Atrial Septostomy

Abstract

In some forms of pulmonary hypertension progression of pulmonary vascular disease may be too fast to be matched by the right ventricle (RV). Indeed, RV failure is the leading cause of high mortality in patients with pulmonary aterial hypertension (PAH), except for those with Eisenmenger syndrome, who can maintain systemic cardiac output through central right to left shunt. Consequently, atrial septostomy (AS) has been proposed to improve left heart filling, systemic flow and outcome in non-Eisenmenger patients with severe pulmonary hypertension. At present, published series provide data on about 350 precedures performed in over 300 patients. The published evidence indicate 6.8 % peri-procedural and 10.8 % cumulative mortality at 1 month, while another 11.5 % patients who were submitted to atrial septostomy could be transplanted. Hemodynamic effects of AS for 104 procedures for which complete hemodynamic data sets were available showed immediate improvement of left heart filling, and systemic flow at a cost of fall of systemic oxygen saturation, most marked in patients with right atrial pressure (RAP) >20 mmHg at baseline. Despite clinically relevant 37 % increase in systemic cardiac index the peri-procedural mortality in this subgroup was very high, with 11 death after 26 procedures (42 %) contrasting with two periprocedural death in patients with RAP below 10 mmHg (2.5 %). No randomized trial have ever been performed to assess the long term effects of AS. Balloon dilatations not supported by stents or fenestrated devices do not protect from elastic recoil and small orifices often close. Therefore septostomies should be made earlier – before severe RV failure with high RAP develops – but larger. New technical developments, including remote controlled devices with modifiable shunt fractions and preventing from re-occlusion of the septostomy orifice should improve safety and long term effects of atrial septostomy.