Effect of microvascular reperfusion on prognosis and left ventricular function in anterior wall myocardial infarction treated with primary angioplasty.

BACKGROUND: Myocardial reperfusion in acute myocardial infarction may fail despite successful recanalization of the infarct-related artery. The purpose of this study was to assess the impact of myocardial reperfusion on clinical outcome and left ventricular (LV) function.
METHODS: The clinical significance of myocardial blush grade (MBG)-angiographic marker of myocardial reperfusion, in 104 patients (age 62+/-13 years) with first anterior myocardial infarction, successfully (TIMI 3) treated with primary angioplasty was analysed. Echocardiography was performed at baseline and after 6 months. Mortality and major cardiovascular event (MACE) rates were analysed 30 days and 1 year after acute myocardial infarction. Patients were divided into two groups according to presence (group 1, MBG 2-3, n=64) or absence of myocardial blush (group 2, MBG 0-1, n=40).
RESULTS: One-year mortality was significantly higher in group 2 in comparison to group 1 (22.5% vs 6.25%, HR: 3.6, 95% CI: 1.187-10.9, p=0.0175). The rate of MACE was significantly lower in patients with MBG 2-3, both after 1 and 12 months (9.4% vs 30%, p=0.008 and 20.3% vs 60%, p<0.001, respectively). At baseline, both global and regional contractile function were significantly better in group 1 than in group 2 (ejection fraction (EF) 47.4+/-8.8% vs 43.3+/-7.9%, p=0.04 and wall motion score index (WMSI) 1.64+/-0.4 vs 1.87+/-0.3, p=0.001, respectively). Similarly, at 6 months follow-up, LV function was better in group 1 as compared with group 2 (EF 54.9+/-14.5% vs 46+/-13.2%, p=0.005 and WMSI 1.43+/-0.4 vs 1.76+/-0.46, p=0.001, respectively).
CONCLUSIONS: Impaired microvascular reperfusion in patients with anterior myocardial infarction is associated with poor prognosis and worse early and late left ventricular function.