Global Pulmonary Vascular Remodeling in Pulmonary Hypertension Associated With Heart Failure and Preserved or Reduced Ejection Fraction

Tricuspid Regurgitation in Patients With Heart Failure and Preserved Ejection Fraction: JACC State-of-the-Art Review

Heart failure with preserved ejection fraction (HFpEF) is associated with high morbidity and mortality. Important risk factors for the development of HFpEF are similar to risk factors for the progression of tricuspid regurgitation (TR), and both conditions frequently coexist and thus is a distinct phenotype or a marker for advanced HF. Many patients with severe, symptomatic atrial secondary TR have been enrolled in current transcatheter device trials, and may represent patients at an advanced stage of HFpEF. Management of HFpEF thus may affect the pathophysiology of TR, and the physiologic changes that occur following transcatheter treatment of TR, may also impact symptoms and outcomes in patients with HFpEF. This review discusses these issues and suggests possible management strategies for these patients.

Pulmonary vascular disease in Veterans with post-deployment respiratory syndrome

Exertional dyspnea has been documented in US military personnel after deployment to Iraq and Afghanistan. We studied whether continued exertional dyspnea in this patient population is associated with pulmonary vascular disease (PVD). We performed detailed histomorphometry of pulmonary vasculature in 52 Veterans with biopsy-proven post-deployment respiratory syndrome (PDRS) and then recruited five of these same Veterans with continued exertional dyspnea to undergo a follow-up clinical evaluation, including symptom questionnaire, pulmonary function testing, surface echocardiography, and right heart catheterization (RHC). Morphometric evaluation of pulmonary arteries showed significantly increased intima and media thicknesses, along with collagen deposition (fibrosis), in Veterans with PDRS compared to non-diseased (ND) controls. In addition, pulmonary veins in PDRS showed increased intima and adventitia thicknesses with prominent collagen deposition compared to controls. Of the five Veterans involved in our clinical follow-up study, three had borderline or overt right ventricle (RV) enlargement by echocardiography and evidence of pulmonary hypertension (PH) on RHC. Together, our studies suggest that PVD with predominant venular fibrosis is common in PDRS and development of PH may explain exertional dyspnea and exercise limitation in some Veterans with PDRS.

The chest CT signs for pulmonary veno-occlusive disease correlate with pulmonary haemodynamics in systemic sclerosis

OBJECTIVES

Pulmonary arterial hypertension associated with systemic sclerosis (PAH-SSc) sometimes accompanies pulmonary veno-occlusive disease (PVOD). We aimed to reveal the relationship between clinical signs of PVOD and severity of pulmonary vasculopathy in SSc.

METHODS

This study included 52 consecutive SSc patients who had pulmonary haemodynamic abnormalities [mean pulmonary arterial pressure (mPAP) >20 mmHg, pulmonary vascular resistance >2 WU or pulmonary artery wedge pressure (PAWP) >15 mmHg]. A chest CT scan was evaluated in all patients. Patients were divided into two groups, the 0-1 group and the 2-3 group, according to the number of chest CT signs for PVOD, including mediastinal lymph node enlargement, thickened interlobular septal wall and ground glass opacity. Pulmonary haemodynamics, echocardiography and MRI-based cardiac function, pulmonary function and serum biomarkers were compared between the two groups.

RESULTS

Mediastinal lymph node enlargement, thickened interlobular septal wall and ground glass opacity were observed in 11 (21%), 32 (62%) and 11 (21%) patients, respectively. The 2-3 group (n = 15) had higher mPAP (P = 0.02) but lower diffusing capacity of carbon monoxide (DLCO)/alveolar volume (P = 0.02) compared with the 0-1 group (n = 37). Other parameters, including PAWP, cardiac output, left ventricular ejection fraction, left atrial diameter, forced vital capacity, brain natriuretic peptide and Krebs von den Lunge-6 were not different between the two groups.

CONCLUSIONS

The CT signs for PVOD had a positive correlation with mPAP but a negative correlation with DLCO in SSc patients, indicating that PAH-SSc may reflect a spectrum of pulmonary vascular disease that ranges from the pulmonary artery to the vein.

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.

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.

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).

Novel insights into the pathobiology of pulmonary hypertension in heart failure with preserved ejection fraction

Heart failure (HF) with preserved ejection fraction (HFpEF) is the most common cause of pulmonary hypertension (PH) worldwide and is strongly associated with adverse clinical outcomes. The American Heart Association recently highlighted a call to action regarding the distinct lack of evidence-based treatments for PH due to poorly understood pathophysiology of PH attributable to HFpEF (PH-HFpEF). Prior studies have described cardiophysiological mechanisms to explain the development of isolated postcapillary PH (ipc-PH); however, the consequent increase in pulmonary vascular (PV) resistance (PVR) may lead to the less understood and more fatal combined pre- and postcapillary PH (cpc-PH). Metabolic disease and inflammatory dysregulation have been suggested to predispose PH, yet the molecular mechanisms are unknown. Although PH-HFpEF has been studied to partly share vasoactive neurohormonal mediators with primary pulmonary arterial hypertension (PAH), clinical trials that have targeted these pathways have been unsuccessful. The increased mortality of patients with PH-HFpEF necessitates further study into viable mechanistic targets involved in disease progression. We aim to summarize the current pathophysiological and clinical understanding of PH-HFpEF, highlight the role of known molecular mechanisms in the progression of PV disease, and introduce a novel concept that lipid metabolism may be attenuating and propagating PH-HFpEF.NEW & NOTEWORTHY Our review addresses pulmonary hypertension (PH) attributable to heart failure (HF) with preserved ejection fraction (HFpEF; PH-HFpEF). Current knowledge gaps in PH-HFpEF pathophysiology have led to a lack of therapeutic targets. Thus, we address identified knowledge gaps in a comprehensive review, focusing on current clinical epidemiology, known pathophysiology, and previously studied molecular mechanisms. We also introduce a comprehensive review of polyunsaturated fatty acid (PUFA) lipid inflammatory mediators in PH-HFpEF.

A clinician's guide to pulmonary hypertension

ABSTRACT

Despite advances in diagnosis and treatment, pulmonary hypertension has high morbidity and mortality. The presenting symptoms often are vague and may mimic other more common diseases, so patients can be misdiagnosed or missed early in the disease process. Early detection of pulmonary hypertension by primary care providers can play an important role in patient outcomes and survival. Identifying signs and symptoms, understanding the causes and classifications, and knowing the systematic approach to evaluating and diagnosing patients with suspected pulmonary hypertension are key to preventing premature patient decline.

A roadmap for therapeutic discovery in pulmonary hypertension associated with left heart failure. A scientific statement of the Heart Failure Association (HFA) of the ESC and the ESC Working Group on Pulmonary Circulation & Right Ventricular Function

Pulmonary hypertension (PH) associated with left heart failure (LHF) (PH-LHF) is one of the most common causes of PH. It directly contributes to symptoms and reduced functional capacity and negatively affects right heart function, ultimately leading to a poor prognosis. There are no specific treatments for PH-LHF, despite the high number of drugs tested so far. This scientific document addresses the main knowledge gaps in PH-LHF with emphasis on pathophysiology and clinical trials. Key identified issues include better understanding of the role of pulmonary venous versus arteriolar remodelling, multidimensional phenotyping to recognize patient subgroups positioned to respond to different therapies, and conduct of rigorous pre-clinical studies combining small and large animal models. Advancements in these areas are expected to better inform the design of clinical trials and extend treatment options beyond those effective in pulmonary arterial hypertension. Enrichment strategies, endpoint assessments, and thorough haemodynamic studies, both at rest and during exercise, are proposed to play primary roles to optimize early-stage development of candidate therapies for PH-LHF.

