Screening for pulmonary arteriovenous malformations using transthoracic contrast echocardiography: a prospective study

¹ Dept of cardiology
² Pulmonology
³ Radiology, St Antonius Hospital, Nieuwegein, The Netherlands: E-mail: m.van.gent@antonius.net;m.post@antonius.net;j.luermans@antonius.net;r.snijder@antonius.net;c.westermann@antonius.net;t.plokker@antonius.net;t.overtoom@antonius.net; jjmager@mesos.nl

^* To whom correspondence should be addressed. E-mail: m.post{at}antonius.net.

	Abstract

Pulmonary arteriovenous malformations (PAVMs) are associated with severe neurological complications in patients with hereditary hemorrhagic telangiectasias (HHT). The objective of our study was to prospectively establish the diagnostic value of TTCE as a screening technique for PAVM using chest HRCT as the gold standard for PAVMs.

All consecutive adult persons referred for HHT screening underwent a chest HRCT (n=299), TTCE (n=281), arterial blood gas analysis (n=291), shunt fraction measurement (n=111) and chest radiography (n=296).

TTCE was positive in 87 (58.8%), 12 (16.7%) and 4 (6.7%), and chest HRCT was positive in 54 (36.5%), 3(4.2%) and 0 patients with respectively a definite, possible and negative clinical diagnosis HHT. Two patients with a negative TTCE were diagnosed with PAVMs on CT; in both cases the PAVMs were too small for embolotherapy. Sensitivity of TTCE was 97% (95% CI 93.6–98.3) and NPV 99% (95% CI 96.9–99.8). The other diagnostic tests showed a considerable lower diagnostic value.

This prospective study shows that TTCE has an excellent diagnostic value and can be used as an initial screening procedure for PAVM. The high falsely positive rate of TTCE possibly represents microscopic PAVMs.