Normal intima-media thickness on carotid ultrasound reliably excludes an ischemic cause of cardiomyopathy.

BACKGROUND

Coronary artery disease (CAD) is the most common cause of left ventricular systolic dysfunction (LVSD). Patients with ischemia as the cause of LVSD may warrant revascularization. Angiography is the most accurate method of CAD diagnosis but is invasive, expensive, and associated with some risk. Noninvasive imaging for CAD often involves expensive equipment, radiation exposure, medication, and/or contrast administration. Carotid ultrasound with measurement of intima-media thickness (IMT) is safe and inexpensive. Carotid IMT is well correlated with the presence of CAD. We assessed the accuracy of carotid ultrasound for identification of CAD as a potential etiology of LVSD.

METHODS

Patients with LVSD (ejection fraction < or =40%) of uncertain etiology referred for angiography underwent carotid ultrasound. Patients with history of myocardial infarction were excluded. Two experienced cardiologists blinded to CAD status determined common carotid artery (CCA) IMT and plaque. Significant CAD was defined as > or =50% stenosis of any major artery. Ischemic LVSD was defined as (1) left main and/or proximal left anterior descending coronary artery > or =75% or (2) > or =2 major arteries with > or =75% stenosis.

RESULTS

Mean ejection fraction was 27% +/- 10% in 150 patients. Significant CAD was found in 64 (42.7%) and ischemic LVSD in 40 (26.7%). Carotid plaque was seen in 95 (63.3%). Mean CCA IMT was > or =0.9 mm in 69 (46.0%). The combination of mean CCA IMT <0.9 mm and no plaque had negative predictive value for ischemic LVSD of 98%.

CONCLUSIONS

Carotid ultrasound with IMT measurement is a valuable screening tool for excluding an ischemic etiology of LVSD when CAD is suspected.