Links
[1] https://www.ctsnet.org/jans/use-frailty-scoring-predict-early-physical-activity-levels-after-cardiac-surgery
[2] https://www.ctsnet.org/home/erobinson
[3] https://doi.org/10.1016/j.athoracsur.2020.06.029
[4] https://www.ctsnet.org/categories/cardiac
[5] https://www.ctsnet.org/taxonomy2018/cardiac