title: Grade of pulmonary right-to-left shunt on contrast echocardiography and cerebral complications: a striking association.
abstract: BACKGROUND
  A pulmonary right-to-left shunt (RLS) carries the risk of cerebral paradoxical embolization and severe neurologic complications. Recognizing patients at risk is important to facilitate appropriate management strategies, but a direct relation between pulmonary shunt size and risk of complications remains controversial. This study evaluated the potential relation between pulmonary shunt grade on transthoracic contrast echocardiography (TTCE) and prevalence of cerebral manifestations in patients screened for hereditary hemorrhagic telangiectasia (HHT).
  
  
  METHODS
  We conducted a two-center, cross-sectional study of all consecutive patients screened for HHT between 2004 and 2011. Pulmonary shunt grading on TTCE (grade 0, no microbubbles; grade 1, &lt; 30 microbubbles; grade 2, 30-100 microbubbles; grade 3, &gt; 100 microbubbles) was performed according to contrast opacification of the left ventricle. Cerebral complications were defined as ischemic stroke, transient ischemic attack, or brain abscess diagnosed by a neurologist and confirmed by appropriate imaging techniques.
  
  
  RESULTS
  A pulmonary RLS was present in 530 out of 1,038 patients (51.1%; mean age, 44.3 ± 15.6 years; 58.6% women). The presence of a cerebral manifestation (n = 51) differed significantly among pulmonary shunt grades on TTCE: 1.4%, 0.4%, 6.5%, and 20.9% for grades 0, 1, 2 and 3, respectively. A pulmonary shunt grade 1 was not associated with an increased prevalence of cerebral manifestations (OR, 0.44; 95% CI, 0.05-4.13; P = .47), whereas pulmonary shunt grade 2 (OR, 4.78; 95% CI, 1.14-20.0; P = .03) and grade 3 (OR, 10.4; 95% CI, 2.4-45.3; P = .002) were both independent predictors for the prevalence of a cerebral ischemic event or brain abscess.
  
  
  CONCLUSIONS
  The pulmonary RLS grade on TTCE is strongly associated with the prevalence of cerebral complications in patients screened for HHT.
authors: Department of Cardiology, St. Antonius Hospital, Nieuwegein, The Netherlands. Electronic address: S.Velthuis@antoniusziekenhuis.nl.
authors: Sebastiaan
authors: S
authors: Velthuis
authors: Department of Gastroenterology, Maggiore Hospital, Crema, Italy.
authors: Elisabetta
authors: E
authors: Buscarini
authors: Department of Cardiology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Marco W F
authors: MWF
authors: van Gent
authors: Department of Cardiology, Maggiore Hospital, Crema, Italy.
authors: Pietro
authors: P
authors: Gazzaniga
authors: Department of Gastroenterology, Maggiore Hospital, Crema, Italy.
authors: Guido
authors: G
authors: Manfredi
authors: Genetic Institute, University of Pavia, Pavia, Italy.
authors: Cesare
authors: C
authors: Danesino
authors: Department of Neurology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Wouter J
authors: WJ
authors: Schonewille
authors: Department of Pulmonology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Cornelis J J
authors: CJJ
authors: Westermann
authors: Department of Pulmonology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Repke J
authors: RJ
authors: Snijder
authors: Department of Pulmonology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Johannes J
authors: JJ
authors: Mager
authors: Department of Cardiology, St. Antonius Hospital, Nieuwegein, The Netherlands.
authors: Martijn C
authors: MC
authors: Post
mesh_terms: D000328:Adult; D001165:Arteriovenous Malformations / Q000150:complications* / Q000000981:diagnostic imaging*; D002561:Cerebrovascular Disorders / Q000453:epidemiology / Q000209:etiology*; D003287:Contrast Media; D003430:Cross-Sectional Studies; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011667:Pulmonary Veins / Q000000981:diagnostic imaging*; D018570:Risk Assessment; D012307:Risk Factors; D013683:Telangiectasia, Hereditary Hemorrhagic / Q000150:complications* / Q000000981:diagnostic imaging*
chemical_list: D003287:Contrast Media