Groundbreaking study challenges long-held beliefs on coronary artery bypass surgery

A recent study, carried out by clinicians at Royal Brompton and Harefield Hospitals, has determined that coronary artery bypass surgery undertaken without a heart-lung bypass machine is associated with better long-term survival rates for patients compared to the conventional technique of using a heart-lung bypass machine.

A coronary artery bypass graft (CABG) is a surgical procedure used to treat coronary heart disease.

It diverts blood around narrowed or clogged parts of the major arteries to improve blood flow and oxygen supply to the heart.

Currently, the standard method for CABG Surgery has involved the use of a special heart and lung bypass machine which takes over the work of the organs and means the oxygen-rich blood can continue to flow around the body while the heart itself is repaired by the surgical team. This is known as on-pump coronary artery bypass (ONCAB).

However, another technique is also possible known as off-pump coronary artery bypass (OPCAB), where the surgery is undertaken without using a heart-lung bypass machine, and the affected part of the heart is repaired as the rest of the heart continues to work as normal.

Last year, the team published a meta-analysis on 10-Year Mortality of Off-Pump Versus On-Pump Coronary Artery Bypass Grafting in the American Journal of Cardiology and addressed a longstanding debate in cardiac surgery, demonstrating that off-pump coronary artery bypass grafting (OPCAB) is not inferior to on-pump CABG (ONCAB) in terms of long-term outcomes. The analysis showed that OPCAB can provide comparable results to ONCAB, challenging historical concerns about safety and quality of revascularisation.

Subsequently, the team then analysed their 25-year institutional experience of performing CABG surgery involving more than 13,000 patients. The study found that 25 years after surgery patients who had undergone off-pump surgery had a 57.5% survival rate compared to 42.7% survival rate in patients who had on-pump coronary artery bypass surgery.

For decades, the prevailing notion has been that off-pump surgery results in poorer long-term outcomes compared to on-pump surgery and the choice between OPCAB and ONCAB has been a topic of debate amongst cardiac surgeons. This study challenges cardiac surgery standard practice.

Cardiac surgeon, Mr Raja, who led the team that performed the study, emphasised the potential impact of these findings: “This study fundamentally challenges the current concepts about poor long-term survival after off-pump coronary artery bypass surgery. Our results demonstrate that with the right expertise and volume, OPCAB can offer superior long-term outcomes and furthermore, these benefits persist in both low-risk and high-risk patients.

“The dedication and skill of our team at Harefield have been crucial in achieving these excellent results.”

Dr Maria Comanici, clinical fellow who contributed to the research, said: “This study not only reinforces the long-term benefits of off-pump coronary artery bypass surgery but also paves the way for further research into optimising patient outcomes.”

Mr Shahzad Raja, cardiac surgeon, and his team’s study was recognised as the “best abstract” at the 2024 International Coronary Congress. The Harefield team plans to continue their research to further refine patient selection criteria and surgical techniques for OPCAB.

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