Oka 1980.

Methods	RCT, parallel design
Participants	Total number of randomized participants: 54 Inclusion criteria: people with stable angina pectoris, scheduled for long‐term propranolol therapy Exclusion criteria: resting HR < 55 bpm; no additional criteria reported Type of surgery: elective CABG Baseline characteristics Intervention group (propranolol continuation) Age, mean (SD): 56 (± 2) years Gender, M/F: 11/8 History of MI, %: 26 History of hypertension, %: 32 Control group (withdrawal of existing propranolol 48 h preoperatively) Age, mean (SD): 56 (± 2) years Gender, M/F: 11/6 History of MI, %: 23 History of hypertension, %: 41 Control group (withdrawal of existing propranolol 10 h preoperatively) Age, mean (SD): 55 (± 2) years Gender, M/F: 12/6 History of MI, %: 28 History of hypertension, %: 28 Country: USA Setting: single centre; hospital
Interventions	Intervention group (propranolol) Randomized, n = 19; losses = 0; analysed, n = 19 Details: continued with existing dose until day of surgery, then half dose 2 h prior to surgery, and 1 mg IV given postoperatively every 4 h for 36 to 48 h Control group (withdrawal of existing propranolol 48 h preoperatively) Randomized, n = 17; losses = 0; analysed, n = 17 Details: continued with existing dose until 48 h before surgery, then treatment withdrawn Control group (withdrawal of existing propranolol 10 h preoperatively) Randomized, n = 18; losses = 0; analysed, n = 18 Details: continued with existing dose until 10 h before surgery, then treatment withdrawn
Outcomes	Outcomes measured/reported by study authors: haemodynamic variables; supraventricular arrhythmias, mortality, acute MI Outcomes relevant to the review: mortality, acute MI
Notes	Funding/declarations of interest: not reported Study dates: not reported Note: study included 2 control arms, which we combined in analysis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not specified
Allocation concealment (selection bias)	Unclear risk	Not specified
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open‐label trial
Blinding of outcome assessors (detection bias) All outcomes	High risk	Open‐label trial
Incomplete outcome data (attrition bias) All outcomes	Low risk	No apparent losses
Selective reporting (reporting bias)	Unclear risk	Study authors did not report prospective clinical trial registration or publication of a protocol. It was not feasible to effectively assess risk of reporting bias
Other bias	Low risk	Not detected