Pressure reflection in the pulmonary circulation by echocardiography in patients with left heart disease indicates reactive pulmonary hypertension

Pulmonary Hypertension Phenotype Can Be Identified in Heart Failure With Reduced Ejection Fraction Using Echocardiographic Assessment of Pulmonary Artery Pressure With Supportive Use of Pressure Reflection Variables

BACKGROUND

Pulmonary hypertension (PH) is frequent in patients with heart failure and reduced ejection fraction (HFrEF) with 2 different phenotypes: isolated postcapillary PH (IpcPH) and, with the worst prognosis, combined pre- and postcapillary PH (CpcPH). The aims of the present echocardiography study were to investigate (1) the ability to identify PH phenotype in patients with HFrEF using the newly adopted definition of PH (mean pulmonary artery pressure >20 mm Hg) and (2) the relationship between PH phenotype and right ventricular (RV) function.

METHODS

One hundred twenty-four patients with HFrEF consecutively referred for heart transplant or heart failure workup were included with echocardiography and right heart catheterization within 48 hours. We estimated systolic pulmonary artery pressure (sPAP_Doppler) and used a method to detect increased pulmonary vascular resistance (>3 Wood units) based on predefined thresholds of 3 pressure reflection (PRefl) variables (the acceleration time in the RV outflow tract [RVOT], the interval between peak RVOT and peak tricuspid regurgitant velocity, and the RV pressure augmentation following peak RVOT velocity).

RESULTS

Using receiver operator characteristic analysis in a derivation group (n = 62), we identified sPAP_Doppler ≥35 mm Hg as a cutoff that in a test group (n = 62) increased the likelihood of PH 6.6-fold. The presence of sPAP_Doppler >40 mm Hg and 2 or 3 positive PRefl variables increased the probability of CpcPH 6- to 8-fold. A 2-step approach with primarily assessment of sPAP_Doppler and the supportive use of PRefl variables in patients with mild/moderate PH (sPAP_Doppler 41-59 mm Hg) showed 76% observer agreement and a weighted kappa of 0.63. The steady-state (pulmonary vascular resistance) and pulsatile (compliance, elastance) vascular loading are increased in both IpcPH and CpcPH with a comparable degree of RV dysfunction.

CONCLUSIONS

The PH phenotype can be identified in HFrEF using standard echocardiographic assessment of pulmonary artery pressure with supportive use of PRefl variables in patients with mild to moderate PH.

A Novel Non-Invasive Method for Estimating Elevated Pulmonary Vascular Resistance Based on Echocardiographic Assessment of Pulmonary Artery Wave Reflection

BACKGROUND

Several non-invasive methods for pulmonary vascular resistance (PVR) measurement are proposed, but none are sufficiently accurate for use in clinical practice. This study proposes a new echocardiographic method of pulmonary artery wave reflection and investigates its efficacy in managing patients with pulmonary hypertension.Methods and Results:In total, 83 patients with left heart disease, pulmonary arterial hypertension, and chronic thromboembolic pulmonary hypertension (CTEPH), who underwent Doppler echocardiography and right heart catheterization, were included in the study. Pulmonary artery wave reflection was characterized by separating the pulmonary artery pressure waveform into forward and backward (Pb) waves, based on wave intensity. Pulmonary artery pressure waveforms were estimated from continuous Doppler tracings of tricuspid regurgitation velocity, and flow velocity was measured using pulsed Doppler of the right ventricular outflow tract. Pb-peak was compared with catheter hemodynamic indices, and with PVR by Abbas 2003, 2013 and Haddad in relation to increased catheter PVR. Catheter PVR and Pb were strongly correlated (r=0.77, P<0.001). The areas under the receiver operator characteristic curve for Pb-peak, PVR by Abbas 2003, 2013 and Haddad were 0.91, 0.72, 0.80, and 0.80, respectively, and were used to detect an increase in PVR (>3 Woods units).

CONCLUSIONS

This study describes a novel, simple, and non-invasive echocardiography method to assess pulmonary wave reflected pressure to identify patients with pulmonary hypertension due to increased PVR.

Shape of the Pulmonary Artery Doppler-Flow Profile Predicts the Hemodynamics of Pulmonary Hypertension Caused by Left-Sided Heart Disease

BACKGROUND

Previous studies demonstrated a relationship between pulmonary hemodynamics and shape of pulmonary artery (PA) Doppler-flow profiles in a mixed pulmonary hypertension (PH) cohort.

HYPOTHESIS

Shape of PA Doppler-flow profiles could illustrate the hemodynamic characteristics of pulmonary venous hypertension (PVH), especially identifying it with or without pulmonary vascular disease (PVD).

METHODS

We retrospectively analyzed hemodynamic, echocardiographic, and clinical data from 47 patients referred for PH caused by left-sided heart disease (PH-LHD). All patients underwent right-sided heart catheterization within 1 week of echocardiography. We concluded a simple echocardiographic prediction rule to give hemodynamic differentiation of PVH with PVD, defined as capillary wedge pressure >15 mm Hg and pulmonary vascular resistance (PVR) >3 Wood units (WU). The PA Doppler-flow profiles were categorized into 2 groups, no notch (NN) and MSN/LSN.

RESULTS

The PVR was higher in the MSN/LSN group at 4.04 WU (interquartile range, 3.1-5.3) vs the NN group at 1.91 WU (interquartile range, 1.8-3.0; P < 0.001). Pulmonary artery Doppler-flow notching (MSN and LSN) was highly associated with PVR >3 WU, whereas the NN pattern predicted a PVR ≤3 WU (odds ratio: 19.8, 95% confidence interval: 4.3-91.3) and normal transpulmonary pressure gradient ≤12 mm Hg (odds ratio: 4.7, 95% confidence interval: 1.3-16.2). The NN pattern had 74% specificity and 88% sensitivity for PVR ≤3 WU.

CONCLUSIONS

Absence of PA Doppler-flow notching was highly associated with PVH, and a notching pattern indicated PVH with PVD in the PH-LHD cohort.