Pulmonary Hypertension in Heart Failure: Pathophysiology, Pathobiology, and Emerging Clinical Perspectives

Considerations in the Diagnosis and Management of Pulmonary Hypertension Associated With Left Heart Disease

Pulmonary hypertension associated with left heart disease (PH-LHD) remains the most common cause of pulmonary hypertension globally. Etiologies include heart failure with reduced and preserved ejection fraction and left-sided valvular heart diseases. Despite the increasing prevalence of PH-LHD, there remains a paucity of knowledge about the hemodynamic definition, diagnosis, treatment modalities, and prognosis among clinicians. Moreover, clinical trials have produced mixed results on the usefulness of pulmonary vasodilator therapies for PH-LHD. In this expert review, we have outlined the critical role of meticulous hemodynamic evaluation and provocative testing for cases of diagnostic uncertainty. Therapeutic strategies-pharmacologic, device-based, and surgical therapies used for managing PH-LHD-are also outlined. PH-LHD in advanced heart failure, and the role of mechanical circulatory support in PH-LHD is briefly explored. An in-depth understanding of PH-LHD by all clinicians is needed for improved recognition and outcomes among patients with PH-LHD.

Post-capillary pulmonary hypertension in heart failure: impact of current definition in the PH-HF multicentre study

BACKGROUND AND AIMS

Based on retrospective studies, the 2022 European guidelines changed the definition of post-capillary pulmonary hypertension (pcPH) in heart failure (HF) by lowering the level of mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR). However, the impact of this definition and its prognostic value has never been evaluated prospectively.

METHODS

Stable left HF patients with the need for right heart catheterization were enrolled from 2010 to 2018 and prospectively followed up in this multicentre study. The impact of the successive pcPH definitions on pcPH prevalence and subgroup [i.e. isolated (IpcPH) vs. combined pcPH (CpcPH)] was evaluated. Multivariable Cox regression analysis was used to assess the prognostic value of mPAP and PVR on all-cause death or hospitalization for HF (primary outcome).

RESULTS

Included were 662 HF patients were (median age 63 years, 60% male). Lowering mPAP from 25 to 20 mmHg resulted in +10% increase in pcPH prevalence, whereas lowering PVR from 3 to 2 resulted in +60% increase in CpcPH prevalence (with significant net reclassification improvement for the primary outcome). In multivariable analysis, both mPAP and PVR remained associated with the primary outcome [hazard ratio (HR) 1.02, 95% confidence interval (CI) 1.00-1.03, P = .01; HR 1.07, 95% CI 1.00-1.14, P = .03]. The best PVR threshold associated with the primary outcome was around 2.2 WU. Using the 2022 definition, pcPH patients had worse survival compared with HF patients without pcPH (log-rank, P = .02) as well as CpcPH compared with IpcPH (log-rank, P = .003).

CONCLUSIONS

This study is the first emphasizing the impact of the new pcPH definition on CpcPH prevalence and validating the prognostic value of mPAP > 20 mmHg and PVR > 2 WU among HF patients.

Pulmonary hypertension across the spectrum of left heart and lung disease

AIMS

Patients with pulmonary hypertension (PH) are grouped based upon clinical and haemodynamic characteristics. Groups 2 (G2, left heart disease [LHD]) and 3 (G3, lung disease or hypoxaemia) are most common. Many patients display overlapping characteristics of heart and lung disease (G2-3), but this group is not well-characterized.

METHODS AND RESULTS

Patients with PH enrolled in the prospective, NHLBI-sponsored PVDOMICS network underwent intensive clinical, biomarker, imaging, gas exchange and exercise phenotyping. Patients with pure G2, pure G3, or overlapping G2-3 PH were compared across multiple phenotypic domains. Of all patients with predominant G2 (n = 136), 66 (49%) were deemed to have secondary lung disease/hypoxaemia contributors (G2/3), and of all patients categorized as predominant G3 (n = 172), 41 (24%) were judged to have a component of secondary LHD (G3/2), such that 107 had G2-3 (combined G2/3 and G3/2). As compared with G3, patients with G2 and G2-3 were more obese and had greater prevalence of hypertension, atrial fibrillation, and coronary disease. Patients with G2 and G2-3 were more anaemic, with poorer kidney function, more cardiac dysfunction, and higher N-terminal pro-B-type natriuretic peptide than G3. Lung diffusion was more impaired in G3 and G2-3, but commonly abnormal even in G2. Exercise capacity was severely and similarly impaired across all groups, with no differences in 6-min walk distance or peak oxygen consumption, and pulmonary vasoreactivity to nitric oxide did not differ. In a multivariable Cox regression model, patients with G2 had lower risk of death or transplant compared with G3 (hazard ratio [HR] 0.51, 95% confidence interval [CI] 0.30-0.86), and patients with G2-3 also displayed lower risk compared with G3 (HR 0.57, 95% CI 0.38-0.86).

CONCLUSIONS

Overlap is common in patients with a pulmonary or cardiac basis for PH. While lung structure/function is clearly more impaired in G3 and G2-3 than G2, pulmonary abnormalities are common in G2, even when clinically judged as isolated LHD. Further study is required to identify optimal systematic evaluations to guide therapeutic innovation for PH associated with combined heart and lung disease.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT02980887.

Early Alteration of Right Ventricle-Pulmonary Artery Coupling in Experimental Heart Failure With Preserved Ejection Fraction

BACKGROUND

Pulmonary hypertension and right ventricular (RV) dysfunction are major prognostic determinants in patients with heart failure with preserved ejection fraction (HFpEF). The underlying pathomechanisms remain unknown. In this context, we sought to study the pathogenesis of pulmonary hypertension and RV dysfunction in a rat model of obesity-associated HFpEF.

METHODS AND RESULTS

HFpEF was induced in obesity-prone rats fed a high-fat diet (n=13) and compared with obesity-resistant rats fed with standard chow (n=9). After 12 months, the animals underwent echocardiographic and hemodynamic evaluation followed by tissue sampling for pathobiological assessment. HFpEF rats presented mild RV pressure overload (with increased RV systolic pressure and pulmonary vascular resistance). No changes in pulmonary artery medial thickness and ex vivo vasoreactivity (to acetylcholine and endothelin-1) were observed and RNA sequencing analysis failed to identify gene clustering in HFpEF lungs. However, released nitric oxide levels were decreased in HFpEF pulmonary artery, while lung expression of preproendothelin-1 was increased. In HFpEF rats, RV structure and function were altered, with RV enlargement, decreased RV fractional area change and free wall longitudinal fractional shortening, together with altered right ventricle-pulmonary artery coupling (estimated by tricuspid annular plane systolic excursion/systolic pulmonary artery pressure). Hypertrophy and apoptosis (evaluated by transferase biotin- dUTP nick-end labeling staining) were increased in right and left ventricles of HFpEF rats. There was an inverse correlation between tricuspid annular plane systolic excursion/systolic pulmonary artery pressure and RV apoptotic rate. Plasma levels of soluble suppression of tumorigenicity-2, interleukin-1β, -6 and -17A were increased in HFpEF rats.

CONCLUSIONS

Obesity-associated HFpEF in rats spontaneously evolves to pulmonary hypertension-HFpEF associated with impaired right ventricle-pulmonary artery coupling that appears disproportionate to a slight increase in RV afterload.

Right ventricular dysfunction in chronic heart failure: clinical laboratory and echocardiographic characteristics. (the RIVED-CHF registry)

BACKGROUND

Right ventricular dysfunction (RVD) and pulmonary hypertension have been recognized as two important prognostic features in patients with left side heart failure. Current literature does not distinguish between right heart failure (RHF) and RVD, and the two terms are used indiscriminately to describe pulmonary hypertension and RVD as well as clinical sign of RHF. Therefore, the right ventricle (RV) adaptation across the whole spectrum of left ventricular ejection fraction (LVEF) values has been poorly investigated.

METHODS

This is a multicenter observational prospective study endorsed by the Italian Society of Cardiology aiming to analyze the concordance between the signs and symptoms of RHF and echocardiographic features of RVD. The protocol will assess patients affected by chronic heart failure in stable condition regardless of the LVEF threshold by clinical, laboratory, and detailed echocardiographic study. During the follow-up period, patients will be observed by direct check-up visit and/or virtual visits every 6 months for a mean period of 3 years. All clinical laboratory and echocardiographic data will be recorded in a web platform system accessible for all centers included in the study.

RESULTS

The main study goals are: to investigate the concordance and discordance between clinical signs of RHF and RVD measured by ultrasonographic examination; to evaluate prognostic impact (in terms of cardiovascular mortality and heart failure hospitalization) of RVD and RHF during a mean follow-up period of 3 years; to investigate the prevalence of different right ventricular maladaptation (isolated right ventricular dilatation, isolated pulmonary hypertension, combined pattern) and the related prognostic impact.

CONCLUSIONS

With this protocol, we would investigate the three main RVD patterns according to heart failure types and stages; we would clarify different RVD and pulmonary hypertension severity according to the heart failure types. Additionally, by a serial multiparametric analysis of RV, we would provide a better definition of RVD stage and how much is it related with clinical signs of RHF (ClinicalTrials.gov Identifier: NCT06002321).

