Association of Radial Artery Graft vs Saphenous Vein Graft with Long-term Cardiovascular Outcomes among Patients Undergoing Coronary Artery Bypass Grafting: A Systematic Review and Meta-analysis

Importance: Observational studies have suggested that the use of radial artery grafts for coronary artery bypass grafting may improve clinical outcomes compared with the use of saphenous vein grafts, but this has not been confirmed in randomized trials. Objective: To compare clinical outcomes between patients receiving radial artery vs saphenous vein grafts for coronary artery bypass grafting after long-term follow-up. Design, Setting, and Participants: Patient-level pooled analysis comparing radial artery vs saphenous vein graft in adult patients undergoing isolated coronary artery bypass grafting from 5 countries (Australia, Italy, Serbia, South Korea, and the United Kingdom), with enrollment from 1997 to 2009 and follow-up completed in 2019. Interventions: Patients were randomized to undergo either radial artery (n = 534) or saphenous vein (n = 502) grafts for coronary artery bypass grafting. Main Outcomes and Measures: The primary outcome was a composite of death, myocardial infarction, or repeat revascularization and the secondary outcome was a composite of death or myocardial infarction. Results: A total of 1036 patients were randomized (mean age, 66.6 years in the radial artery group vs 67.1 years in the saphenous vein group; 376 [70.4%] men in the radial artery group vs 351 [69.9%] in the saphenous vein group); 942 (90.9%) of the originally randomized patients completed 10 years of follow-up (510 in the radial artery group). At a median (interquartile range) follow-up of 10 (10-11) years, the use of the radial artery, compared with the saphenous vein, in coronary artery bypass grafting was associated with a statistically significant reduction in the incidence of the composite outcome of death, myocardial infarction, or repeat revascularization (220 vs 237 total events; 41 vs 47 events per 1000 patient-years; hazard ratio, 0.73 [95% CI, 0.61-0.88]; P <.001) and of the composite of death or myocardial infarction (188 vs 193 total events; 35 vs 38 events per 1000 patient-years; hazard ratio, 0.77 [95% CI, 0.63-0.94]; P =.01). Conclusions and Relevance: In this individual participant data meta-analysis with a median follow-up of 10 years, among patients undergoing coronary artery bypass grafting, the use of the radial artery compared with the saphenous vein was associated with a lower risk of a composite of cardiovascular outcomes.