The adding value of fluid challenge and balloon occlusion tests in patients with atrial septal defect

Background Careful, step-wise assessment is required in all patients with an atrial septal defect (ASD) to exclude pre-existing pulmonary vascular disease or left ventricular disease. Fluid challenge test (FCT) and balloon occlusion testing (BOT) may unmask left ventricular disease and challenge the pulmonary circulation, but their complementary role in the evaluation of patients with “operable” ASD is not well established. Aim To evaluate the haemodynamic changes of the pulmonary circulation by FCT and BOT in ASD patients undergoing percutaneous closure according to the current guidelines. Methods Consecutive patients selected for percutaneous ASD closure underwent invasive hemodynamic assessment at baseline and after BOT, FCT and both. Results Fifty patients (mean age 47.3±11.7 years, 72% female) were included. All patients had a pulmonary-to-systemic flow ratio (QP/QS) ≥1.5, pulmonary vascular resistance (PVR) FCT caused a marked increase in pulmonary blood flow of almost 2 liters (p0.1). No difference was observed in the PAWP response to FCT, BOT or both between groups; no patients reached a PAWP ≥18 mmHg following FCT or BOT alone, but 4 (8%) patients did following the addition of FCT to BOT. No acute clinical adverse events were experienced by any patients. Conclusions None of the reported ASD patients presented with FCT criteria of post-capillary PH (that is a PAWP >18 mmHg). Even small rises in PVR may have significant implications on cardiovascular haemodynamics. In fact, patients with PVR Funding Acknowledgement Type of funding sources: None. Figure 1