Optimal Tricuspid Regurgitation Velocity to Screen for Pulmonary Hypertension in Tertiary Referral Centers

Total bile acids levels as a stratification tool for screening portopulmonary hypertension in patients with decompensated cirrhosis

AIM

Echocardiography is necessary for portopulmonary hypertension diagnosis, and identifying patients with cirrhosis who require it is challenging. In this study, we aimed to investigate the utility of the total bile acid (TBA) levels as a screening tool for identifying patients with decompensated cirrhosis who should undergo echocardiography for portopulmonary hypertension diagnosis.

METHODS

We evaluated 135 patients with decompensated cirrhosis who underwent liver transplantation. Subsequently, factors contributing to tricuspid regurgitation pressure gradient (TRPG) elevation (≥30 mmHg) were analyzed using preoperative data, including the TBA levels.

RESULTS

The median age of patients was 58 years (61 women), and 45 and 90 patients had Child-Turcotte-Pugh grades of B and C, respectively. The median TRPG level was 21 mmHg, and 17 patients (12.6%) showed TRPG elevation. Multiple logistic regression analysis revealed that elevated TBA (odds ratio 4.322; p = 0.013) and main pulmonary artery diameter ≥33 mm (odds ratio 4.333; p = 0.016) were significantly associated with TRPG elevation. The TBA cut-off value (167.7 μmol/L) showed a high diagnostic performance, with 70.6% sensitivity and 64.4% specificity. Ursodeoxycholic acid (UDCA) administration increased the TBA levels dose-dependently. Analysis stratified by UDCA use revealed that in patients not taking UDCA (n = 59), elevated TBA levels and younger age significantly contributed to TRPG elevation. However, in those taking UDCA (n = 76), this contribution disappeared, suggesting that UDCA consumption reduced TBA levels' efficiency in diagnosing TRPG elevation.

CONCLUSIONS

The TBA levels may be a potential screening tool for TRPG elevation; however, caution is warranted when interpreting cases treated with UDCA.

Static Immersion and Negative Static Lung Load-Induced Right Ventricle Systolic Function Adaptation: A Risk Factor for Immersion Pulmonary Edema

BACKGROUND

Immersion pulmonary edema (IPE) is a form of hemodynamic edema likely involving individual susceptibility.

RESEARCH QUESTION

Can assessing right ventricle (RV) systolic adaptation during immersion be a marker for IPE susceptibility?

STUDY DESIGN AND METHODS

Twenty-eight divers participated: 15 study participants with a history of IPE (IPE group; mean ± SD age, 40.2 ± 8.2 years; two women) and 13 control participants (no IPE group; mean ± SD age, 43.1 ± 8.5 years; two women) underwent three transthoracic echocardiography studies under three different conditions: dry (participants were in the supine position on an examination table without immersion), surface immersion (participants were floating prone on the water's surface and breathing through a snorkel), and immersion and negative static lung load (divers were submerged 20 cm below the water's surface in the prone position using a specific snorkel connected to the surface for breathing). Echocardiographic measurements included tricuspid annular plane systolic excursion (TAPSE), tissue S' wave, and right ventricle global strain (RVGLS).

RESULTS

For all divers, immersion increased RV preload. In the no IPE group, the increase in RV preload induced by immersion was accompanied by an improvement in the contractility of the RV, as evidenced by increases in TAPSE (17.08 ± 1.15 mm vs 20.89 ± 1.32 mm), S' wave (14.58 ± 2.91 cm/s vs. 16.26 ± 2.77 cm/s), and RVGLS (25.37 ± 2.79 % vs. 27.09 ± 2.89 %). Negative SLL amplified these RV adaptations. In contrast, among divers with IPE, the increase in RV preload did not coincide with an improvement in RV contractility, indicating altered adaptive responses. In the IPE group, the TAPSE values changed from 17.19 ± 1.28 mm to 21.69 ± 1.67 mm and then to 23.55 ± 0.78 mm, respectively, in the dry, surface immersion, and immersion and negative SLL conditions. The S' wave values changed from 13.42 ± 2.94 cm/s to 13.26 ± 2.96 cm/s and then to 12.49 ± 0.77 cm/s, respectively, and the RVGLS values changed from -24.09% ± 2.91% to -23.99% ± 3.38% and then to -21.96% ± 0.55%, respectively.

