1Universitätsklinikum Schleswig-Holstein Medizinische Klinik II / Kardiologie, Angiologie, Intensivmedizin Lübeck, Deutschland; 2Städtisches Klinikum Dessau Klinik für Innere Medizin II Dessau-Roßlau, Deutschland
Background: Heparin is usually given during transradial coronary angiography to decrease the risk of radial artery occlusion (RAO). However, maintaining radial artery patency during hemostatic compression (patent hemostasis) is another important aspect to prevent RAO and could be hampered by systemic anticoagulation. Furthermore, data are lacking regarding the protective effects of periprocedural heparin in patients with preexisting systemic anticoagulation and in case of a distal transradial access (TRA), which is reportedly associated with lower rates of RAO.
Objectives: This study aimed to compare the efficacy and safety of periprocedural administration of heparin in patients undergoing diagnostic coronary angiography via TRA.
Methods: The RAPID trial is a single-center, open-label, 2x2 factorial, randomized study of patients undergoing coronary angiography through a 6-F radial access. Patients were randomized to receive periprocedural unfractionated heparin or undergo coronary angiography without systemic anticoagulation with further stratification according to radial access site (distal versus conventional TRA) and preexisting oral anticoagulation. Only patients with sole diagnostic coronary angiography without percutaneous coronary intervention were considered for the analysis. The primary endpoints were the incidence of RAO assessed by vascular ultrasound and puncture-site related bleedings.
Results: The trial was stopped early for efficacy by the data and safety monitoring board after the second pre-planned interim analysis and inclusion of 600 participants. Excluding patients with indicated percutaneous coronary intervention (n=161), the final study population consisted of 218 patients randomized to heparin and 221 patients in the group without systemic anticoagulation. Distal TRA was the primary approach in half of patients (52.8% versus 48.4%; p=0.364) and patent hemostasis was achieved in 92.6% in case of conventional TRA without differences between the study groups (p=0.177). The rate of RAO was significantly reduced in patients receiving heparin (7.3% versus 33.9%; p<0.001) while puncture-site related bleedings were of minor severity (Bleeding Academic Research Consortium ≤2) and did not differ significantly between groups (7.3% versus 3.6%; p=0.087). These results were consistent in patients with and without preexisting systemic oral anticoagulation and in the subgroup of patients with a distal TRA. In case of a conventional TRA, RAO rates were also significantly reduced after heparin administration (9.7% versus 31.6%; p<0.001), however, at the expense of a significantly increased bleeding risk (11.7% versus 2.6%; p=0.009).
Conclusions: Periprocedural systemic anticoagulation with unfractionated heparin decreased the risk of RAO in this trial and, therefore, remains standard of care irrespective of patent hemostasis, preexisting oral anticoagulation, or distal TRA.
The “Strategies to maintain Radial Artery Patency following Diagnostic coronary angiography” (RAPID) trial; NCT04301921 and NCT04362020.
Key words: coronary angiography; radial access; heparin; radial artery occlusion; bleeding