Colchicine use and clinical outcomes in acute myocarditis: a retrospective cohort study

Background Acute myocarditis (AM) is an inflammatory disease of the myocardium associated with ventricular dysfunction, arrhythmia, and progression to cardiomyopathy. Current management remains supportive, and no targeted anti-inflammatory therapy has demonstrated proven benefit on cardiovascular outcomes outside specific histological subtypes. Colchicine is an inexpensive, widely available anti-inflammatory agent with an established role in pericarditis, yet real-world data on its association with clinical outcomes in confirmed AM remain limited. Methods Patients with cardiac magnetic resonance-confirmed AM were retrospectively included. The primary outcome was echocardiographic maintenance or recovery of LVEF to a follow-up of ≥50%. Secondary outcomes were all-cause mortality, absolute change in LVEF, and an absolute LVEF improvement of ≥10%. Results A total of 243 patients with AM were included in the study, with 63 receiving colchicine and 178 not. Colchicine-treated patients were significantly younger (median 29 vs. 39 years; p < 0.001) with a similar sex distribution, although clinical presentation differed between groups. Follow-up LVEF of ≥50%, evaluable in 93 patients, was more frequent in colchicine-treated patients (95% vs. 70%; p = 0.035) and persisted after adjustment for age and sex (OR 5.10, 95% CI 1.14–48.7; p = 0.03), with directionally consistent results in a propensity score-matched sensitivity analysis. All-cause mortality occurred in 1 of 63 colchicine-treated patients (1.6%) and 12 of 178 untreated patients (6.7%), with no significant difference after age and sex adjustment (OR 0.58, 95% CI 0.06–2.76; p = 0.53). Absolute change in LVEF and improvement ≥ 10% did not differ significantly between groups. Conclusions Colchicine use was associated with more frequent maintenance or recovery of left ventricular function, although these findings are exploratory in the context of the limitations of this study. Further prospective evidence will highlight the efficacy and scope of colchicine in patients with AM.