White blood cells and neutrophil-to-high density lipoprotein ratio as predictive markers of left ventricular dysfunction in heart failure

Abstract

BACKGROUND

Systemic inflammation, especially of white blood cells (WBCs), is being increasingly accepted as a central mechanism underlying the pathogenesis and development of heart failure (HF). Few studies have assessed their effectiveness as accessible and cost-efficient biomarkers for the early detection of left ventricular dysfunction, as well as their potential predictive value in patients with coronary artery disease (CAD).

AIM

To explore the correlation between WBC parameters and low left ventricular ejection fraction (LVEF) in HF patients and to evaluate its predictive potential.

METHODS

Two-hundred patients with angiographically proven CAD were enrolled in the study. Lymphocyte and neutrophil counts were measured in an automated analyzer. The number of neutrophils was divided by serum level of high density lipoprotein (HDL) to obtain the neutrophil-to-HDL ratio (NHR). Regression analysis was used to examine correlations, and receiver operating characteristic curve analysis was employed to identify predictive value of these hematological markers.

RESULTS

WBC, neutrophils, lymphocytes, and NHR are significantly higher among HF patients with low LVEF. Regression analysis revealed a negative association between LVEF and WBC (r² = 0.007), neutrophils (r² = 0.019), lymphocytes (r² = 0.089), and the NHR (r² = 0.013). ROC analysis revealed that the AUC for WBC was 0.61, with a sensitivity of 72% and specificity of 60%, while neutrophils showed the same AUC (0.61) but with 56% sensitivity and 60% specificity. Lymphocytes showed a higher AUC of 0.68 (72% sensitivity, 60% specificity), while NHR had the lowest AUC at 0.59 (65% sensitivity, 52% specificity).

CONCLUSION

These data indicate that parameters of WBCs, notably lymphocytes, neutrophils, and NHR, can act as useful biomarkers for detection of decreased LVEF in patients with HF. These findings suggest that neutrophils, lymphocytes, and NHR are not only routinely available and cost-effective markers but may also serve as early predictors of reduced LVEF in CAD patients, offering potential utility in clinical risk stratification and management. Further research is needed to validate these findings and explore their potential as clinical risk markers and therapeutic targets in CAD with HF.

Key Words: Heart failure; Left ventricular ejection fraction; Neutrophils to high density lipoprotein ratio; White blood cells; Coronary artery disease

Core Tip: Literature has established white blood cells (WBC) as a key player in the inflammatory response, including ventricular remodeling and interstitial fibrosis. Several studies have demonstrated that WBC differentials such as lymphocytes and neutrophils and neutrophil-to-high density lipoprotein ratio are linked to heart failure (HF) development, particularly, in patients with low left ventricular ejection fraction (LVEF). In the present study, we explore the association between these parameters and LVEF, focusing on their predictive potential in HF.

INTRODUCTION

Cardiovascular diseases continue to be the leading cause of death globally, accounting for around 17.5 million fatalities each year[1]. Heart failure (HF), a complex cardiovascular condition marked by impaired cardiac function and decreased left ventricular ejection fraction (LVEF), is a key manifestation of cardiovascular diseases[2].

Systemic inflammation has emerged as a substantial contributor to the onset and progression of HF[3,4]. Extensive research has explored the intricate link between systemic inflammation and HF, with a particular emphasis on the role of white blood cell (WBC) levels[5,6]. Previous investigations highlighted the critical role of monocytes in facilitating heart muscle migration, thereby contributing to interstitial fibrosis and ventricular remodeling[7]. An elevated WBC count has been associated with reduced blood flow, impaired myocardial perfusion, and increased resistance to thrombus formation, collectively amplifying the risk of congestive HF and mortality[8,9]. In a study examining the association between leukocyte count and in-hospital mortality after MI, authors found that the case-fatality rate significantly rose with each standard deviation increase in leukocyte count[10]. In an earlier study, Lamichhane et al[11] demonstrated that the neutrophil-to-high-density-lipoprotein cholesterol ratio (NHR) exhibits high sensitivity (94.8%) but moderate specificity (59%) in identifying significant coronary stenosis. Additionally, NHR surpasses traditional parameters in predicting prognosis, with a sensitivity of 77.6% and specificity of 74.2% for forecasting adverse events, including mortality, related to acute coronary syndrome[11]. Hence, leukocytosis and NHR may serve as pivotal risk determinants and prognostic indicators for impending cardiovascular events. Despite its affordability, reliability, and routine use in clinical settings, its diagnostic and prognostic value in coronary artery disease (CAD) is often overlooked. While several studies have explored the association between WBC parameters and cardiovascular diseases, limited research has specifically focused on their predictive role in assessing LVEF in patients with angiographically confirmed CAD. In particular, the NHR, despite its emerging relevance in acute coronary syndromes, has not been extensively evaluated as a biomarker for reduced LVEF in chronic HF settings. Our study addresses this gap by systematically analyzing the correlation between WBC specifically neutrophils, lymphocytes, and the NHR and LVEF, aiming to evaluate their role as accessible, cost-effective biomarkers for early identification of left ventricular dysfunction and their utility as potential predictors in patients with CAD.

