Relação neutrófilo-linfócito e parâmetro RDW na fibrilação atrial: comparação entre participantes com valvopatia mitral reumática e aqueles sem valvopatia primária

Abstract

Background: Atrial fibrillation (AF) is associated with a 1.5 to 2 times higher risk of death and adverse outcomes. Rheumatic heart disease (RHD) is one of the leading causes of valvular heart disease in our region and, when associated with AF, leads to a more unfavorable prognosis. Biomarkers such as the neutrophil-to-lymphocyte ratio (NLR) and red cell distribution width (RDW) have been identified as predictors of cardiovascular events in patients with heart disease and those with AF. Objective: To assess the impact of NLR and RDW on the occurrence of events among participants (pts) with AF, comparing a group with mitral valve disease of rheumatic etiology (group 1) to a group without primary valvular disease (group 2). Method: A prospective, observational, and longitudinal study involving 110 pts with AF, divided into two groups (group 1 with 58 pts and group 2 with 52 pts). Risk scores for embolism, bleeding, and the quality of oral anticoagulation were evaluated. Combined and separate events of embolism, bleeding, and cardiac death were monitored during clinical follow-up for at least 12 months. Statistical analysis included Student's t-test, ANOVA, chi-square, or Fisher's test, and Kaplan-Meier survival curves. A p-value < 0.05 was considered the criterion for statistical significance. Results: Group 1 (n=58) had a younger average age (54.4 vs. 63.9 years), a lower proportion of men (24.1% vs. 71.2%), a higher ejection fraction (59.6% vs. 44.5%), and a larger left atrium size (56.9 vs. 50.5 mm), all with p < 0.0001. There was no difference in AF presentation. In group 2, the glomerular filtration rate (67.7 vs. 88.6 min/kg/1.73m²) was lower (p<0.0001). Bleeding scores were higher in group 2. Hemoglobin, hematocrit, and leukocyte levels were similar between groups; however, NLR (5.7 vs. 3.4, p=0.005) and RDW (16.2% vs. 14.2%, p<0.0001) were higher in group 2. NLR ≥ 3.5 was associated with lower event-free survival in group 2, with an odds ratio of 30.7, especially in the first 12 months, unlike RDW. There was no difference regarding sex, AF presentation, or bleeding scores. A higher incidence of events was observed in group 2 (78.8% vs. 34.5%, p<0.0001), although no significant difference was found in individual events such as bleeding, embolism, and cardiac death. Conclusions: NLR and RDW averages were higher in group 2, which also had older age, lower systolic and renal function, with no difference in sex and the proportion of pts with permanent AF. Bleeding scores were also higher in this group, with no difference in hemoglobin levels. NLR and RDW were higher in group 2, which had a higher event proportion, with an odds ratio of 30.7 for NLR.