Management of high-risk pulmonary embolism in the emergency department: A narrative review

BACKGROUND

High-risk pulmonary embolism (PE) is a complex, life-threatening condition, and emergency clinicians must be ready to resuscitate and rapidly pursue primary reperfusion therapy. The first-line reperfusion therapy for patients with high-risk PE is systemic thrombolytics (ST). Despite consensus guidelines, only a fraction of eligible patients receive ST for high-risk PE.

OBJECTIVE

This review provides emergency clinicians with a comprehensive overview of the current evidence regarding the management of high-risk PE with an emphasis on ST and other reperfusion therapies to address the gap between practice and guideline recommendations.

DISCUSSION

High-risk PE is defined as PE that causes hemodynamic instability. The high mortality rate and dynamic pathophysiology of high-risk PE make it challenging to manage. Initial stabilization of the decompensating patient includes vasopressor administration and supplemental oxygen or high-flow nasal cannula. Primary reperfusion therapy should be pursued for those with high-risk PE, and consensus guidelines recommend the use of ST for high-risk PE based on studies demonstrating benefit. Other options for reperfusion include surgical embolectomy and catheter directed interventions.

CONCLUSIONS

Emergency clinicians must possess an understanding of high-risk PE including the clinical assessment, pathophysiology, management of hemodynamic instability and respiratory failure, and primary reperfusion therapies.

Right heart failure as a cause of pulmonary congestion in pulmonary arterial hypertension

AIMS

Recent studies have shown that lung ultrasound-assessed pulmonary congestion is worse in heart failure when pulmonary vascular resistance (PVR) is increased, suggesting a paradoxical relationship between right heart failure and increased lung water content. Accordingly, we wondered if lung ultrasound would reveal otherwise clinically silent pulmonary congestion in patients with pulmonary arterial hypertension (PAH).

METHODS AND RESULTS

All patients referred for suspicion of PAH in a tertiary centre from January 2020 to December 2022 underwent a complete diagnostic work-up including echocardiography, lung ultrasound and right heart catheterization. Pulmonary congestion was identified by lung ultrasound B-lines using an 8-site scan. The study enrolled 102 patients with idiopathic PAH (mean age 53 ± 13 years; 71% female). World Health Organization functional classes I, II, and III were found in 2%, 52%, and 46% of them, respectively. N-terminal pro-brain natriuretic peptide (NT-proBNP) was 377 pg/ml (interquartile range [IQR] 218-906). B-lines were identified in 77 out of 102 patients (75%), with a median of 3 [IQR 1-5]. At univariable analysis, B-lines were positively correlated with male sex, age, NT-proBNP, systolic pulmonary artery pressure (sPAP), right atrial pressure (RAP), PVR, left ventricular end-diastolic volume and tricuspid annular plane systolic excursion (TAPSE), and negatively with cardiac output and stroke volume. At multivariable analysis, RAP (p < 0.001), TAPSE/sPAP (p = 0.001), and NT-proBNP (p = 0.04) were independent predictors of B-lines.

CONCLUSION

Lung ultrasound commonly discloses pulmonary congestion in PAH. This finding is related to right ventricular to pulmonary artery uncoupling, and may tentatively be explained by increased central venous pressure impeding lymphatic outflow.

Heart failure with preserved ejection fraction: New challenges and new hopes

Heart failure (HF) is a major public health problem affecting millions of adults worldwide. HF with preserved ejection fraction, i.e. > 50 %, (HFpEF) accounts for more than half of all HF cases, and its incidence and prevalence are increasing with the aging of the population and the growing prevalence of metabolic disorders such as obesity, diabetes and hypertension. Diagnosis of HFpEF requires a combination of numerous echocardiographic parameters and also results of natriuretic peptide assays, to which may be added the need for a stress test. HFpEF is characterized by complex, interrelated pathophysiological mechanisms, which must be understood. This complexity probably accounts for the lack of evidence-based medicine compared with HF with reduced EF. Nevertheless, significant progress has been made recently, with a high level of evidence obtained for the SGLT2 inhibitor class on the one hand, and promising data with new drugs targeting more specifically certain mechanisms such as obesity and inflammation on the other.

Implantable Hemodynamic Monitors Improve Survival in Patients With Heart Failure and Reduced Ejection Fraction

BACKGROUND

Trials evaluating implantable hemodynamic monitors to manage patients with heart failure (HF) have shown reductions in HF hospitalizations but not mortality. Prior meta-analyses assessing mortality have been limited in construct because of an absence of patient-level data, short-term follow-up duration, and evaluation across the combined spectrum of ejection fractions.

OBJECTIVES

The purpose of this meta-analysis was to determine whether management with implantable hemodynamic monitors reduces mortality in patients with heart failure and reduced ejection fraction (HFrEF) and to confirm the effect of hemodynamic-monitoring guided management on HF hospitalization reduction reported in previous studies.

METHODS

The patient-level pooled meta-analysis used 3 randomized studies (GUIDE-HF [Hemodynamic-Guided Management of Heart Failure], CHAMPION [CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Heart Failure Patients], and LAPTOP-HF [Left Atrial Pressure Monitoring to Optimize Heart Failure Therapy]) of implantable hemodynamic monitors (2 measuring pulmonary artery pressures and 1 measuring left atrial pressure) to assess the effect on all-cause mortality and HF hospitalizations.

RESULTS

A total of 1,350 patients with HFrEF were included. Hemodynamic-monitoring guided management significantly reduced overall mortality with an HR of 0.75 (95% CI: 0.57-0.99); P = 0.043. HF hospitalizations were significantly reduced with an HR of 0.64 (95% CI: 0.55-0.76); P < 0.0001.

CONCLUSIONS

Management of patients with HFrEF using an implantable hemodynamic monitor significantly reduces both mortality and HF hospitalizations. The reduction in HF hospitalizations is seen early in the first year of monitoring and mortality benefits occur after the first year.

Assessing the prognostic significance of mean pulmonary artery velocity in heart failure with slightly reduced ejection fraction

OBJECTIVE

In this study, we assessed the prognostic significance of the mean velocity of the pulmonary artery (mvPA) using CMR in patients who have heart failure with mildly reduced ejection fraction (HFmrEF) and pulmonary hypertension, both as a combined condition and individually.

METHODS

This retrospective study involved 284 consecutive patients diagnosed with HFmrEF who were hospitalized and underwent CMR imaging to assess RV-PA coupling parameters, including mvPA. We collected baseline data clinical profiles, lab test results, and cardiac imaging findings of patients with HFmrEF who had at least two echocardiograms conducted three months apart. The primary endpoint was a composite of all-cause mortality or readmission due to heart failure.

RESULTS

A total of 139 patients met the primary endpoint during an average follow-up of 49 months. The most effective threshold value for predicting the primary endpoint, determined by a receiver operating curve analysis, was 9. cm/s for mvPA. According to the Kaplan-Meier survival plots, when mvPA ≤ 9.05 cm/s, there was a significantly higher mortality rate (Log-Rank: 71.93, p < 0.001). It is important to highlight that the predictive value of mvPA remained consistent, irrespective of RV function. mvPA ≤ 9.05 cm/s served as an independent prognostic indicator, alongside ischemic cardiomyopathy and hyponatremia.

CONCLUSIONS

mvPA has affirmed its significance as an initial prognostic indicator by identifying a group of high-risk patients who have sustained RV function. While the results of this study displayed potential in stratifying the extended prognosis of patients with HFmrEF, additional research is required.

Clinical-imaging-pathological correlation in pulmonary hypertension associated with left heart disease

Pulmonary hypertension (PH) is highly prevalent in patients with left heart disease (LHD) and negatively impacts prognosis. The most common causes of PH associated with LHD (PH-LHD) are left heart failure and valvular heart disease. In LHD, passive backward transmission of increased left-sided filling pressures leads to isolated post-capillary PH. Additional pulmonary vasoconstriction and remodelling lead to a higher vascular load and combined pre- and post-capillary PH. The increased afterload leads to right ventricular dysfunction and failure. Multimodality imaging of the heart plays a central role in the diagnostic work-up and follow-up of patients with PH-LHD. Echocardiography provides information about the estimated pulmonary artery pressure, morphology and function of the left and right side of the heart, and valvular abnormalities. Cardiac magnetic resonance imaging is the gold standard for volumetric measurements and provides myocardial tissue characterisation. Computed tomography of the thorax may show general features of PH and/or LHD and is helpful in excluding other PH causes. Histopathology reveals a spectrum of pre- and post-capillary vasculopathy, including intimal fibrosis, media smooth muscle cell hyperplasia, adventitial fibrosis and capillary congestion. In this paper, we provide an overview of clinical, imaging and histopathological findings in PH-LHD based on three clinical cases.

Post-Capillary Pulmonary Hypertension: Clinical Review

Pulmonary hypertension (PH) caused by left heart disease, also known as post-capillary PH, is the most common etiology of PH. Left heart disease due to systolic dysfunction or heart failure with preserved ejection fraction, valvular heart disease, and left atrial myopathy due to atrial fibrillation are causes of post-capillary PH. Elevated left-sided filling pressures cause pulmonary venous congestion due to backward transmission of pressures and post-capillary PH. In advanced left-sided heart disease or valvular heart disease, chronic uncontrolled venous congestion may lead to remodeling of the pulmonary arterial system, causing combined pre-capillary and post-capillary PH. The hemodynamic definition of post-capillary PH includes a mean pulmonary arterial pressure > 20 mmHg, pulmonary vascular resistance < 3 Wood units, and pulmonary capillary wedge pressure > 15 mmHg. Echocardiography is important in the identification and management of the underlying cause of post-capillary PH. Management of post-capillary PH is focused on the treatment of the underlying condition. Strategies are geared towards pharmacotherapy and guideline-directed medical therapy for heart failure, surgical or percutaneous management of valvular disorders, and control of modifiable risk factors and comorbid conditions. Referral to centers with advanced heart and pulmonary teams has shown to improve morbidity and mortality. There is emerging interest in the use of targeted agents classically used in pulmonary arterial hypertension, but current data remain limited and conflicting. This review aims to serve as a comprehensive summary of postcapillary PH and its etiologies, pathophysiology, diagnosis, and management, particularly as it pertains to advanced heart failure.

