Safety evaluation of oral anticoagulation in pulmonary arterial hypertension: observational study of patients followed in two pulmonary hypertension referral centrers in Spain and United States - Villamañán Bueno, María Elena (Director); Rios Blanco, Juan Jose (Director); Alvarez-Sala Walther, Rodolfo (Miembro del tribunal) Doctorando: Roldán Sevilla, Tamara (2016)