Clinical, demographic, and phenotypic characteristics and management of patients with recurrent pericarditis in real-world practice. Results of the retrospective branch of the international RUDRA registry

Aim . To identify the clinical and demographic profile, disease course, and management of patients with recurrent pericarditis (RP) based on data from the retrospective branch of the RUDRA registry, and to analyze specific patient subgroups. Material and methods . RUDRA (ClinicalTrials.gov: NCT06517966) is an international, multicenter, non-interventional real-world practice registry organized by the Eurasian Association of Internal Medicine, involving 20 centers across 14 regions of the Russian Federation and the Republic of Kazakhstan. The retrospective cohort included men and women aged 18 years and older with a verified diagnosis of RP established within the previous 10 years. Patient enrollment was conducted from September 30, 2024, to July 31, 2025. Statistical data analysis was performed using IBM SPSS Statistics 25. Results. The retrospective branch of the RUDRA registry included 120 patients. Idiopathic recurrent pericarditis (IRP) was verified in 33,3% (n=40), while RP of established etiology was identified in 66,7% (n=80). The median age was 63,0 [50,0;73,0] years; 55,0% were female. Patients with IRP were characterized by a significantly larger volume of pericardial effusion (386 [200;600] vs 200 [100;500] ml; p=0,008), a higher frequency of pericardial strands, clots, and adhesions (40,0% vs 11,4%; p=0,002), as well as higher rates of hospitalization (43,8% vs 9,1%; p<0,001) and disability duration (41,5 [24,2;45,8] vs 0 [0;18,5] days; p=0,024). Regarding anti-inflammatory therapy for RP, colchicine was used in 35,3% of cases overall, being significantly more frequent in the IRP group (70,0% vs 17,1%; p<0,001). Systemic glucocorticoids were prescribed to 28,4% of patients. Interleukin-1 inhibitors were received by only 2,6% of patients. Conclusion . The retrospective branch of the RUDRA registry has provided the first systematized data on real-world clinical practice in the management of patients with RP in the Russian Federation and the Republic of Kazakhstan. IRP was characterized by a more severe clinical course, a higher social burden, and predominantly medication-induced remission. A significant gap between clinical guidelines and real-world practice was identified, specifically regarding the insufficient use of colchicine in RP of known etiology and the critically low availability of interleukin-1 inhibitors.