Liu 2009.

Study characteristics
Methods	Prospective, randomised study Run‐in period: not specified. Received 15 February 2009, received in revised form 17 May 2009, accepted 16 June 2009; available online 15 August 2009 Number of centres and locations: single‐centre. Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, PR China
Participants	Thirty participants with rheumatic heart valve disease receiving valve replacement surgery Exclusion criteria: participants with comorbidities of coronary heart disease and with hepatic, renal, or pulmonary disease were excluded. Participants having additional cardiac diseases, severe noncardiac diseases, hypertension, diabetes mellitus, congenital heart disease, or undergoing a repeat operation were also excluded.
Interventions	Intervention: adenosine 100 mg/kg/min over 10 minutes before application of the aortic cross‐clamp and antegrade 1 mmol/L ADO high‐potassium cold (12 °C) blood cardioplegia after clamp‐on (n = 15) Control: regular institutional high‐potassium ([K+] = 20 mol L1) cold (12 °C) blood cardioplegia (n = 15)
Outcomes	Myocardial recovery and inflammatory response, cTnI, CK‐MB, and inflammatory factors (IL‐6 and IL‐8) (obtained from serial venous blood samples after induction, 5 minutes after cross‐clamp of aorta, 10 minutes after clamp‐off, 1 hour after return to the ICU, and postoperatively 24 hours and 48 hours)
Notes	No clinical outcomes reported, besides death at 30 days
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation process not clearly described
Allocation concealment (selection bias)	Unclear risk	Allocation concealment was not clearly described.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "The cardiologists in the intensive care unit (ICU) were blinded to group allocation in this investigation." It is unclear whether participants were blinded to the intervention. One group of staff caring for participants in the postoperative period (the cardiologists in the ICU) were blinded to the intervention, but it is unclear whether theatre staff were. We cannot therefore make a firm judgement on the risk of bias for this domain.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	The authors state that the cardiologists in the ICU were blinded to group allocation. However, it is not clear from the paper whether they were involved in assessing the outcomes, which are heavily laboratory‐based tests.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants completed the trial and were included in the final analysis.
Selective reporting (reporting bias)	Low risk	It was not possible to access a prospectively registered trial record. However, all the outcomes clearly specified in the methods were reported in the results.
Other bias	Low risk	No clear evidence of funding bias