Intra-aortic balloon pump for ST-elevation myocardial infarction necessitating urgent coronary artery bypass grafting, still a valid indication?

[...]the authors describe the imputation of missing data. [...]the reader cannot know how, and under what assumptions, the imputation was performed and cannot value the imputation step. [...]the authors describe that they used linear regression—which is normally used for continuous outcome variables—to estimate associations with the binary outcome variable (i.e. 30-day mortality).