Platelet/lymphocyte ratio levels as a predictor for echocardiographic abnormalities in patients with systemic lupus erythematosus

Platelet/lymphocyte ratio (PLR) has recently been described as a predictor for adverse cardiovascular outcomes, such as heart failure and coronary artery disease. In systemic lupus erythematosus (SLE), PLR has been studied as a marker of disease activity. PLR has not been evaluated as a cardiovascular biomarker in SLE.

To compare the prevalence of echocardiographic abnormalities between normal and high PLR in patients with SLE.

Cross-sectional, retrospective, descriptive study. Women older than 18 years who met the ACR/EULAR 2019 classification criteria for the diagnosis of SLE. Patients with a history of cardiovascular disease, other connective tissue diseases, or pregnancy were excluded. The platelet/lymphocyte ratio (PLR) was calculated by dividing the platelet count by the lymphocyte count; a value >172.68 was considered a high PLR. Transthoracic echocardiography was performed by a certified cardiologist blinded to clinical information. Diastolic dysfunction was defined according to the following parameters: mitral flow E/A ratio, septal and lateral E/E' ratio, left atrial volume, and mitral valve deceleration time. The distribution between groups was assessed with the Kolmogorov-Smirnov test. Comparisons were made using the Chi-square test or Fisher's exact test and the Student T test or Mann-Whitney U test, as appropriate. A p-value>0.05 was considered statistically significant.

A total of 54 patients were included. The mean age was 35.1 ± 11.8 years. Disease activity measured by SLEDAI was similar between groups (8.0 vs 9.0, p=0.434) and disease duration was longer in patients with high PLR (116 months vs 60 months, p=0.023). The median PLR was 157.1 ± 91.2. There was no difference in indexed left ventricular mass or diastolic dysfunction patterns between patients with high PLR and SLE patients with normal PLR. Complete results are shown in Table 2.

The prevalence of echocardiographic abnormalities is not higher in those with high PLR compared with those with normal PLR in patients with SLE. Prospective studies with serial measurements of PLR are needed to evaluate its prognostic utility in cardiovascular outcomes in patients with SLE.