Decision making in off-pump coronary artery bypass surgery: where does conversion fit in?
- 1Department of Cardiac Surgery, St Thomas' Hospital, London, UK
- 2Department of Cardiothoracic Surgery, Imperial College Healthcare, London, UK
- Correspondence to Prof Thanos Athanasiou, Department of Cardiothoracic Surgery, Imperial College Healthcare NHS Trust, Hammersmith Hospital, Du Cane Road, London W12 0HS, UK;
Contributors TA provided the original concept of this paper in conjunction with AK. AK wrote the paper with advice from TA. Both authors were involved in completion of the final version and submission of the paper.
- Atrial fibrillation
- aortic valve disease
- cardiopulmonary bypass
- surgery-coronary bypass
- heart transplant pathology
- stable angina
- coronary artery disease
The intense debate of earlier years between off-pump coronary artery bypass (OPCAB) grafting and conventional coronary artery bypass grafting (CABG) with the use of cardiopulmonary bypass (CPB) has recently given place to a more balanced and targeted approach to surgical coronary revascularisation. Baseline patient characteristics, coronary and aortic pathology and, most importantly, surgeon experience and training are currently the main factors influencing the decision and implementation of OPCAB. In an era where outcomes following CABG are closely monitored and mortality rarely exceeds 3%, the practice of off-pump revascularisation aims at amelioration of morbidity and at achieving equivalent, if not superior, outcomes compared with on-pump CABG. However, a systematic and indepth analysis of the relevant literature highlights an important issue, which is often neglected and could potentially influence decision making in coronary artery surgery: this is intraoperative conversion.1
Institution of CPB during CABG, which was planned or initiated as off pump, is defined as conversion. In the majority of cases, this is an urgent or even emergency process aiming at correction of haemodynamic instability during manipulation of the heart, particularly during coronary anastomosis, or where the anatomy is unfavourable for safe and complete off-pump revascularisation. The impact of conversion on morbidity and mortality has been recognised as a potential shortcoming of OPCAB but studies have only very recently started to examine this phenomenon in a systematic way. In a meta-analysis of randomised trials presented by our group, it appears that mortality rates often exceed 8% in patients undergoing conversion, whereas the incidence of stroke, myocardial infarction, respiratory and renal complications is significantly higher compared …