Association of neutrophil-to-lymphocyte ratio and monocyte-tolymphocyte ratio with all-cause mortality in patients with ischemia and non-obstructive coronary arteries

Background Ischemia with non-obstructive coronary arteries (INOCA) is a frequent coronary syndrome with important impact on morbimortality. Systemic inflammation, a key pathophysiological mechanism in its development, is reflected in diverse bio-markers, such as the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR) and platelet-to-lymphocyte ratio (PLR). In this retrospective observational study, we aimed to assess the value of NLR, MLR and PLR as predictors of all-cause long-term mortality in INOCA patients. Methods Acute/ chronic consecutive INOCA patients hospitalized from January 2014 to December 2019 were included, after excluding pulmonary hypertension, acute non-cardiac pathology, and in-hospital mortality. The primary endpoint was all-cause mortality. Results Our cohort included 238 INOCA patients (62.2% female, mean age 64.1±9.5 years). Of all patients, 14.3% reached the endpoint during the mean 5.8±1.1 years of follow-up. Age (OR=1.10, p <0.001), diabetes mellitus (OR 2.54, p =0.01), heart failure (OR=3.73, p =0.003), atrial fibrillation (OR=3.52, p =0.001), severe valve disease (OR=3.99, p =0.001), NT-proBNP (OR=3.28, p <0.001), 3rd tertile NLR (OR=4.33, p <0.001) and 3rd tertile MLR (OR=4.34, p <0.001) were mortality predictors, while the 3rd tertile PLR was not. In multivariable analysis the baseline prediction model included age (HR=1.12, p <0.001) and heart failure (HR=3.78, p <0.001). Adding NLR>2.99 (HR=4.58, p <0.001), MLR>0.36 (HR=4.74, p <0.001), or both increased the power of the predictive model from chi-square 33.00 to 51.08 ( p <0.001). Conclusions In patients with acute or chronic INOCA, NLR and MLR were independently correlated with all-cause mortality. The most accurate mortality prediction model included NLR>2.99, MLR>0.36, age and the diagnosis of heart failure.