# The Neutrophil–Lymphocyte Ratio Is Associated with Cardiac Magnetic Resonance Imaging-Derived Myocardial Fibrosis

## TL;DR

This study finds that a blood test measuring neutrophil-lymphocyte ratio is linked to signs of heart tissue scarring seen on MRI scans.

## Contribution

The novel contribution is showing that a simple blood test (NLR) correlates with myocardial fibrosis detected via cardiac MRI.

## Key findings

- Higher NLR tertiles correlated with lower ejection fraction and increased right ventricular volume.
- NLR was significantly associated with prolonged myocardial T1 times and increased extracellular volume (ECV).
- CRP showed similar associations with T1 and ECV as NLR, but both explained only a modest portion of variation.

## Abstract

Background: Sub-clinical inflammation is considered a key mechanism in cardiovascular disease and myocardial remodeling. We therefore evaluated whether the neutrophil–lymphocyte ratio (NLR), a simple inflammatory marker derived from a routine full blood count, is associated with myocardial fibrosis. Methods: Consecutive patients from a cardiac magnetic resonance imaging (CMR) registry were included and stratified by the NLR tertile. The association of the NLR and the levels of C-reactive protein (CRP) with CMR-derived myocardial T1 time and the extracellular volume fraction (ECV) were assessed using linear regression analysis and compared using Z-scores. In addition, an association with outcome was tested utilizing the log-rank test. Results: 1152 patients (72.4 years, 53.1% male) constituted the final cohort. The median NLR was 3.11 [interquartile range (IQR): 2.145–4.67]. Tertiles were based on the cut-off values ≤ 2.5, >2.5 and <4.0, and ≥4.0. A higher NLR tertile was associated with lower biventricular ejection fraction, hypertrophy, and increased right ventricular volume. The myocardial native T1 time [tertile 1 vs. 3: 1010 ms (984–1038) vs. 1030 (1001–1059), p < 0.001] and ECV [tertile 1 vs. 3: 26.3% (24.2–28.6) vs. 28.1% (25.5–31.4), p < 0.001] also significantly differed between the NLR tertiles. The NLR’s and the CRP’s association with elevated myocardial T1 time and ECV were comparable; however, the proportion of variation in the target variables explained by either was generally low. Conclusions: In our CMR all-comer cohort, NLR and CRP were significantly associated with prolonged myocardial T1 times and increased ECV. However, only a modest variation observed in both parameters was explained by either variable.