Colchicine's beneficial in post AF ablation pericarditis? An elusive question in search of an answer

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice. Catheter ablation is now a well-established treatment for the prevention of AF recurrences in symptomatic patients. However, acute postablation pericarditis is one of the most common of complications post ablation (both radio and cryablation). In this regard, a good option could be colchicine, an oral therapeutic agent with broad anti-inflammatory effects.

Exploring the utility of this drug in this regard, the latest issue of JACC: Clinical Electrophysiology, has published 2 papers that interestingly report conflicting results and conclusions.

Study by Mohanty et al:

In the first paper, Mohanty et al studied 1,075 consecutive patients undergoing AF catheter ablation,

1. 607 of whom did not receive colchicine (group 1),

2. 213 received colchicine from 7 days before ablation to 1 month postablation (group 2),

3. 255 started colchicine on the day of the procedure and continued it for 1 month after the procedure (group 3).

In all patients, colchicine was administered at a dosage of 0.3 mg twice a day.

The authors found that colchicine, especially when given both pre- and postablation, significantly reduced the risk of acute pericarditis and the hospitalization rate in comparison with the group that did not receive colchicine (1.2% in group 2 vs 7.5% in group 3 and 17.5% in group 1).

Moreover, in patients with paroxysmal AF, colchicine also reduced the AF recurrence rate over the 1-year follow-up.

Interestingly, the incidence of gastrointestinal adverse effects such as diarrhea, nausea, and vomiting, was not significantly different between patients who received the drug and those who did not.

These results are interesting and strongly suggest that colchicine administered pre- and post-AF ablation is effective and safe in preventing acute postprocedural pericarditis.

PAPERS study:

In this study, Ahmed et al studied a total of 139 patients admitted to the hospital for AF ablation who were randomized to 2 groups:

1. 66 did not receive colchicine (group A),

2. 73 received colchicine at 0.6 mg twice a day for 7 days starting immediately after the procedure (group B).

The study was prematurely terminated as the incidence of acute postablation pericarditis was not significantly different between the 2 study groups (10.6% in group A vs 9.6% in group B).

Moreover, patients who took colchicine had a significantly higher incidence of gastrointestinal side effects than those who did not (47% vs 15%).

These results suggest not only that colchicine is ineffective as an empiric prophylactic treatment for the prevention of acute postablation pericarditis but also that it is associated with an increased risk of gastrointestinal side effects.

Why the opposite outcomes?

In an accompanying editorial, Antonio Raviele attempts to resolve the confusion by stating that “It is possible that the different timing and dosage of drug administration were responsible for the differences encountered.”

In fact, in the study by Mohanty et al, colchicine was administered for a period of at least 1 month and proved highly effective, especially when administration started before AF ablation.

By contrast, in the study by Ahmed et al, colchicine was given for a period of only 7 days after the ablation procedure and did not prove superior to the standard of care therapy.

Moreover, in the study by Mohanty et al, the dosage of colchicine was 0.3 mg twice a day, and, at this dosage, the drug was quite well tolerated.

However, in the study by Ahmed et al, it was twice as high (ie, 0.6 mg twice a day), and the drug was associated with an increased risk of gastrointestinal side effects.

How colchicine be useful in this setting?

Antonio adds, “it is likely that to be effective colchicine must be started in advance of ablation and continued for a sufficient period of time after the procedure, whereas a lower dose of colchicine should be chosen in order to avoid troublesome adverse events and maintain a good safety profile”.

In the meanwhile, the use of colchicine for the prevention of AF ablation-related pericarditis should be considered empirical and limited to patients who are theoretically at higher risk of this complication such as younger people; women; patients with obesity, anemia, autoimmune disease, or persistent AF; and those undergoing extensive or additional ablation lesions beyond pulmonary vein isolation.

Source: JACC CE:

1. DOI: 10.1016/j.jacep.2023.02.015

2. DOI: 10.1016/j.jacep.2023.01.037

3. DOI: 10.1016/j.jacep.2023.02.003