Long-Term Prognosis of Acute Myocardial Infarction Caused by Isolated Diffuse Coronary Artery Ectasia

Isolated coronary artery ectasia (CAE) is a less common form of CAE. The clinical significance of isolated CAE has not been elucidated yet. We aimed to compare the patients with myocardial infarction (MI) due to isolated CAE with the patients without CAE.

We retrospectively included patients who underwent coronary angiography with a diagnosis of first MI caused by isolated CAE. We excluded patients with >20% stenosis in any vessel other than the lesion responsible for the MI. A second group of patients with MI without CAE was selected as the control group. The primary outcome was the composite of all-cause death and nonfatal recurrent MI occurring after index hospitalization.

A total of 404 patients were included. Overall, 63.9% of MIs were ST-elevation MI. Almost all patients in the isolated CAE group had multivessel diffuse ectasia, with 71.3% classified as Markis I, and 26.7% as Markis II. Death or MI recurrence occurred in 54 (26.7%) patients in the isolated CAE group and 33 (16.3%) patients in the control group (P=0.011). Death occurred in 8 (4.0%) patients in the isolated CAE group versus 6 (3.0%) patients in the control group; recurrent MI in 46 (22.8%) versus 27 (13.4%) patients, respectively. Stent thrombosis was more common in the CAE group compared with the control group (8.9% versus 1.5%; P<0.001). In multiple variable analysis, the presence of CAE was associated with death/recurrent MI (hazard ratio, 1.84 [95% CI, 1.11-3.05]; P=0.017), and recurrent MI (hazard ratio, 2.07 [95% CI, 1.08-3.96]; P=0.029).

The patients with MI due to isolated CAE had a higher risk of recurrent MI and stent thrombosis compared with the patients without CAE. In this study, the rate of recurrent MI from the index infarct artery was also higher in the patients with CAE.