Circulating mitochondria promoted endothelial cGAS-derived neuroinflammation in subfornical organ to aggravate sympathetic overdrive in heart failure mice

BACKGROUND

Sympathoexcitation contributes to myocardial remodeling in heart failure (HF). Increased circulating pro-inflammatory mediators directly act on the Subfornical organ (SFO), the cardiovascular autonomic center, to increase sympathetic outflow. Circulating mitochondria (C-Mito) are the novel discovered mediators for inter-organ communication. Cyclic GMP-AMP synthase (cGAS) is the pro-inflammatory sensor of damaged mitochondria.

OBJECTIVES

This study aimed to assess the sympathoexcitation effect of C-Mito in HF mice via promoting endothelial cGAS-derived neuroinflammation in the SFO.

METHODS

C-Mito were isolated from HF mice established by isoprenaline (0.0125 mg/kg) infusion via osmotic mini-pumps for 2 weeks. Structural and functional analyses of C-Mito were conducted. Pre-stained C-Mito were intravenously injected every day for 2 weeks. Specific cGAS knockdown (cGAS KD) in the SFO endothelial cells (ECs) was achieved via the administration of AAV9-TIE-shRNA (cGAS) into the SFO. The activation of cGAS in the SFO ECs was assessed. The expression of the mitochondrial redox regulator Dihydroorotate dehydrogenase (DHODH) and its interaction with cGAS were also explored. Neuroinflammation and neuronal activation in the SFO were evaluated. Sympathetic activity, myocardial remodeling, and cardiac systolic dysfunction were measured.

RESULTS

C-Mito were successfully isolated, which showed typical structural characteristics of mitochondria with double-membrane and inner crista. Further analysis showed impaired respiratory complexes activities of C-Mito from HF mice (C-MitoHF) accompanied by oxidative damage. C-Mito entered ECs, instead of glial cells and neurons in the SFO of HF mice. C-MitoHF increased the level of ROS and cytosolic free double-strand DNA (dsDNA), and activated cGAS in cultured brain endothelial cells. Furthermore, C-MitoHF highly expressed DHODH, which interacted with cGAS to facilitate endothelial cGAS activation. C-MitoHF aggravated endothelial inflammation, microglial/astroglial activation, and neuronal sensitization in the SFO of HF mice, which could be ameliorated by cGAS KD in the ECs of the SFO. Further analysis showed C-MitoHF failed to exacerbate sympathoexcitation and myocardial sympathetic hyperinnervation in cGAS KD HF mice. C-MitoHF promoted myocardial fibrosis and hypertrophy, and cardiac systolic dysfunction in HF mice, which could be ameliorated by cGAS KD.

CONCLUSION

Collectively, we demonstrated that damaged C-MitoHF highly expressed DHODH, which promoted endothelial cGAS activation in the SFO, hence aggravating the sympathoexcitation and myocardial injury in HF mice, suggesting that C-Mito might be the novel therapeutic target for sympathoexcitation in HF.

An updated review of experimental rodent models of pulmonary hypertension and left heart disease

Left heart disease (LHD) is the leading cause of pulmonary hypertension (PH). Its recent growth has not been matched by the design of therapeutic agents directly targeting the disease. Effective therapies approved for pulmonary arterial hypertension (PAH) have been shown to be inefficient in patients with PH-LHD. Hence, there is a need for an animal model that would closely mimic PH-LHD in preclinical experiments. The current study describes and compares a number of rodent models of left ventricular failure and their potential to induce PH. It also evaluates whether, and to what extent, common PH models could develop LV failure. Articles were identified in the Pubmed/Medline and Web of Science online electronic databases following the PRISMA Protocol between 1992 and 2022. Quality assessment was carried out using the SYRCLE risk-of-bias tool for animal studies. Publication bias across studies using Egger's regression test statistic, was performed together with sensitivity analysis. A wide spectrum of protocols-135 studies and 207 interventions, was examined, including systemic hypertensive models, pressure-overload-induced HF, model of ischemic heart failure, and metabolic approaches based on high fat diet or metabolic syndrome. The most pronounced alterations in PH-related parameters were demonstrated for the common PH models, but were also seen in animals with LV failure induced by ischemic conditions, pressure overload or metabolic conditions. Models based on aortic banding, transverse aortic constriction (TAC), or with myocardial infarction (MI) caused by coronary artery ligation, demonstrated more pronounced worsening in PH due to LV failure; however, they also demonstrated poor survival, especially the ischemic-HF model. Common PH models, excluding prolonged exposure to monocrotaline, do not promote LV hypertrophy. Prolonged exposure to a high-fat diet, or a two-hit model of an obese ZSF1 rat combined with SU5416-induced pulmonary endothelial impairment (a VEGF receptor antagonist) worsened PH and impaired diastolic dysfunction. Due to the limited number of protocols, further trials are needed to confirm the utility of such approaches for modeling PH in subjects with metabolic syndrome. This would provide a clearer insight into the complexity of LHD, PH and metabolic disorders in PH-LHD, and thus accelerate the development of new therapies in clinical trials.

Relationship Between Pulmonary Artery Pressure and Inflammation Parameters

Background Inflammation can play a role in the development and progression of pulmonary hypertension (PHT). In this study, inflammatory parameters were compared in congestive heart failure (CHF) patients with and without PHT. The relationship between pulmonary artery pressure (PAP) and inflammatory parameters was investigated. Materials and methods Out of 80 CHF patients, 40 had PHT. The patients' age, gender, smoking status, comorbidities such as diabetes mellitus (DM) and hypertension (HT), and mortality rates were recorded. Inflammatory parameters were recorded. Results The mean age of the PHT group was 64.38 ± 9.17 and the mean age of the non-PHT group was 64.70 ± 8.99. There were 23 men and 17 women in the PHT group, and there were 21 men and 19 women in the non-PHT group. There was no significant difference between the two groups in terms of mean age and gender distribution (p = 0.874 and p = 0.653). Accordingly, the C-reactive protein to albumin ratio (CAR) value was statistically significantly higher in PHT patients (p = 0.023). The eosinophil count was found to be significantly higher in non-PHT patients (p = 0.015). Accordingly, a significant correlation was detected between CAR and PAP (r = 0.392 and p < 0.001). Conclusion In this study, the positive correlation between PAP and CAR and the significantly higher CAR value in PHT patients indicate the presence of inflammation in PHT patients. Studies on the relationship between inflammation and mortality in PHT patients may contribute more to the literature in the future.

The prognostic impact of right ventricular-pulmonary arterial coupling in heart failure: a systematic review and meta-analysis

The echocardiographic tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio is a non-invasive surrogate of right ventricular-pulmonary arterial (RV-PA) coupling which corresponds well with the respective invasively derived index. Recently, a wealth of observational data has arisen, outlining its prognostic value in heart failure (HF) patients. To systematically appraise and quantitatively synthesize the evidence of the prognostic value of TAPSE/PASP ratio in left-sided HF regardless of etiology or left ventricular ejection fraction. A systematic literature review was conducted in electronic databases to identify studies reporting the association of TAPSE/PASP ratio with outcomes in patients with HF and, when appropriate, a random-effects meta-analysis was conducted to quantify the unadjusted and adjusted hazard ratios [(a)HRs] for all-cause death and the composite outcome of all-cause death or HF hospitalization. Eighteen studies were deemed eligible encompassing 8,699 HF patients. The applied cut-off value for RV-PA uncoupling varied substantially from 0.27 to 0.58 mm/mmHg, and in most studies values lower than the applied cutoff conveyed dismal prognosis. Eleven studies reported appropriate data for meta-analysis. TAPSE/PASP reduction by 1 mm/mmHg was independently associated with all-cause death (pooled aHR=1.32 [1.06-1.65]; p=0.01; I2=56%) and the composite outcome (pooled aHR=3.48 [1.67-7.25]; p<0.001; I2=0%). When a TAPSE/PASP cutoff value of 0.36 mm/mmHg was applied it yielded independent association with all-cause death (pooled aHR=2.84 [2.22-3.64]; p<0.001; I2=82%). RV-PA coupling assessed by echocardiographic TAPSE/PASP ratio appears to be an independent outcome predictor for HF patients.

