Right Ventricular Longitudinal Strain Predicts Weaning Success in Cardiogenic Shock Patients Supported by a Microaxial Flow Pump.

Importance: The effect of left ventricular (LV) mechanical unloading on right ventricular (RV) function in patients with cardiogenic shock (CS) remains poorly understood, yet may have significant implications for device weaning and patient outcomes.

Objectives: To investigate the short-term effects of LV unloading using a transaortic valve axial flow pump (Impella) on RV function and to assess its predictive value for successful device weaning in patients with CS.

Design: Retrospective analysis of CS patients who received Impella support between 2018 and 2021.

Setting and participants: Single-center study conducted at the German Heart Center, Charité Universitätsmedizin Berlin, Germany. The study included 41 ICU patients with CS due to LV dysfunction who required Impella support for at least 72 hours.

Main outcomes and measures: Biventricular function was evaluated by echocardiography and advanced strain imaging during the weaning process. The primary outcome was successful Impella weaning. Associations between changes in RV free-wall longitudinal strain (RVFWLS) and weaning outcomes were assessed using multiple logistic regression.

Results: Patients received Impella support for a median duration of 216 hours (interquartile range, 144-264 hr). Eighteen patients (43.9%) were successfully weaned, while 23 (56.1%) required LVAD implantation (31.7%) or died (24.4%). LV unloading significantly improved RV systolic function, as demonstrated by increased RV fractional area change, tricuspid annular systolic velocity, and RVFWLS. Notably, patients who failed weaning showed a significantly lower change in RVFWLS (ΔRVFWLS) during the weaning process, which emerged as an independent predictor of weaning outcome.

Conclusions and relevance: Impella-mediated LV unloading enhances both LV and RV function in CS patients. However, inadequate RV longitudinal systolic reserve, as indicated by lower ΔRVFWLS during weaning, is associated with weaning failure and may guide clinical decisions regarding prolonged mechanical circulatory support or transition to durable devices.