Haemodynamic phenotypes of pulmonary hypertension associated with left heart disease: a moving target

Shifting haemodynamic definitions impact prevalence of CpcPH in PH associated with left heart disease. Diastolic pressure gradient ≥7 mmHg and pulmonary vascular resistance >5 WU predict pulmonary vascular disease similarly well. https://bit.ly/3OEG5pw

Managing Pulmonary Arterial Hypertension With Cardiopulmonary Comorbidities

Pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with left-sided heart and lung diseases are most commonly easily discriminated and treated accordingly. With the changing epidemiology of PAH, however, a growing proportion of patients at the time of diagnosis present with comorbidities of varying severity. In addition to classical PAH, two distinct phenotypes have emerged: a heart failure with preserved ejection fraction-like phenotype and a lung phenotype. Importantly, the evidence supporting the currently proposed treatment algorithm for PAH has been generated mainly from PAH trials in which patients with cardiopulmonary comorbidities have been underrepresented or excluded. As a consequence, the best therapeutic approach for patients with common PAH with cardiopulmonary comorbidities remains largely unknown and requires further investigation. The present article reviews the relevant literature on the topic and describes the authors' views on the current therapeutic approach for these patients.

Impact of inhalation exposure to cigarette smoke on the pathogenesis of pulmonary hypertension primed by monocrotaline in rats

Extensive, long-term exposure to cigarette smoke (CS) was recently suggested to be a risk factor for pulmonary hypertension, although further validation is required. The vascular effects of CS share similarities with the etiology of pulmonary hypertension, including vascular inflammation and remodeling. Thus, we examined the influence of CS exposure on the pathogenesis of monocrotaline (MCT)-induced pulmonary hypertension, hypothesizing that smoking might accelerate the development of primed pulmonary hypertension. CS was generated from 3R4F reference cigarettes, and rats were exposed to CS by inhalation at total particulate matter concentrations of 100-300 μg/L for 4 h/day, 7 days/week for 4 weeks. Following 1 week of initial exposure, rats received 60 mg/kg MCT and were sacrificed and analyzed after an additional 3 weeks of exposure. MCT induced hypertrophy in pulmonary arterioles and increased the Fulton index, a measure of right ventricular hypertrophy. Additional CS exposure exacerbated arteriolar hypertrophy but did not further elevate the Fulton index. No significant alterations were observed in levels of endothelin-1 and vascular endothelial growth factor, or in hematological and serum biochemical parameters. Short-term inhalation exposure to CS exacerbated arteriolar hypertrophy in the lung, although this effect did not directly aggravate the overworked heart under the current experimental conditions.

A Novel Rat Model of Mild Pulmonary Hypertension Associated with Pulmonary Venous Congestion Induced by Left Pulmonary Vein Banding

Pulmonary hypertension (PH) associated with left heart disease (PH-LHD) is the most common form of PH. In PH-LHD, changes in the pulmonary vasculature are assumed to be mainly caused by pulmonary venous congestion. However, the underlying mechanisms of this form of PH are poorly understood. We aimed to establish a model of PH associated with pulmonary venous congestion. Wistar-Kyoto rats underwent partial occlusion of the left pulmonary vein to induce pulmonary venous congestion or sham surgery and were assessed at various time points post-surgery (3, 6, 9, 12 weeks). In vivo cardiopulmonary phenotyping was performed by using echocardiography along with heart catheterization. Histomorphometry methods were used to assess pulmonary vascular remodeling (e.g., wall thickness, degree of muscularization). Left pulmonary vein banding (PVB) resulted in mildly elevated right ventricular systolic pressure and moderate right ventricular hypertrophy. In PVB rats, small- and medium-sized pulmonary vessels in the left lung were characterized by increased wall thickness and muscularization. Taken together, our data demonstrate that left PVB-induced pulmonary venous congestion is associated with pulmonary vascular remodeling and mild PH.

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.

Omics and Extreme Phenotyping Reveal Longitudinal Association Between Left Atrial Size and Pulmonary Vascular Resistance in Group 2 Pulmonary Hypertension

BACKGROUND

Left heart disease is the most common cause of pulmonary hypertension (PH) and is frequently accompanied by increases in pulmonary vascular resistance. However, the distinction between phenotypes of PH due to left heart disease with a normal or elevated pulmonary vascular resistance-isolated postcapillary PH (IpcPH) and combined pre- and postcapillary PH (CpcPH), respectively-has been incompletely defined using unbiased methods.

METHODS AND RESULTS

Patients with extremes of IpcPH versus CpcPH were identified from a single-center record of those who underwent right heart catheterization. Individuals with left ventricular ejection fraction <40% or with potential causes of PH beyond left heart disease were excluded. Medication usage in IpcPH and CpcPH was compared across Anatomical Therapeutic Chemical classes and identified vitamin K antagonists as the only medication with pharmacome-wide significance, being more commonly used in CpcPH and for an indication of atrial fibrillation in ≈90% of instances. Accordingly, atrial fibrillation prevalence was significantly higher in CpcPH in a phenome-wide analysis. Review of echocardiographic data most proximal to right heart catheterization revealed that left atrial diameter indexed to body surface area-known to be associated with atrial fibrillation-was increased in CpcPH regardless of the presence of atrial fibrillation. An independent cohort with serial right heart catheterizations and PH-left heart disease showed a significant positive correlation between change in left atrial diameter indexed to body surface area and change in pulmonary vascular resistance.

CONCLUSIONS

Guided by pharmacomic and phenomic screens in a rigorously phenotyped cohort, we identify a longitudinal association between left atrial diameter indexed to body surface area and pulmonary vascular resistance with implications for the future development of diagnostic, prognostic, and therapeutic tools.

Pulmonary Hypertension Associated with Left Heart Disease

Pulmonary hypertension (PH) is a common complication of diseases affecting the left heart, mostly found in patients suffering from heart failure, with or without preserved left ventricular ejection fraction. Initially driven by a passive increase in left atrial pressure (postcapillary PH), several mechanisms may lead in a subset of patient to significant structural changes of the pulmonary vessels or a precapillary component. In addition, the right ventricle may be independently affected, which results in right ventricular to pulmonary artery uncoupling and right ventricular failure, all being associated with a worse outcome. The differential diagnosis of PH associated with left heart disease versus pulmonary arterial hypertension (PAH) is especially challenging in patients with cardiovascular comorbidities and/or heart failure with preserved ejection fraction (HFpEF). A stepwise approach to diagnosis is proposed, starting with a proper clinical multidimensional phenotyping to identify patients in whom hemodynamic confirmation is deemed necessary. Provocative testing (exercise testing, fluid loading, or simple leg raising) is useful in the cath laboratory to identify patients with abnormal response who are more likely to suffer from HFpEF. In contrast with group 1 PH, management of PH associated with left heart disease must focus on the treatment of the underlying condition. Some PAH-approved targets have been unsuccessfully tried in clinical studies in a heterogeneous group of patients, some even leading to an increase in adverse events. There is currently no approved therapy for PH associated with left heart disease.

Myeloid Cell Derived IL1β Contributes to Pulmonary Hypertension in HFpEF

BACKGROUND

Pulmonary hypertension (PH) in heart failure with preserved ejection fraction (HFpEF) is a common and highly morbid syndrome, but mechanisms driving PH-HFpEF are poorly understood. We sought to determine whether a well-accepted murine model of HFpEF also displays features of PH, and we sought to identify pathways that might drive early remodeling of the pulmonary vasculature in HFpEF.

