Original Research
Relative Importance of Baseline and Longitudinal Evaluation in the Follow-Up of Vasodilator Therapy in Pulmonary Arterial Hypertension

https://doi.org/10.1016/j.jcmg.2018.08.017Get rights and content
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Abstract

Objectives

The aim of this study was to evaluate the relative value of baseline and follow-up echocardiographic assessment of pulmonary artery systolic pressure (PASP) and right ventricular (RV) function in assessing response to vasodilator therapy in pulmonary arterial hypertension (PAH).

Background

Routine follow-up of PASP and RV function is widely obtained in patients undergoing treatment for PAH, but the value of this reassessment is uncertain.

Methods

Of 162 prospectively recruited patients with PAH, 96 were included in this analysis of patients with ≥3 sequential echocardiographic studies. PASP and RV function (including right ventricular free wall strain [RVFWS]) were measured at baseline and on follow-up 2-dimensional echocardiography. Univariate and multivariate Cox regression with nested models was used to determine incremental and independent predictors of all-cause mortality.

Results

Changes between visits were minimal for all parameters (RVFWS, p = 0.46; RV end diastolic area, p = 0.48; tricuspid annular plane systolic excursion, p = 0.32; PASP, p = 0.66; right atrial area, p = 0.39; and inferior vena cava, p = 0.25). Over 3 years of follow-up, 29 patients died. Baseline RVFWS was an independent predictor of outcome (hazard ratio [HR]: 0.90; 95% confidence interval [CI]: 0.83 to 0.97; p = 0.007), incremental to PASP and other clinical covariates (C statistic = 0.74, p = 0.001). Those who died showed no differences in RVFWS (p = 0.50), PASP (p = 0.90), and tricuspid annular plane systolic excursion (p = 0.83) between visits. When baseline measures and follow-up time were accounted for, mean changes in RVFWS (HR: 0.78; 95% CI: 0.63 to 0.96; p = 0.002), right atrial area (HR: 1.20; 95% CI: 1.07 to 1.40; p = 0.003), and inferior vena cava (HR: 66.5; 95% CI: 8.5 to 520.5; p < 0.001) over follow-up were significant in predicting outcome.

Conclusions

In PAH, baseline RV function (RVFWS) is a strong predictor of outcome, independent of PASP. Changes throughout therapy appear minimal, and only changes in RVFWS, inferior vena cava, size, and right atrial area were associated with outcome.

Key Words

pulmonary artery pressure
pulmonary hypertension
RV function
RV strain

Abbreviations and Acronyms

6MWD
6-min walk distance
CMR
cardiac magnetic resonance
FAC
fractional area change
IVC
inferior vena cava
PAH
pulmonary arterial hypertension
PASP
pulmonary artery systolic pressure
RAA
right atrial area
RV
right ventricular
RVEDA
right ventricular end-diastolic area
RVFWS
right ventricular free wall strain
TAPSE
tricuspid annular plane systolic excursion

Cited by (0)

The authors have reported that they have no relationships relevant to the contents of this paper to disclose. Allan Klein, MD, served as Guest Editor for this paper.