The purpose of the RIVA-RAO study is to determine whether the use of Rivaroxaban is an effective treatment of radial artery occlusion (RAO) after cardiac catheterization (both angiography and PCI). This is a prospective, single-center, randomized controlled, open-label study that will randomize patients with RAO into two groups, one receiving Rivaroxaban and the other receiving no anticoagulation. RAO will be detected by radial artery ultrasound up to 24 hours after the procedure. Study objectives: Primary objective: To evaluate the effect of treatment with Rivaroxaban, in patients (both symptomatic and asymptomatic) with RAO after a coronary catheterization procedure (both angiography and percutaneous coronary intervention-PCI), in improving patency rates of the radial artery at 4 weeks after the procedure, compared with no-anticoagulation treatment. Secondary objectives: To compare local access site and systemic complications (bleeding events, pseudoaneurysm, arteriovenous fistula) at 4 weeks after the procedure between the two groups.