Liberal Versus Restrictive Use of Dobutamine in Cardiac Surgery

Study Overview
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Brief Summary
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Inotropic agents are usually administered in the postoperative period after cardiac surgery. In most cases, dobutamine is administered routinely, for the probable occurrence of myocardial dysfunction after cardiopulmonary bypass or a low cardiac output with minimal evidence of altered tissue perfusion. Recent data show that inotropic agents are used in 35-52% of cardiac surgeries in the perioperative period. However, the use of inotropic agents may be associated with adverse events, including myocardial ischemia, by elevation in myocardial oxygen consumption and the imbalance between supply and consumption, and tachyarrhythmias (atrial fibrillation, sinus tachycardia, ventricular tachyarrhythmias), primarily due to the β1-adrenergic effect. This study is a non-inferiority clinical randomized study aiming to compare the use of dobutamine in a liberal strategy (in all patients at the time of withdrawal of CPB) with a restrictive strategy (based on clinical and hemodynamic evidence of low cardiac output syndrome associated with altered tissue perfusion). Our primary hypothesis is that the restrictive use of dobutamine is as safe and effective as the liberal one.

Official Title
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Liberal Versus Restrictive Dobutamine in Cardiac Surgery (DOBUTACS): a Prospective Randomized Non-inferiority Clinical Trial

Conditions
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Coronary Disease, Cardiac Output, Low

Intervention / Treatment
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* Drug: Liberal dobutamine protocol
* Drug: Restrictive dobutamine protocol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoing cardiac surgery of coronary artery bypass graft (CABG) with cardiopulmonary bypass; Age equal or greater than 18 years; Written informed consent. Exclusion Criteria: Previous ventricular dysfunction (ejection fraction lower than 50%) Sustained supraventricular or ventricular arrhythmias; Cardiogenic shock or need for inotropes before surgery; Immediate need of ventricular assist device or intraaortic balloon after CPB; Combined procedure; Pregnancy; Participation in another study.

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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Liberal dobutamine group<br>All patients will receive dobutamine at the cardiopulmonary bypass weaning | Drug: Liberal dobutamine protocol<br>* All patients will receive dobutamine at the cardiopulmonary bypass weaning.<br>|
| Active Comparator: Restrictive dobutamine group<br>Patients will only receive dobutamine if they present clinical signs of cardiogenic shock | Drug: Restrictive dobutamine protocol<br>* Patients will receive dobutamine during the first 8 hours after cardiopulmonary bypass weaning only if they have a cardiac index of ≤ 2.5L/min/m2 and at least one sign of tissue hypoperfusion: ScvO2 ≤ 70% and / or urine output < 2 mL/Kg/h despite adequate fluid replacement.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Combined endpoint of arrhythmias (ventricular and supraventricular), acute myocardial infarction, stroke or transient ischemic attack, low-output syndrome, cardiogenic shock and death from all causes within 30 days after cardiac surgery |  | 30 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mortality rate | We will compare the mortality rate between groups within 30 days after randomization | 30 days | 
| Acute myocardial infarction incidence | We will compare the incidence of acute myocardial infarction between groups within 30 days after randomization | 30 days | 
| Stroke incidence | We will compare the incidence of stroke between groups within 30 days after randomization | 30 days | 
| Low cardiac output syndrome | We will compare the incidence of low cardiac output syndrome between groups within 30 days after randomization | 30 days | 
| Cardiogenic shock | We will compare the incidence of cardiogenic shock between groups within 30 days after randomization | 30 days | 
| Cardiac arrhythmias | We will compare the incidence of ventricular and supraventricular arrhythmias between groups within 30 days after randomization | 30 days | 
| ICU and hospital length of stay |  | 30 days | 
| Days free of mechanical ventilation | We will compare the number of days free of mechanical ventilation between groups within 30 days after randomization | 30 days | 
| Severe sepsis and septic shock | We will compare the incidence of severe sepsis and septic shock between groups within 30 days after randomization | 30 days | 
| SOFA score within 72 hours | We will compare the SOFA score between groups 72 hours after randomization | 72 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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cardiac surgery, dobutamine