Letter by Saha Regarding Article, “Should Off-Pump Coronary Artery Bypass Grafting Be Abandoned?”
To the Editor:
I read with interest the special report by Dr Lazar1 on off-pump coronary artery bypass grafting (OPCAB). I congratulate him for the exhaustive and lucid review. I would like to humbly express my opinion about the conclusions derived by the author.
The Randomized On/Off Bypass (ROOBY) trial had 12.4% conversion to cardiopulmonary bypass. This is way too high and depicts the inexperience of the OPCAB surgeon. We have reported that it is possible to achieve nearly zero conversion to cardiopulmonary bypass in nonselected consecutive patients by the timely use of intra-aortic balloon pump and elective use of cell saver.2 OPCAB has a steep learning curve. The poor OPCAB graft patency rate may have resulted from the inexperience of the OPCAB surgeons (seen by high conversion rate). Moreover, the graft patency data from the Surgical Management of Arterial RevascularizationTherapy (SMART), and Coronary Artery Bypass Surgery Off or On Pump Revascularization Study (CORONARY) trials contradict Dr Lazar’s conclusion that OPCAB has inferior long-term graft patency.1
The superiority of the bilateral internal mammary artery graft is well established.3 We have reported a simple technique of using the bilateral internal mammary artery during OPCAB that can be performed in India with limited resources.4 An additional benefit of OPCAB with aortic no touch is that it has a very low incidence of stroke, which compares favorably with percutaneous coronary intervention.5
In our series reported earlier, the average number of grafts per patient was >4.2 We have even successfully performed 9 grafts in a patient using OPCAB. There is no constraint of increasing bypass or clamp time. All vessels, even the small and diffusely diseased vessels, can be grafted perfectly. Hence, I beg to differ that OPCAB leads to incomplete revascularization. Similar reports have been published from other parts of the world.
A hypercoagulable state after OPCAB may affect graft patency. We routinely start the OPCAB patient on clopidogrel 4 to 6 hours after OPCAB and 2 hours after coronary endarterectomy. Moreover, only 50% of the heparin used during OPCAB is reversed with protamine. Cardiopulmonary bypass–induced coagulopathy may provide some protection against graft thrombosis in on-pump coronary artery bypass grafting. These aspects need to be studied.
OPCAB in India was pioneered by surgeons trained in centers in the United States with excellent results in on-pump coronary artery bypass grafting. The majority of the surgeons now performing OPCAB, including me, received training in renowned centers of the United States. It is inappropriate to conclude that all these highly trained surgeons are committing judgmental errors by adopting OPCAB. In India, treatment is funded by the patient. It is more difficult to have a successful private practice with suboptimal patient outcomes. Moreover, with an aggressive interventional cardiologist breathing down the surgeon’s neck, the surgical results have to be excellent.
It is possible to perform complete revascularization with a very low conversion rate even with low surgical volume.2 The technique and experience of the surgeon determine graft patency rather than OPCAB or on-pump coronary artery bypass grafting, so when performed by the same surgeon, long-term graft patency is similar in both (SMART trial).
I humbly suggest that OPCAB is a relatively new technique that is still evolving. Any surgeon can be trained in OPCAB even with low volume. After all, OPCAB with aortic no touch (with the least incidence of stroke) gives us the best surgical alternatives to percutaneous coronary intervention today.
Kamales Kumar Saha, MCh (AIIMS)
Department of Cardiovascular and Thoracic Surgery
MGM Medical College
Navi Mumbai, India
- © 2014 American Heart Association, Inc.
- Lazar HL
- Grau JB,
- Ferrari G,
- Mak AW,
- Shaw RE,
- Brizzio ME,
- Mindich BP,
- Strobeck J,
- Zapolanski A
- Saha KK
- Taggart DP