BARCELONA, Spain - Saturday 30 August: The anti-inflammatory drug colchicine is not an effective treatment for cardiac patients who develop a condition called post-operative pericardial effusion (POPE) - a build-up of fluid around the heart, according to a new study.
The POPE-2 study, presented as a Hot Line today at the ESC Congress 2014, and published simultaneously in the European Heart Journal, is the second study that has failed to identify a medical treatment for POPE, a potentially serious condition that can lead to the life-threatening complication of cardiac tamponade.
"Colchicine neither reduced the volume of effusions or prevented the occurrence of cardiac tamponade," said study investigator Philippe Meurin, MD from Le centre de réadaptation cardiaque Les Grands Prés in Villeneuve Saint Denis, France.
"When you face a patient with a moderate to large post operative pericardial effusion, your attitude should be to not give him colchicine because the POPE-2 study shows it is useless, and not to give him non-steroidal anti-inflammatory drugs, because our earlier POPE-1 study showed that they are also useless."
Instead, Dr. Meurin recommends close monitoring of the patients with POPE for the first month when the risk of developing cardiac tamponade is about 10%. This should involve two echocardiograms per week and daily clinical follow up.
POPE-2 was a randomized, double-blind, placebo-controlled study conducted in 10 centers in France and including 197 consecutive patients with moderate to large POPEs (grade 2 or higher) between 7 and 30 days after cardiac surgery.
The mean age of subjects was about 64 years, and 86% were male.
Patients were randomly assigned to receive colchicine (n = 98) or a matching placebo (n = 99) for 14 days, with the main endpoint being change in pericardial effusion grade after treatment and a secondary endpoint of cardiac tamponade.
Colchicine was dosed according to patient weight, with patients weighing 70kg or more receiving a loading dose of 1 mg twice daily for the first day followed by a maintenance dose of 1 mg daily for 14 days. Patients weighing less than 70 kg received only 1 mg daily with no loading dose.
After 14 days of treatment the study found no difference between the placebo and treatment groups in terms of the mean decrease in POPE grade from baseline ( -1.1 vs. -1.3 respectively; p=0.23).
In total, there were 13 cases of cardiac tamponade, with 7 in the placebo group and 6 in the colchicine group (p = 0.80).
The study was underpowered to evaluate adverse clinical events, noted Dr. Meurin.
"POPE is a dangerous, yet asymptomatic condition for which there is still no known treatment," he concluded. "Colchicine has been shown to be effective in other pericardial conditions - both the treatment of pericarditis, as well as the prevention of post-pericardotomy syndrome - so it was reasonable to explore its utility in treating POPE. But in the POPE-2 study, in which we had to screen over 8,000 individuals to identify 197 cases, colchicine was no better than placebo at reducing the effusion and the risk of cardiac tamponade."
One possible explanation for colchicine's failure to reduce POPE could be that inflammation is not the predominant mechanism for most cases, he suggested.