Atrial Septostomy and Left Ventricular Venting During Peripheral VA-ECMO

Peripheral venoarterial (VA)-extracorporeal membrane oxygenation (ECMO) increases left ventricular (LV) afterload, and therefore the risk of LV distension, pulmonary edema, and cardiac stasis. Balloon atrial septostomy (BAS) provides atrial-level unloading, but the durability of LV venting remains uncertain.

This study aimed to evaluate the clinical effectiveness of BAS for LV venting in patients requiring peripheral VA-ECMO for cardiogenic shock (CS).

The authors conducted a retrospective study of consecutive adults with CS supported with peripheral VA-ECMO who underwent BAS for LV unloading at an academic center (2019-2024). The primary endpoint was LV venting failure, a composite of pulmonary edema, LV distension, spontaneous echocardiographic contrast, LV or aortic root thrombus, stroke due to ECMO, or escalation to additional mechanical support.

A total of 28 patients were included in the study. BAS resulted in a significant reduction in mean left atrial pressure (20.5-13.5 mm Hg; P < 0.001). Durable LV venting was achieved in a subset of patients; however, LV venting failure occurred in 53.6%, driven primarily by pulmonary edema. Pulse-pressure trajectories differed according to eventual LV venting-failure status (interaction P = 0.018). Model-estimated pulse pressure was higher at 48 hours (P = 0.010) and 72 hours (P = 0.031) among patients who ultimately did not experience venting failure.

Among patients receiving peripheral VA-ECMO for CS, BAS achieves atrial-level decompression and may provide durable LV venting in select patients, although venting failure remains common. Observed arterial pulse-pressure trajectories differed according to eventual LV venting failure status.