MATERIALS AND METHODS

Patient enrollment

This cross-sectional investigation was conducted at the Department of Biochemistry, G.B. Pant Institute of Postgraduate Medical Education and Research in Delhi, India. In this study, a total of 200 patients were enrolled from January 2021 to December 2022. Informed consent was obtained from all the study participants. The study included patients diagnosed with angiographically proven CAD who had persistent HF symptoms, classified according to the New York Heart Association criteria. While HF with preserved ejection fraction (HFpEF) was defined by LVEF ≥ 50%, additional echocardiographic parameters indicating diastolic dysfunction and relevant clinical comorbidities (e.g., hypertension, diabetes) were considered to support this classification where available, in accordance with the guidelines and recommendations of the European Society of Cardiology and the American Heart Association. Patients with acute decompensated HF and those with infections such as pneumonia or cystitis were excluded from the study. HF patients with mild ejection fraction (HFmEF with LVEF 40%-50%) were also excluded due to the smaller number of samples.

Clinical data collection

A standard 2D, M-mode, and Doppler echocardiography examination was conducted using the Philips EpiQ-7C device. The LVEF was calculated using Simpson's method. Enrolled patients were further classified into two groups-Group I: HF with reduced ejection fraction LVEF < 40% and Group II: HFpEF with LVEF ≥ 50%. Patient demographic and clinical profile were noted in pre-structured performa. Venous blood was withdrawn from each participant. 2 mL blood was collected in EDTA vial for complete blood count (CBC) and WBC differential analysis, and 2 mL blood in a plain vial for lipid analysis. CBC and WBC differential, and Serum lipid parameters were measured on fully automated analyzers. The number of neutrophils was divided by serum level of high density lipoprotein (HDL) to obtain the NHR.

Statistical analysis

Data was analyzed using the Statistical Package for the Social Sciences, version 22. Descriptive statistics was elaborated as frequencies and percentages for categorical variables. Comparison between various groups for categorical variables was done using χ² and Fisher exact test. For group comparisons, unpaired t-test was used for comparing two independent continuous variables. Linear regression analysis was performed to assess association between LVEF and blood components. Receiver operating characteristic (ROC) curve analysis of blood components and NHR for prediction of reduced LVEF was done. All statistical analyses were performed with P < 0.05.

RESULTS

Demographic characteristics of group I and group II

The comparison of baseline characteristics represented in Table 1. Group I (81 males, 11 females) had a mean age of 52.26 ± 10.12 years, while Group II (69 males, 12 females) had a mean age of 53.49 ± 9.96 years. Group I showed higher rates of diabetes (53%) and hypertension (41%) compared to Group II (46% and 31%, respectively). Additionally, Group I had a higher prevalence of smoking (67%), alcohol consumption (28%), and tobacco chewing (47%) compared to Group II (59%, 12%, and 38%, respectively). The comparison of biochemical parameters represented in Table 2. WBC, neutrophils, lymphocytes, and the NHR are significantly higher in group I as compared to group II. 2D echocardiography (Table 3) showed that Group I had a higher percentage of patients with anterior wall myocardial infarction (54% vs 25%) and inferior wall myocardial infarction (IWMI) (30% vs 12%) compared to Group II. Group I also had significantly more patients with left ventricular dysfunction (mild, moderate, or severe), while Group II had a much higher proportion with normal left ventricular systolic function (88% vs 1%, P < 0.001). The mean LVEF was significantly lower in Group I (34.83 ± 5.1 vs 59.38 ± 2.2, P = 0.001), indicating greater cardiac impairment.

Table 1 Demographic characteristics of group I and group II, n (%)/mean ± SD.

Demographic characteristics	Group I (n = 92)	Group II (n = 81)	P value
Age, in years	52.26 ± 10.12	53.49 ± 9.96	0.422
Male	81 (89)	69 (85)	0.2021
Female	11 (11)	12 (14)
Non-vegetarian diet	72 (78)	59 (72)	0.5671
Smokers	62 (67)	48 (59)	0.4941
Alcohol consumption	26 (28)	10 (12)	0.1141
Tobacco chewer	44 (47)	31 (38)	0.4041
Hypertensive	38 (41)	28 (31)	0.4081
Diabetic	49 (53)	38 (47)	0.6921

¹χ² test.

