Effect of cholesterol crystals on plaques and intima in arteries of patients with acute coronary and cerebrovascular syndromes.

TLDR: By avoiding ethanol in tissue preparation, CCs perforating the intima were shown to be associated with PD, and crystal content was significantly associated with clinical events, suggesting that cholesterol crystallization may have a role in PD.

Abstract: Plaque disruption (PD) causes most acute cardiovascular events. Although cholesterol crystals (CCs) have been observed in plaques, their role in PD was unknown. However, cholesterol expands with crystallization tearing and perforating fibrous tissues. This study tested the hypothesis that CCs can damage plaques and intima, triggering PD, as observed in tissues prepared without ethanol solvents that dissolve CCs. Coronary arteries of patients who died of acute coronary syndrome (n = 19) and non–acute coronary syndrome causes (n = 12) and carotid plaques from patients with (n = 51) and without (n = 19) neurologic symptoms were studied. Samples were examined for CCs perforating the intima using light and scanning electron microscopy (SEM) with ethanol or vacuum dehydration. In addition, fresh unfixed carotid plaques were examined at 37°C using confocal microscopy. Crystal content using SEM was scored from 0 to +3. SEM using vacuum dehydration had significantly higher crystal content compared with SEM using ethanol dehydration (+2.5 ± 0.53 vs +0.25 ± 0.46; p