Repeated Amiodarone Dosing In Cardiac surgicaL Procedures

Study Overview
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Brief Summary
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This study is a single-center, prospective, randomized, open-label trial of subjects who develop atrial fibrillation after non-emergent cardiac surgery at the University of Kentucky Chandler Medical Center (UKCMC). Patients will be randomized to receive either a conventional amiodarone dosing regimen (CDR) or a repeated amiodarone bolus dosing regimen (RBDR).

Detailed Description
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This study will screen and consent approximately 150 patients undergoing non-emergent cardiac surgery. Approximately 60 of these patients are likely to develop stable postoperative atrial fibrillation (POAF) in the postoperative period. Amiodarone is commonly given as an initial intravenous (IV) bolus (150 mg IV) followed by a combined IV and oral load to a total dose of 8 gm. Because of amiodarone's beta-blocker activity, the IV bolus in patients with POAF is associated with a reduced heart rate that may lead to restoration of NSR. For this reason, some clinicians will provide up to 5 additional IV amiodarone boluses during the drug's loading period to treat RVR.

Official Title
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Repeated Amiodarone Dosing In Cardiac surgicaL Procedures

Conditions
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Atrial Fibrillation

Intervention / Treatment
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* Drug: AMIODARONE


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subject must be 18 years old or older Subject must be willing to give written informed consent Subject must undergo or scheduled for non-emergent cardiac surgery, including coronary artery bypass grafting (CABG), non-infectious valve repair or replacement, atrial or septal defect repair, thoracic aortic replacement surgery, or any combination of these procedures Exclusion Criteria: Documented allergy to amiodarone or iodine History of atrial fibrillation or other heart conduction system abnormality History of cardiac maze, pulmonary vein isolation, or other procedure affecting the conduction system Scheduled cardiac maze, pulmonary vein isolation, or other procedure affecting the conduction system Low cardiac index or cardiogenic shock requiring pharmacologic or mechanical support History of pre-existing respiratory system disease requiring oxygen therapy prior to admission History of cirrhosis or other chronic liver diseases Pregnancy or breastfeeding mothers Prisoner status

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Conventional amiodarone dosing regimen (CDR)<br>Initial amiodarone bolus of 150 mg IV over 10 minutes then a 24-hour amiodarone loading infusion (1 mg/min for 6 hours followed by 0.5 mg/min for 18 hours), followed by enteral (400 mg amiodarone oral or per tube three times daily or 2 times daily if the patient has gastrointestinal intolerance when taking the drug three times daily) or intravenous amiodarone (0.5 mg/min continuous infusion) to complete an 8-gm total amiodarone load. Maintenance amiodarone (200 mg amiodarone oral or per tube once daily) at discretion of attending physician. | Drug: AMIODARONE<br>* Assess the effectiveness of different dosing strategies of amiodarone.<br>|
| Active Comparator: Repeated amiodarone bolus dosing regimen (RBDR)<br>Initial amiodarone bolus of 150 mg IV over 10 minutes, then 1.0 mg/min IV amiodarone infusion for 6 hours, then a 0.5 mg/min IV amiodarone infusion for 18 hours, followed by enteral (400 mg amiodarone oral or per tube three times daily or 2 times daily if the patient has gastrointestinal intolerance when taking the drug three times daily) or intravenous amiodarone (0.5 mg/min continuous infusion) to complete an 8-gm total amiodarone load. In addition, patients in the RBDR will receive an additional 150 mg IV amiodarone bolus whenever the patient develops tachycardia (Heart Rate (HR) = 110 beats per minute) lasting more than 10 minutes. This bolus may be repeated up to a total of 5 times (6 total boluses) over the first 24 hours. Maintenance amiodarone (200 mg amiodarone oral or per tube once daily) at discretion of attending physician. | Drug: AMIODARONE<br>* Assess the effectiveness of different dosing strategies of amiodarone.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Normal Sinus Rhythm -24 HRS | Percentage of patients who develop stable POAF after non-emergent cardiac surgery, the percentage of patients who have converted to NSR at 24-hours after receiving a repeated amiodarone bolus and loading dose regimen to the percentage of patients who have converted to NSR after a conventional amiodarone IV loading dose regimen. | 24-hours after receiving amiodarone bolus | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total Target Heart Rate Time | Total time, in minutes, during the first 24 hours that the patient achieves target HR (HR < 110 bpm) between patients who receive a repeated amiodarone bolus dosing regimen and those who receive a conventional amiodarone bolus dosing regimen | 24-hours after receiving amiodarone bolus | 
| Time to Target Heart Rate | Time to achieve target HR (HR < 110 bpm) between patients who receive a repeated amiodarone bolus dosing regimen and those who receive a conventional amiodarone bolus dosing regimen | 24-hours after receiving amiodarone bolus | 
| Normal Sinus Rhythm -Hospital Index | Percentage of patients who achieve NSR by ICU discharge and hospital discharge between patients who receive a repeated amiodarone bolus dosing regimen and those who receive a conventional amiodarone bolus dosing regimen | duration of ICU and hospital visit, up to 20 days | 
| Recurrent AF | Percentage of patients who have recurrent AF before ICU discharge and before hospital discharge and patients who receive a repeated amiodarone bolus dosing regimen and those who receive a conventional amiodarone bolus dosing regimen | duration of ICU and hospital visit, up to 20 days |