The administration of colchicine in patients who underwent pulmonary vein isolation helps to prevent early recurrences of atrial fibrillation, research shows. The reduction in event recurrences appears to be mediated through a reduction in inflammation following the radiofrequency catheter-ablation procedure, with investigators showing significant reductions in inflammatory mediators such as interleukin-6 (IL-6) and C-reactive protein (CRP).
The idea of fighting inflammation after ablation treatment for atrial fibrillation is not new. One study also showed that the administration of corticosteroids following ablation reduced immediate atrial fibrillation by 77%. However, corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs) are not recommended for prolonged use due to unwanted adverse effects. Colchicine, on the other hand—a low-cost medicine that has been around for long time—possesses a unique combination of features: anti-inflammatory action, antiproliferative action, and no adverse effects on the cardiovascular system.
Given the potent anti-inflammatory action of colchicine and that it can be administered without serious cardiovascular adverse effects for a relatively prolonged time period, the researchers assessed the safety and efficacy of the agent in the setting of atrial-fibrillation ablation.
In the study, published online October 3, 2012 in the Journal of the American College of Cardiology, the researchers randomized 81 patients with paroxysmal atrial fibrillation to a three-month course of colchicine 0.5 mg twice daily and 80 patients to placebo.
After three months of treatment, atrial-fibrillation recurrence was observed in 33.5% of patients treated with placebo and in 16% of patients treated with colchicine (a 62% reduction). The number needed to treat to prevent one recurrence was 5.6. The mean recurrence-free time in the placebo-treated patients was 68.9 days, compared with 82.2 days in the colchicine-treated patients.
In addition to reducing the risk of atrial-fibrillation recurrence, colchicine significantly reduced CRP and IL-6 levels, compared to placebo.
Researchers state that a few more steps are needed before colchicine can be used regularly in clinical practice. While the dose and duration of treatment are not firmly established, they warn that because the primary rationale for catheter ablation of atrial fibrillation is to improve quality of life, physicians should not replace one problem, atrial fibrillation, with another, gastrointestinal upset caused by colchicine use.
Also long-term studies are needed to determine whether the reduction in short-term atrial-fibrillation recurrence translates into long-term success.
Source: Deftereos S, Giannopoulos G, Kossyvakis C, et al. Colchicine for prevention of early atrial fibrillation recurrence after pulmonary vein isolation. J Am Coll Cardiol 2012.