RESUMEN
BACKGROUND: Radial artery occlusion (RAO) remains the Achilles' heel of transradial coronary procedures. Standard over lower systemic anticoagulation levels are believed to reduce RAO rates but this is ill-supported by scientific evidence. We compared whether standard in comparison with less intensive anticoagulation was superior in preventing vessel closure. METHODS AND RESULTS: The two arms of this analysis included 731 pooled patients with the same inclusion and exclusion criteria. We assessed forearm arterial access site occlusion rate by unfractionated heparin (UFH) dose in an individual participant data meta-analysis of this randomized study and of consecutive eligible patients from our previous trial. We randomized 308 consecutive patients undergoing transradial coronary angiography with 5 French (5 Fr) catheters without need to crossover to receive 2500 or 5000 UFH units. The primary end-point was the ultrasonographically determined vessel occlusion rate. Incident RAOs in the randomized arm were 15.9% vs. 14%, in the low and standard UFH dose, respectively (p=0.7). Corresponding figures for forearm arterial occlusion rates in the pooled population were 13.0% vs. 9.9% (relative risk: 1.3, 95% confidence interval - CI: 0.88-1.98; p=0.2). Procedural and fluoroscopy duration was less than 15 and 3 min, respectively. The mean UFH dose difference was 3.52 (95% CI: -0.45 to 7.49) units per kilo body weight between occluded (n=84) and patent forearm arteries (n=647); (p=0.053). CONCLUSIONS: Incident forearm arterial occlusions were high despite using 5 Fr catheters for a short-lasting procedure. Systemic anticoagulation with standard over lower UFH dose did not reduce the frequency of RAOs after coronary angiography.