Walter 2002.

Methods	Prospective randomized controlled trial
Participants	Patients undergoing elective cardiopulmonary bypass surgery Mean age (years): 1. 64.8 ± 1.7 2. 61.9 ± 2.0 Sample size (male): 1. 22(17); 2. 21(16)
Interventions	1. oral 7.5 mg enalapril on the first day and oral 20 mg/d enalapril on the following days 2. placebo
Outcomes	All‐cause mortality; concentration of creatine kinase, MB form ; ST segment change or new Q wave in ECG test; hypotension
Notes	Participants in enalapril group were given 7.5 mg on the first day
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Random allocation, but no details available
Allocation concealment (selection bias)	Unclear risk	No relevant description, and no further details available
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double blind, but no details available
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No relevant description
Incomplete outcome data (attrition bias) All outcomes	Low risk	Information on dropouts specified
Selective reporting (reporting bias)	Unclear risk	Protocol inaccessible
Other bias	Low risk	No other source of bias found

ACEIs: angiotensin‐converting enzyme inhibitors
 ARBs: angiotensin II type 1 receptor blockers
 CABG: coronary artery bypass graft surgery
 ECG: electrocardiograph
 IV: intravenous
 ST: the ST segment in electrocardiography