Lucia Trotta, F. Agozzino, Silvia Berra, Ruggiero Mascolo, Francesco Rubuano, O. B. Blagova, George Lazaros, Elisa Ceriani, Massimo Pancrazi, Angela Mauro, Emilia Lazarou, Nicola Marotta, Francesca Casarin, Ludovico Luca Sicignano, Massimo Imazio, Antonio Brucato
AIM: To assess the effect of hydroxychloroquine (HCQ) in recurrent pericarditis (RP). METHODS: International longitudinal observational study including 80 patients with idiopathic or post-cardiac injury RP, treated with HCQ for at least 6 months (April 2014-August 2025); 3 other patients stopped HCQ within 6 months for side-effects. Recurrences, hospitalizations, side effects and therapies were evaluated before and after HCQ. Patient and physician-reported effectiveness were recorded. RESULTS: Females were 57/80 (71 %); median age 51.5 years [IQR 43.8-62.8]. C-reactive protein (CRP) was >10mg/L in 52 (65 %) patients. The median follow-up after starting HCQ was 27.3 [11.7-47.8] months, and the daily dose was 400 mg in 52 patients (65 %) and 200 mg in 28 (35 %). Among the 62 patients treated with HCQ for at least 12 months, recurrences decreased in the 12 months following treatment (median 1 [0-2]) compared with the 12 months preceding it (median 2 [1-3])(p < 0.001), as well as hospitalizations (5 vs 32) (p < 0.001). HCQ was effective either in CRP positive or CRP negative subjects. Fifty-four patients (67.5 %) were on steroids when HCQ was started, but only 21 (26.3 %) continued them at the last follow-up (p < 0.001); the median daily dose of prednisone was reduced from 10.0 mg [7.5-17.5] to 5.0 [2.5-5.0] (p < 0.001). Regarding patients' opinions about HCQ effectiveness, 64 pts (80 %) judged it useful, 16 (20 %) neutral (8 stopped HCQ for lack of effectiveness); the physicians' opinions were similar (concordance rate 74 (93.7 %), k 0.777; p < 0.001). CONCLUSIONS: HCQ reduced recurrences, hospitalizations, and corticosteroid dose in RP, with no relevant side effects.