Left Heart Disease and Pulmonary Hypertension: Are We Seeing the Full Picture?

Diagnostic Value of Serum Galectin-3 Binding Protein Level in Patients with Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) still lacks effective biomarkers to assist in its diagnosis and prognosis. Galectin-3 binding protein (Gal-3BP) plays a role in immune and inflammatory diseases.

OBJECTIVE

This study aimed to evaluate Gal-3BP as a prognostic and predictive factor in patients with PAH.

METHODS

From January 2017 to December 2019, we enrolled 167 consecutive PAH patients and 58 healthy controls. Right heart catheterization (RHC) was used to diagnose PAH. Serum Gal-3BP levels were measured by high-sensitivity human enzyme-linked immunosorbent assay (ELISA).

RESULTS

Serum Gal-3BP levels in the PAH group were significantly higher compared with the control group (4.87±2.09 vs 2.22±0.86 μg/mL, p<0.001). Gal-3BP level was correlated with several hemodynamic parameters obtained from RHC (p<0.001). Multivariate linear regression analysis showed that Gal-3BP was a risk factor for PAH (odds ratio (OR)=2.947, 95% CI: 1.821-4.767, p<0.001). The optimal cut-off value of serum Gal-3BP level for predicting PAH was 2.89 μg/mL (area under the curve (AUC)=0.860, 95 % CI: 0.811-0.910, p<0.001). Kaplan-Meier analysis showed that Gal-3BP levels above the median (4.87 μg/mL) were associated with an increased risk of death in patients with PAH (hazard ratio (HR)=8.868, 95 % CI: 3.631-21.65, p<0.0001). Cox multivariate risk regression analysis showed that Gal-3BP was a risk factor for death in PAH patients (HR=2.779, 95 % CI: 1.823-4.237, p<0.001).

CONCLUSION

Serum Gal-3BP levels were increased in patients with PAH, and levels of Gal-3BP were associated with the severity of PAH. Gal-3BP might have predictive value for the diagnosis and prognosis of PAH.

Correlation analysis between lung ultrasound scores and pulmonary arterial systolic pressure in patients with acute heart failure admitted to the emergency intensive care unit

Background

No convenient, inexpensive, and non-invasive screening tools exist to identify pulmonary hypertension (PH) - left heart disease (LHD) patients during the early stages of the disease course. This study investigated whether different methods of lung ultrasound (LUS) could be used for the initial investigation of PH-LHD.

Methods

This was a single-center prospective observational study which was performed in the Zigong Fourth People's Hospital. We consecutively enrolled patients with heart failure (HF) admitted to the emergency intensive care unit from January 2018 to May 2020. Transthoracic echocardiography and LUS were performed within 24 h before discharge. We used the Spearman coefficient for correlation analysis between ultrasound scores and pulmonary arterial systolic pressure (PASP). Bland-Altman plots were generated to inspect possible bias, and receiver operating characteristic (ROC) curves were calculated to assess the relationship between ultrasound scores and an intermediate and high echocardiographic probability of PH-LHD.

Results

Seventy-one patients were enrolled in this study, with an overall median age of 79 (interquartile range: 71.5-84.0) years. Among the 71 patients, 36 (50.7%) cases were male, and 26 (36.6%) had an intermediate and high echocardiographic probability of PH. All four LUS scores in patients with an intermediate and high probability of PH were significantly higher than in patients with a low probability of PH (P <0.05). The correlation coefficient (r) between different LUS scoring methods and PASP was moderate for the 6-zone (r=0.455, P <0.001), 8-zone (r=0.385, P=0.001), 12-zone (r=0.587, P <0.001), and 28-zone (r=0.535, P <0.001) methods. In Bland-Altman plots, each of the four LUS scoring methods had a good agreement with PASP (P <0.001). The 8-zone and 12-zone methods showed moderately accurate discriminative values in differentiating patients with an intermediate and high echocardiographic probability of PH (P <0.05).

Conclusions

LUS is a readily available, inexpensive, and risk-free method that moderately correlates with PASP. LUS is a potential screening tool used for the initial investigation of PH-LHD, especially in emergencies or critical care settings.

Pathogenesis of pulmonary hypertension caused by left heart disease

Pulmonary hypertension has high disability and mortality rates. Among them, pulmonary hypertension caused by left heart disease (PH-LHD) is the most common type. According to the 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension, PH-LHD is classified as group 2 pulmonary hypertension. PH-LHD belongs to postcapillary pulmonary hypertension, which is distinguished from other types of pulmonary hypertension because of its elevated pulmonary artery wedge pressure. PH-LHD includes PH due to systolic or diastolic left ventricular dysfunction, mitral or aortic valve disease and congenital left heart disease. The primary strategy in managing PH-LHD is optimizing treatment of the underlying cardiac disease. Recent clinical studies have found that mechanical unloading of left ventricle by an implantable non-pulsatile left ventricular assist device with continuous flow properties can reverse pulmonary hypertension in patients with heart failure. However, the specific therapies for PH in LHD have not yet been identified. Treatments that specifically target PH in LHD could slow its progression and potentially improve disease severity, leading to far better clinical outcomes. Therefore, exploring the current research on the pathogenesis of PH-LHD is important. This paper summarizes and classifies the research articles on the pathogenesis of PH-LHD to provide references for the mechanism research and clinical treatment of PH-LHD, particularly molecular targeted therapy.

