[Prognostic value of white blood cell count in acute myocardial infarction: long-term mortality]

Although traditionally an elevated white blood cell count (WBC), an indicator of systemic inflammation, has been accepted as part of the healing response following acute myocardial infarction (AMI), it has frequently been shown to be a predictor of adverse cardiovascular events. The present study was designed to assess the association between WBC and long-term mortality in AMI patients either with ST-segment elevation (STEMI) or without ST-segment elevation (non-STEMI). Patients and method. The study included 1118 consecutive patients who were admitted with the diagnosis of AMI: 569 non-STEMI and 549 STEMI. The WBC was measured in the 24 hours following admission. Patients were divided into 3 groups: WBC1 (count, <10 x 103 cells/mL), WBC2 (count, 10-14.9 x 10(3) cells/mL), and WBC3 (count, > or =15x10(3) cells/mL). All-cause mortality was recorded during a median follow-up period of 10+/-2 months. The relationship between WBC and mortality was assessed by Cox regression analysis for both types of AMI.

Long-term mortality during follow-up was 18.5% in non-STEMI patients and 19.9% in STEMI patients. In non-STEMI patients, the adjusted hazard ratios for those in the WBC3 and WBC2 groups compared with those in the WBC1 group were 2.07 (1.08-3.94; P=.027) and 1.61 (1.03-2.51; P=.036), respectively. The corresponding figures in STEMI patients were 2.07 (1.13-3.76; P=.017) and 2.22 (1.35-3.63; P=.002), respectively.

WBC on admission was an independent predictor of long-term mortality in both non-STEMI and STEMI patients.