Does Coronary Artery Stenting for Acute Myocardial Infarction Improve Left Ventricular Overloading at the Chronic Stage?

In the present study, we evaluated whether stenting is useful for cardiac overloading, using ANP, BNP, and (99m)Tc-tetrofosmin myocardial scintigraphy. It has been reported that coronary artery stenting is useful for cardiac functions for acute myocardial infarction (AMI). The subjects were 110 patients with AMI successfully treated by direct angioplasty. These patients were subgrouped into two groups: the S group (underwent stenting; 54 patients) and the P group (underwent POBA alone; 56 patients). Extent scores reflecting decreased myocardial blood flow were calculated at myocardial areas showing a radioactivity count of less than (-)2 x standard deviations compared to the database of normal subjects.The ratio of extent scores to defect scores (extent/defect ratio) was compared between the P and S groups. Both ANP and BNP levels in the S group were lower than in the P group at the chronic stage (1 and 3 months after reperfusion therapy). Moreover, the end-diastolic volume index from the left ventriculography 3 months after reperfusion therapy was significantly larger in the P than the S group. The extent/defect ratio was significantly lower in the P group (2.8 +/- 0.2) than the S group (3.5 +/- 0.3), suggestive of a microcirculation disorder. These results suggest that cardiac overloading and left ventricular remodeling are decreased more by stenting than by POBA alone, probably because stenting prevents decreased myocardial blood flow around the infarct myocardium.