Haïssaguerre 2004.

Methods	Randomised controlled trial
Participants	70 patients with drug‐refractory AF undergoing curative ablation were included. 35 patients were arranged to PV isolation group, and 30 to PV isolation plus mitral isthmus ablation group. Age: 53+/‐8 years in PVI group, and 53+/‐9 years in PVI + Mitral isthmus ablation group. % of male:26/35 ( 74.3%) in each group. Follow‐up: 12 months. Location: Bordeaux‐Pessac, France.
Interventions	PV isolation compared with PV isolation plus mitral isthmus ablation
Outcomes	Recurrence of AF, sinus rhythm
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient detail was provided.
Allocation concealment (selection bias)	Unclear risk	B‐Unclear. The authors did not depict allocation concealment method.
Blinding	High risk	Blinding was not reported.
Incomplete outcome data addressed	High risk	There were no patients withdrawn or lost to follow up.
Adequate sequence generation	Unclear risk	It was not addressed.