Radial Artery or Saphenous Vein Grafts in CABG
What are the clinical outcomes of radial artery grafts compared with saphenous vein grafts for coronary artery bypass grafting (CABG)?
The investigators combined individual patient-level data from individual trials in which the use of the radial artery was compared with the use of other conduits for CABG to provide the basis for a combined analysis. Six trials were identified. The primary outcome was a composite of death, myocardial infarction (MI), or repeat revascularization. The secondary outcome was graft patency on follow-up angiography. Mixed-effects Cox regression models were used to estimate the treatment effect on the outcomes.
A total of 1,036 patients were included in the analysis (534 patients with radial artery grafts and 502 patients with saphenous vein grafts). After a mean (± standard deviation) follow-up time of 60 ± 30 months, the incidence of adverse cardiac events was significantly lower in association with radial artery grafts than with saphenous vein grafts (hazard ratio [HR], 0.67; 95% confidence interval [CI], 0.49-0.90; p = 0.01). At follow-up angiography (mean follow-up, 50 ± 30 months), the use of radial artery grafts was also associated with a significantly lower risk of occlusion (HR, 0.44; 95% CI, 0.28-0.70; p < 0.001). As compared with the use of saphenous vein grafts, the use of radial artery grafts was associated with a nominally lower incidence of MI (HR, 0.72; 95% CI, 0.53-0.99; p = 0.04) and a lower incidence of repeat revascularization (HR, 0.50; 95% CI, 0.40-0.63; p < 0.001), but not a lower incidence of death from any cause (HR, 0.90; 95% CI, 0.59-1.41; p = 0.68).
The authors concluded that as compared with the use of saphenous vein grafts, the use of radial artery grafts for CABG resulted in a lower rate of adverse cardiac events and a higher rate of patency at 5 years of follow-up.
This patient-level combined analysis of randomized controlled trials comparing the radial artery and the saphenous vein as a second conduit for CABG reports that radial artery grafts were associated with a significantly lower risk of the composite outcome of death, MI, or repeat revascularization and with a significantly lower risk of two individual components of the outcome (i.e., MI and repeat revascularization at 5 years). Furthermore, use of radial artery grafts was associated with higher rates of angiographic patency, a finding that offers a biologic mechanism to explain the observed advantage in clinical outcomes. These data support the use of multiple arterial grafts, as recommended by current American College of Cardiology guidelines and the position papers of professional societies.
Keywords: Angiography, Cardiac Surgical Procedures, Coronary Artery Bypass, Myocardial Infarction, Myocardial Ischemia, Myocardial Revascularization, Outcome Assessment (Health Care), Radial Artery, Risk, Saphenous Vein, Secondary Prevention
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