival Rate and the Incidence of Subsequent Embolic Event: Very Long-Term Follow-Up Data

Atheromatous plaques of the aorta have been regarded as a potential source of emboli, but there are few reports about the frequency and prognosis of patients with thoracic aortic plaques and about the relationship between plaque morphology and prognosis, especially long-term follow-up data. The purpose of this study is to clarify the impact of aortic atheromatous plaque morphology on survival rate and the incidence of subsequent embolic event. We retrospectively investigated 1570 consecutive patients who underwent transesophageal echocardiography between 1991 and 2003. The presence of severe plaque (>5mm in thickness) in the thoracic aorta were examined. Survival rate and subsequent embolic event rate were compared between patients with severe plaque and 109 control patients. The control patients were selected from the patients who showed no or mild plaque and as they were matched for age, gender, and risk factors of atherosclerosis with the patients with severe aortic plaque. The relationship between aortic plaque morphology and prognosis was also estimated, according to the presence of ulceration, calcification, hypoechoic plaques, and mobile plaques. Mean follow-up period was 8.7 years. Among 1570 patients, severe aortic plaque was detected in 92 patients (5.9%). These 92 patients showed significantly low survival rate and high subsequent embolic event rate compared with control patients (8-year survival rate, 50% vs 87%, 8-year embolic event free rate, 57% vs 90%). The relative risk of death was significantly increased for ulceration (2.4, 95% CI;1.1–5.2) and the relative risk of embolic events was significantly increased for mobile plaques (2.2, 95% CI;1.1–5.1). In conclusion, aortic plaque > 5mm in thickness was a predictor of a low survival rate and a high embolic event rate. Among patients with aortic plaque >5mm in thickness, ulceration was a predictor of a low survival rate and mobile plaque was a predictor of a high embolic event rate.