Overview
The purpose of this study is to find out whether it is safe and practical to perform MIDCAB surgery (a minimally invasive heart bypass procedure) while patients receive a continuous cangrelor infusion during the operation. Cangrelor is a medicine that helps prevent blood clots and works quickly through a vein drip.
The study compares patients receiving cangrelor during surgery to patients who had the same surgery in the past while on aspirin, with or without cangrelor given beforehand.
Study Question: Can MIDCAB surgery be safely performed under cangrelor infusion, without increasing the risk of bleeding or other complications?
Hypothesis: Using cangrelor during MIDCAB surgery is safe and feasible, and it provides effective protection against blood clots during the procedure.
This study will help doctors understand whether intraoperative cangrelor can improve patient safety and outcomes in minimally invasive heart surgery.
Description
Study Design Overview The MINOTAUR study is an open-label, single-center, case-control study assessing patients undergoing MIDCAB surgery under continuous cangrelor infusion at 0.75 μg/kg/min compared with historical controls who underwent the same procedure under aspirin therapy with or without prior cangrelor bridging. The study is exploratory and aims to evaluate safety, feasibility, and procedural aspects of intraoperative cangrelor use.
Prospective Arm: Study Intervention and Procedures
Cangrelor Administration: Prior oral antiplatelet therapies are discontinued. Cangrelor infusion is initiated based on daily platelet function testing (Multiplate®) to achieve adequate platelet inhibition before surgery.
Surgical Procedure: MIDCAB is performed ≥24 hours after cangrelor initiation, with intraoperative anticoagulation using unfractionated heparin monitored by activated clotting time.
Perioperative Monitoring: Includes daily assessment of platelet function, vital signs, ECG parameters, cardiac biomarkers (high-sensitivity troponin), and laboratory chemistry.
Data Collection: Procedural details, transfusion requirements, chest tube outputs, ICU stay, and other relevant perioperative variables are recorded in the study database.
Registry Procedures and Quality Assurance
Electronic Data Capture (EDC): All study data are entered into a secure, validated EDC system with role-based access control, audit trails, and SSL encryption. Retrospective alterations are logged in an audit table including time, user, and field changes.
Data Validation: The EDC system performs automated checks for completeness, range, and internal consistency. Central review and periodic cross-checks with source documents ensure data accuracy.
Source Data Verification: Selected data points are verified against medical records, electronic case report forms, operative reports, and lab results to ensure completeness and representativeness.
Data Dictionary: All variables are defined with source, coding standards (e.g., MedDRA, WHO Drug Dictionary), normal ranges, and units.
Standard Operating Procedures (SOPs): SOPs govern patient recruitment, data collection, data management, adverse event reporting, change management, and analytical procedures.
Audit and Monitoring: On-site monitoring is conducted according to a predefined plan, including verification of informed consent, study drug accountability, and completeness of data capture. Third-party auditing may be performed as required.
Sample Size Assessment: Approximately 30 prospective patients are targeted. No formal sample size calculation is required due to the exploratory nature; analyses are primarily descriptive.
Plan for Missing Data: Any missing, unavailable, or inconsistent data are flagged in the EDC and addressed according to predefined rules to avoid bias in analyses.
Safety Monitoring and Reporting
SAEs and ADRs: Only serious adverse events and adverse drug reactions are reported per local regulations; expected and anticipated events are predefined (e.g., bleeding, cardiac complications, acute kidney injury).
Follow-Up: Participants are monitored from inclusion through discharge. Ongoing SAEs are followed until resolution or stabilization.
Regulatory Reporting: Endpoint-related events are reported to the Ethics Committee/IRB and regulatory authorities according to timelines defined by local regulations (e.g., BASEC in Switzerland).
Statistical Analysis Plan
Continuous variables will be analyzed using t-tests or Mann-Whitney tests, depending on normality.
Categorical variables will be compared using Fisher's exact test. Analyses are exploratory and descriptive, comparing prospective cangrelor patients to historical controls.
No formal hypothesis testing is prespecified; data will inform future studies.
Data Handling and Archiving
Confidentiality: Patient data are stored securely, with restricted access. Archiving: The database, trial master file, and reports are retained electronically and in hard copy for ≥10 years.
Data Extraction: Interim and final analyses will use extracted datasets with full audit trail records.
Conclusion The MINOTAUR study is designed to provide technical and quality-controlled data on MIDCAB surgery under cangrelor infusion, with robust procedures for safety monitoring, data validation, and registry management. Findings will inform the feasibility and safety of perioperative intravenous P2Y12 inhibition for minimally invasive coronary bypass procedures.
Eligibility
Inclusion Criteria for the historical control arm:
- Age ≥18 years old
- CABG with IMA-LAD graft in MIDCAB technique
Inclusion criteria for the prospective arm:
- Age ≥18 years old
- CABG with IMA-LAD graft in MIDCAB technique
- Signed informed consent
Exclusion criteria for the historical control arm
- Administration of fibrinolytics or GP IIb/IIIa inhibitors
- Previous intracranial hemorrhage
- Known bleeding diathesis
- Patients undergoing concomitant PCI and MIDCAB
- Severe renal or liver disease
- Pregnancy or breast feeding
Exclusion criteria for the prospective arm
- Unconsciousness
- Known hypersensitivity to study drug (cangrelor)
- Recent administration of fibrinolytics or GP IIb/IIIa inhibitors
- Previous intracranial hemorrhage
- Known bleeding diathesis
- Patients undergoing concomitant PCI and MIDCAB
- Severe renal or liver disease
- Pregnancy or breast feeding


