Coronary artery grafting in high risk patients randomised to Off Pump or On Pump Surgery
Despite advances in medical therapy and percutaneous coronary interventions (PCI), there is good evidence that coronary artery bypass graft (CABG) offers superior survival and freedom from repeat intervention in patients with multivessel coronary artery disease (CAD). In the recently published New York State registry of almost 60,000 patients, after risk stratification for cardiac and non-cardiac comorbidity, there was a significant reduction in mortality (absolute difference of 5%). There was also a seven fold reduction in the need for repeat interventions at three years in patients undergoing CABG rather than PCI using stents. Predictions that drug eluting stents will significantly reduce the need for CABG are premature. These stents reduce the incidence of restenosis compared to bare metal stents, however, three large meta-analyses have shown that they do not improve survival, or reduce the incidence of subsequent myocardial infarction. There are two reasons why CABG is likely to remain a superior treatment to PCI over the longer term:
CABG protects whole zones of proximal myocardium. This is because the graft is placed to the mid coronary vessel beyond all proximal disease
PCI frequently results in incomplete revascularization. This adversely affects survival proportional to the incompleteness of revascularization.
Around half a million patients worldwide undergo CABG each year. There is a possibility that these numbers will increase. This is due to a growing elderly population and an increasing amount of diabetes and obesity, which all contribute to the development of CAD. There is an increasing realisation that PCI may merely delay definitive treatment.
The paper for this study is available