Abstract 9358: Accelerated Progression of Coronary Atherosclerosis in Patients With Ultrasonic Features of Plaque Vulnerability

Abstract

Backgrounds: Vulnerable plaques typically contain large lipid cores accompanied by expansive vascular remodeling and spotty calcification. While non-occlusive plaque rupture has been proposed as a mechanism for sudden disease progression, the natural history of atheroma progression in patients with vulnerable plaques have not been well characterized. Methods: 3460 patients with angiographic coronary artery disease underwent serial intravascular ultrasound imaging to monitor atheroma progression in 7 clinical trials of anti-atherosclerotic therapies. Patients with (n=1063) and without (n=2397) focal vulnerable plaques, defined as the combination of percent atheroma volume (PAV) >40%, expansive vascular remodeling and spotty calcification, were compared with regard to clinical characteristics and the rate of atheroma progression. Results: Patients with vulnerable plaques were less likely to be female (24 v. 31%, p<0.001) and more likely to have hypertension (82 v. 78%, p=0.01) and diabetes (38 v. 30%, p<0.001). Vulnerable plaque patients harbored more extensive atherosclerotic disease at baseline, with a greater PAV (42.5±7.4 v. 36.9±9.2%, p<0.001) and total atheroma volume (TAV, 207.6±82.7 v. 184.6±82.7 mm3, p<0.001). On serial evaluation, less progression of PAV (0.25±0.28 v. 0.46±0.27%, p=0.08) and TAV (-4.6±2.2 v. -3.0±2.2mm3, p=0.03) was observed in vulnerable plaque patients. Use of statins and optimal control of risk factors including LDL-C and HDL-C levels were associated with the slowest disease progression in patients with vulnerable plaques (Figure). Conclusions: While focal vulnerable plaques are associated with more extensive atherosclerotic burden, these patients demonstrate the greatest benefit of risk factor interventions. These findings suggest that while vulnerable lesions have the propensity to promote ischemic syndromes, they present a modifiable substrate that is sensitive to intensive use of medical therapies.