Pulmonary hemodynamics in heart failure patients with reduced or preserved ejection fraction and pulmonary hypertension: Similarities and disparities

Pulmonary hypertension associated to left heart disease: Phenotypes and treatment

Pulmonary hypertension associated to left heart disease (PH-LHD) refers to a clinical and haemodynamic condition of pulmonary hypertension associated with a heterogeneous group of diseases affecting any of the compartments that form the left ventricle and left atrium. PH-LHD is the most common cause of PH, accounting for 65-80 % of diagnoses. Based on the haemodynamic phase of the disease, PH-LDH is classified into three subgroups: postcapillary PH, isolated postcapillary PH and combined pre-postcapillary PH (CpcPH). Several signaling pathways involved in the regulation of vascular tone are dysfunctional in PH-LHD, including nitric oxide, MAP kinase and endothelin-1 pathways. These pathways are the same as those altered in PH group 1, however PH-LHD can heardly be treated by specific drugs that act on the pulmonary circulation. In this manuscript we provide a state of the art of the available clinical trials investigating the safety and efficacy of PAH-specific drugs, as well as drugs active in patients with heart failure and PH-LHD. We also discuss the different phenotypes of PH-LHD, as well as molecular targets and signaling pathways potentially involved in the pathophysiology of the disease. Finally we will mention some new emerging therapies that can be used to treat this form of PH.

Pulmonary hypertension associated with left heart disease

Left heart disease (LHD) is the most common cause of pulmonary hypertension (PH), which may be classified further as isolated post-capillary (ipcPH) or combined post- and pre-capillary PH (cpcPH). The 7th World Symposium on Pulmonary Hypertension PH-LHD task force reviewed newly reported randomised clinical trials and contemplated novel opportunities for improving outcome. Results from major randomised clinical trials reinforced prior recommendations against the use of pulmonary arterial hypertension therapy in PH-LHD outside of clinical trials, and suggested possible harm. Greater focus on phenotyping was viewed as one general strategy by which to ultimately improve clinical outcomes. This is potentially achievable by individualising ipcPH versus cpcPH diagnosis for patients with pulmonary arterial wedge pressure within a diagnostic grey zone (12-18 mmHg), and through a newly developed PH-LHD staging system. In this model, PH accompanies LHD across four stages (A=at risk, B=structural heart disease, C=symptomatic heart disease, D=advanced), with each stage characterised by progression in clinical characteristics, haemodynamics and potential therapeutic strategies. Along these lines, the task force proposed disaggregating PH-LHD to emphasise specific subtypes for which PH prevalence, pathophysiology and treatment are unique. This includes re-interpreting mitral and aortic valve stenosis through a contemporary lens, and focusing on PH within the hypertrophic cardiomyopathy and amyloid cardiomyopathy clinical spectra. Furthermore, appreciating LHD in the profile of PH patients with chronic lung disease and chronic thromboembolic pulmonary disease is essential. However, engaging LHD patients in clinical research more broadly is likely to require novel methodologies such as pragmatic trials and may benefit from next-generation analytics to interpret results.

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.

A nomogram for predicting the risk of heart failure with preserved ejection fraction

BACKGROUND

This study purposed to design and establish a nomogram to predict the risk of having heart failure with preserved ejection fraction.

METHOD

The clinical data of 1031 patients diagnosed with heart failure (HF) in the First Affiliated Hospital of Jinan University from January 2018 to December 2022 were retrospectively analyzed, among which 618 patients were diagnosed with heart failure with preserved ejection fraction (HFpEF). Patients were randomly divided into a training set (70%, n = 722) and a validation set (30%, n = 309). The prediction model of HFpEF was established by using clinical characteristic data parameters, and the risk of having HFpEF was predicted by using a nomogram. Single-factor analysis was used to select independent risk factors (P < 0.05), and then binary logistic regression was used to screen predictive variables (P < 0.05). The discrimination ability of the model was evaluated by the ROC curve and calculating the area under the curve (AUC). In addition, the predictive ability of the established nomogram was evaluated using calibration curves and the Hosmer-Lemeshow goodness of fit test (HL test), and the clinical net benefit was evaluated using decision curve analysis (DCA).

RESULTS

The results of binary logistic regression analysis showed that age, gender, hypertension, coronary heart disease, glycosylated hemoglobin, serum creatinine, E/e' septal, relative wall thickness (RWT), left ventricular mass index (LVMI) and pulmonary hypertension (PH) were independent influencing factors for the risk of having HFpEF (P < 0.05). Based on the results of logistic regression analysis, a nomogram was established and calibration curves were made. The prediction model showed that the AUC of the training dataset was 0.876 (95%CI, 0.851-0.902), and 0.837 (95%CI, 0.791-0.883) in the validation set. According to the calibration curves and HL test, the nomogram shows good calibration, and DCA shows that our model is clinically useful.

