Inflammatory Indices Linked to Left Atrial Thrombus in Valvular Atrial Fibrillation

In patients with valvular atrial fibrillation (VAF), elevated inflammatory indices are associated with an increased risk for left atrial thrombus, according to the results of a comparative, cross-sectional analytical study published in the journal BMC Cardiovascular Disorders.

Recognizing that inflammation has been implicated in the progressive exacerbation of VAF and thrombogenesis, the researchers sought to examine the link between systemic inflammation, as measured by 6 different indices, and left atrial thrombus in patients with VAF. The 6 indices included the following:

• Neutrophil/lymphocyte ratio
• Monocyte/ lymphocyte ratio (MLR)
• White blood/mean platelet volume ratio
• Neutrophil/mean platelet volume ratio
• Systemic immune inflammation index
• Systemic inflammation response index

A total of 448 individuals with documented VAF who had received transesophageal echocardiography (TEE) at Henan Provincial People’s Hospital, located in Henan Province, China, between January 2015 and September 2022, were retrospectively evaluated. Of these patients, 434 participants were enrolled in the study. The mean patient age was 56.94±9.12 years. Overall, 36.2% of the participants were men.

TEE detected left atrial thrombus in 32.9% of the patients. Compared with individuals without left atrial thrombus, patients with left atrial thrombus were more likely to be men, they were more likely to have heart failure and diabetes, and they were more likely to have a larger left atrial diameter and higher C-reactive protein levels. All 6 inflammatory indices were significantly higher among patients with left atrial thrombus.

Based on correlation analysis, the 6 inflammatory indices were all positively correlated with C-reactive protein levels (P <.001). Neutrophil/lymphocyte ratio had the highest correlation coefficient (r =0.447) and white blood/mean platelet volume ratio had the lowest (r =0.277).

Per multivariate logistic analysis, the 6 inflammatory indices were independent predictors of left atrial thrombus, with MLR appearing to perform the best (odds ratio, 12.006; 95% CI, 3.404-42.347; P <.001) and having the highest area under the curve (0.639; 95% CI, 0.583-0.694; P <.001).

Several limitations of the study should be noted. Due to its retrospective design, the study is not specifically constructed to evaluate the endpoints reported. Prospective studies with larger sample sizes are thus needed to confirm the results of the present analysis. Although many factors, including smoking, alcohol, and mental stress, can generate chronic systemic inflammation, these data were not obtained in this study.

“Elevated inflammatory indices were associated with an increased risk for LAT [left atrial thrombus] in patients with VAF,” the study authors wrote. “Because these indices are extensively used and readily available in the clinical field, we propose that they could be used as cost-effective predictors for thromboembolic risk, which would benefit a large subset of patients with VAF in developing countries.”