Noninvasive evaluation of pulmonary artery stiffness in heart failure patients via cardiovascular magnetic resonance

Heart failure (HF) presents manifestations in both cardiac and vascular abnormalities. Pulmonary hypertension (PH) is prevalent in up 50% of HF patients. While pulmonary arterial hypertension (PAH) is closely associated with pulmonary artery (PA) stiffness, the association of HF caused, post-capillary PH and PA stiffness is unknown. We aimed to assess and compare PA stiffness and blood flow hemodynamics noninvasively across HF entities and control subjects without HF using CMR. We analyzed data of a prospectively conducted study with 74 adults, including 55 patients with HF across the spectrum (20 HF with preserved ejection fraction [HFpEF], 18 HF with mildly-reduced ejection fraction [HFmrEF] and 17 HF with reduced ejection fraction [HFrEF]) as well as 19 control subjects without HF. PA stiffness was defined as reduced vascular compliance, indicated primarily by the relative area change (RAC), altered flow hemodynamics were detected by increased flow velocities, mainly by pulse wave velocity (PWV). Correlations between the variables were explored using correlation and linear regression analysis. PA stiffness was significantly increased in HF patients compared to controls (RAC 30.92 ± 8.47 vs. 50.08 ± 9.08%, p < 0.001). PA blood flow parameters were significantly altered in HF patients (PWV 3.03 ± 0.53 vs. 2.11 ± 0.48, p < 0.001). These results were consistent in all three HF groups (HFrEF, HFmrEF and HFpEF) compared to the control group. Furthermore, PA stiffness was associated with higher NT-proBNP levels and a reduced functional status. PA stiffness can be assessed non-invasively by CMR. PA stiffness is increased in HFrEF, HFmrEF and HFpEF patients when compared to control subjects.Trial registration The study was registered at the German Clinical Trials Register (DRKS, registration number: DRKS00015615).

NLRP3-inflammasome inhibition by MCC950 attenuates cardiac and pulmonary artery remodelling in heart failure with preserved ejection fraction

AIMS

The purpose of this study was to evaluate the role of the NLRP3-inflammasome in heart failure with preserved ejection fraction (HFpEF).

MAIN METHODS

Serum inflammatory cytokines were detected in patients with heart failure. Correlation analysis was performed to investigate the relationship between serum inflammatory cytokines and left ventricular diastolic function. A 'two-hit' (metabolic stress and mechanical stress) mouse model of HFpEF was established. Furthermore, MCC950 was used to determine the role of NLRP3-inflammasome inhibition in cardiac and pulmonary artery remodelling in HFpEF mice.

KEY FINDINGS

Compared with heart failure patients with reduced ejection fraction, patients with HFpEF have significantly elevated serum inflammatory cytokine levels. Serum NLRP3 and interleukin-1β levels were positively correlated with the diastolic function of HFpEF. In the HFpEF mouse model, the inhibition of the NLRP3-inflammasome by MCC950 improved exercise intolerance, glucose intolerance, and left ventricular diastolic function, but had no significant effect on systolic function. Meanwhile, MCC950 attenuated the release of inflammatory cytokines, cardiomyocyte hypertrophy and cardiac fibrosis. Mechanistically, the potential protective effects of MCC950 are achieved by inhibiting activation of the NLRP3-IL-1β pathway and cascade expansion of downstream inflammatory cytokines. Additionally, the inhibition of NLRP3-inflammasome by MCC950 reduced pulmonary artery pressure and improved pulmonary artery remodelling in HFpEF.

SIGNIFICANCE

The NLRP3-inflammasome plays a considerable role in inflammation and cardiac and pulmonary artery remodelling in HFpEF by activating the cascade reaction of inflammatory cytokines. This study is the first to comprehensively elucidate the role of the NLRP3-inflammasome in HFpEF, and will provide reference for future study.

Lung Ultrasound, Echocardiography, and Fluid Challenge for the Differential Diagnosis of Pulmonary Hypertension

OBJECTIVES

The differential diagnosis between pulmonary arterial hypertension (PAH) and postcapillary pulmonary hypertension (PH) in heart failure with preserved ejection fraction (HFpEF) is sometimes difficult despite guidelines-derived standardized step-by-step diagnostic algorithms. We therefore explored the added value of lung ultrasound to a previously validated echocardiographic score of right heart catheterization measurements.

METHODS

Patients referred for PH underwent a right heart catheterization, echocardiography, and lung ultrasound before and after rapid infusion of 7 mL/kg of saline. A 7-point echocardiographic score based on cardiac chamber dimensions and estimates of filling pressures was implemented for the prediction of precapillary PH. Pulmonary congestion was identified by lung ultrasound B lines.

RESULTS

The study enrolled 70 patients with PAH and 77 patients with HFpEF. The PAH patients had a higher echocardiographic score (3.5 ± 1.8 vs 1.6 ± 1.5; P < .001). The HFpEF patients had more B lines both before (8.1 ± 4.2 vs 5.1 ± 3.0; P < .001) and after fluid challenge (14.6 ± 5.4 vs 7.6 ± 3.5; P < .001) and a more important increase (Δ) of B lines after fluid challenge (6.5 ± 2.9 vs 2.5 ± 1.6; P < .001). The sensitivity and specificity of the echocardiographic score (cutoff ≥2) alone for PAH were 0.91 and 0.49, respectively (area under the curve of 0.78). The best diagnostic improvement was observed with addition of ΔB lines + E/e' post-fluid challenge to the echocardiographic score, with a significant increase of the area under the curve (0.98) and (with a cutoff given by the presence of echo score ≥2, ΔB lines <4 and E/e' post < 11) a sensitivity of 0.90 (95% CI, 0.83; 0.97) and specificity of 0.84 (95% CI, 0.76; 0.93).

CONCLUSIONS

Lung ultrasound combined with echocardiography at baseline and after fluid challenge has an incremental value for the differential diagnosis between PAH and PH-HFpEF.

[Pulmonary hypertension associated with left heart disease (group 2)]

Patients with left heart disease (LHD) often display pulmonary hypertension (PH), which impacts morbidity and mortality. The pathophysiology of PH is complex and entails pulmonary congestion due to elevated left-sided filling pressures, pulmonary vasoconstriction as well as vascular remodeling. The recent ESC/ERS Guidelines on pulmonary hypertension updated the hemodynamic definitions of pulmonary hypertension in general, and the subclassification of post-capillary PH. This review summarizes recent advances in the diagnostic work-up and management strategies of PH associated with LHD. Specifically, we summarize revisited hemodynamic definitions and the characteristics of isolated post-capillary PH (IpcPH) and combined post- and pre-capillary PH (CpcPH). Furthermore, we review the current knowledge on the pathogenesis of PH-LHD, the prognostic relevance of hemodynamic parameters, and the management strategies, differentiating between treatment of the underlying left heart disease and therapies targeting the pulmonary circulation. The article emphasises the need for precise diagnostic work-up and individualized treatment strategies in patients with PH-LHD.

Clinical Usefulness of Speckle-Tracking Echocardiography in Patients with Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is defined as HF with left ventricular ejection fraction (LVEF) not less than 50%. HFpEF accounts for more than 50% of all HF patients, and its prevalence is increasing year to year with the aging population, with its prognosis worsening. The clinical assessment of cardiac function and prognosis in patients with HFpEF remains challenging due to the normal range of LVEF and the nonspecific symptoms and signs. In recent years, new echocardiographic techniques have been continuously developed, particularly speckle-tracking echocardiography (STE), which provides a sensitive and accurate method for the comprehensive assessment of cardiac function and prognosis in patients with HFpEF. Therefore, this article reviewed the clinical utility of STE in patients with HFpEF.

Unmet Needs in the Assessment of Right Ventricular Function for Severe Tricuspid Regurgitation

Tricuspid regurgitation (TR) is a highly prevalent valvular heart disease that has been long overlooked, but lately its independent association with adverse cardiovascular outcomes was recognized. The time point to intervene and repair the tricuspid valve is defined by the right ventricular (RV) dilation and dysfunction that comes up at a later stage. While guidelines favor tricuspid valve repair before severe RV dysfunction ensues, the definition of RV dysfunction in a universal manner remains vague. As a result, the candidates for transcatheter or surgical TR procedures are often referred late, when advanced RV dysfunction is established, and any derived procedural survival benefit is attenuated. Thus, it is of paramount importance to establish a universal means of RV function assessment in patients with TR. Conventional echocardiographic indices of RV function routinely applied have fundamental flaws that limit the precise characterization of RV performance. More recently, novel echocardiographic indices such as strain via speckle-tracking have emerged, demonstrating promising results in the identification of early RV damage. Additionally, evidence of the role of alternative imaging modalities such as cardiac computed tomography and cardiac magnetic resonance, for RV functional assessment in TR, has recently arisen. This review provides a systematic appraisal of traditional and novel multimodality indices of RV function in severe TR and aims to refine RV function assessment, designate future directions, and ultimately, to improve the outcome of patients suffering from severe TR.