CONCLUSION

A nomogram prediction model was constructed to predict the patient's risk of having HFpEF. This prediction model indicated that the combination of creatinine, E/e', RWT, LVMI and PH may be valuable in the diagnosis of HFpEF.

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 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.

Association of Mild-to-Moderate Aortic Regurgitation With Outcomes in Heart Failure With Preserved Ejection Fraction

OBJECTIVE

To assess aortic regurgitation (AR) prevalence, its hemodynamic effect, and long-term prognostic implications in patients admitted with de novo or worsened heart failure with preserved ejection fraction (HFpEF).

METHODS

Consecutive patients hospitalized with de novo or worsened HFpEF between 2014 and 2020 were enrolled. Patients with more than moderate aortic and/or mitral valve disease were excluded. Based on the presence and degree of AR, patients were divided into those without AR, those with mild, and those with moderate AR. Data on cardiovascular death, heart failure (HF) rehospitalization, and their composite (major adverse cardiovascular events) were collected.

RESULTS

The final study population consisted of 458 HFpEF patients: 156 (34.1%) with mild-AR, 153 (33.4%) with moderate-AR, and the remaining 149 (32.5%) with no AR. Mild-to-moderate AR patients were older, with larger left atrium-left ventricle (LV) volumes, greater LV mass index, higher filling pressure, and prevalence of diastolic dysfunction compared with the no-AR group (all P<.05). During 5-year follow-up, 113 patients died of cardiovascular causes, 124 patients were rehospitalized for HF, whereas 196 experienced the composite endpoint. Mild-to-moderate AR was identified as an independent predictor of all-cause death (HR, 1.62; 95% CI, 1.14 to 1.58; P=.04) and major adverse cardiovascular event occurrence (HR, 1.48; 95% CI, 1.05 to 2.09; P=.02). A total of 126 (35.5%) of 355 patients showed progression of AR at follow-up echocardiography.

CONCLUSION

Mild-to-moderate AR is common among patients hospitalized for HFpEF. It is associated with adverse LV remodeling and worse long-term outcomes. These findings warrant further prospective studies addressing the importance of AR in prognostic stratification and exploring therapeutic strategies to mitigate its hemodynamic effect on HF.

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.

The emerging role of sacubitril/valsartan in pulmonary hypertension with heart failure

Pulmonary hypertension due to left heart disease (PH-LHD) represents approximately 65%-80% of all patients with PH. The progression, prognosis, and mortality of individuals with left heart failure (LHF) are significantly influenced by PH and right ventricular (RV) dysfunction. Consequently, cardiologists should devote ample attention to the interplay between HF and PH. Patients with PH and HF may not receive optimal benefits from the therapeutic effects of prostaglandins, endothelin receptor antagonists, or phosphodiesterase inhibitors, which are specific drugs for pulmonary arterial hypertension (PAH). Sacubitril/valsartan, the angiotensin receptor II blocker-neprilysin inhibitor (ARNI), was recommended as the first-line therapy for patients with heart failure with reduced ejection fraction (HFrEF) by the 2021 European Society of Cardiology Guidelines. Although ARNI is effective in treating left ventricular (LV) enlargement and lower ejection fraction, its efficacy in treating individuals with PH and HF remains underexplored. Considering its vasodilatory effect at the pre-capillary level and a natriuretic drainage role at the post-capillary level, ARNI is believed to have a broad range of potential applications in treating PH-LHD. This review discusses the fundamental pathophysiological connections between PH and HF, emphasizing the latest research and potential benefits of ARNI in PH with various types of LHF and RV dysfunction.

The fibrosis-4 score is associated with long-term mortality in different phenotypes of acute heart failure

BACKGROUND

Fibrosis-4 score (FIB4) was a non-invasive surrogate to estimate the amount of liver scarring in chronic hepatitis. Considering the presence of increased central venous pressure and congestive hepatopathy in patients with decompensated heart failure, we therefore investigated the prognostic values of FIB4 in acute heart failure (AHF) patients.

METHOD

Patients hospitalised primarily for HF were drawn from an intramural registry. FIB4 was calculated according to age, aspartate aminotransferase, alanine aminotransferase and platelet count. All-cause mortality up to 5 years after discharge was obtained by linking to the national death registry.

