Riess 2007.

Methods	Randomised study
Participants	Patients (n = 20) with coronary artery disease requiring coronary artery bypass grafting with at least 2 bypass grafts. Mean age (± SD): 55.0 ± 0.6 in the lepirudin group and 59.0 ± 0.5 in the UFH group
Interventions	‐ Lepirudin (0.25 mg/kg intravenous bolus and 0.2 mg/kg added to cardiopulmonary bypass priming followed by additional 5 mg lepirudin boluses to maintain lepirudin concentrations above 4 µg/mL) monitored using the ecarin clotting time. During the first 2 days after operation, anticoagulation was performed with an intravenous and aPTT adjusted (target range: 45 to 60 seconds) lepirudin infusion (initial dosage 0.05 mg/kg). From the third postoperative day lepirudin was given subcutaneously until complete mobilisation ‐ UFH (400 IU/kg bolus prior to connection to the cardiopulmonary bypass followed by additional 5000 IU UFH boluses to maintain an activated clotting time above 400 seconds). After the end of the operation, UFH (4 IU/kg/h intravenous) starting 4 hours after surgery if the aPTT was below 45 seconds. UFH was increased to 8 IU/kg/h 24 hours later, and 48 hours after the operation UFH (7500 IU twice daily) was given subcutaneously until complete mobilisation
Outcomes	Blood clots within the cardiopulmonary bypass circuits, perioperative blood loss, haematologic values, blood chemistry, coagulation values
Notes	After the end of subcutaneous anticoagulation treatment, participants in both groups received acetylsalicylic acid (100 mg/day)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of random sequence generation not reported
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open study
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Open study, but blinding of outcome assessors not specifically addressed
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants enrolled were subsequently considered in the analysis
Selective reporting (reporting bias)	Low risk	Study not registered. No published protocol. All outcomes mentioned in the methods section were addressed in the results section
Other bias	Unclear risk	Participant characteristics and risk factors for VTE are not reported. It is not reported if all participants with clinically suspected DVT and/or PE were systematically verified by objective testing