Background: Hematological indices, such as neutrophil-to-lymphocyte (NLR), platelets-to-lymphocyte (PLR), lymphocyte-to-monocyte (MLR), lymphocyte-to-C-reactive protein (LCR) and platelet-to-neutrophil (PNR) ratios; have been proposed as potential prognostic biomarkers for cardiovascular diseases. Rheumatoid arthritis (RA) is an inflammatory chronic joint disease known to increase cardiovascular risk and early atherosclerosis.

Objectives: To evaluate the association of the hematological indices: NLR, PLR, MLR, LCR and PNR, at the moment of diagnosis of RA; with subclinical vascular damage, major adverse cardiovascular events (MACEs) and mortality. To establish a theoretical cut-off value, that allows to identify patients with an increased risk of atherosclerosis, MACEs and death.

Methods: Retrospective observational study. Patients from a longitudinal RA cohort followed at a hospital in eastern Spain between 1986 and 2023 were included. The hematological indices (NLR, PLR, MLR, LCR and PNR) were calculated from the patients’ initial diagnostic blood tests. Epidemiological, clinical, laboratory and radiological findings were obtained by examining the patients’ clinical records. To evaluate subclinical vascular damage, extracranial carotid ultrasound (ESAOTE MyLab XV70 ultrasound) was performed. The appearance of MACEs, before and/or after the diagnosis of RA, as well as deaths, was recovered from patient’s clinical records. The statistical analysis was performed using SPSS 17.0 program.

Results: 143 patients were included, 71.1% women, with a mean age of 61.9 years (SD ± 13.79). At the time of the diagnosis, 28.9% were active or past smokers. 17.6% had arterial hypertension, 7.7% dyslipidemia and 7.7% type 2 diabetes mellitus. The mean Body Mass Index of our sample was 26.68 (SD ± 4.97). In addition, 62% were rheumatoid factor positive, 64.1% tested positive for anti-cyclic citrullinated peptide antibodies and 70.4% presented bony erosions.

In 51.4% of our participants, atheroma plaques were detected. During follow-up, 35.9% suffered a MACE and 21.8% died, with 51.6% of them due to a MACE (cardiac or cerebral).

The mean values of NLR and PNR were 2.72 (SD ± 1.79) y 57.58 (SD ± 38.12) respectively. An association was found between high baseline values of NLR and low values of PNR with atheroma plaques (p = 0.01 y p = 0.02), MACEs (p = 0.000 y p = 0.000) and death by any cause (p = 0.0012 y p = 0.001). A numerical difference was also identified for both ratios for death by a MACE, but it did not achieve statistical significance. There was no relationship between PLR, MLR and LCR with the studied variables.

In our cohort, for the NLR, a cut-off value of 2.3 was established, with higher values related to the presence of atheroma plaques (AUC = 0.667, p = 0-001), with 66% sensitivity and 63% specificity. For MACEs after the diagnosis of RA, the cut-off value was set as higher than 2.33 (AUC 0.747, p = 0.000), with 75% sensitivity and 64% specificity. For death, a cut-off value higher than 2.61 was identified (AUC = 0.685, p = 0.002), with 67.7% sensitivity and 66.1% specificity.

For the PNR, a cut-off value of 51.85 was established, with lower values associated to the presence of atheroma plaques (AUC = 0.69, p = 0.000), with 70% sensitivity and 62% specificity. For MACEs after the diagnosis of RA, the cut-off value was set as lower than 46.73 (AUC 0.723, p = 0.000), with 72.3% sensitivity and 64.7% specificity. For death, a cut-off value lower than 43.14 was identified (AUC = 0.702, p = 0.002), with 71% sensitivity and 58.1% specificity.

Conclusion: High values of NLR and low values of PNR at the time of diagnosis of RA, relate to the development of atheroma plaques, MACEs and mortality. These two hematological indices can be a useful in predicting cardiovascular and fatality risk with good sensitivity and specificity.

REFERENCES: NIL.

Acknowledgements: NIL.

Disclosure of Interests: None declared.