The neutrophil–lymphocyte ratio (NLR) is a readily available inflammatory biomarker that may associate with atherosclerosis and predict cardiovascular (CV) events. The aims of this study are to determine whether the NLR predicts incident major adverse cardiovascular events (MACE) and is modified by anti-inflammatory therapy.

Baseline and on-treatment NLRs were calculated from complete blood counts among 60 087 participants randomized in the CANTOS, JUPITER, SPIRE-1, SPIRE-2, and CIRT trials to receive placebo or canakinumab, rosuvastatin, bococizumab, or methotrexate, respectively, and followed up for MACE. All analyses were performed first in CANTOS, and then externally validated in the other four trials. For the five trials, hazard ratios for major CV events and mortality comparing NLR quartiles were computed using Cox proportional hazards models, and the effect of each randomized intervention on the NLR was evaluated in comparison to placebo. The NLR modestly correlated with interleukin-6, C-reactive protein, and fibrinogen levels but minimally with lipids. In all five randomized trials, baseline NLR predicted incident CV events and death; the per-quartile increase in risk of MACE was 20% in CANTOS [95% confidence interval (CI) 14–25%, P < 0.0001], 31% in SPIRE-1 (95% CI 14–49%, P = 0.00007), 27% in SPIRE-2 (95% CI 12–43%, P = 0.0002), 9% in CIRT (95% CI 0.2–20%, P = 0.045), and 11% in JUPITER (95% CI 1–22%, P = 0.03). While lipid-lowering agents had no significant impact on the NLR, anti-inflammatory therapy with canakinumab lowered the NLR (P < 0.0001).

The NLR, an easily obtained inflammatory biomarker, independently predicts CV risk and all-cause mortality, and is reduced by interleukin-1β blockade with canakinumab.