Colchicine for acute pericarditis. Results from the Investigation on Colchicine in Acute Pericarditis (ICAP). A prospective, randomized, double-blind, placebo-controlled, multicenter trial

Purpose: Despite a large amount of data on recurrent pericarditis, conclusive data are lacking to demonstrate the efficacy and safety of colchicine for the treatment of the first attack of acute pericarditis. The Investigation on Colchicine in Acute Pericarditis (ICAP) trial is a prospective, randomized, double-blind, placebo-controlled, multicenter trial aimed at the evaluation of the efficacy and safety of colchicine to treat acute pericarditis and prevent its recurrences. Methods: Eligible adult patients with acute pericarditis were randomly assigned to placebo or colchicine (0.5 mg twice daily for 3 months for patients>70kg or 0.5 mg once daily if ≤70kg) in addition to conventional anti-inflammatory therapy with aspirin or ibuprofen in a multicenter, double-blind, placebo-controlled trial. The primary study outcome was incessant/recurrent pericarditis within 18 months. Secondary outcomes were symptoms persistence at 72 hours, remission within 1 week, number of recurrences, time to first recurrence, disease-related hospitalization, cardiac tamponade, and constrictive pericarditis. Results: Of the 240 randomly assigned participants (mean age 52.1±16.9 years, 60% males), 65 patients (27.1%) reached the primary outcome: incessant/recurrent pericarditis within 18 months was 16.7% in the colchicine group and 37.5% in the placebo group (relative risk reduction 0.56 95% CI 0.30-0.72; number needed to treat-NNT 4). Colchicine reduced symptoms persistence at 72 hours (respectively, 19.2% vs. 40.0%; p=0.001), number of recurrences, hospitalizations (respectively, 5.0% vs. 14.2%; p=0.016), improved the remission rate at 1 week (respectively, 85.0% vs. 58.3%; p<0.001), and prolonged time to first recurrence. Corticosteroid use (OR 4.17, 95% CI 1.28 to 13.53; p=0.018), and C-reactive protein elevation at presentation (OR 3.15, 95% CI 1.05 to 9.49; p=0.041) were independent risk factors for recurrences in multivariable analysis. Overall adverse effect rates were similar in the study groups (respectively, 11.7% in the colchicine group and 10.0% in the placebo group; p=0.836) as well as withdrawal rates (respectively, 11.7% vs. 8.3%; p=0.519). No serious adverse effects were observed. Conclusions: The ICAP trial is the first multicenter, double-blind, randomized trial to show the efficacy and safety of colchicine as an adjunct to conventional anti-inflammatory therapy to halve incessant/recurrent pericarditis within 18 months, reduce the number of recurrences, and prolong the time to subsequent recurrence after a first episode of acute pericarditis. ClinicalTrials.gov [NCT00128453][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00128453&atom=%2Fehj%2F34%2Fsuppl_1%2F877.atom