Predictive Value of Pulmonary Vascular Remodeling Indices after LVAD Implantation

Abstract

Purpose Secondary pulmonary hypertension with pulmonary vascular (PV) remodeling is deemed to predict poor outcomes after left ventricular assist device (LVAD) implant, but supporting evidence is lacking. This study examines the predictive role of preoperative hemodynamic indices reflecting PV remodeling on right ventricular failure (RVF) and early mortality. Methods and Materials A single-center review of 208 patients receiving LVADs between June 2005 and June 2012 was conducted. Pulmonary artery systolic pressure (PASP), transpulmonary gradient (TPG), PV resistance (PVR), PA compliance (PAC; stroke volume divided by PA pulse pressure), right ventricular stroke work index (RVSWI), LV transmural filling pressure (LVTFP; pulmonary capillary wedge minus right atrial pressure), and PV impedance score (PVIS; ratio of PVR/PAC) were obtained from preoperative catheterization reports. Patients were grouped by operative mortality (death within index hospital stay or 30 days of surgery) and RVF requiring an RVAD. Results Operative mortality and RVF were seen in 41 (19.6%) and 21 (10.1%) patients respectively. Figure 1 shows the groups’ hemodynamic indices. PASP, TPG, and RVSWI were similar in patients with early mortality or RVF and their respective controls. Lower PVR, PVIS, LVTFP, and a higher PAC were associated with early mortality. RVF patients had lower PVIS than controls. Conclusions While the mechanism requires further study, low PVR, high PAC, and low PVIS predicted early mortality instead of better outcome after LVAD implantation. RVF was predicted only by low PVIS, a novel index combining static and dynamic elements of RV afterload. Narrowing of LVTFP may reflect poor RV-PA coupling. These data solicit new perspectives on preoperative hemodynamic indices.