RESUMO
BACKGROUND: Few data exist regarding angiographic predictors of radial artery patency for coronary bypass grafting, and the benefit of calcium antagonists is not clear. METHODS: One hundred fifteen patients were studied who had myocardial revascularization with the radial artery plus internal mammary and vein grafts with 3.5 +/- 1.1 grafts per patient. Sixty-three patients received diltiazem and 52 patients did not. Base line and follow-up angiographies were analyzed 1 year postoperatively in 50 of these patients with a quantitative computerized method. RESULTS: One hundred fourteen patients survived and were followed for 30.1 +/- 12.6 months. Patency for mammary grafts was 100%, for radial grafts it was 80%, and for saphenous vein grafts it was 68%. Patent radial artery grafts had significantly greater degree of stenosis in the native vessels than occluded grafts (73% +/- 14% vs 40% +/- 24%), (p = 0.0007; confidence interval = 95%). Radial artery patency increased to 92% when arteries with 70% or more stenosis were considered. No differences were observed for clinical and angiographic end points in the patients that received diltiazem compared with the rest who had not. CONCLUSIONS: The degree of stenosis in the native coronary artery significantly influences the patency rate of radial artery grafts, independent of diltiazem.