Low-risk patients
Jean-Claude Tardif, MD, Montreal Heart Institute and Université de Montréal, was the invited discussant for the COP-AF presentation and congratulated the researchers on “a job well done.”
He made the point that the risk for perioperative AFib has decreased substantially with the greater use of thoracoscopic rather than open surgical approaches. The population of this trial was relatively young, with an average age of 68 years; the presence of concomitant CVD was low, at about 9%; by design, patients with previous AFib were excluded; and only about 20% of patients had surgery with an open approach.
“So that population of patients were probably at relatively low risk of atrial fibrillation, and sure enough, the incidence of perioperative AFib in that population at 7.5% was lower than the assumed rate in the statistical powering of the study at 9%,” Dr. Tardif noted.
The post-hoc analyses showed a “nominally significant effect on the composite of MINS and AFib; however, that combination is fairly difficult to justify given the different pathophysiology and clinical consequences of both outcomes,” he pointed out.
The incidence of postoperative MI as a secondary outcome was low, less than 1%, as was the incidence of postoperative stroke in that study, Dr. Tardif added. “Given the link between presence of blood in the pericardium as a trigger for AFib, it would be interesting to know the incidence of perioperative pericarditis in COP-AF.”
In conclusion, he said, “when trying to put these results into the bigger picture of colchicine in cardiovascular disease, I believe we need large, well-powered clinical trials to determine the value of colchicine to reduce the risk of AFib after cardiac surgery and after catheter ablation,” Dr. Tardif said.
“We all know that colchicine represents the first line of therapy for the treatment of acute and recurrent pericarditis, and finally, low-dose colchicine, at a lower dose than was used in COP-AF, 0.5 mg once daily, is the first anti-inflammatory agent approved by both U.S. FDA and Health Canada to reduce the risk of atherothombotic events in patients with ASCVD [atherosclerotic cardiovascular disease], I believe offering a new pillar of treatment for the prevention of ischemic events in such patients.”
Session co-moderator Franz Weidinger, MD, Landstrasse Clinic, Vienna, Austria, called the COP-AF results “very important” but also noted that they show “the challenge of doing well-powered randomized trials these days when we have patients so well treated for a wide array of cardiovascular disease.”
The study was supported by the Canadian Institutes of Health Research (CIHR); Accelerating Clinical Trials Consortium; Innovation Fund of the Alternative Funding Plan for the Academic Health Sciences Centres of Ontario; Population Health Research Institute; Hamilton Health Sciences; Division of Cardiology at McMaster University, Canada; Hanela Foundation, Switzerland; and General Research Fund, Research Grants Council, Hong Kong. Dr. Conen reports receiving research grants from CIHR, speaker fees from Servier outside the current study, and advisory board fees from Roche Diagnostics and Trimedics outside the current study.
A version of this article appeared on Medscape.com.