Combined use of right ventricular coupling and pulmonary arterial elastance as a comprehensive stratification approach for right ventricular function

Right ventricular (RV)-pulmonary arterial uncoupling is the consequence of increased afterload and/or decreased RV contractility. However, the combination of arterial elastance (Ea) and end-systolic elastance (Ees)/Ea ratio to assess RV function is unclear. We hypothesized that the combination of both could comprehensively assess RV function and refine risk stratification. The median Ees/Ea ratio (0.80) and Ea (0.59 mmHg/mL) were used to classify 124 patients with advanced heart failure into four groups. RV systolic pressure differential was defined as end-systolic pressure (ESP) minus beginning-systolic pressure (BSP). Patients among different subsets showed dissimilar New York Heart Association functional class (V = 0.303, p = 0.010), distinct tricuspid annular plane systolic excursion/ pulmonary artery systolic pressure (mm/mmHg; 0.65 vs. 0.44 vs. 0.32 vs. 0.26, p < 0.001), and diverse prevalence of pulmonary hypertension (33.3% vs. 35% vs. 90% vs. 97.6%, p < 0.001). By multivariate analysis, Ees/Ea ratio (hazard ratio [HR] 0.225, p = 0.004) and Ea (HR 2.194, p = 0.003) were independently associated with event-free survival. Patients with Ees/Ea ratio greater than or equal to 0.80 and Ea less than 0.59 mmHg/mL had better outcomes (p < 0.05). In patients with Ees/Ea ratio greater than or equal to 0.80, those with Ea greater than or equal to 0.59 mmHg/mL had a higher adverse outcome risk (p < 0.05). Ees/Ea ratio less than or equal to 0.80 was associated with adverse outcomes, even when Ea was less than 0.59 mmHg/mL (p < 0.05). Approximately 86% of patients with ESP-BSP greater than 5 mmHg had an Ees/Ea ratio less than or equal to 0.80 and/or an Ea greater than or equal to 0.59 mmHg/mL (V = 0.336, p = 0.001). Combined use of Ees/Ea ratio and Ea could be a comprehensive approach to assessing RV function and predicting outcomes. An exploratory analysis demonstrated that Ees/Ea ratio and Ea might be roughly estimated based on RV systolic pressure differential.

Hypoxaemia in patients with heart failure and preserved ejection fraction

AIMS

It is widely held that heart failure (HF) does not cause exertional hypoxaemia, based upon studies in HF with reduced ejection fraction, but this may not apply to patients with HF and preserved ejection fraction (HFpEF). Here, we characterize the prevalence, pathophysiology, and clinical implications of exertional arterial hypoxaemia in HFpEF.

METHODS AND RESULTS

Patients with HFpEF (n = 539) and no coexisting lung disease underwent invasive cardiopulmonary exercise testing with simultaneous blood and expired gas analysis. Exertional hypoxaemia (oxyhaemoglobin saturation <94%) was observed in 136 patients (25%). As compared to those without hypoxaemia (n = 403), patients with hypoxaemia were older and more obese. Patients with HFpEF and hypoxaemia had higher cardiac filling pressures, higher pulmonary vascular pressures, greater alveolar-arterial oxygen difference, increased dead space fraction, and greater physiologic shunt compared to those without hypoxaemia. These differences were replicated in a sensitivity analysis where patients with spirometric abnormalities were excluded. Regression analyses revealed that increases in pulmonary arterial and pulmonary capillary pressures were related to lower arterial oxygen tension (PaO2 ), especially during exercise. Body mass index (BMI) was not correlated with the arterial PaO2 , and hypoxaemia was associated with increased risk for death over 2.8 (interquartile range 0.7-5.5) years of follow-up, even after adjusting for age, sex, and BMI (hazard ratio 2.00, 95% confidence interval 1.01-3.96; p = 0.046).

CONCLUSION

Between 10% and 25% of patients with HFpEF display arterial desaturation during exercise that is not ascribable to lung disease. Exertional hypoxaemia is associated with more severe haemodynamic abnormalities and increased mortality. Further study is required to better understand the mechanisms and treatment of gas exchange abnormalities in HFpEF.

Pathophysiology of the right ventricle in health and disease: an update

The contribution of the right ventricle (RV) to cardiac output is negligible in normal resting conditions when pressures in the pulmonary circulation are low. However, the RV becomes relevant in healthy subjects during exercise and definitely so in patients with increased pulmonary artery pressures both at rest and during exercise. The adaptation of RV function to loading rests basically on an increased contractility. This is assessed by RV end-systolic elastance (Ees) to match afterload assessed by arterial elastance (Ea). The system has reserve as the Ees/Ea ratio or its imaging surrogate ejection fraction has to decrease by more than half, before the RV undergoes an increase in dimensions with eventual increase in filling pressures and systemic congestion. RV-arterial uncoupling is accompanied by an increase in diastolic elastance. Measurements of RV systolic function but also of diastolic function predict outcome in any cause pulmonary hypertension and heart failure with or without preserved left ventricular ejection fraction. Pathobiological changes in the overloaded RV include a combination of myocardial fibre hypertrophy, fibrosis and capillary rarefaction, a titin phosphorylation-related displacement of myofibril tension-length relationships to higher pressures, a metabolic shift from mitochondrial free fatty acid oxidation to cytoplasmic glycolysis, toxic lipid accumulation, and activation of apoptotic and inflammatory signalling pathways. Treatment of RV failure rests on the relief of excessive loading.

Development of a complex exercise rehabilitation intervention for people with pulmonary hypertension: the supervised pulmonary hypertension exercise rehabilitation (SPHERe) trial

BACKGROUND

People with pulmonary hypertension (PH) are not routinely referred for exercise rehabilitation despite the potential for reducing breathlessness and improving quality of life. We describe the development of a supervised pulmonary hypertension exercise rehabilitation (SPHERe) programme for people with PH.

METHODS

Development was completed in three phases: (1) systematic review, (2) stakeholder engagement with consensus from patients and experts and (3) prepilot intervention acceptability testing. We completed systematic reviews to identify international cardiopulmonary rehabilitation guidance and trials of exercise-based interventions for people with PH. Evidence from systematic reviews and stakeholder consensus shaped the SPHERe intervention, including addition of individual behavioural support sessions to promote exercise adherence. The draft SPHERe intervention was ratified through discussions with multidisciplinary professionals and people living with PH. We acceptability tested the centre-based intervention with eight participants in a prepilot development phase which identified a number of condition-specific issues relating to safety and fear avoidance of activity. Comprehensive intervention practitioner training manuals were produced to ensure standardised delivery. Participant workbooks were developed and piloted. Trial recruitment began in January 2020 but was subsequently suspended in March 2020 further to COVID-19 pandemic 'lockdowns'. In response to the pandemic, we undertook further development work to redesign the intervention to be suitable for exclusively home-based online delivery. Recruitment to the revised protocol began in June 2021.

DISCUSSION

The final SPHERe intervention incorporated weekly home-based online group exercise and behavioural support 'coaching' sessions supervised by trained practitioners, with a personalised home exercise plan and the optional loan of a stationary exercise bike. The intervention was fully manualised with clear pathways for assessment and individualised exercise prescription. The clinical and cost-effectiveness of the SPHERe online rehabilitation intervention is currently being tested in a UK multicentre randomised controlled trial.

TRIAL REGISTRATION NUMBER

ISCRTN10608766.

3-Year Outcome in Patients With Combined Precapillary and Postcapillary Pulmonary Hypertension: Results From PADN-5 Trial

BACKGROUND

Long-term benefits of pulmonary artery denervation (PADN) for patients with combined precapillary and postcapillary pulmonary hypertension (CpcPH) secondary to left heart failure are unknown.

OBJECTIVES

The authors sought to report the 3-year clinical results of PADN for patients with CpcPH.

METHODS

A total of 98 patients with CpcPH, defined as having mean pulmonary arterial pressure of ≥25 mm Hg, pulmonary capillary wedge pressure of >15 mm Hg, and pulmonary vascular resistance of >3.0 WU, were randomly assigned to receive the sham + sildenafil or PADN. The primary endpoint was the occurrence of clinical worsening defined as cardiopulmonary death, rehospitalization or heart/lung transplantation at 3-year follow-up. Changes in the 6-minute walk distance and N-terminal pro-B-type natriuretic peptide served as secondary points.

RESULTS

At the 3-year follow-up, clinical worsening was reported in 49 (50.0%) patients, with 31 (62.0%) in the sham + sildenafil group and 18 (37.5%) in the PADN group (HR: 2.13 [95% CI: 1.19-3.81]; P = 0.011), largely driven by a higher rate of rehospitalization in the sham + sildenafil group (56.2% vs 35.4%; HR: 1.96 [95% CI: 1.07-3.58]; P = 0.029) by Cox proportional hazards regression. At the end of the study, cardiopulmonary-related deaths occurred in 16 (32.0%) patients in the sham and 9 (18.8%) (P = 0.167) patients in the PADN group. PADN also resulted in a more profound increase in the 6-minute walk distance and reduction in N-terminal pro-B-type natriuretic peptide.

CONCLUSIONS

PADN is associated with significant improvements in exercise capacity, cardiac function, and clinical outcomes. Further study without approved drugs for pulmonary arterial hypertension is required to confirm the benefits of PADN for patients with CpcPH. (Pulmonary Arterial Denervation in Patients With Pulmonary Hypertension Associated With the Left Heart Failure [PADN-5]; NCT02220335).

Pulmonary Hypertension in Left Heart Diseases: Pathophysiology, Hemodynamic Assessment and Therapeutic Management

Pulmonary hypertension (PH) associated with left heart diseases (PH-LHD), also termed group 2 PH, represents the most common form of PH. It develops through the passive backward transmission of elevated left heart pressures in the setting of heart failure, either with preserved (HFpEF) or reduced (HFrEF) ejection fraction, which increases the pulsatile afterload of the right ventricle (RV) by reducing pulmonary artery (PA) compliance. In a subset of patients, progressive remodeling of the pulmonary circulation resulted in a pre-capillary phenotype of PH, with elevated pulmonary vascular resistance (PVR) further increasing the RV afterload, eventually leading to RV-PA uncoupling and RV failure. The primary therapeutic objective in PH-LHD is to reduce left-sided pressures through the appropriate use of diuretics and guideline-directed medical therapies for heart failure. When pulmonary vascular remodeling is established, targeted therapies aiming to reduce PVR are theoretically appealing. So far, such targeted therapies have mostly failed to show significant positive effects in patients with PH-LHD, in contrast to their proven efficacy in other forms of pre-capillary PH. Whether such therapies may benefit some specific subgroups of patients (HFrEF, HFpEF) with specific hemodynamic phenotypes (post- or pre-capillary PH) and various degrees of RV dysfunction still needs to be addressed.

