Limitations
ischemia, death
ISCHEMIA
The present study is a post hoc analysis of SYNTAXES trial and may not have adequate statistical power. The main limitation is that RR was no longer recorded after 5 years, we cannot be confident that our findings are reflective of RR in its entirety up to 10 years. Second, the number of patients who underwent RR was limited, especially for those who had repeat CABG or both procedures. Our analysis may lead to the likelihood of spurious findings, all results should be considered exploratory and hypothesis generating. Third, angiographic follow-up was not routinely performed in SYNTAX trial and may underestimate the true rate of RR, especially in patients with silent ischemia. Moreover, not all confounders may have been identified in our multivariable Cox model which assessed the association between RR and all-cause death. Furthermore, the endpoint in SYNTAXES study was all-cause death only; however, death has been considered the most robust and unbiased index for clinical assessment, and is less likely to be affected by ascertainment bias [