Off pump CABG has been performed for the first time 40 years ago. Although conventional CABG is considered both safe and effective, the use of CBP is associated with several adverse effects. Improved survival and freedom from adverse cardiac events after CABG for patients with CAD have already been established.
Perioperative myocardial infarction is the most important postoperative complications after coronary bypass grafting. Biochemical markers (CK, CK-MB and troponin) are used for assessment of myocardial injury postoperatively. PMI can be diagnosed if there is ECG changes (new Q wave) or CK-MB elevation with CK/CK-MB ratio more than 0.1
Type of the study This is a prospective descriptive study including 60 patients undergoing coronary artery bypass grafting either on-pump or off-pump.
Sixty patients with coronary artery disease subjected to coronary artery bypass grafting either on pump or off pump with the following inclusion and exclusion criteria.
Inclusion criteria: Patients with coronary artery disease indicated for coronary artery bypass grafting operation for the first time either on-pump or off-pump
Exclusion criteria: Poor left ventricular function. Patients with deep intramyocardial coronaries. Patients require endarterectomy or vein patch. Patients who were planned to be off pump but it was changed to on pump intraoperatively. Redo coronary artery bypass graft. Emergency cases. Patients with other concomitant valve surgery
Group A 30 patients underwent coronary artery bypass grafting on beating heart. Group B 30 patients underwent coronary artery bypass grafting using CPB
Preoperative assessment Clinical assessment ECG Echocardiography Coronary angiography Carotid duplex for all patients over 60 Complete blood picture, liver function, kidney function tests.
Operative assessment Number, types of grafts and targets. The ratio between the numbers of the performed grafts over the number of the intended grafts, incomplete revascularization. The use of inotropic drugs, intra aortic balloon. Number of blood unit transfused. Duration of the operation
Postoperative assessment Every patient was subjected to: Clinical assessment for post operative morbidity. Mechanical ventilation with the assessment of the time of ventilation The use of inotropic drugs or intra-aortic balloon. Occurrence of arrhythmias. Amount of postoperative blood drainage
ECG for detection of perioperative myocardial infarction if occurred. Echocardiogram at the first day postoperative. Total blood unit transfused. Total ICU stay in hours. Total hospital stay in days
Laboratory assessment: ACT and coagulation profiles on arrival of the patient. CK-MB at 4h, 12h, 24h, 48h postoperatively. Cardiac troponin T at 4h, 12h, 24h, 48h postoperatively. Liver and kidney function tests every 24 h for 3 days postoperatively. Complete blood picture every 24 h.
Most of the cases were in the age group between 51-60 yrs old.
Mean operation time was longer in group B than A (219.8 ± 26vs.167.4±28.5min; P-value< 0.05). Number of grafts per patients was significantly higher in group B (2.7±.83) than group A (1.4±.73); P < 0.05.
Single-vessel grafting is significantly higher in the off-pump group, while three-vessel grafting is significantly higher in on-pump group.
On-pump group included more patients with ( OM, RCA and PDA) grafting.
Incomplete revascularization was higher in the off-pump group, but non- significant.
Patients on the On-pump group show a higher incidence(36.7%-46.7%0) respectively for blood and fresh frozen plasma transfusion intra-operatively (significant). The On-pump group shows a higher incidence of pulmonary and neurological complication, but non-significant. Non-significant difference was found between the two groups as regard to creatinine level post-operatively.
Non-significant difference was found between the two groups as regard to bilirubin level post-operatively. More patients in the On-pump group were re- explored for bleeding. Superficial and harvest site infection occurred less in the Off-pump group however, non- significant.
The on-pump group showed a higher duration of mechanical ventilation( statistically significant P < 0.05 ), otherwise patients in the off-pump group had less ICU and hospital stay but (non- significant).
Cardiac TnT concentrations were significantly higher in the on pump group than in the off pump group at hours 4, 12, 24, and 48.
The release of CK-MB was significantly higher in the on pump group however, it does not indicate MI.
There was no statistically significant difference between both groups as regard the occurrence of perioperative MI.
Perioperative effectiveness outcomes were similar for both OPCAB and on-pump with the exception of the number of grafts performed per patient, which was significantly lower during OPCAB No technique was found to be superior over the other for less incidence of occurrence of perioperative myocardial infarction
Surgeons must consider achieving complete revascularization on the beating heart with only minor alterations in hemodynamics. OPCAB should be used appropriately in indicated patients to achieve effective and safe revascularization