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.
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.
Study Type
OBSERVATIONAL
Enrollment
30
Cangrelor-guided MIDCAB surgery: Patients undergo minimally invasive direct coronary artery bypass (MIDCAB) with continuous intravenous cangrelor infusion at 0.75 μg/kg per minute. Prior oral antiplatelet therapy is discontinued, and platelet function is monitored daily using Multiplate® testing. Cangrelor infusion is started when platelet aggregation reaches predefined thresholds and continued throughout surgery until it is safe to restart oral antiplatelet therapy.
Aspirin MIDCAB surgery: Historical control patients underwent MIDCAB under aspirin therapy, with or without prior bridging with cangrelor. Perioperative management follows standard care, including anticoagulation with unfractionated heparin during surgery and routine monitoring of laboratory and clinical outcomes.
Istituto Cardiocentro Ticino
Lugano, Ch/ti, Switzerland
RECRUITINGExcessive CABG-related bleeding during and after MIDCAB surgery
Excessive bleeding is defined as the occurrence of at least one of the following: (1) bleeding requiring surgical re-exploration, (2) 24-hour chest tube output greater than 1 liter, or (3) transfusion of more than 4 units of packed red blood cells. This measure assesses the safety of cangrelor-guided MIDCAB compared with historical aspirin-treated controls.
Time frame: From the start of surgery through 24 hours postoperatively
In-hospital MACCE
Occurrence of all-cause death, myocardial infarction, stroke, or urgent revascularization; each component assessed separately.
Time frame: From surgery through hospital discharge, an average of 8 days
Probable or Defined Stent Thrombosis
Incidence of stent thrombosis confirmed by angiography or clinical criteria (probable or definite).
Time frame: From surgery through hospital discharge, an average of 8 days
Cardiac Injury (High-Sensitivity Troponin)
Daily measurement of high-sensitivity troponin before and after MIDCAB to assess perioperative myocardial injury.
Time frame: Preoperative baseline until hospital discharge, an average of 10 days
Chest Tube Output
Volume of postoperative chest drainage measured at 6, 12, 24, and 48 hours after surgery.
Time frame: 6, 12, 24, and 48 hours postoperatively
Blood Transfusion Requirements and Nadir Hemoglobin
Number of packed red blood cell units transfused and lowest hemoglobin level recorded, corrected for transfusions.
Time frame: From surgery through hospital discharge, an average of 8 days
ICU Length of Stay and Mechanical Ventilation Duration
Duration of stay in intensive care and total hours of mechanical ventilation postoperatively.
Time frame: From ICU admission post-surgery to ICU discharge, an average of 12-24 hours
BARC-4 Bleeding and Universal Definition of Perioperative Bleeding
Bleeding severity assessed using BARC-4 criteria and the Universal Definition for Perioperative Bleeding (UDPB).
Time frame: From surgery through hospital discharge, an average of 8 days
Acute Kidney Injury and Renal Replacement Therapy
Incidence of acute kidney injury (creatinine increase ≥0.3 mg/dl or ≥1.5x baseline, or urine output \<0.5 ml/kg/h for ≥6h) and need for renal replacement therapy.
Time frame: From surgery through hospital discharge, an average of 8 days
Length of Hospital Stay
Total duration of hospitalization from surgery to discharge.
Time frame: From Surgery to hospital discharge, an average of 10 days
Platelet Function Under Cangrelor Infusion
Daily platelet function testing (Multiplate®) measuring ADP and arachidonic acid pathways during cangrelor infusion.
Time frame: From initiation of cangrelor infusion until hospital discharge, an average of 10 days
Vital Signs and 12-lead ECG Parameters
Monitoring of heart rate (HR, bpm), blood pressure (mmHg), and ECG parameters (PR, QRS, QTc in ms) during hospital stay.
Time frame: From surgery through hospital discharge, an average of 8 days
Standard Hematology and Blood Chemistry
Routine hematology assessments including complete blood count (CBC) parameters (e.g., hemoglobin \[g/dL\], hematocrit \[%\], white blood cell count \[×10⁹/L\], platelet count \[×10⁹/L\]). Routine blood chemistry assessments including electrolytes (e.g., sodium \[mmol/L\], potassium \[mmol/L\]), liver function tests (e.g., ALT \[U/L\], AST \[U/L\], bilirubin \[µmol/L\]), kidney function tests (e.g., creatinine \[µmol/L\], urea \[mmol/L\]), and other relevant chemistry parameters, each reported in their respective units of measure.
Time frame: Preoperative baseline through hospital discharge, an average of 10 days
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