A critical analysis of the noninferiority design of the TALENT trial

In recent years, regulatory approval of stents has been based on studies that have a noninferiority design, which has its own inherent complexities. We critically appraise in this article, the TALENT trial that established the noninferiority of the Indian-manufactured Supraflex stent (a third-generation, sirolimus-eluting stent with an ultrathin strut thickness) compared with the Xience stent (an internationally available, everolimus-eluting stent with a thicker strut) for a device-oriented composite end point at the end of 12 months. Our analysis shows that if the risk ratio rather than absolute risk difference was used to calculate the noninferiority margin, we would obtain a value of 1.48 for the risk ratio. Supraflex would then be noninferior to Xience by 0.92 [95% confidence interval (CI) = 0.59 to 1.47]. The upper bound of the 95% CI of 1.47 is dangerously close to 1.48, indicating that the TALENT trial would just about manage to prove noninferiority.