Recurrent pericardial effusion: An extra-articular manifestation of undiagnosed seropositive rheumatoid arthritis

Background: Rheumatoid arthritis (RA) is a multisystemic chronic inflammatory autoimmune disorder that predominantly affects peripheral joints in a symmetrical pattern. While extraarticular manifestations are rarely the first sign of undiagnosed RA, cardiovascular involvement can present as endocarditis, myocarditis, pericarditis, pericardial effusion (PE), valvular heart disease, amyloidosis, heart failure, and arrhythmia. Importantly, RA patients have a 50% higher risk of cardiovascular mortality compared to general population. Case Report: A 41-year- old Malay lady admitted to Sarawak Heart Centre in October 2023 with a 2-week history of reduced effort tolerance and bilateral lower limb swelling. Upon arrival, her vital signs were: BP: 123/78 mmHg, HR: 100/min, SPO2: 98% under room air. Chest X-ray showed cardiomegaly with normal sinus rhythm from ECG. Laboratory tests showed haemoglobin: 9.3 g/dL, total white cell: 8.13 x 109/L, platelet: 489 x 109/L, urea: 8.5 mmol/L, creatinine: 67 μmol/L, total bilirubin: 8.3 μmol/L, AST: 20 U/L, ALT: 10 U/L, albumin: 32 g/L, CRP: 573.8 mg/L. Echocardiography revealed global PE, largest at left ventricular posterior wall (LV-PW) measuring 2.7 cm with normal ejection fraction. 590 mL haemorrhagic fluids was aspirated from pericardiocentesis. Analysis of the PE showed an exudative picture. Investigations for tuberculosis and malignancy were negative. A CT scan of the thorax, abdomen and pelvis was normal. ANA, C3 and C4 were normal. She received 2-week course antibiotics and was started on colchicine 0.5mg once daily. 1 month later, she was admitted to Bintulu Hospital, Sarawak for acute decompensated heart failure. Troponin I: 0.06 ng/ml. Repeated echocardiography showed moderate global PE, largest measured 1.5cm at LV-PW. Serial blood and fungal cultures revealed no growth. It was noted that she had right wrist pain for the past 16 years, followed by a 1-month history of multiple joint pains. Examination showed arthritis of the bilateral wrists, right 2nd-4th proximal interphalangeal joints, right elbow, right shoulder and bilateral ankles. There were no rheumatoid nodules. X-rays showed erosive changes over the right wrist. Serum rheumatoid factor was positive. She was finally diagnosed with seropositive erosive rheumatoid arthritis with pericardial effusion as the extra-articular manifestation. She was treated with a short course of steroids and weekly methotrexate. Conclusion: Recurrent PE should prompt consideration of RA as a potential diagnosis once all infectious and non-infectious causes have been thoroughly investigated. A comprehensive evaluation based on detailed history-taking and physical examination can greatly influence treatment outcomes.