Pulmonary hypertension associated with left heart disease

Pulmonary hypertension (PH) is a common condition in patients with left heart disease (LHD) that is highly relevant for morbidity and mortality. While post-capillary in nature, the pathophysiology of PH in patients with LHD (heart failure/cardiomyopathy, valvular heart disease; other: congenital/acquired) is complex, and decisions about management strategies are challenging. Recently, the updated European Society of Cardiology/European Respiratory Society guidelines on the diagnosis and treatment of PH revisited hemodynamic definitions and the sub-classification of post-capillary PH, and provided numerous new recommendations on the diagnosis and management of PH associated with various types of LHD. Here, we review several novel aspects that focus on: (a) updated hemodynamic definitions, including the distinction between isolated post-capillary PH (IpcPH) and combined post- and pre-capillary PH (CpcPH); (b) the pathogenesis of PH-LHD, considering various components contributing to PH, such as pulmonary congestion, vasoconstriction, and vascular remodeling; (c) the prognostic relevance of PH and hemodynamic markers; (d) the diagnostic approach to PH-LHD; (e) management strategies in PH-LHD, distinguishing between targeting the underlying left heart condition, the pulmonary circulation, and/or impaired right ventricular function. In conclusion, precise clinical and hemodynamic characterization and detailed phenotyping are essential for prognostication and the management of patients with PH-LHD.

Characteristics of cardiopulmonary exercise testing in patients with combined post- and pre-capillary pulmonary hypertension due to left heart disease

BACKGROUND

Pulmonary hypertension (PH) is a common and morbid complication of left heart disease (LHD), comprising two subtypes: (1) isolated post-capillary pulmonary hypertension (Ipc-PH) and (2) combined post-capillary and pre-capillary pulmonary hypertension (Cpc-PH). Knowledge regarding the physiological characteristics that distinguish Cpc-PH, which has a worse prognosis, from Ipc-PH remains limited. Therefore, this study aimed to assess the utility of cardiopulmonary exercise testing (CPET) variables in detecting Cpc-PH.

METHODS AND RESULTS

Among 105 consecutive patients with LHD (age: 55 ± 13 years; male/female = 79/26) who underwent right heart catheterization and CPET, 45 (43%) were classified as PH-LHD (mean pulmonary artery pressure >20 mmHg). Ipc-PH (n = 24) was defined as pulmonary vascular resistance (PVR) ≤ 3 WU and Cpc-PH (n = 21) as PVR > 3 WU. Patients with Cpc-PH had a significantly lower peak partial pressure of carbon dioxide (PETCO2) (Non-PH/Ipc-PH/Cpc-PH = 38.2 ± 6.6 vs. 38.3 ± 6.0 vs 33.0 ± 4.4 mmHg, p = 0.006), higher VE vs. VCO2 slope (Non-PH/Ipc-PH/Cpc-PH = 33.0 [28.3, 36.6] vs. 32.5 [28.1, 37.8] vs. 40.6 [33.6, 46.1], p = 0.007), and lower ΔVO2/ΔWR (Non-PH/Ipc-PH/Cpc-PH = 8.5 ± 1.4 vs. 8.0 ± 1.7 vs. 6.8 ± 2.0 mL/min/watt, p = 0.001) than those with Ipc-PH and non-PH. Using multivariable logistic regression analysis, CPET variables were found to be independent predictors of Cpc-PH (lower peak PETCO2: odds ratio, 0.728 [95% confidence interval {CI}: 0.616-0.840], p = 0.003 and lower ΔVO2/ΔWR: odds ratio, 0.747 [95% CI: 0.575-0.872], p = 0.003).

CONCLUSION

From our exploratory analysis, CPET variables, especially in the lower peak PETCO2 and lower ΔVO2/ΔWR, were associated with Cpc-PH in patients with left heart disease.

Endothelial progenitor cell-derived exosomes inhibit pulmonary artery smooth muscle cell in vitro proliferation and resistance to apoptosis by modulating the Mitofusin-2 and Ras-Raf-ERK1/2 signaling pathway

Pulmonary arterial hypertension (PAH) mainly occurs as a result of abnormal proliferation and apoptosis resistance of pulmonary artery smooth muscle cells (PASMCs). Endothelial progenitor cell (EPC)-derived exosomes (Exos) (EPC-Exos) relieve PAH. However, there is still insufficient knowledge of whether EPC-Exos contribute to the pathological process of PAH, especially for PASMC repair. This study aimed to determine the effects of EPC-Exos on the proliferation, migration, and apoptosis of PASMCs and explore the possible underlying molecular mechanisms through bioinformatics analysis and in vitro testing. Bioinformatics analysis showed that the Ras signaling pathway and Exos were crucial in PAH. The PAH differential microRNAs (miRNAs) and miRNAs identified in EPC-Exos were intersected to obtain miR-21-5p. A target gene prediction program predicted mitofusin-2 (Mfn2) as a potential target of miR-21-5p. Cellular experiments demonstrated that EPC-Exos attenuated the viability, proliferation, migration, and apoptosis resistance of PASMCs under hypoxia. Mechanistically, EPC-Exos significantly upregulated Mfn2 expression and attenuated Ras-Raf-ERK1/2 signaling pathway activity. In conclusion, EPC-Exos suppress cell viability, proliferation, and migration and promote apoptosis in PASMCs under hypoxic conditions. It is possible to transport miR-21-5p to improve the expression of Mfn2 and inhibit the Ras-Raf-ERK1/2 signaling pathway directly or by targeting the expression of Mfn2. EPC-Exos are a potential therapeutic candidate for the treatment of PAH.

Long-Term Effects of Sacubitril-Valsartan on Cardiac Remodeling: A Parallel Echocardiographic Study of Left and Right Heart Adaptive Response

Sacubitril/Valsartan (S/V) carries potential anti-remodeling properties, however long-term effects and biventricular adaptive response are poorly described. 76 HFrEF patients who underwent progressive uptitration of S/V, completed the annual scheduled follow-up. After a median follow-up of 11 (8-13) months, left ventricular (LV) reverse remodeling (RR) is defined as (1) absolute increase in LV ejection fraction (EF) ≥ 10% or LVEF ≥ 50% at follow-up and (2) decrease in indexed LV end-diastolic diameter (LVEDDi) of at least 10% or indexed LVEDDi ≤ 33 mm/m2, occurred in 27.6%. Non-ischemic etiology, shorter duration of HF, and absence of a history of AF were independently associated with LVRR (p < 0.05). TAPSE and TAPSE/PASP, a non-invasive index of right ventricular (RV) coupling to the pulmonary circulation, significantly improved at follow-up (0.45 vs. 0.56, p = 0.02). 41% of patients with baseline RV dysfunction obtained favorable RV remodeling despite only a moderate correlation between RV and LV function was observed (r = 0.478, p = 0.002). Our data point to a potential long-term reverse global remodeling effect by S/V, especially in patients who start S/V at an early stage of the disease, and focus our attention on a possible direct effect of the drug in synergistic hemodynamics between RV and pulmonary circulation.

PARM1 Drives Smooth Muscle Cell Proliferation in Pulmonary Arterial Hypertension via AKT/FOXO3A Axis

Pulmonary arterial hypertension (PAH) is a group of severe, progressive, and debilitating diseases with limited therapeutic options. This study aimed to explore novel therapeutic targets in PAH through bioinformatics and experiments. Weighted gene co-expression network analysis (WGCNA) was applied to detect gene modules related to PAH, based on the GSE15197, GSE113439, and GSE117261. GSE53408 was applied as validation set. Subsequently, the validated most differentially regulated hub gene was selected for further ex vivo and in vitro assays. PARM1, TSHZ2, and CCDC80 were analyzed as potential intervention targets for PAH. Consistently with the bioinformatic results, our ex vivo and in vitro data indicated that PARM1 expression increased significantly in the lung tissue and/or pulmonary artery of the MCT-induced PAH rats and hypoxia-induced PAH mice in comparison with the respective controls. Besides, a similar expression pattern of PARM1 was found in the hypoxia- and PDGF--treated isolated rat primary pulmonary arterial smooth muscle cells (PASMCs). In addition, hypoxia/PDGF--induced PARM1 protein expression could promote the elevation of phosphorylation of AKT, phosphorylation of FOXO3A and PCNA, and finally the proliferation of PASMCs in vitro, whereas PARM1 siRNA treatment inhibited it. Mechanistically, PARM1 promoted PAH via AKT/FOXO3A/PCNA signaling pathway-induced PASMC proliferation.

