DIAMOND 2001.

Methods	RCT Double‐blind Loss to follow‐up reported: yes
Participants	Persistent AF (mean duration: NS) in people with heart failure or recent myocardial infarction and reduced LVEF. n = 506 Men: 77% Age (mean): 72 (range 36–92) years Structural heart disease: 100%. LAD: NS. LVEF: NS, all < 35%
Interventions	Dofetilide 500 µg/day vs placebo Method of AF cardioversion: spontaneous or pharmacological 63%, electrical 37% Warfarin discretionary
Outcomes	At 12 and 24 months: Mortality Proarrhythmia Heart failure AF recurrence
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random sequence.
Allocation concealment (selection bias)	Low risk	Allocation by a central office after inclusion.
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blind study using matching placebo.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No participant was lost to follow‐up.
Selective reporting (reporting bias)	Low risk	All outcomes prespecified and all expected outcomes of interest were well reported. Members of an events committee reviewed available data on a blinded basis and classified deaths.
Other bias	Unclear risk	Substudy from the 2 DIAMOND RCTs which were not stratified by rhythm.