PROGNOSTIC-SIGNIFICANCE OF SPONTANEOUS ECHO CONTRAST IN THE THORACIC AORTA - RELATION WITH ACCELERATED CLINICAL PROGRESSION OF CORONARY-ARTERY DISEASE

Objectives. The purposes of this study were to identify the incidence of aortic smoke in an unselected cohort of patients and to determine t he utility of this measurement as a clinical marker for future coronar y events and long-term cardiac prognosis. Background. Although spontan eous echo contrast detected within the cardiac chambers has been assoc iated with an increased risk of thromboembolism, less is known about ' 'smoke'' within the thoracic aorta and its relation to progression of coronary artery disease. Methods. We prospectively assessed 118 unsele cted, consecutive male patients (mean age 67 years, range 29 to 86) wh o underwent transesophageal echocardiography (TEE). The presence of ao rtic smoke was identified by swirling echodense shadows distinct from high gain artifact. A positive result required confirmation by two of three independent observers. Results. Aortic smoke without dissection was found in 25 of the patients (21%). Indications for TEE, coronary r isk factors, the incidence of reduced left ventricular ejection fracti on and mitral insufficiency and known coronary artery disease severity collectively did not differ significantly at baseline between the gro ups with and without smoke. Follow-up averaged 20.4 months (range 18 t o 24) and was 100% complete for mortality and 98% complete for morbidi ty. The presence of aortic smoke was an independent predictor of myoca rdial infarction (16.0% vs. 2.2%, p < 0.005) and cardiac death (20.0% vs. 1.1%, p < 0.0001). These statistics remained significant after cov arying for age, ejection fraction <50%, hypertension, diabetes, aortic dimension, the presence of an atheromatous plaque and smoke in the le ft atrium. Conclusions. Spontaneous echo contrast detected within the thoracic aorta by transesophageal echocardiography is a common and imp ortant clinical marker that is strongly associated with an increased r isk for future myocardial infarction and cardiac mortality. Future stu dies will attempt to define the pathophysiology of this relation and a ssess whether aggressive revascularization strategies and antithrombot ic therapy may aid in the reduction of this risk. (C) 1997 by the Amer ican College of Cardiology.