METHODS

Eight-week-old male and female C57BL/6J mice received either Nγ-nitro-L-arginine methyl ester and high-fat diet or control water and diet for 2, 5, and 12 weeks. The db/db mice were studied as a second model of HFpEF. Early pathways regulating PH were identified by bulk and single-cell RNA sequencing. Findings were confirmed by immunostain in lungs of mice or lung slides from clinically performed autopsies of patients with PH-HFpEF. ELISA was used to verify IL-1β (interleukin-1 beta) in mouse lung, mouse plasma, and also human plasma from patients with PH-HFpEF obtained at the time of right heart catheterization. Clodronate liposomes and an anti-IL-1β antibody were utilized to deplete macrophages and IL-1β, respectively, to assess their impact on pulmonary vascular remodeling in HFpEF in mouse models.

RESULTS

Nγ-nitro-L-arginine methyl ester/high-fat diet-treated mice developed PH, small vessel muscularization, and right heart dysfunction. Inflammation-related gene ontologies were overrepresented in bulk RNA sequencing analysis of whole lungs, with an increase in CD68+ cells in both murine and human PH-HFpEF lungs. Cytokine profiling showed an increase in IL-1β in mouse and human plasma. Finally, clodronate liposome treatment in mice prevented PH in Nγ-nitro-L-arginine methyl ester/high-fat diet-treated mice, and IL-1β depletion also attenuated PH in Nγ-nitro-L-arginine methyl ester/high-fat diet-treated mice.

CONCLUSIONS

We report a novel model for the study of PH and right heart remodeling in HFpEF, and we identify myeloid cell-derived IL-1β as an important contributor to PH in HFpEF.

Different right ventricular dysfunction and pulmonary coupling in acute heart failure according to the left ventricular ejection fraction

BACKGROUND

Right ventricular (RV) dysfunction and pulmonary uncoupling are two acknowledged features associated with poor outcome, however few data defined RV adaptation across the different left ventricular ejection fraction (EF) cut-off. Additionally, less data are reported in patients with acute heart failure (AHF).

AIMS

The aim of present study was to analyse RV function in AHF patients presenting with either reduced or preserved EF.

METHODS

This is a multi-center observational study including 380 patients affected by AHF: 235 had AHF with reduced EF (AHFrEF) and 145 had AHF with preserved EF (AHFpEF). Pulmonary artery systolic pressure (PASP), tricuspid annular plane systolic excursion (TAPSE), S' wave velocity, and the RV end-diastolic diameter (RVEDD) were measured by echocardiography. TAPSE/PASP and S'/PASP ratios were calculated as non-invasive surrogates of RV-pulmonary arterial coupling.

RESULTS

Factors associated with poor outcome were higher values of PASP (45 [40-55] mmHg vs 40 [35-46] mmHg; p < 0.001), RVEDD (44 [38-47] mm vs 37 [35-42] mm; p < 0.001), lower TAPSE values (17 [15-20] mm vs 20 [18-22] mm; p < 0.001) and S' wave (10 [8-12] cm/s vs 11 [10-13] cm/s; p < 0.001), reduced TAPSE/PASP (0.37 [0.29-0.47] vs 0.50 [0.40-0.60]; p < 0.001) and S'/PASP ratios (0.22 [0.18-0.28] vs 0.28 [0.22-0.34]; p < 0.001). However, the prognostic parameters differed according to the LVEF value: in AHFpEF S'/PASP between 0.22 and 0.29 and > 0.29 demonstrated a protective prognostic value (Respectively HR 0.29 (0.16-0.53), p < 0.001 and HR 0.22 [0.12-0.42], p < 0.001). Conversely, in AHFrEF, TAPSE <16 mm (HR 2.59 [1.67-4.03], p < 0.001), ICV > 21 mm (HR 1.17 [1.17-1.28], p = 0.001) and TAPSE/PASP <0.49 HR 1.92 [1.10-3.37], p = 0.023) were related to adverse outcome.

CONCLUSIONS

RV adaptation and RV pulmonary coupling differ in AHF according to the level of LVEF. S' wave, and S'/PASP are associated with adverse outcome in patients with preserved EF; reduced TAPSE and TAPSE/PASP are better prognostic predictors in patients with reduced EF.

Coronary perfusion pressure is associated with adverse outcomes in advanced heart failure

BACKGROUND

Myocardial perfusion is an important determinant of cardiac function. We hypothesized that low coronary perfusion pressure (CPP) would be associated with adverse outcomes in heart failure. Myocardial perfusion impacts the contractile efficiency thus a low CPP would signal low myocardial perfusion in the face of increased cardiac demand as a result of volume overload.

METHODS

We analyzed patients with complete hemodynamic data in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial using Cox Proportional Hazards regression for the primary outcome of the composite risk of death, heart transplantation, or left ventricular assist device [(LVAD). DT × LVAD] and the secondary outcome of the composite risk of DT × LVAD and heart failure hospitalization (DT × LVADHF). CPP was calculated as the difference between diastolic blood pressure and pulmonary artery wedge pressure. Heart failure categories (ischemic vs non-ischemic) were also stratified based on CPP strata.

RESULTS

The 158 patients (56.7 ± 13.6 years, 28.5% female) studied had a median CPP of 40 mmHg (IQR 35-52 mmHg). During 6 months of follow-up, 35 (22.2%) had the composite primary outcome and 109 (69.0%) had the composite secondary outcome. When these outcomes were then stratified based on the median, CPP was associated with these outcomes. Increasing CPP was associated with lower risk of both the primary outcome of DT × LVAD (HR 0.96, 95% CI 0.94-0.99 p = .002) and as well as the secondary outcome of DT × LVADHF (p = .0008) There was significant interaction between CPP and ischemic etiology (p = .04).

CONCLUSION

A low coronary artery perfusion pressure below (median) 40mmHg in patients with advanced heart failure undergoing invasive hemodynamic monitoring with a pulmonary artery catheter was associated with adverse outcomes. CPP could useful in guiding risk stratification of advanced heart failure patients and timely evaluation of advanced heart failure therapies.

Differential drug response in pulmonary arterial hypertension: The potential for precision medicine

Pulmonary arterial hypertension (PAH) is a rare, complex, and deadly cardiopulmonary disease. It is characterized by changes in endothelial cell function and smooth muscle cell proliferation in the pulmonary arteries, causing persistent vasoconstriction, resulting in right heart hypertrophy and failure. There are multiple drug classes specific to PAH treatment, but variation between patients may impact treatment response. A small subset of patients is responsive to pulmonary vasodilators and can be treated with calcium channel blockers, which would be deleterious if prescribed to a typical PAH patient. Little is known about the underlying cause of this important difference in vasoresponsive PAH patients. Sex, race/ethnicity, and pharmacogenomics may also factor into efficacy and safety of PAH-specific drugs. Research has indicated that endothelin receptor antagonists may be more effective in women and there have been some minor differences found in certain races and ethnicities, but these findings are muddled by the impact of socioeconomic factors and a lack of representation of non-White patients in clinical trials. Genetic variants in genes such as CYP3A5, CYP2C9, PTGIS, PTGIR, GNG2, CHST3, and CHST13 may influence the efficacy and safety of certain PAH-specific drugs. PAH research faces many challenges, but there is potential for new methodologies to glean new insights into PAH development and treatment.

Shedding Light on Latent Pulmonary Vascular Disease in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Among patients with heart failure with preserved ejection fraction (HFpEF), a distinct hemodynamic phenotype has been recently described, ie, latent pulmonary vascular disease (HFpEF-latentPVD), defined by exercise pulmonary vascular resistance (PVR) >1.74 WU.

OBJECTIVES

This study aims to explore the pathophysiological significance of HFpEF-latentPVD.

METHODS

The authors analyzed a cohort of patients who had undergone supine exercise right heart catheterization with cardiac output (CO) measured by direct Fick method, between 2016 and 2021. HFpEF-latentPVD patients were compared with HFpEF control patients.

