title: Sildenafil versus nitric oxide for acute vasodilator testing in pulmonary arterial hypertension.
abstract: Vasoreactivity testing with inhaled NO is recommended for pulmonary arterial hypertension (PAH) because of its therapeutic and prognostic value. Sildenafil has acute pulmonary vasodilating properties, but its diagnostic and prognostic impact in PAH is unknown. Our objective was to compare acute vasodilating responses to sildenafil and those to NO during right heart catheterization and also their prognostic values in patients with PAH. Ninety-nine patients with idiopathic PAH and 99 with associated PAH underwent vasoreactivity testing with NO and sildenafil. Only mild adverse effects of sildenafil, in the form of hypotension, were observed, at a rate of 4.5%. The acute responder rate was 8.1% for NO and 11.6% for sildenafil. The NO-induced response in mean pulmonary arterial pressure and cardiac output correlated with the response to sildenafil. Thirteen patients were long-term responders to calcium channel blockers (CCBs), and 3 of them were correctly identified by acute vasoreactivity test with both drugs. The specificity of the vasoreactivity test for identifying long-term CCB responders was 88.9% for NO and 85.1% for sildenafil testing. A trend toward better survival was found in sildenafil and NO responders, compared with nonresponders. Use of sildenafil for vasoreactivity testing is safe. Sildenafil may be useful as alternative vasoreactivity-testing agent, identifying the same number of long-term CCB responders as NO. However, NO seems to be a more ideal testing drug because of its pharmacologic properties. Moreover, sildenafil vasoreactivity testing might contribute to an improved estimate of prognosis among patients with PAH.
authors.affiliation: University of Giessen and Marburg Lung Center, Giessen, Germany, member of the German Center for Lung Research (DZL) ; Department of Internal Medicine V, University of Munich, Munich, Germany ; Comprehensive Pneumology Center, Munich, Germany, member of the German Center for Lung Research (DZL).
authors.forename: Katrin
authors.initials: K
authors.lastname: Milger
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Janine F
authors.initials: JF
authors.lastname: Felix
authors.affiliation: University of Giessen and Marburg Lung Center, Giessen, Germany, member of the German Center for Lung Research (DZL) ; Department of Internal Medicine, Health Center Wetterau, Friedberg, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Voswinckel
authors.affiliation: University of Giessen and Marburg Lung Center, Giessen, Germany, member of the German Center for Lung Research (DZL).
authors.forename: Natascha
authors.initials: N
authors.lastname: Sommer
authors.affiliation: Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Oscar H
authors.initials: OH
authors.lastname: Franco
authors.affiliation: University of Giessen and Marburg Lung Center, Giessen, Germany, member of the German Center for Lung Research (DZL).
authors.forename: Friedrich
authors.initials: F
authors.lastname: Grimminger
authors.affiliation: University of Giessen and Marburg Lung Center, Giessen, Germany, member of the German Center for Lung Research (DZL) ; Comprehensive Pneumology Center, Munich, Germany, member of the German Center for Lung Research (DZL) ; Asklepios Klinik Gauting, Gauting, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Reichenberger
authors.affiliation: University of Giessen and Marburg Lung Center, Giessen, Germany, member of the German Center for Lung Research (DZL).
authors.forename: Werner
authors.initials: W
authors.lastname: Seeger
authors.affiliation: University of Giessen and Marburg Lung Center, Giessen, Germany, member of the German Center for Lung Research (DZL).
authors.forename: Hossein A
authors.initials: HA
authors.lastname: Ghofrani
authors.affiliation: University of Giessen and Marburg Lung Center, Giessen, Germany, member of the German Center for Lung Research (DZL) ; Department of Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands.
authors.forename: Henning
authors.initials: H
authors.lastname: Gall
keywords: nitric oxide; pulmonary arterial hypertension; sildenafil; vasoreactivity testing