Treatment and Prognosis of Pulmonary Hypertension in the Left Ventricular Assist Device Patient

Right Atrial Pressure Predicts Mortality Among LVAD Recipients: Analysis of the INTERMACS Database

INTRODUCTION

Risk stratifying candidates for left ventricular assist device (LVAD) is challenging. While INTERMACS profiles provide some prognostic insights, there is an ongoing search for better tools. We studied pre-LVAD haemodynamic parameters in predicting post-LVAD mortality.

METHODS

We analysed the INTERMACS dataset for the ability of right atrial pressure (RAP), pulmonary capillary wedge pressure (PCWP), pulmonary arterial systolic (PASP) and diastolic pressures (PADP), mean pulmonary artery pressure, transpulmonary gradient, cardiac output, cardiac power output and INTERMACS profiles, all recorded before LVAD implantation, to predict mortality.

RESULTS

Among 18,733 patients in the INTERMACS dataset, we found that, RAP was the main significant haemodynamic predictor of mortality (13.1 vs. 14.4 mmHg in survivors and non-survivors, respectively, p<0.001), and a higher RAP also predicted the need for extra-corporeal membrane oxygenation (ECMO) support (p<0.001) and intra-aortic balloon pump (p<0.001). Right atrial pressure had a significantly higher area under the curve (AUC) in predicting mortality compared with PASP (difference between areas 0.0338, p<0.0001), PADP (difference between areas 0.0414, p<0.0001), PCWP (difference between areas 0.0290, p=0.0001) and pulmonary artery pulsatility index (difference between areas 0.0105, p=0.0052). Kaplan Meier survival curves showed that RAP≥13 mmHg was the optimal cut-off value to predict mortality (log-rank p<0.001). On Cox regression analysis, RAP remained an independent predictor of mortality (hazard ratio 1.008, 95% confidence interval 1.003-1.013, p=0.003) after covariate adjustment. According to time of death, a higher RAP remained a significant predictor of mortality at 1 month, 3 months, 6 months, 1 year, and beyond 1 year (all p<0.001). RAP remained a predictor for mortality within INTERMACS profiles. After excluding early deaths (first 3 months), the RAP remained a significant predictor of mortality, while INTERMACS profiles were no longer significant.

CONCLUSIONS

In general, haemodynamic variables, as well as other criteria including INTERMACS profiles, are weak predictors of mortality. Right atrial pressure is the main consistent haemodynamic predictor of mortality in LVAD recipients. It outperforms other haemodynamic parameters, and keeps its value within each INTERMACS profile.

MIF associated with pulmonary hypertension susceptibility and severity in non-dialysis Chronic kidney disease patients

Pulmonary hypertension (PAH) is one of the more serious complications of Chronic kidney disease (CKD), and its exact pathogenesis has not been clarified. As an upstream proinflammatory factor, macrophage migration inhibitor (MIF) is involved in the occurrence and development of many diseases. This study aimed to detect the relationship between serum MIF and PAH in non-dialysis CKD patients. A total of 382 non-dialysis CKD patients were enrolled in this study. Bio-Plex cytokine assay was used to detect MIF. CKD patients were divided into the PAH group and non-PAH group according to echocardiographic results. Relative risk was determined by logistic regression analysis. The pulmonary artery pressure in the CKD group was higher than that in the control group ( p < 0.01). Pulmonary arterial pressure was higher in stage 4 to 5 CKD patients than in Stage 1 to 3 CKD patients ( p < 0. 01), and the incidence of PAH was also increased ( p < 0. 01). MIF in the CKD group were higher than in the control group ( p < 0.05). MIF in CKD patients with PAH were higher than those without PAH ( p < 0.05). Multivariate logistic regression analysis showed that MIF is correlated with PAH (OR = 10.745; 95% CI 2.288–89.447, p < 0.05). PAH is common in non-dialysis CKD patients, and with the deterioration of kidney disease, the incidence of PAH is gradually increased, indicating that MIF plays an important role in the development of PAH in CKD patients.

Implication of Hemodynamic Assessment during Durable Left Ventricular Assist Device Support

Durable left ventricular assist device therapy has improved survival in patients with advanced heart failure refractory to conventional medical therapy, although the readmission rates due to device-related comorbidities remain high. Left ventricular assist devices are designed to support a failing left ventricle through relief of congestion and improvement of cardiac output. However, many patients still have abnormal hemodynamics even though they may appear to be clinically stable. Furthermore, such abnormal hemodynamics are associated with an increased risk of future adverse events including recurrent heart failure, gastrointestinal bleeding, stroke, and pump thrombosis. Correction of residual hemodynamic derangements post-implantation may be a target in improving longitudinal clinical outcomes during left ventricular assist device support. Automatic and timely device speed adjustments considering a patients' hemodynamic status (i.e., with a smart pump) are potential improvements in forthcoming devices.

Decoupling Between Diastolic Pulmonary Artery Pressure and Pulmonary Capillary Wedge Pressure as a Prognostic Factor After Continuous Flow Ventricular Assist Device Implantation

BACKGROUND

A cohort of heart failure (HF) patients receiving left ventricular assist devices (LVADs) has decoupling of their diastolic pulmonary artery pressure and pulmonary capillary wedge pressure. However, the clinical implications of this decoupling remain unclear.

METHODS AND RESULTS

In this prospective study, patients with LVADs underwent routine invasive hemodynamic ramp testing with right heart catheterization, during which LVAD speeds were adjusted. Inappropriate decoupling was defined as a >5 mm Hg difference between diastolic pulmonary artery pressure and pulmonary capillary wedge pressure. The primary outcomes of survival and heart failure readmission rates after ramp testing were assessed. Among 63 LVAD patients (60±12 years old and 25 female [40%]), 27 patients (43%) had inappropriate decoupling at their baseline speed. After adjustment of their rotation speed during ramp testing, 30 patients (48%) had inappropriate decoupling. Uni/multivariable Cox analyses demonstrated that decoupling was the only significant predictor for the composite end point of death and heart failure readmission during the 1 year following the ramp study (total of 18 events; hazards ratio, 1.09; 95% confidence interval, 1.04-1.24; P<0.05). Furthermore, normalization of decoupling (n=8) during ramp testing was significantly associated with higher 1-year heart failure readmission-free survival rate compared with the non-normalized group (n=19, 100% versus 53%; P=0.035).

CONCLUSIONS

The presence of inappropriate decoupling was associated with worse outcomes in patients with LVADs. Prospective, large-scale multicenter studies to validate the result are warranted.