P1647Prognostic significance of circulating leukocyte subtype counts in patients with chronic heart failure
Authors: Takae M , Yamamoto E , Oike F , Nishihara T , Fujisue K , Sueta D , Usuku H , Takashio S , Sakamoto K , Kaikita K , Tsujita K 
Published: October 2019

Abstract

Background
Inflammation, characterized by early leukocyte recruitment, is known to be associated with vascular endothelial dysfunction and atherosclerosis. Previous studies have reported that an increased leukocyte count is a risk factor for the progression of atherosclerosis in cardiovascular diseases, and we previously reported that a high monocyte count was an independent and incremental of cardiovascular events in patients with coronary artery disease. Furthermore, previous study also reported that inflammation play a role in the pathophysiology of heart failure (HF), but few studies have evaluated the prognostic role of monocyte in patients with HF.

Purpose
To elucidate the prognostic value of monocyte in HF, we investigated the association of monocyte counts in patients with HF with their future cardiovascular events, and compared them among new categories of HF in this study.

Methods
Consecutive HF patients referred for hospitalization at Kumamoto University Hospital between 2006 and 2015 were registered. Finally, a total of 678 HF patients were enrolled in the study, and were followed prospectively until 2016 or until the occurrence of cardiovascular events. We defined high monocyte group as monocyte counts ≥360/mm3 according to previous clinical reports. We further divided HF patients into three types according to left ventricular ejection fraction (LVEF) (HF with reduced LVEF (HFrEF), HF with mid-range LVEF (HFmrEF), and HF with preserved LVEF (HFpEF)).

Results
In this study, HFrEF was 82 patients, HFmrEF was 118 patients and HFpEF was 478 patients, respectively. The average of total monocyte counts were 397±136 in HFrEF and 375±172 in HFmrEF, and 341±138 in HFpEF patients. Kaplan-Meier analysis revealed that both HFrEF and HFmrEF patients with high monocyte group (≥360 /mm3) had a significant higher risk of HF-related events (P=0.03 and P=0.02, respectively) but not of total cardiovascular events compared with those with low monocyte groups (<360/mm3) (P=0.001). By contrast, high and low monocyte groups in HFpEF patients had no significant difference in both total cardiovascular and HF-related events. Multivariate Cox hazard analysis identified a high monocyte count as an independent and significant predictor of future HF-related events in HFrEF and HFmrEF patients (hazard ratio: 3.02, 95% confidence interval: 1.20–7.59, p=0.018).
Next, by whether they had ischemic heart disease (IHD), we divided HFrEF and HFmrEF patients into two groups. Non-ischemic HF group with high monocyte counts had a significant higher risk of HF-related events compared to those with low monocyte counts (P=0.014). By contrast, there was no statistically significant difference of the occurrences of future HF-related events between in ischemic HF group with high and low monocyte counts.

Conclusion
A high monocyte count was an independent and incremental predictor of HF-related events in HFrEF and HFmrEF especially with IHD, but not in HFpEF patients.