INTRODUCTION
Pulmonary hypertension (PH) is a pathophysiological disorder, which may
result from multiple cardiovascular and respiratory diseases. According
to ESC/ERS Guidelines for PH in 2022, PH can be classified into two main
subtypes: pre-capillary PH (pulmonary arterial wedge pressure (PAWP) ≤15
mmHg) and post-capillary PH (PAWP >15 mmHg). Pre-capillary
PH is usually related to pulmonary arterial hypertension,
thrombo-embolic PH, or PH due to lung disease or hypoxia, while
postcapillary is mainly associated with heart failure (HF) or valvular
heart diseases, and the two PH subtypes require different therapeutic
strategies.[1] The current guidelines on PH recommend the invasive
measurement of PAWP using right heart catheterization (RHC). However,
when distinguishing pre- from post-capillary PH, except for PAWP
threshold, the patient phenotype and echocardiographic findings
including left atrial (LA) volume, are also needed to be
considered[1].
Echocardiography is an importance modality in the assessment of patients
with suspected or known PH. Also, it is recommended for the non-invasive
diagnostic assessment of suspected PH, especially in patients with lung
disease[1]. Besides, it had been proved that echocardiography had
become an effective alternative method to invasive cardiac
catheterization to help evaluate hemodynamic like PAWP and pulmonary
vascular resistance (PVR) [2-4]. In previous studies,
echocardiographic parameters could be used to accurately differentiate
pre- and post- capillary PH, such as echocardiographic pulmonary to LA
ratio (ePLAR), echocardiographic pulmonary to LA global strain ratio
(ePLAGS), the body surfaced area–indexed left atrial minimum volume
(LAVImin) and so on[5-9]. However, the software above used for
evaluating LA volume and strain were not specifically dedicated to 3D
left atrial measurements.
Recently, commercial software specially used to evaluate left atrial
function has been applied in clinical practice, including 4D auto LA
quantification analysis (LAQ). 4D
auto LAQ is a LA analysis technique that uses 3D volume data to
determine the LA volume of different periods in diastole as well as LA
longitudinal and circumferential strains. It was reported that it had
the advantages of high sensitivity, reproducibility and
accuracy[10], and it was applied to multiple clinical diseases, such
as patients with arrhythmia, the high risk of thromboembolism, type 2
diabetes, heart failure and so on[11-14].
There are no studies published
about LA function assessed by 4D auto LAQ for distinguishing pre- from
post-capillary PH. The purpose of this study was to investigate the
value of LA volume and strain by 4D LAQ for differentiating pre- and
post-capillary PH, and compare with ePLAGS.