Coronary plaque morphology and frequency of ulceration distant from culprit lesions in patients with unstable and stable presentation

Objective - Intravascular ultrasound studies describe ruptured coronary plaques at sites remote from the culprit lesion in patients with acute myocardial infarction (MI), suggesting multifocal plaque vulnerability. However, the role of intravascular ultrasound in the diagnosis of lesion vulnerability before rupture is unclear. Methods and Results - We compared morphology and frequency of ulceration of additional plaques proximal to the culprit lesion in 105 patients treated with emergent stenting during an evolving, acute MI in the CADILLAC study and 92 patients with stable/subacute presentation who underwent elective stenting. Additional plaques proximal to the culprit lesion were found in 52 (50%) and 54 (59%) patients in the acute MI and stable/subacute group, respectively. The prevalence of ulceration was significantly higher in the acute MI than in the stable/subacute group (19% versus 4%; P=0.014). However, there was no significant difference in other morphological lesion characteristics. Conclusions - Additional plaques are frequently found adjacent to the culprit lesions in patients undergoing percutaneous coronary intervention independent of clinical presentation. The increased prevalence of plaque ulceration but otherwise similar morphology of additional lesions in patients with acute MI versus stable/subacute presentation demonstrates the limitations of imaging in the assessment of plaque vulnerability.