Dexmedetomidine and Myocardial Protection

Study Overview
=================
Brief Summary
-----------------
Dexmedetomidine, an alpha-2 agonist, is a sedative that is widely used in various clinical settings because, compared to benzodiazepines, it preserves respiratory function better and its duration of action is short. Recent experimental studies showed a possibility that dexmedetomidine may have an organoprotective effect from ischemic-reperfusion injury by reducing inflammatory response. Besides, dexmedetomidine is known to be related with attenuated sympathetic tone and improved microcirculation. Taken together, it is plausible that dexmedetomidine exerts cardioprotection in patients undergoing cardiac surgery with cardiopulmonary bypass and aortic cross-clamp. The aim of this trial is to test the effect of dexmedetomidine on postoperative cardiac troponin I measurements in patients undergoing cardiac surgery.

Official Title
-----------------
Cardioprotective Effect of Dexmedetomidine in Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass: a Randomized, Placebo-controlled Trial

Conditions
-----------------
Cardiac Surgery, Cardiopulmonary Bypass

Intervention / Treatment
-----------------
* Drug: Dexmedetomidine
* Drug: Control


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: cardiac surgery utilizing cardiopulmonary bypass and aortic cross-clamp Exclusion Criteria: Coronary artery bypass grafting Concomitant cryo-Maze procedure Myectomy Heart transplantation Concomitant major non-cardiac surgery Isolated complicated congenital heart surgery descending thoracic aorta surgery with partial cardiopulmonary bypass Emergency surgery Minimally invasive or robot-assisted surgery Estimated GFR <30 ml/min/1.73 m2 Documented end-stage renal disease Preoperative renal replacement therapy Preoperative history of percutaneous coronary intervention within 6 month before surgery Acute coronary syndrome within 4 weeks before surgery Preoperative mechanical circulatory support devices

Ages Eligible for Study
-----------------
Minimum Age: 19 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Control<br>Placebo group using normal saline infusion | Drug: Control<br>* During the same time window for dexmedetomidine, normal saline is infused at the same rate calculated for dexmedetomidine.<br>|
| Active Comparator: Dexmedetomidine<br>From anesthesia induction before the initiation of cardiopulmonary bypass, dexmedetomidine is infused intravenously at a rate of 0.5 mcg/kg/hr after a loading dose infusion of 0.75 mcg/kg for 10 mins. | Drug: Dexmedetomidine<br>* Anesthesia is induced using midazolam or etomidate, and sufentanil. A target-controlled infusion of propofol and remifentanil is used for anesthesia maintenance. From anesthesia induction before the initiation of cardiopulmonary bypass, dexmedetomidine is infused intravenously at a rate of 0.5 mcg/kg/hr after a loading dose infusion of 0.75 mcg/kg for 10 mins.<br>* Other names: Precedex;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cardiac troponin I | Area under the curve of cardiac troponin I measured at 0, 6, 24, 48, 72 hours after surgery | Three days after surgery |