Abstract 251: Density and Distribution of Thin-Cap Fibroatheroma and Ruptured Plaque in Human Coronary Arteries – A Pathologic Study
Background - Most cases of acute coronary syndrome and sudden death are believed to arise from rupture of a thin cap fibroatheroma (TCFA) with resultant intracoronary thrombosis. Although atherosclerosis is a diffuse disease, it is unclear whether plaques at high risk of rupture are focally or diffusely distributed.
Methods and Results - To determine the frequency and extent of TCFA and ruptured plaque, we performed longitudinal sectioning of 148 human coronary arteries from 50 cardiac autopsy specimens (mean age 73 years, 64% male) taken from patients dying of cardiovascular (n=33), non-cardiovascular (13) and unknown (4) causes. A total of 3639 longitudinal segments of length 3 mm were sectioned in 148 coronary arteries, comprising 10.9 meters of total coronary tissue length. Overall, 23 TCFAs and 19 ruptured plaques were found (mean ± SD: 0.46 ± 0.95 and 0.38 ± 0.70 per heart, respectively), accounting for only 1.5% and 1.2%, respectively, of the total length of all coronary trees examined. The majority of TCFA and ruptured plaque localized in the proximal third of the major coronary arteries, and in 92% of cases these lesions clustered within 2 or fewer non-overlapping 20-mm segments.
Conclusions - TCFA and ruptured plaques, the suspected precursor lesions of intracoronary thrombi, are relatively infrequent and have a limited, focal distribution in human coronary arteries, supporting ongoing research to pre-emptively identify and passivate vulnerable plaque.