Clinical features and outcome of coronary artery aneurysm in patients with acute myocardial infarction undergoing a primary percutaneous coronary intervention.

BACKGROUND

While coronary artery aneurysm is an uncommon anatomic disorder and has various forms, its clinical features and outcome and its impact on thrombus formation and the no-reflow phenomenon in the clinical setting of acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (p-PCI) have not been discussed. The purpose of this study was to evaluate whether this anatomic disorder predisposes to a high burden of thrombus formation, and subsequently leads to the no-reflow phenomenon and untoward clinical outcome in patients with AMI undergoing p-PCI.

METHODS AND RESULTS

In our hospital, emergency p-PCI was performed in 924 consecutive patients with AMI between May 1993 and July 2001. Of these 924 patients, 24 patients (2.6%) who had an infarct-related artery (IRA) with aneurysmal dilatation were retrospectively registered and constituted the patient population of this study. Angiographic findings demonstrated that the ectasia type (defined as diffuse dilatation of 50% or more of the length of the IRA) was found most frequently (70%), followed by the fusiform type (20%; defined as a spindle-shaped dilatation in the IRA) and the saccular type (10%; defined as a localized spherical-shaped dilatation in the IRA). The right coronary artery was the most frequently involved vessel (54.2%), followed by the left anterior descending (25.0%) and the left circumflex arteries (20.8%). Coronary angiography revealed that all of these aneurysmal IRA filled with heavy thrombus (indicated as high-burden thrombus formation). The no-reflow phenomenon (defined as <or=TIMI-2 flow) and distal embolization after p-PCI were found in 62.5 and 70.8% of the IRA, respectively. The incidence of cardiogenic shock and the 30-day mortality rate were 25 and 8.3%, respectively. The survival rate was 90.9% (20/22) during a mean follow-up of 19 +/- 30 months.

CONCLUSIONS

While aneurysmal dilatation of an IRA is an uncommon angiographic finding in the clinical setting of AMI, it is frequently associated with high-burden thrombus formation and has a significantly lower incidence of successful reperfusion. However, the long-term survival of these patients is excellent.