INTERPRETATION

Changes in RV systolic function induced by immersion (especially with the addition of negative static lung load) vary among divers based on the history of IPE. Analyzing ventricular contractility during immersion, particularly RVGLS, could help to identify individual susceptibility in divers. These findings provide insights for the development of preventive strategies.

TRIAL REGISTRY

Comité de Protection des Personnes; No.: 21.05.05.35821; Recherche Impliquant la Personne Humaine de type 1 (RIPH1) HPS; No.: 2021-A01225-36.

Accuracy of Pulse Oximetry for Long-Term Oxygen Therapy Assessment in Chronic Obstructive Pulmonary Disease

Rationale: Landmark studies of long-term oxygen therapy (LTOT) in patients with chronic obstructive pulmonary disease (COPD) used arterial oxygen pressure (PaO2) to define severe hypoxemia; however, oxygen saturation as measured by pulse oximetry (SpO2) is commonly used instead. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines recommend evaluation with arterial blood gas (ABG) analysis if SpO2 is ⩽92%. This recommendation has not been evaluated in stable outpatients with COPD undergoing testing for LTOT. Objectives: To evaluate the performance of SpO2 compared with ABG analysis of PaO2 and arterial oxygen saturation (SaO2) to detect severe resting hypoxemia in patients with COPD. Methods: Retrospective analysis of paired SpO2 and ABG values from stable outpatients with COPD who underwent LTOT assessment in a single center. We calculated false negatives (FNs) as an SpO2 >88% or >89% in the presence of pulmonary hypertension with a PaO2 ⩽55 mm Hg or ⩽59 mm Hg in the presence of pulmonary hypertension. Test performance was assessed using receiver operating characteristic (ROC) analysis, intraclass correlation coefficient (ICC), test bias, precision, and accuracy root-mean-square (Arms). An adjusted multivariate analysis was used to evaluate factors affecting SpO2 bias. Results: Of 518 patients, the prevalence of severe resting hypoxemia was 74 (14.3%), with 52 missed by SpO2 (FN, 10%), including 13 (2.5%) with an SpO2 > 92% (occult hypoxemia). FNs and occult hypoxemia in Black patients were 9% and 1.5%, respectively, and were 13% and 5%, respectively, among active smokers. The correlation between SpO2 and SaO2 was acceptable (ICC = 0.78; 95% confidence interval, 0.74-0.81); and the bias of SpO2 was 0.45%, with a precision of 2.6 (-4.65 to +5.55%) and Arms of 2.59. These measurements were similar in Black patients, but in active smokers, correlation was lower and bias showed greater overestimation of SpO2. ROC analysis suggests that the optimal SpO2 cutoff to warrant LTOT evaluation by ABG analysis is ⩽94%. Conclusions: SpO2 as the only measure of oxygenation carries a high FN rate in detecting severe resting hypoxemia in patients with COPD undergoing evaluation for LTOT. Reflex measurement of PaO2 by ABG analysis should be used as recommended by GOLD, ideally at a cutoff higher than an SpO2 ⩽92%, especially in active smokers.

Pulmonary Hypertension Association's 2022 International Conference Scientific Sessions Overview

The considerable progress made in recent years in the diagnosis, risk stratification, and treatment of pulmonary hypertension was highlighted during the most recent edition of the Pulmonary Hypertension Association Scientific Sessions, which was held in Atlanta, Georgia from June 9 to 11, 2022, with the theme: Vision for the PHuture: The Evolving Science and Management of PH. Content presented over the 3-day conference focused on scientific and management updates since the last sessions were held in 2018 and included didactic talks, debates, and roundtable discussions across a broad spectrum of topics related to pulmonary hypertension. This article aims to summarize the key messages from each of the session talks.