RESULTS

Among a total of 1854 participants, 940 patients died during a mean follow-up of 28.3 ± 21.8 months. FIB4 score was related to mortality and the composite of cardiovascular death or HF rehospitalisation, independent of age, sex, left ventricular ejection fraction, left atrial dimension, sodium and haemoglobin levels, estimated glomerular filtration rate, comorbidities, and medications [hazard ratio and 95% confidence interval of mortality: 1.009 (1.002-1.015), and the composite of cardiovascular death or HF hospitalisation: 1.020 (1.010-1.031)]. The prognostic value of FIB4 was predominantly in the subjects with heart failure and preserved or mildly reduced ejection fraction (HFpEF and HFmrEF), or coronary artery disease (CAD) than the counterparts [interaction p-value <0.001, and 0.004, respectively].

CONCLUSIONS

FIB4 was an independent predictor of survival in AHF patients, irrespective of the phenotypes of HF. The higher predictive value of mortality of FIB4 was observed in the subjects with HFpEF, HFmrEF or CAD.

The Conundrum of HFpEF Definition: Non-Invasive Assessment Uncertainties and Alternative Diagnostic Strategies

Heart failure (HF) with preserved ejection fraction (HFpEF) is a heterogeneous syndrome including several morphological phenotypes and varying pathophysiological mechanisms. The conventional classification of HF based on left ventricular ejection fraction (LVEF) has created an oversimplification in diagnostic criteria. Although LVEF is a standardized parameter easy to calculate and broadly applied in the large clinical trials, but it is erroneously considered an index of left ventricular (LV) systolic function. Indeed,  it is affected by preload and afterload and it has limitations related to reproducibility, reduced sensitivity and scarce prognostic values especially when above 50%. Notably, additional diagnostic parameters have been recently proposed in order to improve diagnostic accuracy and to homogenise the different HFpEF populations. Unfortunately, these algorithms comprise sophisticated measurements that are difficult to apply in the daily clinical practice. Additionally, the scarce diffusion of these diagnostic criteria may have led to neutral or negative results in interventional phase 3 trials . We propose changes to the current HFpEF diagnostic approach mainly based on LVEF stratification measurement aiming towards a more inclusive model taking into consideration an integrative approach starting from the main diseases responsible for cardiac dysfunction  through to cardiac structural and functional alterations. Accordingly, with recent universal HF definitions, a stepwise model could be helpful in recognizing patients with early vs. overt HFpEF by the appraisal of specific Doppler echocardiographic variables. Thus, we would encourage the application of new criteria in order to better identify the different phenotypes and to move towards more personalized medicine.

Prevalence, risk factors, and survival associated with pulmonary hypertension and heart failure among patients with underlying coronary artery disease: a national prospective, multicenter registry study in China

BACKGROUND

Coronary artery disease (CAD) is the commonest cause of heart failure (HF), whereas pulmonary hypertension (PH) has not been established or reported in this patient population. Therefore, we assessed the prevalence, risk factors, and survival in CAD-associated HF (CAD-HF) complicated with PH.

METHODS

Symptomatic CAD-HF patients were continuously enrolled in this prospective, multicenter registry study. Echocardiography, coronary arteriography, left and right heart catheterization (RHC), and other baseline clinical data were recorded. Patients were followed up and their survival was recorded.

RESULTS

One hundred and eighty-two CAD-HF patients were enrolled, including 142 with HF with a preserved ejection fraction (heart failure with preserved ejection fraction [HFpEF]; left ventricular ejection fraction [LVEF] ≥50%) and 40 with a reduced ejection fraction (heart failure with reduced ejection fraction [HFrEF]; LVEF < 50%). PH was diagnosed with RHC in 77.5% of patients. Patients with PH showed worse hemodynamic parameters and higher mortality. HFrEF-PH patients had worse survival than HFpEF-PH patients. CAD-HF patients with an enlarged left ventricular end-diastolic diameter and reduced hemoglobin were at higher risk of PH. Nitrate treatment reduced the risk of PH. Elevated creatinine and mean pulmonary arterial pressure (mPAP), diastolic pressure gradient (DPG) ≥7 mmHg, and previous myocardial infarction (MI) entailed a higher risk of mortality in CAD-HF patients with PH.

CONCLUSIONS

PH is common in CAD-HF and worsens the hemodynamics and survival in these patients. Left ventricle enlargement and anemia increase the risk of PH in CAD-HF. Patients may benefit from nitrate medications. Renal impairment, elevated mPAP, DPG ≥7 mmHg, and previous MI are strong predictors of mortality in CAD-HF-PH patients.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02164526.