RESULTS

Out of 86 HFpEF patients, 21% qualified as having HFpEF-latentPVD, 78% of whom had PVR >2 WU at rest. Patients with HFpEF-latentPVD were older, with a higher pretest probability of HFpEF, and more frequently experienced atrial fibrillation and at least moderate tricuspid regurgitation (P < 0.05). PVR trajectories differed between HFpEF-latentPVD patients and HFpEF control patients (Pinteraction = 0.008), slightly increasing in the former and reducing in the latter. HFpEF-latentPVD patients displayed more frequent hemodynamically significant tricuspid regurgitation during exercise (P = 0.002) and had more impaired CO and stroke volume reserve (P < 0.05). Exercise PVR was correlated with mixed venous O2 tension (R2 = 0.33) and stroke volume (R2 = 0.31) in HFpEF-latentPVD patients. The HFpEF-latentPVD patients had had higher dead space ventilation during exercise and higher PaCO2 (P < 0.05), which correlated with resting PVR (R2 = 0.21). Event-free survival was reduced in HFpEF-latentPVD patients (P < 0.05).

CONCLUSIONS

The results suggest that when CO is measured by direct Fick, few HFpEF patients have isolated latent PVD (ie, normal PVR at rest, becoming abnormal during exercise). HFpEF-latentPVD patients present with CO limitation to exercise, associated with dynamic tricuspid regurgitation, altered ventilatory control, and pulmonary vascular hyperreactivity, portending a poor prognosis.

Application of homocysteine as a non-invasive and effort-free measurements for risk assessment of patients with pulmonary hypertension

BACKGROUND

Current guideline-recommended multiparameters used to assess the risk levels of pulmonary arterial hypertension (PAH) are invasive hemodynamic measurements or effort-dependent exercise tests. Serum natriuretic peptide is only one kind of effort-free biomarker that has been adopted for risk assessment. This study aimed to investigate the application of homocysteine as a non-invasive and effort-free measurement for the risk assessment of patients with PAH.

METHODS

Samples of 50 patients diagnosed with PAH via right heart catheterization were obtained, and the patients were divided into low-, intermediate- and high-risk groups for further analysis. Additionally, serum N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) and homocysteine levels of monocrotaline (MCT)-induced PAH rats were analyzed at each week with progressed severity of PAH, and they were sacrificed on day 28 with pathology being assessed.

RESULTS

Hyperhomocysteinemia was an independent predictor (odds ratio [OR]: 1.256; 95% confidence interval [CI]: 1.002-1.574) and showed a linear correlation with NT-proBNP. Hyperhomocysteinemia could discriminate between low/intermediate and high-risk levels in PAH with a cut-off value in 12 μmol/L. Moreover, the elevated homocysteine levels by weeks in MCT rats also demonstrated the association between homocysteine and the severity of PAH.

CONCLUSIONS

Homocysteine can be a non-invasive and effort-free risk assessment for patients with pulmonary hypertension. Homocysteine level had a linear correlation with NT-proBNP level, and patients with hyperhomocysteinemia had a higher risk level, higher NT-proBNP level, and decreased lower diffusing capacity for carbon monoxide. The correlation between homocysteine level and PAH severity was also demonstrated in MCT rats.

Efficient Uncertainty Quantification in a Multiscale Model of Pulmonary Arterial and Venous Hemodynamics

Computational hemodynamics models are becoming increasingly useful in the management and prognosis of complex, multiscale pathologies, including those attributed to the development of pulmonary vascular disease. However, diseases like pulmonary hypertension are heterogeneous, and affect both the proximal arteries and veins as well as the microcirculation. Simulation tools and the data used for model calibration are also inherently uncertain, requiring a full analysis of the sensitivity and uncertainty attributed to model inputs and outputs. Thus, this study quantifies model sensitivity and output uncertainty in a multiscale, pulse-wave propagation model of pulmonary hemodynamics. Our pulmonary circuit model consists of fifteen proximal arteries and twelve proximal veins, connected by a two-sided, structured tree model of the distal vasculature. We use polynomial chaos expansions to expedite the sensitivity and uncertainty quantification analyses and provide results for both the proximal and distal vasculature. Our analyses provide uncertainty in blood pressure, flow, and wave propagation phenomenon, as well as wall shear stress and cyclic stretch, both of which are important stimuli for endothelial cell mechanotransduction. We conclude that, while nearly all the parameters in our system have some influence on model predictions, the parameters describing the density of the microvascular beds have the largest effects on all simulated quantities in both the proximal and distal circulation.

Sinus venosus adaptation models prolonged cardiovascular disease and reveals insights into evolutionary transitions of the vertebrate heart

How two-chambered hearts in basal vertebrates have evolved from single-chamber hearts found in ancestral chordates remains unclear. Here, we show that the teleost sinus venosus (SV) is a chamber-like vessel comprised of an outer layer of smooth muscle cells. We find that in adult zebrafish nr2f1a mutants, which lack atria, the SV comes to physically resemble the thicker bulbus arteriosus (BA) at the arterial pole of the heart through an adaptive, hypertensive response involving smooth muscle proliferation due to aberrant hemodynamic flow. Single cell transcriptomics show that smooth muscle and endothelial cell populations within the adapting SV also take on arterial signatures. Bulk transcriptomics of the blood sinuses flanking the tunicate heart reinforce a model of greater equivalency in ancestral chordate BA and SV precursors. Our data simultaneously reveal that secondary complications from congenital heart defects can develop in adult zebrafish similar to those in humans and that the foundation of equivalency between flanking auxiliary vessels may remain latent within basal vertebrate hearts.

Group 2 pulmonary hypertension: from diagnosis to treatment

PURPOSE OF REVIEW

Pulmonary hypertension associated with left heart disease (PHLHD) is common and associated with adverse prognosis. Proper diagnosis is critical to avoid inappropriate treatment. Practical approaches to noninvasive diagnosis are available, though invasive hemodynamics including volume loading or exercise are often necessary for definitive diagnosis. Treatment strategies and research in the field is rapidly evolving.

RECENT FINDINGS

Combined pre and post capillary pulmonary hypertension is associated with remodeling of the pulmonary vasculature that is proportional to the severity of the pulmonary hypertension. Even quite mild elevation of pulmonary vascular resistance (PVR), (greater than 2.0 Wood units (WU)) is associated with adverse outcome. Guideline-directed medical therapy (GDMT) for left heart failure has rapidly evolved, including approval of SGLT2 inhibitors for treatment of heart failure with preserved ejection fraction (HFpEF). However, full implementation of GDMT is lagging. Utilization of implanted pulmonary artery pressure monitoring can facilitate patient management in selected patient phenotypes and has been utilized to demonstrate improvement in pulmonary pressures with emerging therapies in HFpEF including SGLT2 inhibitors and sacubitril/valsartan. A variety of shunt devices to create a left-to-right shunt in order to decompress the left heart are available or undergoing clinical trials. There is concern that there could be adverse response to such devices in patients who have even mild elevation of pulmonary vascular resistance. Sleep disordered breathing is common in PHLHD and should be aggressively sought out and treated.

SUMMARY

Even mild elevation in pulmonary vascular resistance is associated with adverse outcome. A systematic approach to diagnosis of PHLHD is essential. Guideline-directed medical therapy for PHLHD prioritizes optimal management of the left heart disease. Pulmonary artery pressure sensors are useful in selected patients.

