Formica 2009.

Study characteristics
Methods	Prospective, randomised study Run‐in period: April 2007 to October 2007 Number of study centres and locations: Single centre. San Gerardo Hospital, Monza, Italy
Participants	Sixty consecutive patients were randomised to MECC (n = 30) or off‐pump coronary revascularisation (OPCABG, n = 30). Mean age: 65.6 years Sex (female/male ratio): 31.67% No high‐risk population Inclusion criteria: primary and isolated CABG operation, at least two‐vessel disease, EF ≥ 40%, 30 years to 85 years of age, serum Cr < 1.8 mg/100 mL, and absence of acute or chronic inflammatory syndrome Exclusion criteria: small, calcified, and intramyocardial coronaries; recent or current steroid treatments; urgent or salvage operation; recent MI (< 10 days); unstable angina with IV medications; and conversion of OPCABG to standard CPB during the operation
Interventions	Intervention group: MECC (the MECC is a Bioline fully heparin‐coated system that includes a centrifugal pump (Rotaflow RF‐32, Maquet‐Jostra AG, Hirrlingen, Germany) and a continuous diffusion polymethylpentene membrane oxygenator Quadrox D with an integrated heat exchanger (Maquet‐Jostra AG, Hirrlingen, Germany) Control group: off‐pump coronary revascularisation (in the OPCABG group, heparin was given at a dose of 1.5 mg/kg with an activated clotting time target of 250 seconds. The anastomosis between the left ITA and the left anterior descending artery was always performed first, and then the proximal anastomosis in the aortic root was performed with the HeartString II Proximal Seal System device [Maquet AG, Hirrlingen, Germany])
Outcomes	Clinical outcomes (postoperative bleeding, requirement of blood transfusions, and incidence of AF), inflammatory response (CRP, leucocyte and neutrophil, monocyte cell level, IL‐6, and TNF‐α at the end of operation, post 24 hours and 48 hours), blood lactate, haemodilution (Hct and Hb levels), coagulative disorder (fibrinogen and Plt count), and markers of myocardial damage (cTnT and CK‐MB and CK mass, myoglobin) Blood samples for myocardial damage, haemodilution, and coagulative disorder were serially collected the day before surgery (T0), at the end of operation (T1), 24 hours after operation (T2), and 48 hours after operation (T3). Blood lactate and cytokine levels were analysed before the anaesthesia induction (T0), before CPB initiation in the MECC group or before the first distal anastomosis in the OPCABG group (T1), 5 minutes after aortic clamp removal in the MECC group or 5 minutes after the last distal anastomosis in the OPCABG group (T2), at the end of operation (T3), 12 hours after operation (T4), and 24 hours after operation (T5).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	A randomisation list was generated by a computer algorithm. Preoperative characteristics did not differ between groups.
Allocation concealment (selection bias)	Unclear risk	All operations were performed by the same senior surgeon, but there was no information about how patients were placed in groups.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not specified
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not specified
Incomplete outcome data (attrition bias) All outcomes	Low risk	No participant was withdrawn from the study. One participant in the OPCABG group died of acute severe respiratory disease on the fifth POD. There was no ITT analysis, but there were accurate descriptions of group size and cause of the observed death.
Selective reporting (reporting bias)	Unclear risk	One of the outcomes (coagulative disorder) was not properly assessed as the others.
Other bias	Low risk	No funding was disclosed.