Table 2 Comparison of biochemical parameters of group I and group II, mean ± SD.

Biochemical profile	Group I (n = 92)	Group II (n = 81)	P value
Total Cholesterol (mg/dL)	136.2 ± 39.6	144.2 ± 62.0	0.836
Triglycerides (mg/dL)	152.7 ± 136.4	159.2 ± 100.7	0.211
HDL (mg/dL)	38.4 ± 18.4	36.6 ± 12.2	0.999
LDL (mg/dL)	72.1 ± 34.0	78.8 ± 47.6	0.705
VLDL (mg/dL)	30.5 ± 27.3	31.6 ± 20.1	0.250
Hemoglobin (g/dL)	13.8 ± 2.0	13.8 ± 2.0	0.565
WBC (cells/µL)	10845.2 ± 5312.3	10043.5 ± 7036.5	0.009
Neutrophils (cells/µL)	7203.4 ± 4224.8	6158.2 ± 4060.2	0.007
Lymphocytes (cells/µL)	3489.4 ± 1818.1	2454.6 ± 1091.3	0.001
Monocytes (cells/µL)	733.1 ± 639.0	620.9 ± 409.7	0.103
Eosinophils (cells/µL)	327.5 ± 383.9	363.8 ± 565.2	0.543
NHR	223.8 ± 146.9	199.7 ± 149.4	0.042

HDL: High density lipoprotein; LDL: Low density lipoprotein; VLDL: Very low-density lipoprotein; WBC: White Blood cells; NHR: Neutrophil-to-high density lipoprotein ratio.

Table 3 Echocardiography parameters of Group I and Group II.

Echocardiography parameters	Group I	Group II	P value
Anterior wall myocardial infarction	50 (54%)	21 (25%)	0.14
Inferior wall myocardial infarction	28 (30%)	6 (12%)
Normal LV systolic function	1 (1%)	72 (88%)	0.001
Mild LV systolic dysfunction	26 (28%)	5 (6%)
Moderate LV systolic dysfunction	32 (34%)	2 (2%)
Severe LV systolic dysfunction	33 (35%)	2 (2%)
LVEF	34.83 ± 5.1	59.38 ± 2.2	0.001

LVEF: Left ventricular ejection fraction; LV: Left ventricular.

Regression analysis between LVEF and blood components

Linear regression analysis revealed a negative association between LVEF and WBC (r² = 0.007), neutrophils (r² = 0.019), lymphocytes (r² = 0.089), and the NHR (r² = 0.013), indicating their role as predictors of reduced LVEF in HF (Table 4).

Table 4 Regression analysis between left ventricular ejection fraction and blood components.

Parameters	R2	P value
WBCs	0.007	0.237
Neutrophils	0.019	0.051
Lymphocytes	0.089	0.001
NHR	0.013	0.111

R²: Coefficient of determination; LVEF: Left ventricular ejection fraction; NHR: Neutrophil-to-high density lipoprotein ratio; WBC: White blood cells.

ROC curve analysis of NHR for prediction of reduced l LVEF

ROC curve analysis was conducted to assess the specificity and sensitivity of blood components for predicting reduced LVEF in CAD patients (Table 5). The area under the curve (AUC) for WBCs was 0.61, with 72% sensitivity and 60% specificity. For neutrophils, the AUC was 0.61 with 56% sensitivity and 60% specificity. Lymphocytes had an AUC of 0.68 (72% sensitivity, 60% specificity), and NHR had an AUC of 0.59 (65% sensitivity, 52% specificity) (Figure 1).

Figure 1 Receiver operating characteristic curve for prediction for reduced left ventricular ejection fraction. ROC: Receiver operating characteristic.

Table 5 Receiver operating characteristic curve analysis for prediction for reduced left ventricular ejection fraction.

	Area under curve (95%CI)	Sensitivity	Specificity	P value
WBC	0.61 (0.53-0.70)	72%	60%	0.009
Neutrophils	0.61 (0.53-0.71)	56%	60%	0.007
Lymphocytes	0.68 (0.61-0.76)	72%	60%	0.001
NHR	0.59 (0.50-0.67)	65%	52%	0.04

WBC: White blood cell; NHR: Neutrophil-to-high density lipoprotein ratio.

