Carotid Atherosclerosis in Predicting Coronary Artery Disease: A Systematic Review and Meta-Analysis

Objective: This meta-analysis aims to compare the relationship between phenotypic manifestation of coronary and carotid atherosclerosis using available imaging techniques. Approach and Results: We searched all electronic databases until October 2020 for studies which reported relationship between carotid and coronary atherosclerosis. The primary end point was correlation between carotid intima-media thickness (CIMT) and carotid plaque features (calcification and lipid-rich necrotic core) with coronary artery disease (CAD). Secondary end points included carotid pathology that predicts CAD. Eighty-nine papers with 22 683 patients comparing carotid and coronary atherosclerosis were included in the analysis. CIMT was increased linearly with severity of CAD irrespective of its significance (P<0.001), mono versus 2 vessel disease (P=0.003), and 2 versus multivessel disease (P<0.001). Carotid plaque presence and calcification were less, and lipid-rich necrotic core was highly prevalent in nonsignificant versus significant CAD (P<0.001, P=0.03, P<0.001, respectively). Moderate correlation was found between CIMT and severity of CAD (r=0.60, P<0.001) and the number of diseased vessels (r=0.49, P<0.001). There was a moderate correlation between carotid and coronary stenosis (r=0.53, P<0.001) and between carotid and coronary calcification (r=0.61, P<0.001). CIMT ≥1.0 mm with a summary sensitivity of 77% and summary specificity of 72% and respective values of 80% and 67% for carotid plaque were the best predictors of CAD, irrespective of the technique used for its diagnosis. Conclusions: These results support the concept that atherosclerosis affects both carotid and coronary systems, although not always in identical phenotypic manner. These findings highlight the beneficial examination of carotid arteries whenever CAD is suspected.