[Frequency of acute plaque ruptures and thin cap atheromas at sites of maximal stenosis]

There have been few autopsy studies relating sites of thin cap atheroma (TCFA) to sites of acute plaque rupture in culprit arteries, and sites of maximal narrowing in non-culprit arteries.

We aimed to quantify and locate the frequency of TCFA related to the sites of maximal stenosis in atherosclerotic plaques.

We studied 88 hearts in victims of sudden death dying with coronary thrombus overlying acute plaque rupture. Thin cap atheromas were defined as fibrous cap < 65 microns overlying a necrotic core. Percent luminal narrowing was determined at the sites of plaque rupture and thin cap atheromas.

There were 81 men and 7 women, mean age 50 years +/- 9 SD. The plaque rupture was the site of maximal luminal narrowing in 47% of culprit arteries. TCFAs were present in 67 hearts (83%). Of these, 49 (73%) demonstrated TCFAs in the culprit artery; 17 (25%) in the culprit artery only, 32 (48%) in the culprit artery and in a non-culprit artery, and 18 (27%) only in a non-culprit artery. In non-culprit arteries, TCFAs represented the maximal site of stenosis in 44% of arteries. The acute rupture site is the site of maximal luminal narrowing in the involved vessel in 47% of hearts from patients dying with acute plaque rupture.

These data may suggest that luminal narrowing is not a reliable marker for TCFA.