Pulmonary Hypertension: A Contemporary Review

Major advances in pulmonary arterial hypertension, pulmonary hypertension (PH) associated with lung disease, and chronic thromboembolic PH cast new light on the pathogenetic mechanisms, epidemiology, diagnostic approach, and therapeutic armamentarium for pulmonary vascular disease. Here, we summarize key basic, translational, and clinical PH reports, emphasizing findings that build on current state-of-the-art research. This review includes cutting-edge progress in translational pulmonary vascular biology, with a guide to the diagnosis of patients in clinical practice, incorporating recent PH definition revisions that continue emphasis on early detection of disease. PH management is reviewed including an overview of the evolving considerations for the approach to treatment of PH in patients with cardiopulmonary comorbidities, as well as a discussion of the groundbreaking sotatercept data for the treatment of pulmonary arterial hypertension.

The future of group 2 pulmonary hypertension: Exploring clinical trials and therapeutic targets

Pulmonary hypertension due to left heart disease (PH-LHD) or group 2 PH is the most common and lethal form of PH, occurring secondary to left ventricular systolic or diastolic heart failure (HF), left-sided valvular diseases, and congenital abnormalities. It is subdivided into isolated postcapillary PH (IpcPH) and combined pre- and post-capillary PH (CpcPH), with the latter sharing many similarities with group 1 PH. CpcPH is associated with worse outcomes and increased morbidity and mortality when compared to IpcPH. Although IpcPH can be improved by treatment of the underlying LHD, CpcPH is an incurable disease for which no specific treatment exists, likely due to the lack of understanding of its underlying mechanisms. Furthermore, drugs approved for PAH are not recommended for group 2 PH, as they are either ineffective or even deleterious. With this major unmet medical need, a better understanding of mechanisms and the identification of effective treatment strategies for this deadly condition are urgently needed. This review presents relevant background of the molecular mechanisms underlying PH-LHD that could translate into innovative therapeutic targets and explores novel targets currently being evaluated in clinical trials.

Elastin stabilization prevents impaired biomechanics in human pulmonary arteries and pulmonary hypertension in rats with left heart disease

Pulmonary hypertension worsens outcome in left heart disease. Stiffening of the pulmonary artery may drive this pathology by increasing right ventricular dysfunction and lung vascular remodeling. Here we show increased stiffness of pulmonary arteries from patients with left heart disease that correlates with impaired pulmonary hemodynamics. Extracellular matrix remodeling in the pulmonary arterial wall, manifested by dysregulated genes implicated in elastin degradation, precedes the onset of pulmonary hypertension. The resulting degradation of elastic fibers is paralleled by an accumulation of fibrillar collagens. Pentagalloyl glucose preserves arterial elastic fibers from elastolysis, reduces inflammation and collagen accumulation, improves pulmonary artery biomechanics, and normalizes right ventricular and pulmonary hemodynamics in a rat model of pulmonary hypertension due to left heart disease. Thus, targeting extracellular matrix remodeling may present a therapeutic approach for pulmonary hypertension due to left heart disease.

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.

Association of Size Matching Using Predicted Heart Mass With Mortality in Heart Transplant Recipients With Obesity or High Pulmonary Vascular Resistance

Importance

Pretransplant obesity and higher pulmonary vascular resistance (PVR) are risk factors for death after heart transplant. However, it remains unclear whether appropriate donor-to-recipient size matching using predicted heart mass (PHM) is associated with lower risk.

Objective

To investigate the association of size matching using PHM with risk of death posttransplant among patients with obesity and/or higher PVR.

Design, Setting, and Participants

All adult patients (>18 years) who underwent heart transplant between 2003 and 2022 with available information using the United Network for Organ Sharing cohort database. Multivariable Cox models and multivariable-adjusted spline curves were used to examine the risk of death posttransplant with PHM matching. Data were analyzed from October 2022 to March 2023.

Exposure

Recipient's body mass index (BMI) in categories (<18.0 [underweight], 18.1-24.9 [normal weight, reference], 25.0-29.9 [overweight], 30.0-34.9 [obese 1], 35-39.9 [obese 2], and ≥40.0 [obese 3]) and recipient's pretransplant PVR in categories of less than 4 (29 061 participants), 4 to 6 (2842 participants), and more than 6 Wood units (968 participants); and less than 3 (24 950 participants), 3 to 5 (6115 participants), and 5 or more (1806 participants) Wood units.

Main Outcome

All-cause death posttransplant on follow-up.

Results

The mean (SD) age of the cohort of 37 712 was 52.8 (12.8) years, 27 976 (74%) were male, 25 342 were non-Hispanic White (68.0%), 7664 were Black (20.4%), and 3139 were Hispanic or Latino (8.5%). A total of 12 413 recipients (32.9%) had a normal BMI, 13 849 (36.7%) had overweight, and 10 814 (28.7%) had obesity. On follow-up (median [IQR] 5.05 [0-19.4] years), 12 785 recipients (3046 female) died. For patients with normal weight, overweight, or obese 2, receiving a PHM-undermatched heart was associated with an increased risk of death (normal weight hazard ratio [HR], 1.20; 95% CI, 1.07-1.34; overweight HR, 1.12; 95% CI, 1.02-1.23; and obese 2 HR, 1.07; 95% CI, 1.01-1.14). Moreover, patients with higher pretransplant PVR who received an undermatched heart had a higher risk of death posttransplant in multivariable-adjusted spline curves in graded fashion until appropriately matched. In contrast, risk of death among patients receiving a PHM-overmatched heart did not differ from the appropriately matched group, including in recipients with an elevated pretransplant PVR.

Conclusion and Relevance

In this cohort study, undermatching donor-to-recipient size according to PHM was associated with higher posttransplant mortality, specifically in patients with normal weight, overweight, or class II obesity and in patients with elevated pretransplant PVR. Overmatching donor-to-recipient size was not associated with posttransplant survival.

Current Knowledge of Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is the most common type of heart failure (HF) - predominantly in the elderly population - and the most difficult to treat. The diagnosis is based, apart from clinical data, on data provided by imaging and biochemical evaluation: left ventricular (LV) diastolic dysfunction, EF ≥50% and increase of natriuretic peptide (NP). Several phenotypes of HFpEF have been identified based on etiological and pathophysiological data. Defining the phenotypes has allowed a wider knowledge of specific pathogenic mechanisms and conducting therapeutic studies with pharmacological and non-pharmacological agents . but with uncertain results. The diagnosis is based, apart from clinical data, on data provided by imaging and biochemical evaluation: left ventricular (LV) diastolic dysfunction, EF ≥50% and increase of natriuretic peptide (NP). Several phenotypes of HFpEF have been identified based on etiological and pathophysiological data. Defining the phenotypes has allowed a wider knowledge of specific pathogenic mechanisms and conducting therapeutic studies with pharmacological and non-pharmacological agents . but with uncertain results.

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.

Myeloid Cell Derived IL1β Contributes to Pulmonary Vascular Remodeling in Heart Failure with Preserved Ejection Fraction

Background

Pulmonary hypertension (PH) in heart failure with preserved ejection fraction (HFpEF) is a common and highly morbid syndrome, but mechanisms driving PH-HFpEF are not well understood. We sought to determine whether a well-accepted murine model of HFpEF also displays features of PH in HFpEF, and we sought to identify pathways that might drive early remodeling of the pulmonary vasculature in HFpEF.

Methods

Eight week old male and female C57/BL6J mice were given either L-NAME and high fat diet (HFD) or control water/diet for 2,5, and 12 weeks. Bulk RNA sequencing and single cell RNA sequencing was performed to identify early and cell-specific pathways that might regulate pulmonary vascular remodeling in PH-HFpEF. Finally, clodronate liposome and IL1β antibody treatments were utilized to deplete macrophages or IL1β, respectively, to assess their impact on pulmonary vascular remodeling in HFpEF.

