Thirteen RCTs (7,964 participants) were included.
There was no statistically significant difference in the risk of death or cardiac death between CABG and PTCA at 1 year (11 studies), 3 years (11 studies) or 8 years (4 studies). However, the 5-year follow-up data did show a statistically significant benefit for patients who received CABG: the RD at 5 years was 1.9% (95% CI: 0.33, 3.4, P=0.02) for death (7 studies) and 2.0% (95% CI: 0.29, 3.7, P=0.02) for cardiac death (5 studies). The NNT was about 50 patients. Statistical heterogeneity between the trials was not significant.
The number of subsequent revascularisations required was reduced with CABG, compared with PTCA, at all time points (RD: 24 to 38%, P<0.001). There was statistically significant heterogeneity between the trials for this outcome (P<0.001).
There was no statistically significant effect of either CABG or PTCA on the number of nonfatal MIs.
For the combined outcome (death, MI, revascularisation) the risk of an event was greater in the PTCA treated group at 1, 3 and 5 years (RD: 26 to 31%, P<0.001). Statistical heterogeneity between the trials was not significant.
Compared with PTCA, there was a reduction in angina with CABG at 1 and 3 years: the RD was 11% (95% CI: 7.5, 14, P<0.001) at 1 year and 9% (95% CI: 5, 13, P<0.001) at 3 years. There was statistically significant heterogeneity between the trials (P<0.02).
CABG was associated with a reduction in subsequent revascularisations in trials that used stents with PTCA and in trials that did not use stents: the RDs at 3 years were 15% (3 trials; 95% CI: 10, 20, P<0.001) and 34% (7 trials; 95% CI: 28, 40, P<0.001), respectively. There was statistically significant heterogeneity between the trials that did not use stents. No trial directly compared PTCA with and without stents versus CABG.
In the subgroup analyses, CABG provided a survival advantage over PTCA for multi-vessel disease at 5 and 8 years: the RD was 2.3% (95% CI: 0.29, 4.3, P=0.025) at 5 years and 3.4% (95% CI: 0.32, 6.4, P=0.03) at 8 years. At 4 years' follow-up, CABG provided a survival advantage over PTCA in diabetic patients (RD 8.6%, 95% CI: 2.2, 15, P=0.01), but this was not significant at 6.5 years.