Nyström 1993.

Methods	RCT, parallel design
Participants	Total number of randomized participants: 101 Inclusion criteria: scheduled for CABG surgery because of severe angina pectoris Exclusion criteria: repeat CABG surgery, if preoperative rhythm was not sinus, or if HR < 45 bpm, known intolerance to beta‐blocking agents, significant pulmonary disease or uncompensated heart failure Type of surgery: elective CABG Baseline characteristics Intervention group (sotalol) Age, mean (range): 59 (33‐75) years Gender, M/F: 45/5 History of MI, mean (SD): 1 (± 1.3) Ejection fraction, mean (SD): 0.6 (± 0.1) Preoperative use of beta‐blockers, n: 42 Control group (standard care) Age, mean (range): 60 (43‐71) years Gender, M/F: 43/8 History of MI, mean (SD): 1 (± 0.9) Ejection fraction, mean (SD): 0.6 (± 0.2) Preoperative use of beta‐blockers, n: 40 Country: Sweden Setting: single centre; hospital
Interventions	Intervention group (sotalol) Randomized, n = 50; losses = 0; analysed, n = 50 (use of ITT analysis not reported) Details: 160 mg sotalol, orally, on morning of surgery, continued once participant was able to resume oral medication usually the morning of 1st postoperative day, then given 160 mg twice a day for 6 days Control group Randomized, n = 51; losses = 0; analysed, n = 51 Details: participants who were already on beta‐blocking treatment had dose of beta‐blocker changed to half dose immediately after operation
Outcomes	Outcomes measured/reported by study authors: AF, HR, bradycardia (not defined), hypotension (not defined), mortality, ventricular arrhythmias Outcomes relevant to the review: AF, mortality, ventricular arrhythmias, bradycardia and hypotension (see notes below)
Notes	Funding/declarations of interest: not reported Study dates: not reported Note: 11 participants in the sotalol group needed a reduction in dose due to bradycardia, and 2 participants needed a reduction in dose also due to hypotension. We did not include these data in analysis because we could not be certain whether these outcomes were recorded for the control group
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