Compared with percutaneous coronary intervention (PCI), coronary artery bypass graft surgery (CABG) was more effective in relieving angina and led to fewer repeated revascularizations but had a higher risk for procedural stroke, according to a study published yesterday in The Annals of Internal Medicine.
The two coronary revascularization techniques are some of the most common major medical procedures performed in North America and Europe. In 2005, 261,000 CABG procedures and 645,000 PCI procedures were performed in the United States alone. However, the comparative effectiveness of CABG and PCI remains poorly understood for patients in whom both procedures are feasible, according to the researchers.
The trial took place at Stanford University School of Medicine in Stanford, Calif., and Veterans Affairs Palo Alto Health Care System in Palo Alto, Calif.
The researchers examined the Medline, Embase and Cochrane databases for studies published between January 1966 and August 2006. They sought randomized, controlled trials (RCTs) that compared health outcomes of PCI and CABG.
The authors identified 23 RCTs, in which 5,019 patients were randomly assigned to PCI and 4,944 patients were randomly assigned to CABG.
The average age of the trial participants was 61 years, 27 percent were women and most were of European ancestry. Approximately 20 percent had diabetes; half had hypertension; half had hyperlipidemia; 40 percent had a previous myocardial infarction; and a few had heart failure or poor left ventricular function.
The difference in survival after PCI or CABG was less than 1 percent over 10 years of follow-up. Survival did not differ between PCI and CABG for patients with diabetes in the six trials that reported on this subgroup.
Angina relief was greater after CABG than after PCI, with risk differences ranging from 5 percent to 8 percent at 1 to 5 years. The absolute rates of angina relief at 5 years were 79 percent after PCI and 84 percent after CABG. Repeated revascularization was more common after PCI than after CABG (24 percent at 1 year and 33 percent at 5 years); the absolute rates at 5 years were 46.1 percent after balloon angioplasty, 40.1 percent after PCI with stents, and 9.8 percent after CABG.
Overall, older patients had more procedural complications, especially stroke. Long-term survival after PCI or CABG did not differ significantly among patients older than 65 years of age compared with younger patients, but very few patients older than 75 years of age were enrolled.