Off-pump and On-Pump CABG have Comparable Survival with Potential Benefits in Myocardial Protection: Study

A recent observational analysis compared the choice of surgical techniques like off-pump (OPCABG) and on-pump (ONCABG) coronary artery bypass grafts and found that both OPCABG and ONCABG procedures are safe to perform and have a good prognosis as per the results published in the journal Annals of Medicine and Surgery.

Coronary artery bypass grafting (CABG) is the most common cardiac surgery procedure despite several percutaneous procedures. Due to their pros and cons, there has been long ambiguity on the efficiency of on-pump (ONCABG) and off-pump (OPCABG) CABG methods. OPCABG is complex requires a skilled surgeon and compromises the technical performance of the surgeon, while ONCABG requires a heart-lung machine. Hence, researchers from the University Hospital and the University of Turku, Finland conducted a study to determine which surgical technique affects prognosis in coronary artery bypass grafting (CABG).

They performed a single-center, retrospective observational study on all the off-pump (OPCABG) and on-pump (ONCABG) patients at Turku University Central Hospital. Patients who underwent concomitant valve surgery and re-operative CABG were excluded. The main outcome of measurement was the length of stay in the intensive care unit (ICU), need for resternotomy, perioperative mortality, and 1-year mortality.

Statistical analyses were performed with R 4.0.2 software. Numerical variables between ONCABG and OPCABG groups were compared using the Mann-Whitney U test. One-to-one propensity score matching was used to account for bias in patient selection.

Findings:

• Out of 217 CABG patients operated, 86 were OPCABG.
• The mean (SD) age of all patients was 68,3 (9,2) years and 15,7% were women.
• The perioperative, 1-year, and 3-year mortality did not differ between the groups after propensity score matching.
• The ONCABG patients received more allogenic red blood cells (1.3 vs. 0.6 units, p = 0.020), autologous red blood cells (564 vs. 285 ml, p < 0.001) and crystalloids (3388 vs. 2808 ml, p < 0.001), and had higher postoperative values of troponin T (581 vs. 222, p = 0.001) and lactate (1.69 vs. 1.23, p < 0.001) than the OPCABG patients.

Thus, the study concluded that surgical outcomes were equally good between the two groups at 1-year and 3-year follow-ups. Despite low-risk profiles and preoperative characteristics, the ONCABG patients received more often red blood cells and higher amounts of crystalloids and had higher postoperative TnT and lactate values. They also suggested that the OPCABG technique may be particularly suitable for frail patients due to milder myocardial damage and more balanced postoperative hemodynamics.

Further reading: Rantanen M, Yousif R, Kallioinen M, et al. Retrospective observational analysis of a coronary artery bypass grafting surgery patient cohort: Off-pump versus on-pump. Ann Med Surg (Lond). 2022;84:104812. Published 2022 Nov 9. doi:10.1016/j.amsu.2022.104812