Coronary artery bypass grafting was more effective at relieving angina, and required fewer repeat revascularization procedures, than did percutaneous coronary interventions, according to investigators who conducted a review of randomized clinical trials reported in the literature.
Neither procedural survival nor long-term survival differed significantly between CABG and PCI, but the short-term risk for stroke was significantly higher for CABG, the researchers said.
Dr. Dena M. Bravata and her associates at Stanford (Calif.) University's center for primary care and outcomes research reviewed 23 randomized trials that directly compared the effectiveness of the two approaches to revascularization. The trials included nearly 10,000 subjects in whom both procedures were technically feasible (5,019 randomly assigned to undergo PCI and 4,944 assigned to CABG). Most of the studies took place in Europe.
The rate of procedure-related stroke, reported in 15 of the trials, was higher for CABG (1.2%) than for PCI (0.6%).
Follow-up in the clinical trials ranged from 6 months to 13 years. Long-term survival was not significantly different at any time point: 96.4% for CABG and 96.5% for PCI at 1 year; 90.7% and 89.7%, respectively, at 5 years.
Angina relief was superior for CABG. At 1 year, 84% of CABG patients, compared with 75% of PCI patients, were free of angina. At 5 years, the proportions were 84% and 79%, respectively.
PCI patients were 24% more likely to require repeat revascularization (26% at 1 year and 40% at 5 years), compared with CABG patients (4% at 1 year and 10% at 5 years).
The review's finding of similar long-term survival for CABG and PCI differ from reports based on clinical registries, which show improved survival after CABG, the investigators noted. “These observations suggest that the seemingly disparate results of randomized trials and clinical registries can be reconciled by taking into account that the overall outcomes in clinical registries are heavily weighted by the large number of events in the higher-risk patients with the most extensive disease, who appear to have better outcomes after CABG than after PCI.” By contrast, overall outcomes in the randomized trials “were assessed in intermediate-risk patients, in whom CABG and PCI outcomes were also similar in clinical registries,” they explained.
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