Myhre 1984.

Methods	RCT, parallel design
Participants	Total number of randomized participants: 41 Inclusion criteria: undergoing CABG, with stable angina pectoris treated with beta‐blocking agents, normotensive and in sinus rhythm Exclusion criteria: not reported Type of surgery: elective CABG Baseline characteristics Intervention group (propranolol) Age, mean (SD): 53 (± 8.9) years Gender, M/F: 15/5 Ejection fraction, mean (SD), %: 67.4 (± 11.6) Control group (standard care) Age, mean (SD): 59 (± 8.5) years Gender, M/F: 17/3 Ejection fraction, mean (SD), %: 65.4 (± 16.1) Country: Norway Setting: single centre; hospital
Interventions	Intervention group (propranolol) Randomized, n = 21; losses = 5 (1 death ‐ see notes below; 2 did not receive propranolol; 1 due to reduced HR of < 70 bpm; 1 due to MI); analysed, n = 21 (for mortality), 16 (for other outcomes (ITT analysis not used) Details: beta‐blockers given as usual until morning of surgery, then 2 h before surgery a dose of approximately half was given, then 2 h after surgery beta‐blockers were continued with bolus injection of propranolol 1 mg per 6 h, IV. After 24 h, propanolol 20 mg, given orally, every 6 h for 7 days Control group (standard care) Randomized, n = 20; losses = 0; analysed, n = 20 Details: treatment was stopped 12 h before surgery, then restarted 2 h postoperatively
Outcomes	Outcomes measured/reported by study authors: supraventricular tachyarrhythmias, acute MI, mortality, hypotension Outcomes relevant to the review: acute MI, mortality
Notes	Funding/declarations of interest: not reported Study dates: not reported Notes: 1 participant in the intervention group died, and was excluded from study authors' analysis. An additional participant was then included. We have reported the number of randomized participants in the intervention group as 21, which includes the additional participant. We have used the lost participant in analysis of mortality in the review we did not re‐include lost participants due to reduced HR, or due to MI
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	1 participant died and was excluded from the analysis (we included this participant in analysis of mortality). An additional participant was added to the study after this loss. We used the total number of randomized participants as 41, rather than 40, to account for this. Loss was < 10%
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