Ann Thorac Surg 2009;88:53. doi:10.1016/j.athoracsur.2009.04.051
© 2009 The Society of Thoracic Surgeons
Original Articles: Adult Cardiac
Invited Commentary
Craig Selzman, MD
University of Utah, 30 N 1900 E, 3C 127 SOM, Salt Lake City, UT 84132
(Email: craig.selzman{at}med.unc.edu).
No doubt exists as to the benefit of the left internal mammary artery (LIMA) to the left anterior descending artery (LAD) bypass in coronary artery bypass graft surgery (CABG). Despite provocative evidence that additional arterial grafting can provide survival advantages, many surgeons remain reluctant to deviate from the LIMA and saphenous vein conduits. A number of reasons might explain this strategy, including speed of procurement, ease of working with vein grafts, issues related to competitive flow and less complete revascularization, and perceived notions of inadequate immediate flow. Conversely, many surgeons have aggressively adopted off-pump coronary artery bypass (OPCAB) approaches. Although others have demonstrated the safety of all arterial grafting during OPCAB, few have actually compared this with conventional conduits during OPCAB.
In this impressive single surgeon study, Raja and colleagues [1] review and compare their experience in nearly 1,300 patients with OPCAB using all arterial or conventional (LIMA and saphenous vein conduits) grafts during a 10-year period. They used both propensity scoring to match 346 patients as well traditional variate analysis to demonstrate similar survival, but potentially less in-hospital morbidity associated with arterial grafting. The authors should be congratulated on their results and their rigorously developed database. Several obvious caveats exist that limit its ability to generalize, but should not distract from their report. It is a single surgeon study with grafting strategies that are not well laid out. For example, although they acknowledge their carefulness with arterial grafting in patients with chronic renal failure and peripheral vascular disease, it is not clear if they avoided using arterial grafts in territories that had lower grade lesions.
Importantly, these data must be interpreted with some circumspect. They have created an artificially derived combined endpoint that includes mortality, stroke, myocardial infarction, reoperation, intra-aortic balloon pump (IABP), and prolonged ventilation (> 24 hours). I would submit that adding the latter two endpoints deviates from standard assessment of perioperative morbidity. We do not routinely discuss patients in our morbidity and mortality conference that have been on a ventilator for 25 hours (more in the controls group). We do discuss takebacks (more in the arterial group). As noted, more patients in the control group had IABPS. Indeed, nearly twice as many patients in the control group had emergent operations. These details point to the fact these were important differences in the patient population studied. Obviously, patients on an IABP are sicker, and thus they will be on the ventilator for a longer period of time. As such, I would be curious to know how their statistics would play out if they removed the softer two endpoints. Because there were no differences in death, myocardial infarction, or stroke, but significantly more reoperations for bleeding in the arterial group, I would submit that their conclusion might actually be the opposite of what they propose.
Although I question their ultimate conclusion that arterial grafting with OPCAB provides "superior" in-hospital outcomes, I do believe that it is a valuable report. It demonstrates that despite increased risk of bleeding, short-term outcomes with arterial grafting and OPCAB are excellent and comparable with conventional strategies. The putative advantage of arterial grafting is the long-term patency of the grafts that could potentially impact survival. Because the perioperative data is encouraging and relatively safe, we await their follow-up study that will look at the long-term outcomes of this cohort of patients.
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References
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- Raja SG, Siddiqui H, Ilsley CD, Amrani M. In-hospital outcomes of off-pump multivessel total arterial and conventional coronary artery bypass grafting: single surgeon, single center experience Ann Thorac Surg 2009;88:47-53.[Abstract/Free Full Text]
Related Article
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In-Hospital Outcomes of Off-Pump Multivessel Total Arterial and Conventional Coronary Artery Bypass Grafting: Single Surgeon, Single Center Experience
- Shahzad G. Raja, Hajira Siddiqui, Charles D. Ilsley, and Mohamed Amrani
Ann. Thorac. Surg. 2009 88: 47-52.
[Abstract]
[Full Text]
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