Abstract 4196: Inflammation and Impaired Microvascular Reperfusion Independently Influence on Infarct Size and Mortality After ST-Elevation Myocardial Infarction
Background: Elevated white blood cell (WBC) count on admission, a simple measure of inflammation, and absence of ST segment resolution (ST-R) after reperfusion, a surrogate of impaired microvascular reperfusion, are associated with adverse outcomes after ST-elevation myocardial infarction (STEMI). Prognostic utility of combination of WBC count and ST-R remains unknown.
Method: This study consisted of 264 patients with STEMI who underwent primary angioplasty within 24 hours after the onset. Elevated WBC count was defined as WBC count on admission ≥10,000/mm3. Electrocardiograms were recorded before and 1 hour after angioplasty. ST-R was defined as ≥50% decrease of ST segment elevation.
Results: There was no significant difference in the incidence of ST-R between patients with or without elevated WBC count (53% vs 54% p=0.8). In-hospital mortality rate was higher in patients with elevated WBC count than those without (7.4% vs 2.3%, p=0.04), and lower in patients with ST-R (2.1% vs 7.4%, p=0.04). Peak creatine kinase (CK) was higher in patients with elevated WBC count (3,812±2,584 vs 2,835±1,620 IU/L, p<0.01) and lower in patients with ST-R (2,687±2,244 vs 4,102±1,964 IU/L, p<0.01). Multivariate analysis showed elevated WBC count (p=0.04) and absence of ST-R (p<0.001) were independently associated with mortality and peak CK. When a combination of each variable was analyzed, a stepwise increase in mortality and peak CK was seen (Figure⇓).
Conclusion: These results suggested inflammation and microvascular dysfunction may deteriorate myocardial damage independently. A combination of WBC count and ST-R is useful for early prediction of prognosis in patients with STEMI.