Evolution of pulmonary arteriovenous malformations: the role of contrast echocardiography

Abstract

Background

Pulmonary arteriovenous malformations (PAVMs) are direct connections between the pulmonary artery and the pulmonary vein, mostly associated with hereditary haemorrhagic telangiectasia (HHT). PAVMs can lead to severe neurological complications – such as stroke and brain abscess. The risk of complications decreases after embolisation. Therefore, screening for PAVMs using transthoracic contrast echocardiography (TTCE) is recommended, including a rescreening interval of 5 years.

Research question

Is extension of the interval for re-screening patients without a pulmonary right-to-left shunt (RLS) up to ten years appropriate?

Study design and methods

Adult HHT patients with five- and/ or ten-year follow-up TTCE were included. Patients who underwent PAVM embolisation in the past or at baseline were excluded. The RLS grades and presence of a treatable PAVM were compared to baseline.

Results

In total, 387 patients (median age 45 years (IQR 33-54), 56% female) involving five- and ten-year follow-up data in respectively 363 and 166 patients were included. None of the patients (n=148) without a pulmonary RLS at baseline developed a treatable PAVM after five and ten years. Of the patients with a pulmonary RLS at baseline, 20 (9%) and 3 (3%) developed a treatable PAVM at five- and ten-year follow-up respectively. In the majority of patients, the RLS grade remained stable over time.

Interpretation

On the basis of the results of this retrospective study, we believe that the rescreening interval for HHT patients without a pulmonary RLS at initial screening may be extended to ten years. Those with a pulmonary RLS should be rescreened every five years because treatable PAVMs can evolve.