Matsuura 2001.

Methods	Quasi‐randomized trial, parallel design
Participants	Total number of randomized participants: 80 Inclusion criteria: scheduled for CABG surgery Exclusion criteria: history of AF or atrial flutter, contraindications to beta‐blockers (such as asthma; or concomitant valvular, anti‐arrhythmic, or aortic surgery), severe bradycardia, hypotension Type of surgery: elective CABG Baseline characteristics Intervention group (sotalol) Age, mean (SD): 62 (± 10) years Gender, M/F: 32/8 History of hypertension, %: 55 Ejection fraction, mean (SD), %: 56 (± 15) Preoperative use of beta‐blockers, %: 50 Control group (standard care) Age, mean (SD): 60 (± 9) Gender, M/F: 33/7 History of hypertension, %: 50 Ejection fraction, mean (SD), %: 55 (± 14) Preoperative use of beta‐blockers, %: 40 Country: Japan Setting: single centre; hospital
Interventions	Intervention group (sotalol) Randomized, n = 40; losses = 0; analysed, n = 40 Details: 80 mg/day, started on the 1st postoperative day and was continued for 2 weeks Control group (standard care) Randomized, n = 40; losses = 0; analysed, n = 40 Details: standard care
Outcomes	Outcomes measured/reported by study authors: haemodynamic variables, plasma creatinine concentrations, AF, length of stay, mortality, adverse events relating to discontinuation of intervention drug (to include bradycardia and hypotension) Outcomes relevant to the review: AF; length of stay; mortality; bradycardia and hypotension (see notes below)
Notes	Funding/declarations of interest: not reported Study dates: February 1999‐December 2000 Note: we did not include outcome data for bradycardia and hypotension because we were uncertain whether events were measured in the control group. Study authors reported discontinuation of sotalol due to bradycardia in 2 participants, and due to hypotension (and other conditions) in 1 participant
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quote: "Patients were randomised alternately" Comment: quasi‐randomization
Allocation concealment (selection bias)	High risk	See above
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