Multicenter Randomized Evaluation of High Versus Standard Heparin Dose on Incident Radial Arterial Occlusion After Transradial Coronary Angiography The SPIRIT OF ARTEMIS Study

OBJECTIVES The aim of this study was to test the hypothesis that more intensive over standard anticoagulation administered during coronary angiography would significantly reduce rates of radial artery occlusion (RAO). BACKGROUND RAO, although silent, remains a frequent and therefore worrisome complication following transradial coronary angiography. Anticoagulation is effective in reducing RAO, but the optimal heparin dose remains ill defined. METHODS In this multicenter, randomized superiority trial, a high dose (100 IU/kg body weight administered in divided doses) and a standard dose (50 IU/kg body weight) of heparin during 5- or 6-F coronary angiography were compared. A total of 3,102 patients were randomized, of whom 1,836 patients not proceeding to percutaneous coronary intervention and without need for arterial access crossover entered the trial. Post-catheterization hemostasis did not follow a rigid protocol. RESULTS A total of 102 early RAOs were found on ultrasonography (incidence 5.6%). In the high-dose heparin group, the rate of RAO was significantly lower compared with the standard-dose heparin group (27 [3.0%] vs. 75 [8.1%]; odds ratio: 0.35; 95% confidence interval: 0.22 to 0.55; p < 0.001), without compromising safety. The time to achieve hemostasis was similar between groups. To avoid 1 RAO, the number of patients needed to treat in the high-dose heparin group was approximately 20. These results were corroborated by our integrated database, showing an 80% reduction of forearm artery occlusions in high versus low heparin dose patients and our updated meta-analysis of randomized controlled trials demonstrating significant benefit of higher over lower anticoagulation intensity. CONCLUSIONS High compared with standard heparin dose significantly reduced the rate of RAO in patients undergoing coronary angiography. High-intensity anticoagulation should be considered in transradial diagnostic procedures. (High [100IU/Kg] Versus Standard [50IU/Kg] Heparin Dose for Prevention of Forearm Artery Occlusion; NCT02570243) (c) 2018 by the American College of Cardiology Foundation.