Femoral Plaque Quantification by Ultrasound for the Prediction of Obstructive Coronary Artery Disease in Symptomatic Men and Women
Cardiovascular risk remains difficult to assess, particularly in women. It is known that patients with ankle-brachial index (ABI)-indicated peripheral arterial disease (PAD) have an increased risk of cardiovascular morbidity and mortality. Femoral ultrasound, a sensitive marker of PAD, has potential value as a screening tool. However, the association of femoral plaque burden with coronary artery disease (CAD) severity and extent remains unknown. Furthermore, little information is available on sex differences in the burden of PAD and its relationship to CAD, a consideration that may improve patient risk management algorithms. To explore this, five hundred study participants (34% female) underwent bilateral carotid and femoral ultrasound within 24 hours of coronary angiography. A subset of 124 participants underwent ABI measurements. It was found that in women, increased combined common femoral and carotid bulb plaque area yielded the strongest association with significant CAD (odds ratio (OR) 7.3 (95% CI 3.5-16.8)), independently of age and traditional cardiac risk factors, while in men, this was achieved by increased combined plaque height at the carotid bulb and femoral bifurcation (OR 4.3 (CI 2.4-8.2)). Additionally, ultrasound-detected femoral plaque burden more accurately identified participants with significant CAD (area under the curve (AUC) = 0.731) than ABI (AUC = 0.578) (p = 0.02). Femoral plaque burden had a higher sensitivity (84%) than ABI (25%) for ruling out disease. In conclusion, we determined sex-specific markers of ultrasound-detected atherosclerotic disease that may improve risk stratification when used uniquely in women and men. A combined assessment of common femoral and carotid plaque area is most advantageous in women, while men may benefit most from a combined analysis of carotid and femoral bifurcation plaque height. Furthermore, femoral ultrasound, while being an equally safe, inexpensive, and rapid tool, more accurately predicts significant coronary disease than a traditional ABI assessment. Used clinically, vascular ultrasound may have immense value when incorporated into cardiovascular management algorithms, especially for those patients in which risk remains uncertain despite the use of conventional stratification tools.