CvLPRIT 2015.

Methods	RCT multi‐centre. Randomisation ratio: 1:1. Number of study centres: 7 centres in the UK.
Participants	Inclusion criteria: suspected or confirmed acute MI, significant ST elevation or LBBB on ECG (in cases of LBBB, angiographic confirmation of culprit coronary occlusion was required), < 12 hours of symptom onset, scheduled for P‐PCI for clinical reasons, provision of verbal assent followed by written informed consent, MVD, the non‐culprit vessel had to be a major (> 2 mm) epicardial coronary artery or branch (> 2 mm) and be suitable for stent implantation. Exclusion criteria: any exclusion criteria for P‐PCI; aged < 18 years; clear indication for, or contraindication to, multi‐vessel P‐PCI according to operator judgement; previous Q‐wave MI; people with prior CABG, cardiogenic shock, ventricular septal defect, or moderate/severe mitral regurgitation; chronic kidney disease (Cr > 200 μmol/L or eGFR < 30 mL/minute/1.73 m2); suspected or confirmed thrombosis of a previously stented artery; where the only significant non‐IRA lesion is a chronic total occlusion. Diagnostic criteria MVD: culprit vessel plus at least 1 non‐culprit coronary artery with at least 1 lesion deemed angiographically significant. Significant stenosis: > 70% diameter stenosis in 1e plane or > 50% in 2 planes. Sample size: complete revascularisation n = 150 and culprit‐only revascularisation n = 146.
Interventions	Complete revascularisation: complete revascularisation at the same procedure, unless operator decided, for clinical reasons, that the procedure needed to be staged, in the cases of staged intervention, it was mandated that the non‐culprit lesions be treated during the index admission. Culprit‐only revascularisation: intervention on the culprit artery unless participant needed revascularisation based on ischaemic symptoms or significant ischaemia evidenced in imaging tests.
Outcomes	Primary: composite of all‐cause mortality, recurrent MI, heart failure, and ischaemia‐driven revascularisation within 12 months after index procedure. Secondary: cardiovascular death, individual components of the primary endpoint, stroke, major bleeding, and contrast‐induced nephropathy.
Notes	Protocol ID: ISRCTN70913605.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	An interactive voice‐response program was utilised to randomise participants.
Allocation concealment (selection bias)	Low risk	Randomisation was performed immediately after the angiography and before the intervention of the culprit artery via a centralised 24/7 telephone randomisation service.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Study was open label for the participants.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcomes adjudicator clinicians were blinded to the group allocation.
Incomplete outcome data (attrition bias) All outcomes	High risk	Similar dropout rate in both groups, 7.3% culprit‐only vs 5.5% complete revascularisation group; however, given the small number of events, the result may be affected by attrition bias.
Selective reporting (reporting bias)	Low risk	Study reported the primary outcomes indicated in the published protocol in www.isrctn.com ISRCTN70913605.
Other bias	Low risk	Study was funded by the national funding institution British Heart Foundation and Medical Research Council (MRC)/National Institutes of Health Research (NIHR) (UK) and the funding institution was not involved in the study other than economically.