Discussion
In opposition to previous studies [This study is a post-hoc analysis of the RIC-STEMI study [A relation between MI and day-time variation was previously reported considering the higher incidence and larger dimensions of MI in the early morning [Our study points to the existence of a biorhythm for the cardioprotective effect of RIC since RIC was an independent predictor of the primary follow-up endpoint just in the afternoon group (HR = 0.098; 95% CI 0.012–0.785; Accordingly, our study revealed an important cardioprotective effect of RIC, namely in the afternoon period, suggesting that the afternoon period enhances the cardioprotection induced by RIC.The authors consider that is still unclear whether RIC, restricted to high-risk patients, is cardioprotective and future clinical investigation should take into consideration the previously pointed features.Therefore, larger studies are necessary to confirm these results and it would also be interesting to perform this sub-analysis in the studies previously published.