Impact of myocardial blush on left ventricular remodeling after first anterior myocardial infarction treated successfully with primary coronary intervention

Background: Myocardial blush grade is a useful marker of microvascular reperfusion that may influence left ventricular dilation. Objectives: To assess the impact of MB grade on LV remodeling in patients undergoing successful primary PCI for first anterior ST elevation myocardial infarction. Methods: In 26 consecutive patients MB grade was evaluated immediately after primary PCI. Each patient underwent transthoracic echocardiography at 24 hours and 6 months after PCI for evaluation of LV volumes. LV remodeling was defined as an increase in end-diastolic volume by ≥ 20%. Results: The presence of myocardial reperfusion (MB 2-3) after primary PCI was associated with a significantly lower rate of remodeling than the absence of myocardial reperfusion (MB 0-1) (17.6% vs. 66.6%, P = 0.012). Accordingly, at 6 months, patients with MB 2-3 had significantly smaller LV end-diastolic volume (94 ± 21.5 vs. 115.2 ± 26 ml) compared with patients with MB 0-1. In univariate analysis, only MB (0-1 versus 2-3) was associated with increased risk of LV remodeling (odds ratio 9.3, 95% confidence interval 1.45- 60.21, P = 0.019). Conclusions: Impaired microvascular reperfusion, as assessed by MB 0-1, may be associated with LV remodeling in patients with STEMI treated successfully with primary PCI.