Right ventricular-pulmonary arterial uncoupling in mild-to-moderate asthma

OBJECTIVE

Persistent pulmonary hypertension and resulting right ventricular (RV) failure are highly encountered phenomenon in severe pulmonary diseases. However, in this study, we aimed to examine the effects of mild-to-moderate asthma on RV functions, pulmonary arterial stiffness (PAS), and coupling of RV to the pulmonary artery (PA) in the absence of overt pulmonary hypertension.

METHODS

We enrolled 53 patients with mild-to-moderate asthma, and 50 healthy control subjects. A comprehensive two dimensional transthoracic echocardiography was performed on each individual. The parameters measuring RV function were all examined. PAS was calculated by dividing maximal frequency shift of pulmonary flow by pulmonary acceleration time. RV-PA coupling was estimated by the tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP) ratio (TAPSE/PASP).

RESULTS

Baseline demographics, clinical and laboratory parameters of both groups were similar (p > 0.05). Most of conventional echocardiographic parameters measuring RV function were impaired in patients with asthma compared to control subjects. PAS values were significantly higher in the asthma group [24 (21-26) vs. 20 (18-22), p < 0.001], and TAPSE/PASP ratio was significantly lower in the asthma group versus the control group [0.81 ± 0.08 vs. 0.96 ± 0.11, p < 0.001]. Multilinear regression analysis revealed PAS, TAPSE, and PASP as independent predictors of TAPSE/PASP ratio.

CONCLUSION

Mild-to-moderate asthma was shown to be associated with both subclinical RV dysfunction and increased PAS values. TAPSE/PASP ratio was also markedly decreased, suggesting RV-PA uncoupling even in the absence of overt pulmonary hypertension. PAS referring RV afterload was shown to be an independent predictor of TAPSE/PASP ratio.

An Update on the Diagnosis and Management of Acute Right Heart Failure

Right ventricular (RV) dysfunction and resultant acute right heart failure (ARHF) is a rapidly growing field of interest, driven by increasing appreciation of its contribution to heart failure morbidity and mortality. Understanding of ARHF pathophysiology has advanced dramatically over recent years and can be broadly described as RV dysfunction related to acute changes in RV afterload, contractility, preload, or left ventricular dysfunction. There are several diagnostic clinical signs and symptoms as well as imaging and hemodynamic assessments that can provide insight into the degree of RV dysfunction. Medical management is tailored to the different causative pathologies, and in cases of severe or end-stage dysfunction, mechanical circulatory support can be utilized. In this review, we describe the pathophysiology of ARHF, how its diagnosis is established by clinical signs and symptoms and imaging findings, and provide an overview of treatment options, both medical and mechanical.

IL-12α deficiency attenuates pressure overload-induced cardiac inflammation, hypertrophy, dysfunction, and heart failure progression

IL-12α plays an important role in modulating inflammatory response, fibroblast proliferation and angiogenesis through modulating macrophage polarization or T cell function, but its effect on cardiorespiratory fitness is not clear. Here, we studied the effect of IL-12α on cardiac inflammation, hypertrophy, dysfunction, and lung remodeling in IL-12α gene knockout (KO) mice in response to chronic systolic pressure overload produced by transverse aortic constriction (TAC). Our results showed that IL-12α KO significantly ameliorated TAC-induced left ventricular (LV) failure, as evidenced by a smaller decrease of LV ejection fraction. IL-12α KO also exhibited significantly attenuated TAC-induced increase of LV weight, left atrial weight, lung weight, right ventricular weight, and the ratios of them in comparison to body weight or tibial length. In addition, IL-12α KO showed significantly attenuated TAC-induced LV leukocyte infiltration, fibrosis, cardiomyocyte hypertrophy, and lung inflammation and remodeling (such as lung fibrosis and vessel muscularization). Moreover, IL-12α KO displayed significantly attenuated TAC-induced activation of CD4+ T cells and CD8+ T cells in the lung. Furthermore, IL-12α KO showed significantly suppressed accumulation and activation of pulmonary macrophages and dendritic cells. Taken together, these findings indicate that inhibition of IL-12α is effective in attenuating systolic overload-induced cardiac inflammation, heart failure development, promoting transition from LV failure to lung remodeling and right ventricular hypertrophy.

Biomechanical and Mechanobiological Drivers of the Transition From PostCapillary Pulmonary Hypertension to Combined Pre-/PostCapillary Pulmonary Hypertension

Combined pre-/postcapillary pulmonary hypertension (Cpc-PH), a complication of left heart failure, is associated with higher mortality rates than isolated postcapillary pulmonary hypertension alone. Currently, knowledge gaps persist on the mechanisms responsible for the progression of isolated postcapillary pulmonary hypertension (Ipc-PH) to Cpc-PH. Here, we review the biomechanical and mechanobiological impact of left heart failure on pulmonary circulation, including mechanotransduction of these pathological forces, which lead to altered biological signaling and detrimental remodeling, driving the progression to Cpc-PH. We focus on pathologically increased cyclic stretch and decreased wall shear stress; mechanotransduction by endothelial cells, smooth muscle cells, and pulmonary arterial fibroblasts; and signaling-stimulated remodeling of the pulmonary veins, capillaries, and arteries that propel the transition from Ipc-PH to Cpc-PH. Identifying biomechanical and mechanobiological mechanisms of Cpc-PH progression may highlight potential pharmacologic avenues to prevent right heart failure and subsequent mortality.

Lung Dysfunction and Chronic Kidney Disease: A Complex Network of Multiple Interactions

Chronic kidney disease (CKD) is a progressive disease that affects > 10% of the total population worldwide or >800 million people. CKD poses a particularly heavy burden in low- and middle-income countries, which are least able to cope with its consequences. It has become one of the leading causes of death worldwide and is one of the few non-communicable diseases where the number of related deaths has increased over the last two decades. The high number of people affected, and the significant negative impact of CKD should be a reason to increase efforts to improve prevention and treatment. The interaction of lung and kidney leads to highly complex and difficult clinical scenarios. CKD significantly affects the physiology of the lung by altering fluid homeostasis, acid-base balance and vascular tone. In the lung, haemodynamic disturbances lead to the development of alterations in ventilatory control, pulmonary congestion, capillary stress failure and pulmonary vascular disease. In the kidney, haemodynamic disturbances lead to sodium and water retention and the deterioration of renal function. In this article, we would like to draw attention to the importance of harmonising the definitions of clinical events in pneumology and renal medicine. We would also like to highlight the need for pulmonary function tests in routine clinical practise for the management of patients with CKD, in order to find new concepts for pathophysiological based disease-specific management strategies.

Lasso algorithm and support vector machine strategy to screen pulmonary arterial hypertension gene diagnostic markers

BACKGROUND

This study employs machine learning strategy algorithms to screen the optimal gene signature of pulmonary arterial hypertension (PAH) under big data in the medical field.

METHODS

The public database Gene Expression Omnibus (GEO) was used to analyze datasets of 32 normal controls and 37 PAH disease samples. The enrichment analysis was performed after selecting the differentially expressed genes. Two machine learning methods, the least absolute shrinkage and selection operator (LASSO) and support vector machine (SVM), were used to identify the candidate genes. The external validation data set further tests the expression level and diagnostic value of candidate diagnostic genes. The diagnostic effectiveness was evaluated by obtaining the receiver operating characteristic curve (ROC). The convolution tool CIBERSORT was used to estimate the composition pattern of the immune cell subtypes and to perform correlation analysis based on the combined training dataset.

RESULTS

A total of 564 differentially expressed genes (DEGs) were screened in normal control and pulmonary hypertension samples. The enrichment analysis results were found to be closely related to cardiovascular diseases, inflammatory diseases, and immune-related pathways. The LASSO and SVM algorithms in machine learning used 5 × cross-validation to identify 9 and 7 characteristic genes. The two machine learning algorithms shared Caldesmon 1 (CALD1) and Solute Carrier Family 7 Member 11 (SLC7A11) as genetic signals highly correlated with PAH. The results showed that the area under ROC (AUC) of the specific characteristic diagnostic genes were CALD1 (AUC = 0.924) and SLC7A11 (AUC = 0.962), indicating that the two diagnostic genes have high diagnostic value.

CONCLUSION

CALD1 and SLC7A11 can be used as diagnostic markers of PAH to obtain new insights for the further study of the immune mechanism involved in PAH.

A review of cardio-pulmonary microvascular dysfunction in pulmonary hypertension

Microvascular dysfunction progressing to pulmonary hypertension can be a primary cause of right ventricular failure or a secondary cause because of an underlying systemic illness. Little is known regarding the etiology and epidemiology of coronary microvascular dysfunction in pulmonary hypertension. Despite this limitation, its presence has been described in patients with pulmonary hypertension. This review focuses on the pathogenesis of cardiac and pulmonary microvascular dysfunction in pulmonary hypertension. Additionally, this review provides a contemporary assessment on the diagnosis and treatment of microvascular dysfunction in patients in pulmonary hypertension. This topic is important to raise awareness of microvascular dysfunction in the coronary and pulmonary circulation, so that future studies will investigate its impact on the pulmonary hypertension patient cohort.

