Relationship between inflammation and atrial fibrillation in patients with isolated rheumatic mitral stenosis.

BACKGROUND AND AIM OF THE STUDY: Atrial fibrillation (AF) is the most common arrhythmia in patients with rheumatic mitral stenosis (MS), with an increased risk of mortality and morbidity. Although recent data have suggested that the inflammatory process is associated with non-valvular AF, the relationship between inflammation and AF occurrence in MS patients remains unknown. The study aim was to determine whether plasma levels of high-sensitivity C-reactive protein (hs-CRP), as a marker of inflammation, are elevated in patients with isolated rheumatic MS and AF compared to patients with MS but without AF.

METHODS: The study population comprised 89 patients with isolated rheumatic MS (57 patients in sinus rhythm and 32 in AF) and 35 healthy controls. Patients with MS were categorized into subgroups in terms of their mitral valve area (MVA). Mean transmitral diastolic gradients and pulmonary artery pressure were monitored, and morphologic features of the mitral valve classified using an echocardiographic scoring system. Plasma levels of hs-CRP were monitored in all patients and control subjects, using a commercially available analytical kit.

RESULTS: Patients with AF were shown to have significantly higher plasma levels of hs-CRP compared to those in sinus rhythm and controls (p < 0.001). In general, patients with AF were older (p < 0.001) and had a larger left atrial diameter (LAD) (p < 0.001). Plasma levels of hs-CRP were associated with LAD only in the AF group (rho = 0.437; p = 0.012). Multivariate logistic regression analysis revealed a significant independent relationship between AF and hs-CRP plasma level (odds ratio (OR) 3.57; 95% confidence interval (CI) 1.2-10.5; p = 0.021), age (OR 1.08; 95% CI 1.03-1.14; p = 0.003), and LAD (OR 1.2; 95% CI 1.02-1.4; p = 0.023).

CONCLUSION: The study results indicated that hs-CRP plasma levels are associated with the presence of AF in patients with MS. This finding may have important implications for the development of new therapeutic and preventive approaches of AF in the setting of MS.