Once the radial sheaths are successfully inserted, eligible patients will be consecutively, sequentially, and randomly assigned in a 1:1 ratio and with a block size of 4 to either the Planned Single-dose group (0.75 mg/kg) or the Planned Staged-dose group (0.5 ± 0.25 mg/kg).~The first dose enoxaparin will be administered immediately after randomization. In the Planned Single-dose group, enoxaparin 0.75 mg/kg will be given to all patients before CAG irrespective of whether they will undergo subsequent PCI or not. In the Planned Staged-dose group, enoxaparin 0.5 mg/kg will be administered to all patients before CAG and additional 0.25 mg/kg will be given only to those who will undergo subsequent PCI immediately before PCI.~Trans-radial CAG will be performed immediately after the first dose enoxaparin is given. When the angiographic results are available, whether the patients will proceed to subsequent PCI or not will be at the discretion of the procedure operators, who are blinded to the assignment of enoxaparin dosing regimens. Patients who undergo CAG alone in each group will be defined as the High-dose (0.75 mg/kg) and the Standard-dose (0.5 mg/kg) groups, respectively; while, patients who undergo both CAG and subsequent PCI in each group will be defined as the Single-dose PCI (0.75 mg/kg) and the Staged-dose PCI (0.5 + 0.25 mg/kg) groups, respectively.~Anti-Xa levels will be assessed: 1) at 0 min (immediately before), 10 min and 90 min after the first dose enoxaparin is given (CAG-0 min, CAG-10 min, and CAG-90 min, respectively) in all patients; 2) at 0 min (immediately before) and 10 min after the beginning of PCI (PCI-0 min and PCI-10 min, respectively), and at the end of PCI (PCI-End) in patients undergoing PCI.~Target anticoagulation is defined as: 1) anti-Xa level of 0.5-1.8 IU/ml in patients in the High-dose and Standard-dose groups; 2) anti-Xa level of 0.5-1.2 IU/ml before PCI and anti-Xa level of 0.5-1.8 IU/ml from the beginning of PCI up to 90 min after the first dose enoxaparin is given in the Single-dose PCI and the Staged-dose PCI groups.~The information on cardiac ischemic and bleeding events will be collected 24 h after randomization.~The OPTIENOX-PCI study will assess the anticoagulation profile between: 1) the High-dose and the Standard-dose groups (0.75 mg/kg vs. 0.5 mg/kg); 2) the Staged-dose PCI and the Single-dose PCI groups (0.5+0.25 mg/kg vs. 0.75 mg/kg). The result of the present study will provide pharmacodynamical data for the design of future outcome studies.
The OPTIENOX-PCI is a single-center, prospective, randomized, open-label, controlled study, which is designed to assess the anticoagulation profile of: 1) High-dose (0.75 mg/kg) vs. Standard-dose (0.5 mg/kg) enoxaparin; 2) Staged-dose (0.5+0.25 mg/kg) vs. Single-dose (0.75 mg/kg) enoxaparin in about 376 patients who plan to undergo elective trans-radial coronary angiography (CAG) with or without subsequent percutaneous coronary intervention (PCI).