Postoperative Pulmonary Hypertension and Right Ventricular Dysfunction are Independently Associated with Poor Outcomes after LVAD Implantation

Abstract

<h3>Purpose</h3> While preoperative hemodynamic risk factors associated with right ventricular (RV) dysfunction after LVAD are well-established, the relationship between postoperative hemodynamics and subsequent outcomes is poorly defined. <h3>Methods</h3> We analyzed adult patients from the STS-INTERMACS registry with hemodynamic data available at 1 or 3 months after LVAD implant. Hemodynamic parameters analyzed included measures of RV afterload (mean PA pressure [mPAP] and pulmonary vascular resistance [PVR]) and RV function (right atrial pressure [RAP], RAP:PCWP, and pulmonary artery pulsatility index [PAPi]). The primary outcome was the composite of death or late right heart failure (LRHF), and the secondary outcome was gastrointestinal bleeding (GIB), both conditional on survival to 1 month. Associations were assessed using Cox proportional hazards modeling, adjusted for 10 relevant clinical covariates. <h3>Results</h3> Among 1328 patients meeting inclusion criteria, postoperative mean RAP was 9.6 ± 6.0 mmHg and mean PCWP was 13.1 ± 6.9 mmHg. Post-LVAD pulmonary hypertension was common, with 775 (58.4%) patients having mPAP ≥ 20 mmHg and 227 (17.1%) having PVR ≥ 3 WU. mPAP (HR 1.1 per 5 mmHg increase), PVR (HR 1.1 per 1 WU increase), PAPi (HR 1.26 per log-decrease), and RAP:PCWP (HR 1.37 per log-increase) were independently associated with death or LRHF (p < 0.05 for all). When stratified by tertiles of mPAP and either PAPi or RAP:PCWP, risk varied 4-5 fold between patients with the most vs least favorable hemodynamic profiles (Figure). RAP (HR 1.21 per 5 mmHg increase), PAPi (HR 1.3 per log-decrease) and RAP:PCWP (HR 1.39 per log-increase) were associated with GIB (p < 0.01 for all). <h3>Conclusion</h3> Postoperative RV dysfunction and elevated RV afterload are associated with mortality, LRHF, and GIB after LVAD implantation. Whether strategies aimed at optimizing RV function and afterload can reduce the burden of adverse events requires prospective study.