Suttorp 1991.

Methods	RCT, parallel design
Participants	Total number of randomized participants: 303 Inclusion criteria: people who had undergone CABG surgery without concomitant procedures (valve replacement, ventricular aneurysmectomy or others), in sinus rhythm Exclusion criteria: people with left ventricular ejection fraction < 40% or postoperative resting ventricular rate < 50 bpm; history of obstructive lung disease, recurrent or persistent ST during 1st 4 h after surgery, conduction disturbances, ventricular tachycardia or fibrillation immediately after surgery, postoperative intra‐aortic balloon pumping, inotropic support for ≥ 6 h, renal failure, potassium ion concentration not between 3.5 and 5.3 mmol/L, or contraindications to beta‐blockers Type of surgery: elective CABG Baseline characteristics Intervention group (sotalol) Age, mean (SD): 62 (± 8.4) years Gender, M/F: 121/29 NYHA, mean (SD): 2.9 (± 0.7) History of MI, n: 75 Preoperative use of beta‐blockers, n: 118 Control group (placebo) Age, mean (SD): 62 (± 9.5) years Gender, M/F: 113/37 NYHA, mean (SD): 2.9 (± 0.8) History of MI, n: 77 Preoperative use of beta‐blockers, n: 108 Country: Netherlands Setting: single centre; hospital
Interventions	Intervention group (sotalol) Randomized, n = unclear; losses = unclear (loss of 3 participants but study authors do not report to which group these participants belonged); analysed, n = 150 (ITT analysis not used) Details: sotalol 40 mg every 6 h, started within 4‐6 h after surgery, and continued for 6 days Control group (placebo) Randomized, n = unclear; losses = unclear (loss of 3 participants but study authors do not report to which group these participants belonged); analysed, n = 150 (ITT analysis not used) Details: placebo dose every 6 h same as the intervention group
Outcomes	Outcomes measured/reported by study authors: supraventricular tachyarrhythmias (to include AF, atrial tachycardia, SVT), mortality, MI (perioperative); adverse events requiring discontinuation of study medication (to include hypotension with bradycardia) Outcomes relevant to the review: AF, mortality, MI (perioperative); adverse events (to include hypotension with bradycardia)
Notes	Funding/declarations of interest: not reported Study dates: September 1989‐February 1990
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	Low risk	Randomized, double‐blind, placebo‐controlled trial
Blinding of outcome assessors (detection bias) All outcomes	Unclear risk	Not specified
Incomplete outcome data (attrition bias) All outcomes	Low risk	3 participants were excluded from analysis because of protocol violations (per‐protocol analysis); 303 participants enrolled. Few losses (< 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	Unclear risk	Quote: "In patients with persistent sinus tachycardia, trial medication was stopped and treatment with a beta‐blocking agent was begun". Comment: it is unclear from the study results whether any participants had persistent sinus tachycardia