Echocardiographic dP/dt as a Novel Tool to Predict Early Right Ventricular Failure in Patients with Left Ventricle Assist Devices

Abstract

Introduction Right ventricle failure (RVF) remains a major source of morbidity and mortality with Left Ventricle Assist devices (LVAD) use. Common invasive and non-invasive measurements of RV function have not been predictive of RVF post-LVAD placement. The rate of rise of intra-ventricular pressure (dP/dt) correlates with myocardial contractility and is less dependent of loading conditions. We sought to evaluate if TTE derived dP/dt predicts early RVF after LVAD implantation. Methods We retrospectively reviewed all patients who had TTE, off inotropic support within 3 months prior to LVAD implant in our center. RV dP/dt was assessed by two independent reviewers using continuous-wave TR Doppler recordings. The time required for TR velocity to increase from 0.5 to 2 m/s was measured and used to calculate dP/dt by the simplified Bernoulli equation. Baseline demographics, right heart catheterization measurements, and clinical outcomes of RVF failure and mortality were obtained by chart review. Presence and severity of RVF was based on current INTERMACS criteria. Non-parametric Mann-Whitney U test was used to compare groups that had mild or no RVF vs those that had moderate or severe RVF. Results From a total of 60 patients, 39 had TTE performed while off inotropic support and 23 had an adequate TR Doppler signal for analysis. Moderate or severe RVF was present in 10/23 (43%) of patients with average dP/dt 233 ± 58 mmHg/sec. The remaining 13/23 had mild or no RVF with an average dP/dt 314 ± 93 mmHg (p = 0.036). Pre-operative tricuspid annular plane systolic excursion (TAPSE), RV free wall tissue Doppler velocity (s’), RV fractional area change, pulmonary artery pulsatility index (PAPi), and the ratio of central venous pressure to pulmonary capillary wedge pressure (CVP/PCWP) ratio did not significantly differ between groups (Figure 1). Of note, no patients with dP/dt greater than 325 mmHg/sec had moderate or severe RVF. Conclusions TTE derived RV dP/dt strongly correlates with post LVAD RVF, and when greater than 325 mmHg/sec identifies those at low risk for RVF. Future prospective studies are needed to determine if this TTE measurement independently predicts a favorable outcome in LVAD patients.