DISCUSSION

The relationship between systemic inflammation and HF is well-established and has been associated with WBC levels[3-5,12]. In this study we focused on the utility of WBC to assess the early prediction of reduced LVEF. Our findings revealed a significant inverse relationship between WBC, neutrophil, and lymphocyte levels and reduced LVEF in HF patients. These results are in concordance with the findings of several previous studies[13,14]. In an investigation among stable hemodialysis patients, a significant inverse association between WBC count and LV ejection fraction and a significant positive correlation between WBC count and stages of left ventricular hypertrophy were observed[15]. Additionally, prior reports have shown that the HFpEF pathology and symptoms are primarily influenced by comorbidities like obesity, hypertension, diabetes, and CAD, which are linked to cardiac and systemic inflammation[16]. In our study, we found these comorbidities more prevalent in HFpEF patients, suggesting a connection between immune cell expansion as evidenced by elevated leukocyte count and HFpEF pathogenesis and outcomes.

Furthermore, in our study, regression analysis revealed a negative correlation between LVEF and various blood components although the associations between blood markers and LVEF reached statistical significance, the very low r² values (e.g., 0.007, 0.013) indicate that these markers explain only a small fraction of the variability in LVEF. This suggests limited practical relevance in predicting cardiac function. These findings align with a substantial body of prior research[17-20]. A previous study conducted by W. Koenig, which indicated that analyzing WBC differentials can provide comparable or even greater improvement in risk prediction compared to the widely used inflammatory marker, high-sensitivity C-reactive protein[21]. Additionally, Horne et al[22] found that the predictive ability of WBC differentials surpasses that of the total WBC count alone. Huang et al[23] found that Hematological parameters were identified as independent risk factors for mortality in patients hospitalized for acute HF, particularly in those with impaired left ventricular systolic function. Taken together these findings underscore the potential utility of WBC differentials as prognostic biomarkers for identifying individuals at elevated risk of mortality in HF patients. Additionally, in ROC curve analysis, our findings demonstrated that lymphocytes, WBCs, neutrophils, and NHR are effective predictors in discerning reduced LVEF in CAD patients.

The ROC curve analysis showed AUC values from 0.59 to 0.68, which means these blood markers have some ability to help identify the condition. Although their accuracy is moderate, these results are promising and suggest that with more research, their usefulness in diagnosis or prognosis could improve. Similarly, in an earlier study by Kou et al[17], ROC analysis identified a cut-off value of 1.51 for the NHR to predict CAD, achieving a sensitivity of 94.8%. The authors posited that NHR is an independent predictor of severe coronary stenosis. Varasteh-Ravan et al[24] assessed the predictive value of admission parameters in acute ST elevation myocardial infarction (STEMI) patients treated with Streptokinase. They found that WBC count (AUC 0.65), along with mean platelet volume, platelet distribution width, can predict impaired ST segment resolution and guide adjunctive therapy in acute STEMI patients treated with streptokinase[22]. Collectively, these findings suggest that leukocyte count and NHR may serve as more robust biomarkers for the better prediction of CAD.

Our study reinforces the established link between systemic inflammation and HF by demonstrating a significant inverse association between WBC, neutrophil, and lymphocyte levels and reduced LVEF. These findings support previous research suggesting that WBC differentials may serve as early predictors of cardiac dysfunction. Additionally, the NHR emerged as a promising biomarker, aligning with earlier studies. These hematological parameters could offer cost-effective, accessible tools for early risk stratification in CAD and HF patients.

Some limitations of this study should be acknowledged. The small sample size may limit the external validity of the findings to more diverse populations. Furthermore, longitudinal studies with longer follow-up periods and wider ethnicities could provide stronger evidence on the prognostic value of WBC differentials and NHR in CAD, facilitating the development of tailored therapeutic approaches. Additionally, patients with HFmEF (LVEF 40%-49%) were excluded due to limited sample size (n = 27), which did not allow for meaningful statistical analysis. The omission of this intermediate group limits the generalizability of findings across the full HF spectrum.

CONCLUSION

This study revealed a significant inverse relationship between WBC, neutrophil, and lymphocyte levels and LVEF in HF patients. The results of regression analysis and ROC analysis provided further support for the predictive value of WBC differentials, highlighting their importance in risk assessment. Additionally, lymphocytes, neutrophils, and NHR exhibited potential as predictors of reduced ejection fraction in patients with CAD, and as prognostic markers for future cardiovascular events. Further prospective studies with a larger cohort are needed to better determine the actual impact of WBC differentials and NHR on CAD, thereby improving risk stratification and supporting the development of personalized treatment strategies.