Spencer, Philip J.

The effects of left ventricular unloading on septal function in patients with left ventricular assist devices (LVADs) have not been well characterized in vivo. The purpose of this study was to evaluate the relationship between markers of septal function with echocardiography in relationship to RV dysfunction and late RV failure after LVAD implantation. A retrospective study was conducted of patients supported on centrifugal-flow LVADs implanted over a 10-year period. Echocardiographic data were collected pre-operatively and up to 2 years after implantation. Interventricular septum (IVS) measurements were taken at end-systole and end-diastole. Interventricular-septal output (ISO) was calculated using the formula: (IVSs–IVSd)×heart rate. A total of 110 patients were included. An immediate and sustained reduction in both lateral annulus systolic velocity (RVS’) and TAPSE were observed after implant (p < 0.0001). However, ISO gradually decreased over time (p < 0.0001). While ISO was not predictive of late RV failure, a decrease in ISO by 25% or greater from pre-implant to hospital discharge was associated with late RV failure (OR 4.8; 95% CI, 1.4–16.5; p = 0.012) even after adjusting for relevant clinical variables (p ≤ 0.01 for each model). RV function is known to be influenced by mechanical ventricular interdependence and we demonstrate that measurement of ISO may be a useful marker in assessing RV dysfunction and predicting RV failure in patients following LVAD implantation.

Although continuous-flow left ventricular assist devices (CF-LVADs) provide an augmentation in systemic perfusion, there is a scarcity of in vivo data regarding systemic pulsatility on support. Patients supported on CF-LVAD therapy (n = 71) who underwent combined left/right catheterization ramp study were included. Aortic pulsatility was defined by the pulsatile power index (PPI), which was also calculated in a cohort of high-output heart failure (HOHF, n = 66) and standard HF cohort (n = 44). PPI was drastically lower in CF-LVAD–supported patients with median PPI of 0.006 (interquartile range [IQR], 0.002–0.012) compared with PPI in the HF population at 0.09 (IQR, 0.06–0.17) or HOHF population at 0.25 (IQR, 0.13–0.37; p < 0.0001 among groups). With speed augmentation during ramp, PPI values fell quickly in patients with higher PPI at baseline. PPI correlated poorly with left ventricular ejection fraction (LVEF) in all groups. In CF-LVAD patients, there was a stronger correlation with LV dP/dt (r = 0.41; p = 0.001) than LVEF (r = 0.21; p = 0.08; p int < 0.001). CF-LVAD support is associated with a dramatic reduction in arterial pulsatility as measured by PPI relative to HOHF and HF cohorts and decreases with speed. Further work is needed to determine the applicability to the next generation of device therapy.

Abstract OBJECTIVES Approximately 10% of lung transplant recipients have had previous cardiothoracic surgery. We sought to determine if previous surgery affects outcomes after lung transplant at a national level. METHODS The United Network for Organ Sharing database was analysed from 2005 to 2019 to include adult patients who underwent lung transplant who had previous cardiac surgery and previous thoracic surgery. T-test and chi-squared analysis were used to compare perioperative outcomes. Long-term survival comparison was performed using the Kaplan–Meier method in an unadjusted and propensity-matched analysis. RESULTS Out of 24 784 lung transplants, 691 (2.7%) had previous cardiac surgery and 1321 (6.5%) had previous thoracic surgery. Operative mortality was worse in previous cardiac surgery [42 (6.1%)] versus no previous cardiac surgery [740 (3.1%), P &lt; 0.001] and in previous thoracic surgery [65 (4.9%)] versus no previous thoracic surgery [717 (3.1%), P &lt; 0.001]. The previous thoracic surgery group had more primary graft failure and treated rejection during the first-year post-transplant. There was no difference in stroke, dialysis, intubation and extracorporeal membrane oxygenation at 72 h. Long-term survival was significantly worse for lung transplant patients who had undergone previous cardiac surgery (median 3.8 vs 6.3 years, P &lt; 0.001) due to an increase in cardiovascular deaths (P = 0.008) and malignancy (P = 0.043). However, there was no difference in previous thoracic surgery (median 6.6 vs 6.1 years, P = 0.337). CONCLUSIONS Previous cardiac surgery prior to lung transplant results in worse survival related to cardiovascular death and malignancies. Previous thoracic surgery worsens perioperative outcomes but does not affect long-term survival.