J Thorac Cardiovasc Surg 2003;126:1668
© 2003 The American Association for Thoracic Surgery
Is there an evidence in favor of off-pump coronary artery bypass?
Reida Menshawe El Oakley, MD, FRCSa,
Oon Cheong Ooi, AFRCSa,
Chuen Neng Lee, FRCSa
a Department of Cardiac, Thoracic, and Vascular Surgery, The Heart Institute, National University Hospital, Singapore, Singapore
To the Editor:
We read with interest the report of Mack and colleagues1 that shows "improved outcome in coronary artery bypass grafting with beating-heart techniques." In the era of evidence-based medicine and megatrials, class A level evidence will remain the standard tool that forces change of direction of currently applied surgical procedures, including coronary artery bypass grafting. We concede that in the absence of major prospective randomized trials2,3 retrospective studies such as this may contribute enough evidence to sway the balance in favor of or against off-pump coronary artery bypass grafting (OPCAB).
However, we wish to highlight two issues that could have a significant impact on the conclusions derived from the study. First, at one point the authors claimed that the conversion rate was 2.9% and stated that "these patients were analyzed with the on-pump group." Later, however, they reported a conversion rate of 1.6% and suggested that the analysis was performed on an intent-to-treat basis (that conversions were analyzed with the OPCAB group). These conflicting statements require further clarification. Second, the need for a subgroup analysis of the cases converted from OPCAB to an on-pump procedure cannot be overemphasized. This analysis may provide the answer to a number of important questions regarding OPCAB, such as indications, timing, predictors, and, more importantly, the outcome of conversion in terms of mortality and morbidity.
References
- Mack M, Bachand D, Acuff T, Edgerton J, Prince S, Dewey T, et al. Improved outcomes in coronary artery bypass grafting with beating-heart techniques. J Thorac Cardiovasc Surg. 2002;124:598–607[Abstract/Free Full Text]
- Yacoub M. Off-pump coronary bypass surgery: in search of an identity. Circulation. 2001;104:1743–1745[Free Full Text]
- van Dijk D, Nierich AP, Jansen EW, Nathoe HM, Suyker WJ, Diephuis JC, et al. Early outcome after off-pump versus on-pump coronary bypass surgery: results from a randomized study. Circulation. 2001;104:1761–1766[Abstract/Free Full Text]