Results

Mice given L-NAME/HFD developed PH, small vessel muscularization, and right heart dysfunction after 2 weeks of treatment. Inflammation-related gene ontologies were over-represented in bulk RNA sequencing analysis of whole lungs, with an increase in CD68+ cells in both murine and human PH-HFpEF lungs. Cytokine profiling of mouse lung and plasma showed an increase in IL1β, which was confirmed in plasma from patients with HFpEF. Single cell sequencing of mouse lungs also showed an increase in M1-like, pro-inflammatory populations of Ccr2+ monocytes and macrophages, and transcript expression of IL1β was primarily restricted to myeloid-type cells. Finally, clodronate liposome treatment prevented the development of PH in L-NAME/HFD treated mice, and IL1β antibody treatment also attenuated PH in L-NAME/HFD treated mice.

Conclusions

Our study demonstrated that a well-accepted model of HFpEF recapitulates features of pulmonary vascular remodeling commonly seen in patients with HFpEF, and we identified myeloid cell derived IL1β as an important contributor to PH in HFpEF.

Heart Failure With Preserved Ejection Fraction: JACC Scientific Statement

The incidence and prevalence of heart failure with preserved ejection fraction (HFpEF) continue to rise in tandem with the increasing age and burdens of obesity, sedentariness, and cardiometabolic disorders. Despite recent advances in the understanding of its pathophysiological effects on the heart, lungs, and extracardiac tissues, and introduction of new, easily implemented approaches to diagnosis, HFpEF remains under-recognized in everyday practice. This under-recognition presents an even greater concern given the recent identification of highly effective pharmacologic-based and lifestyle-based treatments that can improve clinical status and reduce morbidity and mortality. HFpEF is a heterogenous syndrome and recent studies have suggested an important role for careful, pathophysiological-based phenotyping to improve patient characterization and to better individualize treatment. In this JACC Scientific Statement, we provide an in-depth and updated examination of the epidemiology, pathophysiology, diagnosis, and treatment of HFpEF.

Optical coherence tomography assessment of pulmonary vascular remodeling in advanced heart failure. The OCTOPUS-CHF study

INTRODUCTION AND OBJECTIVES

Pulmonary vascular remodeling is common among patients with advanced heart failure. Right heart catheterization is the gold standard to assess pulmonary hypertension, but is limited by indirect measurement assumptions, a steady-flow view, load-dependency, and interpretation variability. We aimed to assess pulmonary vascular remodeling with intravascular optical coherence tomography (OCT) and to study its correlation with hemodynamic data.

METHODS

This observational, prospective, multicenter study recruited 100 patients with advanced heart failure referred for heart transplant evaluation. All patients underwent right heart catheterization together with OCT evaluation of a subsegmentary pulmonary artery.

RESULTS

OCT could be performed and properly analyzed in 90 patients. Median age was 57.50 [interquartile range, 48.75-63.25] years and 71 (78.88%) were men. The most frequent underlying heart condition was nonischemic dilated cardiomyopathy (33 patients [36.66%]). Vascular wall thickness significantly correlated with mean pulmonary artery pressure, pulmonary vascular resistance, and transpulmonary gradient (R coefficient=0.42, 0.27 and 0.32 respectively). Noninvasive estimation of pulmonary artery systolic pressure, acceleration time, and right ventricle-pulmonary artery coupling also correlated with wall thickness (R coefficient of 0.42, 0.27 and 0.49, respectively). Patients with a wall thickness over 0.25mm had significantly higher mean pulmonary pressures (37.00 vs 25.00mmHg; P=.004) and pulmonary vascular resistance (3.44 vs 2.08 WU; P=.017).

CONCLUSIONS

Direct morphological assessment of pulmonary vascular remodeling with OCT is feasible and is significantly associated with classic hemodynamic parameters. This weak association suggests that structural remodeling does not fully explain pulmonary hypertension.

Lung diffusion capacity correlates with pre-implant pulmonary hypertension and predicts outcome after LVAD implantation

AIMS

Diffusing capacity of the lung for carbon monoxide (DLCO ) reduction is common in heart failure (HF) and is associated with a worse prognosis. Correlations between DLCO and pulmonary hypertension (PH) are unclear, and published data are conflicting; it has been shown that DLCO impairment may persist or even worsen after normalization of pulmonary pressures following left ventricle assist device (LVAD) implantation, maybe reflecting persistent pulmonary damage. We aimed to investigate the impact of pre-implant DLCO and central haemodynamics on outcome in patients with advanced HF implanted with a LVAD.

METHODS AND RESULTS

We retrospectively analysed pre-implant and post-implant data from 42 patients implanted with a LVAD at our institution. Out of 42 patients, 35 had post-capillary PH before implantation, including 17 with combined post- and pre-capillary PH (Cpc-PH). Median DLCO was 59% (IQR 47-68%), and it inversely correlated with pulmonary vascular resistance (PVR) (P 0.037) and diastolic pulmonary gradient (DPG) (P 0.042). Compared with baseline, LVAD resulted in improvement in LV diameter (LVDd, P < 0.001), mitral regurgitation (P 0.022), and PH (mPAP 24 vs. 36 mmHg, P < 0.001; PAWP 12 vs. 23 mmHg, P 0.001; pulmonary artery compliance, CPA 3.1 vs. 1.9 mL/mmHg, P 0.021). Lower DLCO and Cpc-PH at baseline were associated with a better LV reverse remodelling post-implantation (P 0.027 for LVDd) but also with a smaller gain in CPA (P 0.049).

CONCLUSIONS

Before LVAD implantation, DLCO impairment is associated with higher PVR and DPG, suggesting that it might be an expression of persistent pulmonary damage occurring in Cpc-PH. After LVAD implantation, both LV dimension and haemodynamics improve. Lower pre-implant DLCO is associated with better LV reverse remodelling.

Significance of Pulmonary Hypertension in Cardiac Amyloidosis

Pulmonary hypertension (PH) portends a poor prognosis in chronic heart failure and within distinct cardiomyopathies. There is a paucity of data on the impact of PH in patients with light-chain (AL) and transthyretin (ATTR) cardiac amyloidosis (CA). We sought to define the prevalence and significance of PH and PH subtypes in CA. We retrospectively identified patients with a diagnosis of CA who underwent right-sided cardiac catheterization (RHC) from January 2000 to December 2019. PH was defined as mean pulmonary artery pressure >20 mm Hg. PH was phenotyped as precapillary PH (PC-PH; pulmonary capillary wedge pressure [PCWP] <15, pulmonary vascular resistance [PVR] ≥3), isolated postcapillary PH (IpC-PH; PCWP >15, PVR <3), and combined postcapillary and precapillary PH (CpC-PH; PCWP >15 and PVR ≥3). Survival was assessed in those with CA and PH and for PH phenotypes. A total of 132 patients were included, 69 with AL CA and 63 with ATTR CA. A total of 75% (N = 99) had PH (76% of patients with AL and 73% of patients with ATTR, p = 0.615) and the predominant PH phenotype was IpC-PH. The degree of PH was comparable between ATTR CA and AL CA, and PH was observed in advanced stage disease (National Amyloid Center or Mayo stage II or greater). The overall survival for patients with CA and PH was similar to to those without PH. Higher mean pulmonary artery pressure independently predicted mortality in CA with PH (odds ratio 1.06, confidence interval 1.01 to 1.12, p = 0.03). In conclusion, PH was seen frequently in CA and tended to be IpC-PH; however, its presence did not significantly impact survival.

Pulmonary hypertension with a precapillary component in heart failure with preserved ejection fraction

OBJECTIVES

Heart failure with preserved ejection fraction (HFpEF) is often complicated by pulmonary hypertension (PH), which is mainly characterised by postcapillary PH and occasionally accompanied by a precapillary component of PH. Haemodynamic changes in worsening heart failure (HF) can modify the characteristics of PH. However, the clinical features of PH after HF treatment in HFpEF remain unclear. We investigated the prevalence and clinical significance of the precapillary component of PH after HF treatment in HFpEF, using data from the Prospective Multicentre Observational Study of Patients with HFpEF (PURSUIT-HFpEF).

