 Actually, randomized controlled trials RCTs have failed to demonstrate a significant mortality benefit for OPCAB13. However, the available RCTs were underpowered to detect significant differences between the groups and suffered from high selection and exclusion biases. Even more important is the fact that the available RCTs so far have primarily focused only on low-risk ROOBY, CORONARY, elevated-risk GOPCABE or high-risk patients BBS, but not on frail patients in whom the benefits of OPCAB should be well defined. Moreover, the conversion rates 12.4 in ROOBY, 7.9 in CORONARY, and 5 in GOPCABE may suggest that some of the participating surgeons were inexperienced because expert centers report conversion rates between 2 and 414, which significantly affects long-term outcomes. 