Redefining the threshold: pre-transplant pulmonary vascular resistance and post-transplant survival in the HeartMate 3 era
B Aboufrekha, O Khayat, H Itani, A Sena, A Zayed, M Amor, K DulnuanAbstract
Introduction
Elevated pulmonary vascular resistance (PVR) is a known risk factor for right ventricular failure and mortality following heart transplantation. However, the optimal PVR threshold for risk stratification remains undefined in the era of the HeartMate 3 (HM3) left ventricular assist device (LVAD), which offers superior hemocompatibility compared to prior generations.
Methods
We analyzed the UNOS registry for adult heart transplant recipients (2018–2024) bridged with a durable HM3 LVAD. The primary endpoint was post-transplant mortality. An iterative log-rank optimization analysis was performed to identify the PVR cutoff that maximally stratified survival. A multivariable Cox proportional hazards model was constructed to assess independence from confounders, including UNOS listing status.
Results
The final cohort comprised 3,003 patients. The optimal PVR threshold was identified at 3.25 Wood Units (WU). Patients in the High PVR group (≥ 3.25 WU, n=329) had significantly higher mortality than the Low PVR group (< 3.25 WU) at 30 days (7.0% vs. 4.0%, p=0.015) and 3 years (19.1% vs. 13.7%, p=0.010). In multivariable analysis, PVR ≥ 3.25 WU remained a significant independent predictor of mortality (HR 1.31, 95% CI 1.02–1.70, p=0.034). Notably, High Acuity Listing Status (Status 1 or 2) was not independently associated with survival (p=0.110) after adjustment.
Conclusion
In the HeartMate 3 era, pre-transplant PVR ≥ 3.25 WU is a robust independent predictor of post-transplant mortality, distinct from clinical acuity. This threshold offers a novel, physiological benchmark for risk stratification, suggesting that residual pulmonary hypertension requires targeted management even in patients supported by contemporary centrifugal-flow devicesFor image description, please refer to the figure legend and surrounding text.For image description, please refer to the figure legend and surrounding text.