title: Pulmonary artery distensibility in pulmonary arterial hypertension: an MRI pilot study.
abstract: Pulmonary arterial hypertension (PAH) is a disease of the small vessels in which there is a substantial increase in pulmonary vascular resistance leading to right ventricle failure and death. Invasive haemodynamic evaluation is mandatory not only for diagnosis confirmation but also to address prognosis and eligibility for the use of calcium-channel blockers through an acute vasodilator challenge. Noninvasive surrogate response markers to the acute vasodilator test have been sought. In the present study, the relationship between pulmonary artery distensibility, assessed using magnetic resonance imaging (MRI), and response to acute vasodilator tests was investigated. In total, 19 patients diagnosed with idiopathic PAH without any specific treatment were evaluated. Within a 48-h window after pulmonary artery catheterisation, patients underwent cardiac MRI. Cardiac index, calculated after the determination (invasively and noninvasively) of cardiac output, showed excellent correlation, as did right atrial pressure and right ventricle ejection fraction. Pulmonary artery distensibility was significantly higher in responders. A receiver operating characteristic curve analysis has shown that 10% distensibility was able to differentiate responders from nonresponders with 100% sensitivity and 56% specificity. The present findings suggest that magnetic resonance imaging and pulmonary artery distensibility may be useful noninvasive tools for the evaluation of patients with pulmonary hypertension.
authors.affiliation: Pulmonary Division, Pulmonary Hypertension Unit, Heart Institute, University of São Paulo Medical School, São Paulo, Brazil.
authors.forename: C
authors.initials: C
authors.lastname: Jardim
authors.forename: C E
authors.initials: CE
authors.lastname: Rochitte
authors.forename: M
authors.initials: M
authors.lastname: Humbert
authors.forename: G
authors.initials: G
authors.lastname: Rubenfeld
authors.forename: D
authors.initials: D
authors.lastname: Jasinowodolinski
authors.forename: C R R
authors.initials: CR
authors.lastname: Carvalho
authors.forename: R
authors.initials: R
authors.lastname: Souza
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology*; D007091:Image Processing, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide; D010865:Pilot Projects; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000503:physiopathology; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D013318:Stroke Volume / Q000502:physiology; D014664:Vasodilation / Q000502:physiology*; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology
chemical_list: D009569:Nitric Oxide