Abstract 4367008: Pulmonary Artery Pulsatility Index as Predictor of Right Heart Failure During Left Ventricular Unloading With Microaxial Flow Pump

Research Questions: Whether baseline pulmonary artery pulsatility index (PAPi) predicts right heart failure (RHF) in patients treated for cardiogenic shock with temporary left ventricular mechanical support using microaxial flow pump (mAFP). Background: RHF can lead to increased mortality and morbidity after durable mechanical circulatory support (dMCS) implantation and often occurs during the immediate peri-implant period. While PAPi has emerged as a powerful predictor of RHF in patients undergoing dMCS implantation, its utility in this setting among patients receiving temporary support with mAFP remains unclear. Methods: Patients treated for cardiogenic shock with mAFP support (Impella 2.5, CP, 5.0, or 5.5) between 2016 and 2022 were retrospectively identified. Baseline PAPi was defined as the last recording available prior to mAFP implant. Post-implant hemodynamics were defined as the median values recorded within 24 hours after device placement. RHF was defined by, based on the INTERMACS statement, cardiac index (CI) < 2.2 L/min/m 2 with central venous pressure (CVP) > 16 mmHg post-implantation. Receiver operating characteristic (ROC) curve was constructed to evaluate the ability of baseline PAPi to predict RHF after mAFP placement. Results: A total of 93 patients were included in the analysis. The most frequently used mAFP was Impella CP (n = 76), followed by Impella 5.5 (n = 7), 5.0 (n = 7), and 2.5 (n = 3). Median baseline CI and CVP were 2.11 L/min/m 2 and 16 mmHg, respectively, with a median baseline PAPi of 1.35. Following implantation, 6 patients (6.5%) met criteria for RHF, with a median CI of 1.65 L/min/m 2 and CVP of 20 mmHg. The ROC curve for baseline PAPi yielded an area under the curve (AUC) of 0.696, with an optimal PAPi cutoff of less than 1.06 providing a sensitivity of 83.3% and specificity of 73.6% in predicting RHF post mAFP placement. Conclusion: Baseline decreased PAPi demonstrates moderate predictive value for RHF following mAFP placement. However, the optimal cutoff of less than 1.06 found in our patient cohort undergoing temporary mechanical support is notably lower than the 1.85 threshold previously proposed in dMCS populations. Further study is needed to establish the clinical utility of PAPi in predicting RHF among patients receiving mAFP support.