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

Abstract

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.

Clinical implications of hemodynamic assessment during left ventricular assist device therapy

“…Excessive decoupling was a strong prognostic predictor of outcomes compared with other indices of PH such as PVR. Normalization of decoupling following a hemodynamic ramp test was associated with lower HF readmission rates [67]. The decoupling itself was not a target of optimization in this study, and the prognostic impact of aggressive normalization of decoupling during ramp test requires further study.…”

Decoupling Between Diastolic Pulmonary Arterial Pressure and Pulmonary Arterial Wedge Pressure at Incremental Left Ventricular Assist Device (LVAD) Speeds Is Associated With Worse Prognosis After LVAD Implantation

“…9 In this study, we focused on the change in the degree of decoupling between the lowest and highest LVAD speeds, which may represent a patient-specific index of decoupling that is independent of the LVAD speed setting.…”

“…Decoupling was defined as the difference between dPAP and PAWP. 9 For example, when dPAP is 14 mmHg and PAWP is 9 mmHg, decoupling is calculated as 5 mmHg.…”

“…9 The aim of this study was to assess if the degree of decoupling changes with incremental changes in LVAD speed during a hemodynamic ramp test, 10 and whether changes in the degree of decoupling predict clinical outcomes.…”

Editor’s Perspective

“…The critical nature of accurate measurement of pulmonary hemodynamics and the importance of those measurements to HF, mechanical circulatory support, and transplant outcomes are explored in several original investigations, as well as expert commentary. [2][3][4][5] The science of pulmonary hypertension intersects in important ways with HF, particularly group 2 pulmonary hypertension, but also the importance of right ventricular function in all types of pulmonary hypertension, centering on coupling between the right ventricle and the pulmonary vasculature. In the coming year, you will see several such Spotlight issues, highlighting areas of growing scientific importance that are increasingly overlapping with the clinical areas of HF, mechanical circulatory support, and transplant.…”