Outcomes Following Myocardial Revascularization: On and Off Cardiopulmonary Bypass

Study Overview
=================
Brief Summary
-----------------
Ischemic heart disease is one of the most frequent diagnoses in the VA system. Moreover, 5,819 coronary artery bypass graft (CABG-only) procedures were performed in the VA in Fiscal Year (FY) 1999. Throughout VA and non-VA cardiac surgery programs nationwide, myocardial revascularization is now being performed using two surgical techniques. One technique is performed with cardiopulmonary bypass (CPB) usually with cardioplegic arrest (on-pump) and the other without CPB on a beating heart (off-pump). The overall purpose of this proposed randomized, controlled, clinical trial is to rigorously evaluate the impact of using an on-pump versus off-pump surgical technique for coronary artery bypass graft (CABG-only) procedures (performed with a traditional median sternotomy incision) upon patient clinical outcomes and resource utilization.

Detailed Description
-----------------
Primary Hypotheses: The study has two primary hypotheses to evaluate the impact of using an off-pump versus an on-pump surgical technique for CABG procedures. One is a short term objective to assess the immediate impact of the two surgical techniques while the second assesses the long-term impact of the two techniques: 1) Short-Term Null Hypothesis: For patients having CABG-only procedures performed, there will be no difference in the short-term composite clinical outcome (30 day death or major morbidity) between patients randomized to the on-pump and off-pump procedures, 2) Long-Term Null Hypothesis: For patients undergoing CABG-only procedures, there will be no difference in long-term clinical outcome as measured by one year mortality and/or acute myocardial infarction prior to one year and/or a subsequent revascularization procedure within one year between patients randomized to the on-pump and off-pump procedures. Secondary Hypotheses: Major secondary objectives are to determine if there are differences in patients undergoing CABG-only procedures using the on-pump and off-pump techniques for 1) long-term completeness of revascularization, 2) one year graft patency and stenosis rates as determined by angiography at one year, and 3) short-term completeness of revascularization. Other secondary objectives are to evaluate the two surgical techniques on 1) changes in neuropsychological function, 2) traditional clinical outcomes, 3) general and disease specific quality of life, and 4) use of system resources. Intervention: Patients requiring an elective or urgent CABG-only (no other procedures to be done) surgical procedure will be randomized to either the off-pump procedure or to the on-pump procedure. Primary Outcomes: The short-term primary outcome measure is a composite measure of death, repeat cardiac surgery, new technical support, cardiac arrest, coma, prolonged stroke and/or renal failure requiring dialyses occurring within 30 days of surgery or prior to discharge, whichever is latest. The long-term primary outcome measure is a composite of death, acute myocardial infarction, and/or subsequent revascularization procedure prior to one year post-surgery. Study Abstract: Ischemic heart disease is one of the most frequent diagnoses in the VA system. Moreover, 5,819 coronary artery bypass graft (CABG-only) procedures were performed in the VA in FY 1999. Throughout VA and non-VA cardiac surgery programs nationwide, myocardial revascularization is now being performed using two surgical techniques. One technique is performed with cardiopulmonary bypass (CPB) usually with cardioplegic arrest (on-pump) and the other without CPB on a beating heart (off-pump). The overall purpose of this proposed randomized, controlled, clinical trial is to rigorously evaluate the impact of using an on-pump versus off-pump surgical technique for coronary artery bypass graft (CABG-only) procedures (performed with a traditional median sternotomy incision) upon patient clinical outcomes and resource utilization.

Official Title
-----------------
CSP #517 - Outcomes Following Myocardial Revascularization: On and Off Cardiopulmonary Bypass

Conditions
-----------------
Ischemic Heart Disease

Intervention / Treatment
-----------------
* Procedure: Coronary artery bypass - on-pump
* Procedure: Coronary artery bypass - off-pump


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Elective or Urgent CABG CABG only procedure to be performed Exclusion Criteria: Patient's surgeon is not a participant that meets study off-pup criteria Valve or Valve/CABG procedure Emergent, hemodynamically unstable, or in cardiogenic shock preoperatively Moderate, moderate, to severe, or severe valvular disease Enrolled in another therapeutic or interventional study Majority of diffusely diseased distal vessels Clinical Care Team has reservations History of on-compliance Patient preference for treatment arm Inability to provide informed consent
Sexes Eligible for Study
-----------------
All

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

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

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Arm 1<br>Coronary artery bypass - on-pump | Procedure: Coronary artery bypass - on-pump<br>* CABG procedure performed on heart lung machine<br>|
| Other: Arm 2<br>Coronary artery bypass - off-pump | Procedure: Coronary artery bypass - off-pump<br>* CABG procedure performed without the use of the heart lung machine<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Short-term End Point | Short-term end point was a composite of death or major complications (reoperation, new mechanical support, cardiac arrest, coma, stroke, or renal failure requiring dialysis) occuring within 30 days after surgery or before discharge, whichever was later. | 30 day | 
| Long-term Composite | Long-term composite endpoint was death from any cause within 1 year, nonfatal myocardial infarction between 30 days and 1 year, or repeat revascularization between 30 days and 1 year. | one-year |