Colchicine for pericarditis

We read with great interest the recent article by Eun and Smith,1 which provides a commendable review on the safety and efficacy of colchicine for treating acute and recurrent pericarditis. We would like to highlight yet additional important aspects about colchicine therapy and some areas that need further investigation. The data from recent randomized controlled trials have indeed strengthened our understanding and the existing evidence about the efficacy of colchicine in treating acute and recurrent pericarditis. Except for the COPPS trial, which specifically evaluated the efficacy of colchicine in postpericardiotomy syndrome,2 the majority (close to 80%) of the patients in other trials had idiopathic pericarditis, which is a low-risk subset of pericarditis with respect to long-term prognostic outcomes.3,4 The role of colchicine in other nonidiopathic forms of pericarditis remains underinvestigated. The CORP-2 trial was recently published5 and was not included in the analysis by Eun and Smith. A post hoc analysis on the subset of patients with nonidiopathic pericarditis in that study revealed a reduction of >10% in the frequency of recurrent pericarditis, but the frequency of recurrent pericarditis did not differ significantly between patients receiving colchicine (8 of 24 patients [33%]) and those treated with placebo (8 of 18 patients [44%]) (p = 0.68).3,4 Although this finding may indicate no benefit from using colchicine in nonidiopathic pericarditis, it should be considered cautiously since this particular study question was not pre-specified by the CORP-2 investigators and there were too few patients to draw definitive conclusions. Thus, a benefit of colchicine treatment in this subset of patients may reach significance in larger prospective studies.