Usefulness of neutrophil-to-lymphocyte ratio for predicting acute pericarditis outcomes

In daily practice, C-reactive protein (CRP) may be used to predict recurrence and treatment response in patients with acute pericarditis; however, the predictive role of CRP might be insufficient for clinical prediction in some patients. In this study, we aimed to investigate the relationship between neutrophil-to-lymphocyte ratio (NLR) and the composite endpoint of pericarditis recurrence and/or tamponade within 1 year in patients with acute pericarditis.

A total of 104 patients diagnosed with acute idiopathic pericarditis (mean age 42.8 ± 15.2 years, 55.8% male) were included in the study. Physical examination findings of these patients, electrocardiography, echocardiography, chest X-ray and laboratory findings were evaluated and analysed. During the 1-year follow-up, the composite of cardiac tamponade and/or pericarditis recurrence was investigated as the primary endpoint of the study.

Compared to the group without the composite outcome, the group with the composite outcome had significantly higher rates of moderate and severe pericardial effusion (p < 0.01) and higher white blood cell (WBC) count (p:0.001), platelet count (p = 0.003), NLR (2.14 (1.49-3.02) vs 6.60 (5.50-8.68); p < 0.001) and high-sensitivity C-reactive protein (hs-CRP) (8.01 (5.1-24.5 vs 69.5 (40.8-128); p:0.001). Higher hs-CRP (p < 0.001), WBC (p:0.001), NLR (p < 0.001) and platelets (p:0.02) were associated with pericarditis recurrence. NLR and hs-CRP were independently associated with the composite endpoint (p < 0.001 and p < 0.001, respectively).

NLR and hs-CRP were found to be independent predictors for the composite endpoint of tamponade and/or recurrence in acute pericarditis patients during the 1-year follow-up. Similar to hs-CRP, NLR may also be used for risk assessment in patients with idiopathic pericarditis.