Study of the effect of Occlutech Atrial Flow Regulator on symptoms, hemodynamics, and echocardiographic parameters in advanced pulmonary arterial hypertension

Abstract

Optimal sized balloon atrial septostomy improves hemodynamics in advanced pulmonary arterial hypertension. Occlutech Atrial Flow Regulator is designed to provide an atrial septal fenestration diameter titrated according to the age and right atrial pressures. This observational study analyzed symptoms, exercise distance, oxygen saturations, hemodynamics and echocardiographic parameters after Atrial Flow Regulator implantation in patients with syncope or right-heart failure. Patients with high-risk predictors of mortality during septostomy were scrutinized. Thirty-nine patients (9 children) with syncope (34/39) or right-heart failure (27/39) underwent Atrial Flow Regulator implantation without procedural complications. Six-minute walk distance increased from 310 ± 158.2 to 376.4 ± 182.6 m, none developed syncope. Oxygen saturations reduced from 96.4 ± 6.4% to 92 ± 4.9% at rest and further to 80.3 ± 5.9% on exercise. Right atrial pressures reduced from 9.4 ± 5 (2–27) mmHg to 6.9 ± 2.6 (1–12) mmHg, while cardiac index increased from 2.4 ± 0.8 (0.98–4.3) to 3 ± 1 (1.1–5.3) L/min/m 2 and systemic oxygen transport increased from 546.1 ± 157.9 (256.2–910.5) to 637.2 ± 191.1 (301.3–1020.2) ml/min. Echocardiographic improvement included significant reduction of pericardial effusion and inferior caval congestion at a median follow-up of 37 months. Overall survival improved except two early and one late deaths in high-risk patients. Five of seven patients with advanced disease and key hemodynamic predictors of mortality survived. Acute hemodynamic benefits in pulmonary arterial hypertension after Atrial Flow Regulator were improved cardiac output, systemic oxygen transport, and reduced right atrial pressures. Improvement of symptoms especially syncope, exercise duration, and right ventricular systolic function as well as device patency were sustained on mid-term follow-up. Implantation was safe in all including young children without procedural complications. Mortality was noted only in patients who had high-risk predictors and patients at advanced stage of the disease.