Rationale and design of SCOPE trial: a prospective, multicentre, open-label, randomised controlled trial to evaluate the overall efficacy and safety of a <i>s</i> hort-term anticoagulation strategy versus <i>co</i> nventional single antiplatelet therapy in patients with severe aortic stenosis without indications for anticoagulation or dual antiplatelet therapy <i>p</i> ost-transcatheter aortic valve r <i>e</i> placement