Angiographic predictors of Left Ventricular Remodelling in Patients with Acute Myocardial Infarction successfully treated with Primary Coronary Angioplasty

Background: The goal of the treatment of acute myocardial infarction (AMI) is to achieve a prompt and sustained reperfusion of the epicardial vessel. Primary percutaneous coronary angioplasty is by far the treatment of choice over thrombolysis. However, it fails to restore an adequate tissue perfusion in 25-30% of patients, despite Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow. Inadequte tissue perfusion is associated with left ventricular remodeling, thus negatively affecting patient prognosis. Aim: to investigate angiographic predictors of left ventricualr remodeling in patients treated with primary coronary angioplasty (PCI). Methods: in 210 consecutive patients undergoing primary angioplasty, myocardial reperfusion was evaluated by means of Myocardial Blush Grade (MBG), TIMI Myocardial Perfusion Grade (TMPG), and corrected TIMI frame count (cTFC). Clinical data and the use of abciximab and distal protection devices were also analyzed. All patients underwent echocardiographic follow-up at 6 months to evaluate the contractile recovery and the presence of LV remodeling (increase in end-diastolic volume ¡Ý20%). Results: Mean symptom onset-to-balloon time was 219¡À96 min. A final TIMI 3 flow was obtained in 196 patients (93.8%), but a MBG 3 and a TMPG 3 were observed only in 87 patients (41.6%) and in 78 patients (37.3%), respectively. Mean final cTFC was 27.7¡À9.6 f/s. A filter-based distal protection device was used in 41 patients (19.5%), of whom 26 (12.4%) also received abciximab. Abciximab alone was used in 116 patients (56%). LV remodelling occurred in 45 patients (22%), and was associated with: shock (P<0.001), baseline LV ejection fraction<40% (P<0.001), anterior wall infarction (P=0.04), final TIMI <3 flow (P<0.001), cTFC>40 f/s (P=0.002), MBG 0-1 (P<0.001), TMPG 0-1 (P<0.001) and peak creatine kinase (P<0.001). Use of abciximab and/or distal protection devices was not associated with a lower rate of LV remodelling. At multivariate analysis, only MBG 0-1 (P<0.001), LV ejection fraction<40% (P=0.048) and CK peak (P=0.036) were independent predictors of LV remodelling. In the prediction of 12-month major adverse cardiac events, the only independ predictor was MBG 0-1. Conclusion: The assessment of MBG is a feasible and simple method to evaluate the effectiveness of myocardial reperfusion during primary angioplasty and predicts LV remodelling and clinical prognosis. MBG should routinely be used for the prognostic stratification of patients undergoing primary angioplasty.