Background: Although it has declined in developed countries, mitral valve stenosis is problematic in developing countries; its main cause is rheumatic fever. In patients with rheumatic mitral stenosis (RMS), ongoing chronic inflammation may resultin the progression of valvular damage and the formation of spontaneous echocardiographic contrast (SEC).

Aim: We investigated the role of the neutrophil/lymphocyte ratio (NLR) as an indicator of ongoing inflammation and independentpredictive risk factor for SEC in RMS patients.

Methods: A total of 112 patients (mean age 46 ± 10.6; 73.2% female) with RMS who underwent both transthoracic echocardiography and transoesophageal echocardiography were enrolled; the control group comprised 100 healthy volunteers (mean age 44 ± 9.1; 62% female). Patients were divided into two subgroups according to the formation of SEC in the left atrium and appendage. Haematological and biochemical indices were measured in all patients and controls.

Result: NLR was higher in the patients than controls (2.6 ± 1.15 vs. 1.71 ± 0.53, p < 0.001). In addition, it was higher in the SEC-positive group (mean age 47 ± 10.3; 68.4% female) compared to the SEC-negative group (mean age 44 ± 10.7; 78.2% female; 3.21 ± 1.25 vs. 1.97 ± 0.55, p < 0.001). In multivariate analysis, NLR (odds ratio [OR] 20.602, 95% confidence interval [CI] 4.678–90.731; p < 0.001) and left atrial diameter (OR 5.966, 95% CI 2.166–16.429; p = 0.01) were found tobe independent predictors of SEC in RMS patients.

Conclusions: RMS patients exhibit on-going inflammation; NLR is a good marker of this. The formation of SEC is associated with inflammation and NLR is an independent predictive risk factor for SEC.