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Author Block M Matangi, D Brouillard, D Armstrong, A Dillon, A Johri

Kingston, Ontario

BACKGROUND: ICEBERG is an attempt to define the prevalence of high-risk carotid disease in patients presenting for routine echocardiography who have no known history of vascular disease.
METHODS: Males aged 40-65 years and females aged 50-65 years referred for routine echocardiography underwent limited carotid Doppler imaging. Two images were performed on each carotid artery. One of the common carotid artery (CCA) and one of the carotid bulb and the internal carotid artery. Maximal CCA intimal medial thickness (IMT) was performed offline using an automated edge detection program. The presence of carotid plaque was defined using the ARIC (Atherosclerosis Risk in Communities Study) criteria. Patients were considered to have high-risk carotid disease if there was either the presence of carotid plaque or the maximal CCA IMT was ≥1.20mm (the highest O'Leary quintile). Patients were excluded if they had any history of vascular disease. Patients were also excluded if they were >65 years old. In our experience 85% of patients >65 years already have carotid plaque.
RESULTS: Fourteen patients were called back for a formal carotid Doppler study because of the appearance of a visually apparent significant carotid stenosis. The main results are seen in the table below.
CONCLUSION: Of 314 consecutive patients presenting for routine ECHO Doppler studies aged between 40 and 65 years 59.9% had high-risk carotid disease. Our study suggests that while such a patient is in the ECHO laboratory the opportunity to gather important prognostic information regarding vascular health should not be overlooked. The study likely underestimates the extent of carotid disease due to the limited number of images acquired. We did not want to prolong the routine ECHO/Doppler study.

Table 1.
ECHO/Doppler studies 1172
Excluded males213
Excluded patients >65 years. 545
Excluded patients with known vascular disease 70
Potential for screening 344
Number screened (males/females) 314 (145/169)
Mean age (years) 57.1 ± 6.0
Maximal CCA IMT (mm) 1.03 ± 0.35
Plaque (%) 170 (54.1)
Plaque or CCA IMT ≥1.20mm 188 (59.9)