Abstract 13095: Regression of Left Main Coronary Arterial Atherosclerosis: Implications for Major Adverse Cardiovascular Events
Background: Progression and rupture of atherosclerotic disease within the left main coronary artery (LMCA) has major clinical implications for a large area of myocardium. While studies have demonstrated slowing of disease progression in epicardial coronary arteries with risk factor modification, the impact within the LMCA has not been investigated.
Methods: In 3479 patients with angiographic coronary artery disease, serial coronary imaging with intravascular ultrasound was used to evaluate the effects of anti-atherosclerotic therapies on plaque progression in 7 clinical trials. Disease progression was characterized in 340 patients who underwent serial imaging within the LMCA (age 57.5±9.2 years, 36.5% female). The relationship between changes in plaque burden with both remodeling parameters and the incidence of major adverse cardiovascular events (MACE: death, myocardial infarction, hospitalization for unstable angina and coronary revascularisation) were investigated.
Results: At baseline the LMCA harboured less percent atheroma volume (PAV) compared with the epicardial coronary artery imaged in the same patients (30.7±8.8 vs 37.1±9.0%, p<0.001). On serial evaluation, less progression of PAV was observed in the LMCA (-0.39±0.13 vs +0.37±0.13, p<0.001). Disease regression in the LMCA was associated with an increase in lumen volume (+3.25±2.3mm3, p<0.001) and reduction in total vessel wall volume (-1.12±2.6mm3, p<0.001). The change in lumen volume correlated strongly with the change in total vessel volume (r = 0.96, p<0.0001) and negatively with the change in PAV (r = -0.55, p<0.0001). The incidence of MACE was associated with greater progression of PAV in the LMCA (+0.51±0.33 vs -0.35±0.15, p=0.02) and associated reductions in both vessel wall (-22.5±7.3 vs -5.12±3.4mm3, p=0.04) and lumen ( 19.0±6.2 vs -0.8±2.9mm3, p=0.009) volumes.
Conclusion: Atherosclerotic plaque within the LMCA demonstrates a propensity to undergo regression in response to use of risk factor modification. Disease progression and constrictive remodeling of the LMCA are associated with a greater likelihood of MACE. This highlights the need for more aggressive management of patients with coronary artery disease.
- © 2011 by American Heart Association, Inc.