(7.6%), and 61 deaths among the 373 patients using medical treatment (16.3%) (European Coronary Surgery Study Group 1982; Hampton 1984). The CASS followed 780 patients under 65 years allocated to medical or surgical treatment between 1975 and 1979 (90% male). The overall 5-year cumulative survival rates in the medically assigned group (92%) and the surgically assigned group (95%) were similar. No significant differences in survival were found between medically and surgically treated groups at baseline in extent of coronary heart disease (CHD) or in ventricular function. In patients with three-vessel disease and low ejection fractions, a distinct (but not significant) trend for improved 5-year survival was observed in patients treated surgically (90%) compared with those treated medically (80%). This difference persisted and reached statistical significance when the 7-year cumulative survival was 88% in the surgically assigned group and 65% in the medically assigned group (CASS PI 1983; Hampton 1984). Since these early randomized studies it has become clear that there were a number of methodological issues with these trials. First, there were few females in the early trials, which is concerning as there appears to be a gender difference in outcome following surgery. Second, the types of patients included in these studies represented only 20% of the total coronary artery disease population, and thus results cannot be extrapolated to the entire population (Pollick 1993). Finally, the CABG procedure has advanced significantly over the years to a point where operative mortality is now much lower than reported in the early trials, at less than 3% for routine CABG (Pollick 1993; Senes-Ferrari 1999; Ferguson et al 2002). One such procedural change in CABG has been routine use of the internal mammary artery as a conduit for revascularizing the coronary arteries, as 10 years after CABG three quarters of vein conduits are blocked or severely diseased (Fitzgibbon et al 1996), whereas more than 90% of internal thoracic artery grafts are patent and disease free (Pollick 1993; Damgaard et al 2005). Vein graft failure leads to reduced survival, recurrent angina, late myocardial infarction, and the need for further intervention (Eagle et al 1999), so that by 10–15 years after the initial operation up to 40% of patients may require redo CABG at increased risk and cost (Weintraub et al 1994; Kaul et al 1995; Lytle et al 1999). Thus, recent studies suggest that the use of the left internal thoracic artery to the left anterior descending coronary artery is the most important factor for survival and reduction of late cardiac events after CABG (Loop et al 1986; Yusuf et al 1994; Cameron et al 1996). Outcomes of coronary bypass surgery Furthermore, while there have been no randomized trials of total arterial revascularization compared with conventional surgery, several large studies have reported that multiple arterial revascularization offers survival advantages over a single internal thoracic artery graft (Pick et al 1997; Schmidt et al 1997; Buxton et al 1998; Lytle et al 1999; Calafiore et al 2000; Dion et al 2000). In a meta-analysis of almost 16 000 patients comprising 11 269 single and 4693 bilateral internal thoracic artery patients matched for age, gender, left ventricular function, and diabetes, the bilateral internal thoracic artery group had significantly better survival (hazard ratio for death 0.81, 95% confidence interval 0.70–0.94) (Taggart et al 2001). More recently, up to 25% of CABG operations are being performed without the use of a heart-lung pump— “off-pump CABG”. A number of non-randomized studies have shown off-pump CABG is as safe as on-pump surgery, and in experienced hands offers less early complications, particularly in those patients with significant comorbidity. In high-risk groups, particularly those with renal impairment, off-pump surgery makes the need for postoperative renal support less likely, and in groups over 70 years of age, there is a reduction in the incidence of cerebral injury when an off-pump technique is employed. However, randomized trials have not yet revealed a significant reduction in morbidity or mortality (Pepper 2005). In parallel with the progress of the revascularization techniques for patients with stable angina, several randomized trials have also been performed comparing: medical management with surgery; medical management with PTCA or percutaneous coronary intervention (PCI); and PCI with surgery (Spargias and Cokkinos 2004; Bakhai et al 2005). In a review of seven trials, survival was greater in high risk patients following CABG compared with medical therapy, where patient risk was defined by severity of ischemia, number of diseased vessels, and left ventricular dysfunction. In low-risk patients, a strategy of initial medical therapy has been shown to be effective (Solomon and Gersh 1998). Despite the difficulty of drawing conclusions from trials comparing outperformed treatments, a recent article attempts to outline the comparative efficacy of the available treatment strategies and we refer the reader to that publication for more information (Spargias and Cokkinos 2004). Overall, the three early major randomized trials and more recent studies indicate that patients with narrowing of the left main coronary artery, or triple-vessel disease and subnormal Vascular Health and Risk Management 2006:2(4) 479