Does Cardioplegia Type Affect Outcome and Survival in Patients With Advanced Left Ventricular Dysfunction? Results From the CABG Patch Trial - CABG Patch Cardioplegia Substudy

Description:

Does Cardioplegia Type Affect Outcome and Survival in Patients With Advanced Left Ventricular Dysfunction? Results From the CABG Patch Trial.

Hypothesis:

Comparison of cardioplegic solution, temperature and route of administration to identify techniques that provide cardioplegic protection in high-risk patients enrolled in the CABG Patch Trial (studying prophylactic implantable cardioverter defibrillators in patients undergoing coronary artery bypass surgery having an ejection fraction of <36% and positive signal average electrocardiogram).

Study Design

Study Design:

Drug/Procedures Used:

All patients randomized into the trial were compared with respect to the use of blood and crystalloid cardioplegia. In addition, blood cardioplegic temperature and route, obtained through a questionnaire sent to surgeons, were also compared.

Principal Findings:

Operative deaths (2% vs. 0.3%, p = 0.02), postoperative myocardial infarctions (10% vs. 2%, p < 0.001), shock (13% vs. 7%, p = 0.013) and postoperative conduction defects (21.6% vs. 12.4%, p = 0.001) were significantly more common in patients receiving crystalloid than those receiving blood cardioplegia. Patients receiving normothermic blood had less postoperative right ventricular dysfunction (10%) than did patients receiving cold blood (25%) or cold blood with warm reperfusion (30%) (p = 0.004), a finding confounded by the fact that 95% of patients in the normothermic group had cardioplegia administered by combined antegrade/retrograde routes. Finally, inotrope use (71% vs. 84%, p = 0.002), right ventricular dysfunction (23% vs. 41%, p = 0.001) and postoperative balloon pump use (12% vs. 19%, p = 0.02) were less frequent in the combined antegrade/retrograde cardioplegia than in those who received antegrade cardioplegia. Irrespective of the type, temperature and route of administration of the cardioplegic solution, there was no difference in early and late survival.

Blood and combined antegrade/retrograde cardioplegia are superior to crystalloid and antegrade cardioplegia alone for reducing postoperative morbidity.

Interpretation:

Although earlier studies have demonstrated that blood cardioplegia reduces the rates of perioperative myocardial infarction and creatine phosphokinase-MB release as compared to crystalloid cardioloplegia, these studies were limited to patients with near normal ejection fractions, a group with relatively low operative risk. Myocardial preservation techniques are more important in patients with coronary artery disease who have depressed ejection fraction. It is in this high-risk subset undergoing CABG that the current study supports the routine use of blood cardioplegia administered using combined route to decrease post-operative morbidity.

References:

1. Flack JE, Cook JR, May SJ, et al. Circulation 2000;103(suppl III):III84-9.

Clinical Topics: Arrhythmias and Clinical EP, Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Atherosclerotic Disease (CAD/PAD), Implantable Devices, SCD/Ventricular Arrhythmias, Cardiac Surgery and Arrhythmias, Cardiac Surgery and Heart Failure, Interventions and Coronary Artery Disease

Keywords: Coronary Artery Disease, Myocardial Infarction, Temperature, Cardioplegic Solutions, Creatine Kinase, MB Form, Electrocardiography, Isotonic Solutions, Coronary Artery Bypass, Ventricular Dysfunction, Left, Defibrillators, Implantable, Ventricular Dysfunction, Right, Heart Arrest, Induced


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