Relationship Between Baseline White Blood Cell Count and Degree of Coronary Artery Disease and Mortality in Patients wiht Acute Coronary Syndromes - TACTICS-TIMI 18 Substudy

Description:

The goal of this study was to assess the relationship between baseline white blood cell (WBC) count and angiographic and clinical outcomes in patients with unstable angina (UA) and non-ST-segment elevation myocardial infarction (NSTEMI). Is the baseline WBC count a significant predictor of outcomes independent of other biomarkers in patients with UA/STEMI?

Study Design

Study Design:

Patients Enrolled: 2208

Drug/Procedures Used:

Data of 2,208 patients in the Treat angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction 18 (TACTICS-TIMI 18) trial were analyzed to address the relationship between baseline WBC count, other baseline variables and biomarkers, angiographic findings, and clinical outcomes.

Principal Findings:

Higher baseline WBC counts were associated with lower Thrombolysis In Myocardial Infarction (TIMI) flow grades (p = 0.0045) and TIMI myocardial perfusion grades (p = 0.03) as well as a greater extent of coronary artery disease (CAD, p<0.0001) and angiographically apparent thrombus (p =0.04). While there was no relationship between elevated WBC count and new or recurrent myocardial infarction or rehospitalization for acute coronary syndromes, a higher baseline WBC count was associated with higher six-month mortality (1.5% to 3.6% to 5.1% for patients with low, intermediate, and high WBC counts, respectively [p = 0.0017]). Six-month risk of death was significantly higher in patients with a low C-reactive protein (CRP) but an elevated WBC (hazard ratio [HR] 4.3, P = 0.049), and was even higher for patients with a high CRP (HR 8.6, P = 0.004).

Interpretation:

Among patients UA/NSTEMI elevated WBC counts were associated with impaired epicardial and myocardial perfusion, more extensive CVD, and higher six-month mortality. The assessment of two inflammatory markers, WBC counts and CRP, can be used to stratify patients across and eightfold gradation of six-month mortality risk. While inflammatory markers have been shown to be associated with higher risk of mortality in patients with acute coronary syndromes, the mechanism underlying this higher risk has not been well studied and warrants future evaluation.

References:

Sabatine MS, Morrow DA, Cannon CP, et al. Relationship Between Baseline White Blood Cell Count and Degree of Coronary Artery Disease and Mortality in Patients with Acute Coronary Syndromes. A TACTICS-TIMI 18 Substudy. J Am Coll Cardiol 2002;40:1761-68.

Keywords: Coronary Artery Disease, Myocardial Infarction, Acute Coronary Syndrome, C-Reactive Protein, Platelet Aggregation Inhibitors, Biomarkers, Thrombosis, Fibrinolytic Agents, Tyrosine, Leukocytes


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