Updates in the Pharmacotherapy of Pulmonary Hypertension in Patients with Heart Failure with Preserved Ejection Fraction

Pulmonary hypertension (PH) associated with left heart disease (LHD) is a complex cardiopulmonary condition where a variable degree of pulmonary congestion, arterial vasoconstriction and vascular remodeling can lead to PH and right heart strain. Right heart dysfunction has a significant prognostic impact on these patients. Therefore, preserving right ventricular (RV) function is an important treatment goal. However, the treatment of PH in patients with left heart disease has produced conflicting evidence. The transition from pure LHD to LHD with PH is a continuum and clinically challenging. The heart failure with preserved ejection fraction (HFpEF) patient population is heterogeneous when it comes to PH and RV function. Appropriate clinical and hemodynamic phenotyping of patients with HFpEF and concomitant PH is paramount to making the appropriate treatment decision. This manuscript will summarize the current evidence for the use of pulmonary arterial vasodilators in patients with HFpEF.

Right ventricular failure: Current strategies and future development

Right heart failure can be defined as a clinical syndrome consisting of signs and symptoms of heart failure resulting from right ventricular dysfunction. Function is normally altered due to three mechanisms: (1) pressure overload (2) volume overload, or (3) a decrease in contractility due to ischaemia, cardiomyopathy or arrythmias. Diagnosis is based upon a combination of clinical assessment plus echocardiographic, laboratory and haemodynamic parameters, and clinical risk assessment. Treatment includes medical management, mechanical assist devices and transplantation if recovery is not observed. Distinct attention to special circumstances such as left ventricular assist device implantation should be sought. The future is moving towards new therapies, both pharmacological and device centered. Immediate diagnosis and management of RV failure, including mechanical circulatory support where needed, alongside a protocolized approach to weaning is important in successfully managing right ventricular failure.

Determinants of exercise capacity in patients with heart failure without left ventricular hypertrophy

BACKGROUND

Determinants of exercise intolerance in a phenotype of heart failure with preserved ejection fraction (HFpEF) with normal left ventricular (LV) structure have not been fully elucidated.

METHODS

Cardiopulmonary exercise testing and exercise-stress echocardiography were performed in 44 HFpEF patients without LV hypertrophy. Exercise capacity was determined by peak oxygen consumption (peak VO₂). Doppler-derived cardiac output (CO), transmitral E velocity, systolic (LV-s') and early diastolic mitral annular velocities (e'), systolic pulmonary artery (PA) pressure (SPAP), tricuspid annular plane systolic excursion (TAPSE), and peak systolic right ventricular (RV) free wall velocity (RV-s') were measured at rest and exercise. E/e' and TAPSE/SPAP were used as an LV filling pressure parameter and RV-PA coupling, respectively.

RESULTS

During exercise, CO, LV-s', RV-s', e', and SPAP were significantly increased (p < 0.05 for all), whereas E/e' remained unchanged and TAPSE/SPAP was significantly reduced (p < 0.001). SPAP was higher and TAPSE/SPAP was lower at peak exercise in patients showing lower-half peak VO₂. In univariable analyses, LV-s' (R = 0.35, p = 0.022), SPAP (R = -0.40, p = 0.008), RV-s' (R = 0.47, p = 0.002), and TAPSE/SPAP (R = 0.42, p = 0.005) were significantly correlated with peak VO₂. In multivariable analyses, not only SPAP, but also TAPSE/SPAP independently determined peak VO₂ even after the adjustment for clinically relevant parameters.

CONCLUSIONS

In HFpEF patients without LV hypertrophy, altered RV-PA coupling by exercise could be associated with exercise intolerance, which might not be caused by elevated LV filling pressure.

Hemodynamic Responses to Provocative Maneuvers during Right Heart Catheterization

Rationale: Current guidelines recognize the utility of provocative maneuvers during right heart catheterization to aid the diagnosis of pulmonary hypertension. Few studies have compared the performance of different provocation maneuvers. Objectives: To assess the hemodynamic correlation among three provocative maneuvers, including their effect on pulmonary hypertension classification. Methods: This prospective trial was conducted between October 2016 and May 2018. Adult patients underwent three provocative maneuvers during right heart catheterization: passive leg raise (PLR), load-targeted supine bicycle exercise, and rapid crystalloid fluid infusion. Patients were classified as follows: no pulmonary hypertension, precapillary pulmonary hypertension, isolated postcapillary pulmonary hypertension, combined pre- and postcapillary pulmonary hypertension, and uncategorized pulmonary hypertension. We assessed the hemodynamic changes associated with each maneuver. We also assessed whether provocative maneuvers led to hemodynamic reclassification of the patient to either postcapillary pulmonary hypertension with provocation or exercise pulmonary hypertension. Results: Eighty-five patients (mean age 62 ± 12 years, 53% women) were included. Correlation between exercise and fluid challenge was moderate to strong (0.49-0.82; P < 0.001) for changes in right atrial pressure, mean pulmonary arterial pressure, pulmonary arterial wedge pressure, and cardiac index from baseline. Correlation between PLR and exercise (0.4-0.65; P < 0.001) and between PLR and fluid challenge (0.45-0.6; P < 0.001) was moderate for changes in right atrial pressure, mean pulmonary arterial pressure, pulmonary arterial wedge pressure, pulmonary vascular resistance, and cardiac index. Hemodynamic correlation between other provocative maneuvers was poor. Depending on provocative maneuver and classification criteria, there was significant variation in the number of patients reclassified as having exercise pulmonary hypertension (3-50%) or postcapillary pulmonary hypertension with provocation (11-48%). Conclusions: Hemodynamic determinations during exercise and fluid challenge showed moderate to strong hemodynamic correlation. Moderate hemodynamic correlation was seen between PLR and exercise or fluid challenge. Although some provocative maneuvers demonstrate good hemodynamic correlation, there is inconsistency when using these maneuvers to identify patients with postcapillary or exercise pulmonary hypertension.

Comprehensive Monitoring in Patients With Dual Lumen Right Atrium to Pulmonary Artery Right Ventricular Assist Device

Right ventricular assist devices (RVADs) can be used in patients with acute right heart failure. A novel device that has recently been deployed is the right atrium to pulmonary artery (RA-PA) dual lumen single cannula (DLSC). One of the limitations is that it occupies a large proportion of the right ventricular outflow tract and PA; therefore, standard continuous hemodynamic monitoring with a pulmonary artery catheter is commonly not used. Serial echocardiography is pivotal for device deployment, monitoring device position, assessing RV readiness for decannulation, and surveilling for short-term complications. We performed a retrospective case series of 24 patients with RA-PA DLSC RVAD assessing echocardiographic RV progression and vasoactive infusion requirements. The overall survival was 66.6%. The average vasoactive infusion score at the time of cannulation was 24.9 ± 43.9, at decannulation in survivors 4.6 ± 4.9 vs . 25.4 ± 21.5 in nonsurvivors, and 2.7 ± 4.9 at 48 hours post decannulation. On echocardiography, the average visual estimate of RV systolic function encoded (0 = none and 5 = severe) in survivors was 3.9 ± 1.2, 2.8 ± 1.6, 2.5 ± 1.7, and 2.8 ± 1.9, respectively, and in nonsurvivors 3.8 ± 1.6 and 3.4 ± 1.8, respectively. This demonstrated an RV systolic function improvement over time in survivors as opposed to nonsurvivors. This was also demonstrated in RV size visual estimate, respectively. Quantitatively, at the predefined four timepoints, the RV:LV, tricuspid annular plane systolic excursion, and fractional area change all improve over time and there is statistically significant difference in survivors versus nonsurvivors. In this study, we describe a cohort of patients treated with RA-PA DLSC RVAD. We illustrate the critical nature of echocardiographic measures to rate the progression of RV function, improvement in vasoactive infusion requirements, and ventilator parameters with the RA-PA DLSC.

Effects of remote haemodynamic-guided heart failure management in patients with different subtypes of pulmonary hypertension: insights from the MEMS-HF study

AIM

The CardioMEMS European Monitoring Study for Heart Failure (MEMS-HF) investigated safety and efficacy of pulmonary artery pressure (PAP)-guided remote patient management (RPM) in New York Heart Association (NYHA) class III outpatients with at least one heart failure hospitalization (HFH) during the previous 12 months. This pre-specified subgroup analysis investigated whether RPM effects depended on presence and subtype of pulmonary hypertension (PH).

METHODS AND RESULTS

In 106/234 MEMS-HF participants, Swan-Ganz catheter tracings obtained during sensor implant were available for off-line manual analysis jointly performed by two experts. Patients were classified into subgroups according to current PH definitions. Isolated post-capillary PH (IpcPH) and combined post- and pre-capillary PH (CpcPH) were present in 38 and 36 patients, respectively, whereas 31 patients had no PH. Clinical characteristics were comparable between subgroups, but among patients with PH pulmonary vascular resistance was higher (p = 0.029) and pulmonary artery compliance lower (p = 0.003) in patients with CpcPH. During 12 months of PAP-guided RPM, all PAPs declined in IpcPH and CpcPH subgroups (all p < 0.05), whereas only mean and diastolic PAP decreased in patients without PH (both p < 0.05). Improvements in post- versus pre-implant HFH rates were similar in CpcPH (0.639 events/patient-year; hazard ratio [HR] 0.37) and IpcPH (0.72 events/patient-year; HR 0.45) patients. Participants without PH benefited most (0.26 events/patient-year; HR 0.17, p = 0.04 vs. IpcPH/CpcPH patients). Quality of life and NYHA class improved significantly in all subgroups.

CONCLUSIONS

Outpatients with NYHA class III symptoms with at least one HFH during 1 year pre-implant benefitted significantly from PAP-guided RPM during post-implant follow-up irrespective of presence or subtype of PH at baseline.