Why is this study important?

The Co-STAR trial addressed the efficacy of using colchicine for the prevention of new-onset atrial fibrillation and conduction disturbances requiring the implantation of a permanent pacemaker in patients undergoing transcatheter aortic valve implantation. The study was halted due to heightened stroke risk post-TAVR in the colchicine arm.   

Should I change my practice because of these findings?  

Based on this study, we expect the current practice to continue without changes.  

What question was the study supposed to answer?  

This study sought to determine whether using colchicine post-TAVR could lower the risk of the primary composite of new-onset atrial fibrillation or atrioventricular conduction disturbances requiring the implantation of a PPM at 30 days.  

What did the study show?  

The Co-STAR trial randomized 120 patients either to a colchicine (n=60; 61.7% male) or placebo group (n=60; 66.7% male) in a 1:1 ratio. The colchicine group received an initial dose of 1mg the day before TAVR and another dose on the day of the procedure, followed by a 0.5 mg daily dose for 12 days. The trial was terminated prematurely after the results found a statistically significant difference in stroke incidence between the colchicine and placebo groups, with the stroke rate difference reaching 8.2% (95% confidence interval [CI] 1.12 to 15.08, p=0.022) in favor of the placebo group. The colchicine group experienced a lower rate of prosthetic valve leaflet thickening and >50% reduced motion or thickening at 30 days compared to the placebo group (p=0.007). The primary endpoint of new-onset AF or new permanent pacemaker implantation at 30 days occurred in 10% of those treated with colchicine compared with 25% of those treated with placebo (P = 0.031). The rates of new-onset AF were 5.0% and 6.7% in the colchicine- and placebo-treated patients, respectively, while the rates of new permanent pacemaker implantation were 8.3% and 18.3%, respectively (both not statistically significant differences).    

How good was the approach/methodology? 

The incidence of strokes and PPM implant is elevated and maybe related to high-risk population. The investigators don’t believe the strokes were attributed to the anti-inflammatory medications. The reduction in conduction disturbances, new onset A.fib and leaflet thickening is intriguing and will need to be assessed in larger trials.