Background: Patients with acute myocardial infarction (AMI) may have multiple complex coronary plaques that are not limited to the culprit lesions. However, it is unknown whether they tend to progress in severity, regress, or remain stable. The aim of this angiographic study is to evaluate the natural history of these lesions.
Methods: We consecutively enrolled 229 patients who underwent coronary angiography at the time of their hospitalization to treat AMI with primary angioplasty. Baseline and follow-up (mean follow-up duration, 192 +/- 33 days) coronary angiographic data in patients with multiple complex coronary plaques characterized by thrombus, ulceration, plaque irregularity, and impaired flow were compared.
Results: Single complex coronary plaques were identified in 167 patients (73%), and multiple complex plaques were identified in the other 62 patients (27%). Among the patients with multiple complex plaques (62 patients, 83 non-culprit complex plaques), the angiographic examinations were reviewed simultaneously in 43.5% (27 patients, 35 non-culprit complex plaques). Of 35 non-culprit complex lesions, 29 lesions (82%) remained complex without changing into smooth lesions, 1 lesion became totally occluded, and 4 lesions regressed. The severity of non-culprit complex lesions between baseline and follow-up angiography is equal (maximal diameter stenosis, 74% +/- 15% vs 72% +/- 15%, P =.4). Long-term cardiac events after discharge were more likely to develop in patients with multiple complex plaques than in patients with single complex plaques (24% vs 10%, respectively; P <.01).
Conclusions: In patients with AMI, little angiographic change occurred during 6 months of follow-up in the non-culprit complex plaques.