Trajectories of the systemic pulsatility index after CF-LVAD implantation and clinical impact

INTRODUCTION: Continuous-flow left ventricular assist devices (CF-LVAD) have been increasingly implemented in China as a vital life-support strategy for patients with end-stage heart failure. Non-pulsatile blood flow is a defining physiological characteristic of CF-LVAD. Although an association between reduced pulsatility and adverse outcomes continues to be proposed, robust clinical evidence remains lacking. METHODS: Retrospective study of adults (>18 years) receiving CF-LVAD at four Chinese centers (Jan 2019 - Jul 2024) was conducted. Systemic pulsatility index (SPI, calculated as pulse pressure divided by the mean arterial pressure) was derived from blood pressure measurements pre-LVAD and serially post-LVAD (days 1,7,14,21,28). Latent Class Trajectory Modeling (LCTM) identified distinct population groups based on SPI trajectories. The primary outcome of this study was major adverse events (MAE) within 90 days, including all-cause mortality and complication events. The secondary outcome was the evaluation of each complication event, mortality, ICU and hospital-free days. RESULTS: Among 115 LVAD patients (mean age 49.4 years, 87.8% male, mean LVEF 24.8%), LCTM failed to identify distinct groups when including pre-LVAD SPI. Overall, SPI markedly declined post-implantation compared to baseline. However, LCTM using only post-LVAD data revealed four distinct SPI trajectory classes. For primary outcome, no significant differences were observed among four groups (Chi-square test P value=0.973). For the secondary outcomes, a significant between-group difference was detected only for postoperative myocardial infarction (MI) (Chi-square test P value=0.040). Specifically, patients with persistently higher SPI post-LVAD had a significantly lower incidence of postoperative MI compared to those with persistently low SPI (OR 0.19, 95% CI 0.05–0.73, p=0.015). Further logistic regression confirmed this association. CONCLUSION: For CF-LVAD patients, a persistently higher SPI in the early post-LVAD period was associated with a reduced incidence of postoperative myocardial infarction.