Abstract 16323: Leukocyte Count Predicts Cardiovascular Events in Patients With HIV
Background: We aim to determine the role of white blood cell (WBC) count as a predictor of cardiac events in patients with HIV.
Methods: 330 patients (age 52±9 years, 74% male) with HIV who were referred for echocardiographic evaluation formed the study cohort. WBC, platelet and CD4 counts were obtained. Patients were divided into quartiles (0–4.21, 4.22–5.5, 5.6–7.2 and 7.3–14.2 x103 cells/μL, respectively) based on WBC count and followed for the occurrence of myocardial infarction (MI) and cardiac death.
Results: Baseline clinical characteristics were comparable among WBC quartiles, except for the CD4 count which increased with increasing quartiles (281±190, 371±239, 495±301 and 544±385 cells/ml). After 2.8±1.9 years, 32 events occurred. Patients within the third and fourth quartiles had a 5 to 6-fold elevated risk for cardiac events compared with patients in the second quartile (HR 4.9, 95% CI 1.4–17, p=0.01; HR 5.7, 95% CI 1.6–20, p=0.007, respectively). There was a trend towards worse outcome in patients with low WBC (first quartile) when compared with patients in the second quartile (p=0.13)(Figure). On univariate analysis age (HR 1.05, 95% CI 1.01–1.08, p=0.006), history of MI (HR 2.9, 95% CI 1.3–6.4, p=0.01), WBC (HR 1.2, 95% CI 1.06–1.4, p=0.007) and neutrophil count (HR 1.0002, 95% CI 1.0001–1.0004, p=0.004) were predictors of cardiac events. After multivariate analysis, age (HR 1.05, 95% CI 1.01–1.08, p=0.008), history of MI (HR 3.05, 95% CI 1.3–6.9, p=0.008), WBC count in the third (HR 5.1, 95% CI 1.4–18, p=0.015) and fourth quartiles (HR 5.6, 95% CI 1.3–24, p=0.02) remained independent predictors of cardiac events.
Conclusions: The WBC count, a well-standardized, widely available and inexpensive measure of systemic inflammation, is an independent predictor of cardiovascular events in patients with HIV. A WBC count greater than 5.5 x103 cells/μL may identify high-risk individuals who are not currently identified by traditional cardiovascular risk factors.
- © 2010 by American Heart Association, Inc.