Initial white blood cell count is an independent risk factor for survival in patients with dilated cardiomyopathy

Abstract Background The impact of white blood cell count (WBCc) on the outcome of patients with non-ischemic left ventricular (LV) dysfunction is unknown. In the present study we investigated the influence of WBCc on mortality and cardiac inflammation in patients with reduced LV systolic function in the absence of ischemic or valvular etiology. Methods and results We included 381 patients with reduced left ventricular (LV) ejection fraction (LVEF ≤ 45%) quantified by two-dimensional echocardiography. Coronary artery disease and valvular diseases were excluded by angiography and echo, respectively, in all patients. WBCc was quantified routinely upon first hospital admission. In 291 patients, endomyocardial biopsies from the right ventricle were performed upon first hospital admission for assessment of cardiac inflammation. Follow-up was up to 5.5 years (median 2.93 [1.7;4.0]). Information on vital status of patients was obtained from official resident data files. WBCc > 11 Gpt/l was associated with significantly increased mortality in patients with severe LV dilation (end-diastolic diameter (LVEDD) > 70 mm quantified by echocardiography) in comparison to patients showing WBCc ≤ 11 Gpt/l (41.7% vs 13.6%, p = 0.02). Multivariable Cox regression analysis showed that WBCc predicts mortality independently of other cardiovascular risk factors and LVEF (hazard ratio 1.14; p = 0.04). Doses of heart failure medication did not differ significantly in patients with LVEDD > 70 mm and WBCc > 11 Gpt/l when compared to LVEDD > 70 mm and WBCc ≤ 11 Gpt/l (percent of maximum doses: ß-blockers p = 0.51, ACE inhibitors p = 0.56, AT1 antagonists p = 0.77, aldosterone antagonists p = 0.35). WBCc including its subpopulations (monocytes, lymphocytes and granulocytes) did not show a significant correlation with cardiac amounts of CD3+ -lymphocytes (r = 0.02, p = 0.78) or CD68+ -macrophages (r = 1.0, p = 0.09) (n = 291). Conclusion WBCc at first hospital admission predicts long term-mortality in patients with dilated cardiomyopathy independently of cardiovascular risk factors.