Targeted therapy with phosphodiesterase 5 inhibitors in patients with pulmonary hypertension due to heart failure and elevated pulmonary vascular resistance: a systematic review

Pulmonary Hypertension due to left heart disease is the most common type of Pulmonary Hypertension. Morbidity and mortality significantly increase once Pulmonary Hypertension is present. Treatment is aimed toward optimizing the underlying condition. Targeted therapy has been evaluated in small studies with mixed results. The goal of this systematic review is to identify the possible benefit and safety of Phosphodiesterase 5 inhibitors in Pulmonary Hypertension due to left heart disease with elevated pulmonary vascular resistance, diagnosed by right heart catheterization. Electronic searches using MEDLINE/PREMEDLINE, EMBASE, and The Cochrane Library were searched on 21 October 2018. Randomized clinical trials comparing Phosphodiesterase 5 inhibitors versus placebo in patients with proven Pulmonary Hypertension by right heart catheterization secondary to left heart disease (both heart failure with reduced ejection fraction and with preserved ejection fraction) and reported pulmonary vascular resistance were included. We identified 436 potentially relevant studies. After reviewing the titles and abstracts to exclude irrelevant articles, five randomized clinical trials were considered for the study. Sildenafil was well tolerated among all studies. Sildenafil was found to improve hemodynamics, exercise capacity, and quality of life in patients with elevated pulmonary vascular resistance. Phosphodiesterase 5 inhibitors therapy in patients with proven Pulmonary Hypertension due to left heart disease and elevated pulmonary vascular resistance by right heart catheterization may improve the quality of life, exercise capacity, and pulmonary hemodynamics. Further prospective randomized controlled studies are needed to confirm.

Echocardiographic Assessment of Right Ventriculo-arterial Coupling: Clinical Correlates and Prognostic Impact in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

BACKGROUND

Right ventriculo-arterial coupling (RV-PA) can be estimated by echocardiography using the ratio between tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) and it has prognostic value in the general heart failure (HF) population. We aimed to study the clinical correlates and prognostic value of RV-PA in HF patients undergoing cardiac resynchronization therapy (CRT).

METHODS

We retrospectively studied 70 HF patients undergoing CRT implantation.

RESULTS

RV-PA coupling was estimated by TAPSE/PASP ratio using baseline echocardiography. Non-response to CRT was defined as improvement of left ventricular ejection fraction < 5% in a follow-up echo 6-12 months after CRT. Those with lower TAPSE/PASP ratios (worse RV-PA coupling) had higher NT-proBNP concentrations and increased E/e' ratio. TAPSE/PASP ratio and PASP, but not TAPSE, predicted nonresponse to CRT with TAPSE/PASP ratio showing the best discriminative ability with a sensitivity of 76% and specificity of 71%. Among these parameters, PASP independently predicted all-cause mortality.

CONCLUSIONS

RV-PA coupling estimated by TAPSE/PASP ratio was associated with established prognostic markers in HF. It numerically outperformed PASP and TAPSE in predicting the response to CRT. Our data suggest that this simple and widely available echocardiographic parameter conveys significant pathophysiological and prognostic meaning in HF patients undergoing CRT.

Improvement of Left Ventricular Ejection Fraction and Pulmonary Hypertension Are Significant Prognostic Factors in Heart Failure with Reduced Ejection Fraction Patients

BACKGROUND

We evaluated long-term prognosis according to improvement of pulmonary hypertension (PH) and left ventricular ejection fraction (LVEF) in patients with heart failure with reduced ejection fraction (HFrEF) and PH.

METHODS

We included all consecutive patients with HFrEF and PH who had a baseline and follow-up echocardiographic examinations from September 2011 to March 2017. PH was defined as maximal velocity of tricuspid regurgitation (TR Vmax) over 3.0 m/s, and LVEF improvement was defined as LVEF change ≥ 15% from the baseline echocardiography. Primary outcome was 5-year major adverse cardio-cerebrovascular events (MACCE).

RESULTS

We analyzed 271 patients. Mean LVEF was 28±8% and TR Vmax was 3.4±0.4 m/s. On follow-up, 183 (68%) showed improvement of LVEF, and 165 (61%) demonstrated improvement of PH. We classified patients into 4 groups according to improvement of PH and LVEF; group 1 (both improvement, 134 patients), group 2 (PH improvement only, 31 patients), group 3 (LVEF improvement only, 49 patients) and group 4 (no improvement, 57 patients). Group 4 had older age, higher incidence of myocardial infarction and aggravation of pre-existing HF. During the follow-up (31±20 months), 27% died and 40.8% experienced MACCE. Group 4 had the worst survival (HR=4.332, 95% CI=2.396-7.833, p<0.001), and group 3 had increased MACCE rate (HR=2.030, 95% CI=1.060-3.888, p=0.033) compared with group 1. Group 2 had similar long-term clinical events (HR=1.085, 95% CI=0.458-2.571, p=0.853) to group 1.

CONCLUSIONS

In patients with HFrEF and PH, persistence of PH and no LVEF improvement was associated with the worst long-term outcome.

Autophagy in pulmonary hypertension: Emerging roles and therapeutic implications

Autophagy is an important mechanism for cellular self-digestion and basal homeostasis. This gene- and modulator-regulated pathway is conserved in cells. Recently, several studies have shown that autophagic dysfunction is associated with pulmonary hypertension (PH). However, the relationship between autophagy and PH remains controversial. In this review, we mainly introduce the effects of autophagy-related genes and some regulatory molecules on PH and the relationship between autophagy and PH under the conditions of hypoxia, monocrotaline injection, thromboembolic stress, oxidative stress, and other drugs and toxins. The effects of other autophagy-related drugs, such as chloroquine, 3-methyladenine, rapamycin, and other potential therapeutic drugs and targets, in PH are also described.