Angiographic determinants of infarct size after successful percutaneous intervention for acute ST-elevation myocardial infarction: the impact of distal embolisation

Background: We investigated the impact of distal embolisation and other angiographic determinants in patients after successful primary angioplasty for acute myocardial infarction.

Methods: Angiographic data were assessed on the coronary angiogram carried out immediately after successful (TIMI 2 or 3) coronary angioplasty in 631 consecutive patients with acute myocardial infarction. Embolisation was defined as a distal filling defect with an abrupt 'cutoff' in ≥1 of the peripheral coronary artery branches of the infarct-related artery, distal to the site of angioplasty. Endpoints were left ventricular ejection fraction (LVEF) and enzymatic infarct size.

Results: Left anterior descending artery related myocardial infarction, impaired myocardial blush and distal embolisation were independent determinants of infarct size. Distal embolisation was present in 102 patients (16%) and was associated with a larger enzymatic infarct size (LDH Q₄₈ 2250 vs. 1532, p=0.001) and a lower LVEF (41% vs. 44%, p=0.04). There was no difference in the frequency of distal embolisation between patients treated with or without stents.

Conclusions: In successful primary angioplasty, infarct-related artery, impaired myocardial blush and distal embolisation are independent determinants of infarct size. Distal embolisation can be visualised in 16% of the patients and is associated with a larger enzymatic infarct size and lower LVEF. Intracoronary stenting is not associated with an increased risk of distal embolisation during primary angioplasty.