METHODS

From the PURSUIT-HFpEF registry, 219 patients hospitalised with acute HF who underwent right heart catheterisation after initial HF treatment were divided into four groups according to the 2015 and 2018 PH definitions: non-PH, isolated postcapillary pulmonary hypertension (Ipc-PH), precapillary PH and combined postcapillary and precapillary pulmonary hypertension (Cpc-PH). The latter two were combined as PH with the precapillary component.

RESULTS

Using the 2015 definition, we found that the prevalence of PH after HF treatment was 27% (Ipc-PH: 20%, precapillary PH: 3%, Cpc-PH: 4%). Applying the 2018 definition resulted in a doubled frequency of precapillary PH (6%). PH with a precapillary component according to the 2015 definition was associated with poor clinical outcomes and characterised by small left ventricular dimension and high early diastolic mitral inflow velocity/early diastolic mitral annular tissue velocity.

CONCLUSION

After initial HF treatment, 7% of hospitalised patients with HFpEF had precapillary component of PH according to the 2015 definition. Echocardiographic parameters of the left ventricle can contribute to the risk stratification of patients with HFpEF with a precapillary component of PH.

Histologic and proteomic remodeling of the pulmonary veins and arteries in a porcine model of chronic pulmonary venous hypertension

AIMS

In heart failure (HF), pulmonary venous hypertension (PVH) produces pulmonary hypertension (PH) with remodeling of pulmonary veins (PV) and arteries (PA). In a porcine PVH model, we performed proteomic-based bioinformatics to investigate unique pathophysiologic mechanisms mediating PA and PV remodeling.

METHODS AND RESULTS

Large PV were banded (PVH, n = 10) or not (Sham, n = 9) in piglets. At sacrifice, PV and PA were perfusion labelled for vessel-specific histology and proteomics. The PA and PV were separately sampled with laser-capture micro-dissection for mass spectrometry. Pulmonary vascular resistance [Wood Units; 8.6 (95% confidence interval: 6.3, 12.3) vs. 2.0 (1.7, 2.3)] and PA [19.9 (standard error of mean, 1.1) vs. 10.3 (1.1)] and PV [14.2 (1.2) vs. 7.6 (1.1)] wall thickness/external diameter (%) were increased in PVH (P < 0.05 for all). Similar numbers of proteins were identified in PA (2093) and PV (2085) with 94% overlap, but biological processes differed. There were more differentially expressed proteins (287 vs. 161), altered canonical pathways (17 vs. 3), and predicted upstream regulators (PUSR; 22 vs. 6) in PV than PA. In PA and PV, bioinformatics indicated activation of the integrated stress response and mammalian target of rapamycin signalling with dysregulated growth. In PV, there was also activation of Rho/Rho-kinase signalling with decreased actin cytoskeletal signalling and altered tight and adherens junctions, ephrin B, and caveolae-mediated endocytosis signalling; all indicating disrupted endothelial barrier function. Indeed, protein biomarkers and the top PUSR in PV (transforming growth factor-beta) suggested endothelial to mesenchymal transition in PV. Findings were similar in human autopsy specimens.

CONCLUSION

These findings provide new therapeutic targets to oppose pulmonary vascular remodeling in HF-related PH.

Heart Failure With Preserved Ejection Fraction: A Review

IMPORTANCE

Heart failure with preserved ejection fraction (HFpEF), defined as HF with an EF of 50% or higher at diagnosis, affects approximately 3 million people in the US and up to 32 million people worldwide. Patients with HFpEF are hospitalized approximately 1.4 times per year and have an annual mortality rate of approximately 15%.

OBSERVATIONS

Risk factors for HFpEF include older age, hypertension, diabetes, dyslipidemia, and obesity. Approximately 65% of patients with HFpEF present with dyspnea and physical examination, chest radiographic, echocardiographic, or invasive hemodynamic evidence of HF with overt congestion (volume overload) at rest. Approximately 35% of patients with HFpEF present with "unexplained" dyspnea on exertion, meaning they do not have clear physical, radiographic, or echocardiographic signs of HF. These patients have elevated atrial pressures with exercise as measured with invasive hemodynamic stress testing or estimated with Doppler echocardiography stress testing. In unselected patients presenting with unexplained dyspnea, the H2FPEF score incorporating clinical (age, hypertension, obesity, atrial fibrillation status) and resting Doppler echocardiographic (estimated pulmonary artery systolic pressure or left atrial pressure) variables can assist with diagnosis (H2FPEF score range, 0-9; score >5 indicates more than 95% probability of HFpEF). Specific causes of the clinical syndrome of HF with normal EF other than HFpEF should be identified and treated, such as valvular, infiltrative, or pericardial disease. First-line pharmacologic therapy consists of sodium-glucose cotransporter type 2 inhibitors, such as dapagliflozin or empagliflozin, which reduced HF hospitalization or cardiovascular death by approximately 20% compared with placebo in randomized clinical trials. Compared with usual care, exercise training and diet-induced weight loss produced clinically meaningful increases in functional capacity and quality of life in randomized clinical trials. Diuretics (typically loop diuretics, such as furosemide or torsemide) should be prescribed to patients with overt congestion to improve symptoms. Education in HF self-care (eg, adherence to medications and dietary restrictions, monitoring of symptoms and vital signs) can help avoid HF decompensation.

CONCLUSIONS AND RELEVANCE

Approximately 3 million people in the US have HFpEF. First-line therapy consists of sodium-glucose cotransporter type 2 inhibitors, exercise, HF self-care, loop diuretics as needed to maintain euvolemia, and weight loss for patients with obesity and HFpEF.

Disproportionate exercise-induced pulmonary hypertension in relation to cardiac output in heart failure with preserved ejection fraction: a non-invasive echocardiographic study

AIMS

Pulmonary hypertension (PH) and pulmonary vascular remodelling are common in patients with heart failure with preserved ejection fraction (HFpEF). Many patients with HFpEF demonstrate an abnormal pulmonary haemodynamic response to exercise that is not identifiable at rest. This can be estimated non-invasively by the mean pulmonary artery pressure-cardiac output relationship (mPAP/CO slope). We sought to characterize the pathophysiology of disproportionate exercise-induced PH in relation to CO (DEi-PH) and its prognostic impact in patients with HFpEF.

METHODS AND RESULTS

A total of 345 patients (166 HFpEF and 179 controls) underwent ergometry exercise stress echocardiography with simultaneous expired gas analysis. DEi-PH was defined as the mPAP/CO slope >5.2 mmHg/L/min (median value). At rest, there were no differences in right ventricular (RV) function and severity of PH between HFpEF patients with and without DEi-PH. Compared with controls (n = 179) and HFpEF without DEi-PH (n = 83), HFpEF with DEi-PH (n = 83) demonstrated worse exercise capacity (lower peak oxygen consumption), depressed RV systolic function, impaired RV-pulmonary artery coupling, limitation in CO augmentation, more right-sided congestion, and worse ventilatory efficiency (higher minute ventilation vs. carbon dioxide volume) during peak exercise. Kaplan-Meier analyses showed that HFpEF patients with DEi-PH had higher rates of composite outcomes of all-cause mortality or heart failure events than those without (log-rank p = 0.0002).

CONCLUSION

Patients with HFpEF and DEi-PH demonstrated distinct pathophysiologic features that become apparent only during exercise. These data suggest that DEi-PH is a pathophysiologic phenotype of HFpEF and reinforce the importance of exercise stress echocardiography for detailed characterization of HFpEF.

