Abstract 1762: Relationship Between Leucocyte Count, Myonecrosis, Myocardial Perfusion and Outcomes Following Primary Angioplasty
Background: Earlier studies have identified leukocytosis as a predictor of mortality in AMI. The aim of this study was to examine whether leukocytosis is a negative prognostic factor in patients undergoing contemporary primary PCI for acute myocardial infarction (AMI), and if so, to determine whether it is associated with impaired myocardial perfusion.
Methods and Results: Clinical outcomes and reperfusion success, utilizing TIMI flow and myocardial blush grades (MBG), were examined according to tertiles of baseline leukocyte count among 1268 patients undergoing primary PCI for AMI in the CADILLAC trial. Patients with higher leukocyte count were younger and more likely to be current smokers. Preprocedure TIMI 0 flow was more frequent in patients with higher leukocyte counts, but post-procedural TIMI-3 flow rates were equally high ( > 94%) in all 3 groups. MBG 2/3 was achieved at similar rates post-PCI in patients with low, intermediate and high baseline leukocyte counts (52.0% vs. 51.5% vs. 50.1%, p = 0.8). Higher baseline leukocyte counts were associated with greater myonecrosis (p < 0.0001) and increased mortality (figure⇓) at 1-year (2.7% vs. 4.6% vs. 5.4% respectively, p = 0.047). By multivariate analysis, baseline leukocyte count (in increments of 1000, hazard ratio [95% confidence interval] = 1.07 [1.02, 1.10], p = 0.005), and peak CPK (1.22 [1.14, 1.29], p < 0.001), were independent predictors of 1-year mortality.
Conclusions: Despite being associated with younger age, baseline leukocytosis is an independent correlate of increased infarct size and mortality after primary PCI in AMI, an effect not explained by decreased myocardial perfusion.