Off-Pump Bypass: Technically Challenging, with No Benefit

A recent 2,203 patient randomized trial conducted at VA hospitals has revealed that, despite the technical challenges of performing coronary artery bypass grafting procedures "off-pump" — i.e., without the use of cardiopulmonary bypass — and despite the perceived benefits of the procedure, off-pump procedures fare no better than on-pump procedures.  Indeed the trend toward better outcomes after one year post-surgery favors the on-pump procedure. The highlights of the ROOBY trial (Randomized On/Off Bypass) are well described at

There was no significant difference between the on-pump and off-pump groups in the 30-day composite outcome, and the on-pump group did slightly better in the one-year composite outcome. There was also no difference between the groups in neuropsychological outcomes or use of major resources. 


Performance of coronary artery bypass grafting is traditionally accomplished with circulation re-routed through the heart-lung machine.  There has a long been a presumption, however (but not by all clinicians), that such cardiopulmonary bypass is associated with cognitive deficit post-surgery and that, further, cardiopulmonary bypass (CPB) is in fact contraindicated for frail patients and/or those with calcified aortas, which need to be clamped during CPB, or patients with renal insufficiency.

The results of the ROOBY trial will unlikely change the perspective of those cardiac surgeons who have already adapted to the approach of off-pump bypass, also in certain cases referred to as "beating-heart bypass", it will likely dampen the enthusiasm of physicians, at least for those patients without clear contraindication for CPB.


Report from MedMarket Diligence:  Coronary Artery Stents Worldwide.

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