Parameter inference in a computational model of haemodynamics in pulmonary hypertension

Pulmonary hypertension (PH), defined by a mean pulmonary arterial pressure (mPAP) greater than 20 mmHg, is characterized by increased pulmonary vascular resistance and decreased pulmonary arterial compliance. There are few measurable biomarkers of PH progression, but a conclusive diagnosis of the disease requires invasive right heart catheterization (RHC). Patient-specific cardiovascular systems-level computational models provide a potential non-invasive tool for determining additional indicators of disease severity. Using computational modelling, this study quantifies physiological parameters indicative of disease severity in nine PH patients. The model includes all four heart chambers, the pulmonary and systemic circulations. We consider two sets of calibration data: static (systolic and diastolic values) RHC data and a combination of static and continuous, time-series waveform data. We determine a subset of identifiable parameters for model calibration using sensitivity analyses and multi-start inference and perform posterior uncertainty quantification. Results show that additional waveform data enables accurate calibration of the right atrial reservoir and pump function across the PH cohort. Model outcomes, including stroke work and pulmonary resistance-compliance relations, reflect typical right heart dynamics in PH phenotypes. Lastly, we show that estimated parameters agree with previous, non-modelling studies, supporting this type of analysis in translational PH research.

Evidence of Advanced Pulmonary Vascular Remodeling in Obstructive Hypertrophic Cardiomyopathy With Pulmonary Hypertension

BACKGROUND

Elevated mean pulmonary artery pressure (mPAP) is common in patients with hypertrophic cardiomyopathy (HCM) and heart failure symptoms. However, dynamic left ventricular (LV) outflow tract obstruction may confound interpretation of pulmonary hypertension (PH) pathophysiologic features in HCM when relying on resting invasive hemodynamic data alone.

RESEARCH QUESTION

Do structural changes to the lung vasculature clarify PH pathophysiologic features in patients with HCM with progressive heart failure?

STUDY DESIGN AND METHODS

Clinical data and ultrarare lung autopsy specimens were acquired retrospectively from the National Institutes of Health (1975-1992). Patients were included based on the availability of lung tissue and recorded mPAP. Discarded tissue from rejected lung donors served as control specimens. Histomorphology was performed on pulmonary arterioles and veins. Comparisons were calculated using the Student t test and Mann-Whitney U test; Pearson correlation was used to assess association between morphometric measurements and HCM cardiac and hemodynamic measurements.

RESULTS

The HCM cohort (n = 7; mean ± SD age, 43 ± 18 years; 71% men) showed maximum mean ± SD LV wall thickness of 25 ± 2.8 mm, mean ± SD outflow tract gradient of 90 ± 30 mm Hg, median mPAP of 25 mm Hg (interquartile range [IQR], 6 mm Hg), median pulmonary artery wedge pressure (PAWP) of 16 mm Hg (IQR, 4 mm Hg), and median pulmonary vascular resistance of 1.8 Wood units (WU; IQR, 2.4 WU). Compared with control samples (n = 5), patients with HCM showed greater indexed pulmonary arterial hypertrophy (20.7 ± 7.2% vs 49.7 ± 12%; P < .001) and arterial wall fibrosis (11.5 ± 3.4 mm vs 21.0 ± 4.7 mm; P < .0001), which correlated with mPAP (r = 0.84; P = .018), PAWP (r = 0.74; P = .05), and LV outflow tract gradient (r = 0.78; P = .035). Compared with control samples, pulmonary vein thickness was increased by 2.9-fold (P = .008) in the HCM group, which correlated with mPAP (r = 0.81; P = .03) and LV outflow tract gradient (r = 0.83; P = .02).

INTERPRETATION

To the best of our knowledge, these data demonstrate for the first time that in patients with obstructive HCM, heart failure is associated with pathogenic pulmonary vascular remodeling even when mPAP is elevated only mildly. These observations clarify PH pathophysiologic features in HCM, with future implications for clinical strategies that mitigate outflow tract obstruction.

Clinical phenotyping of plasma thrombospondin-2 reveals relationship to right ventricular structure and function in pulmonary hypertension

Background

Converging evidence from proteogenomic analyses prioritises thrombospondin-2 (TSP2) as a potential biomarker for idiopathic or heritable pulmonary arterial hypertension (PAH). We aimed to assess TSP2 levels in different forms of pulmonary hypertension (PH) and to define its clinical phenotype.

Methods

Absolute concentrations of TSP2 were quantified in plasma samples from a prospective single-centre cohort study including 196 patients with different forms of PH and 16 disease controls (suspected PH, but normal resting pulmonary haemodynamics). In an unbiased approach, TSP2 levels were related to 152 clinical variables.

Results

Concentrations of TSP2 were increased in patients with PH versus disease controls (p<0.001 for group comparison). The discriminatory ability of TSP2 levels to distinguish between patients and controls was superior to that of N-terminal pro-brain natriuretic peptide (p=0.0023 for comparison of areas under the curve). Elevation of TSP2 levels was consistently found in subcategories of PAH, in PH due to lung disease and due to left heart disease. Phenotypically, TSP2 levels were robustly related to echocardiographic markers that indicate the right ventricular (RV) response to chronically increased afterload with increased levels in patients with impaired systolic function and ventriculoarterial uncoupling. Focusing on PAH, increased TSP2 levels were able to distinguish between adaptive and maladaptive RV phenotypes (area under the curve 0.87, 95% CI 0.76-0.98).

Interpretation

The study indicates that plasma TSP2 levels inform on the presence of PH and associate with clinically relevant RV phenotypes in the setting of increased afterload, which may provide insight into processes of RV adaptability.

Quantitative Assessment of Regional Pulmonary Transit Times in Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) contributes to restricted flow through the pulmonary circulation characterized by elevated mean pulmonary artery pressure acquired from invasive right heart catheterization (RHC). MRI may provide a noninvasive alternative for diagnosis and characterization of PH.

PURPOSE

To characterize PH via quantification of regional pulmonary transit times (rPTT).

STUDY TYPE

Retrospective.

POPULATION

A total of 43 patients (58% female); 24 controls (33% female). RHC-confirmed patients classified as World Health Organization (WHO) subgroups 1-4.

FIELD STRENGTH/SEQUENCE

A 1.5 T/time-resolved contrast-enhanced MR Angiography (CE-MRA).

ASSESSMENT

CE-MRA data volumes were combined into a 4D matrix (3D resolution + time). Contrast agent arrival time was defined as the peak in the signal-intensity curve generated for each voxel. Average arrival times within a vessel region of interest (ROI) were normalized to the main pulmonary artery ROI (t₀ ) for eight regions to define rPTT for all subjects. Subgroup analysis included grouping the four arterial and four venous regions. Intraclass correlation analysis completed for reproducibility.

STATISTICAL TESTS

Analysis of covariance with age as covariate. A priori Student's t-tests or Wilcoxon rank-sum test; α = 0.05. Results compared to controls unless noted. Significant without listing P value. ICC ran as two-way absolute agreement model with two observers.

RESULTS

PH patients demonstrated elevated rPTT in all vascular regions; average rPTT increase in arterial and venous branches was 0.85 ± 0.15 seconds (47.7%) and 1.0 ± 0.18 seconds (16.9%), respectively. Arterial rPTT was increased for all WHO subgroups; venous regions were elevated for subgroups 2 and 4 (group 1, P = 0.86; group 3, P = 0.32). No significant rPTT differences were found between subgroups (P = 0.094-0.94). Individual vessel ICC values ranged from 0.58 to 0.97.

DATA CONCLUSION

Noninvasive assessment of PH using standard-of-care time-resolved CE-MRA can detect increased rPTT in PH patients of varying phenotypes compared to controls.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 3.