Pulmonary Arterial Hypertension and Consecutive Right Heart Failure Lead to Liver Fibrosis

Hepatic congestion occurs in patients with right heart failure and can ultimately lead to liver fibrosis or cardiac cirrhosis. Elevated pulmonary arterial pressure is found in patients with hepatic congestion. However, whether pulmonary arterial hypertension (PAH) can be a cause of liver fibrosis is unknown. The aim of this study was to investigate whether rats in the SuHx model with severe PAH develop liver fibrosis and to explore the mechanisms of congestive hepatic fibrosis both in rats and humans. To achieve this, PAH was induced in six to eight-week old male Sprague Dawley rats by a single subcutaneous injection of the VEGFR 2 inhibitor SU5416 and subsequent hypoxia for 3 weeks, followed by a 6-week period in room air. SuHx-exposed rats developed severe PAH, right ventricular hypertrophy (RVH), and consecutive right ventricular failure. Cardiac magnetic resonance imaging (MRI) and histological analysis revealed that PAH rats developed both hepatic congestion and liver fibrosis. Gene set enrichment analysis (GSEA) of whole liver RNA sequencing data identified a hepatic stellate cell specific gene signature in PAH rats. Consistently, tissue microarray from liver of patients with histological evidence of hepatic congestion and underlying heart disease revealed similar fibrogenic gene expression patterns and signaling pathways. In conclusion, severe PAH with concomitant right heart failure leads to hepatic congestion and liver fibrosis in the SU5416/hypoxia rat PAH model. Patients with PAH should therefore be screened for unrecognized liver fibrosis.

Risk prediction in pulmonary hypertension due to chronic heart failure: incremental prognostic value of pulmonary hemodynamics

Background

There is no generally accepted comprehensive risk prediction model cooperating risk factors associated with heart failure and pulmonary hemodynamics for patients with pulmonary hypertension due to left heart disease (PH-LHD). We aimed to explore outcome correlates and evaluate incremental prognostic value of pulmonary hemodynamics for risk prediction in PH-LHD.

Methods

Consecutive patients with chronic heart failure undergoing right heart catheterization were prospectively enrolled. The primary endpoint was all-cause mortality. Individual variable selection was performed by machine learning methods. Cox proportional hazards models were conducted to identify the association between variables and mortality. Incremental value of hemodynamics was evaluated based on the Seattle heart failure model (SHFM) and Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) scores.

Results

A total of 276 PH-LHD patients were enrolled, with a median follow-up time of 34.7 months. By L1-penalized regression model and random forest approach, diastolic pressure gradient (DPG) and mixed venous oxygen saturation (SvO₂) were the hemodynamic predictors most strongly associated with mortality (coefficient: 0.0255 and -0.0176, respectively), with consistent significance after adjusted for SHFM [DPG: HR 1.067, 95% CI 1.024–1.113, P = 0.022; SvO₂: HR 0.969, 95% CI 0.953–0.985, P = 0.002] or MAGGIC (DPG: HR 1.069, 95% CI 1.026–1.114, P = 0.011; SvO₂: HR 0.970, 95% CI 0.954–0.986, P = 0.004) scores. The inclusion of DPG and SvO₂ improved risk prediction compared with using SHFM [net classification improvement (NRI): 0.468 (0.161–0.752); integrated discriminatory index (IDI): 0.092 (0.035–0.171); likelihood ratio test: P < 0.001] or MAGGIC [NRI: 0.298 (0.106–0.615); IDI: 0.084 (0.033–0.151); likelihood ratio: P < 0.001] scores alone.

Conclusion

In PH-LHD, pulmonary hemodynamics can provide incremental prognostic value for risk prediction.

Clinical trial registration: NCT02164526 at https://clinicaltrials.gov.

Right Heart Pulmonary Circulation Unit Involvement in Left-Sided Heart Failure: Diagnostic, Prognostic, and Therapeutic Implications

Although long neglected, the right heart (RH) is now widely accepted as a pivotal player in heart failure (HF) either with reduced or preserved ejection fraction. The chronic overload of the pulmonary microcirculation results in an initial phase characterized by right ventricular (RV) hypertrophy, right atrial dilation, and diastolic dysfunction. This progresses to overt RH failure when RV dilation and systolic dysfunction lead to RV-pulmonary arterial (RV-PA) uncoupling with low RV output. In the context of its established relevance to progression of HF, clinicians should consider assessment of the RH with information from clinical assessment, biomarkers, and imaging. Notably, no single parameter can predict prognosis alone in HF. Assessments simultaneously should encompass RV systolic function, pulmonary pressures, an estimation of RV-PA coupling, and RH morphologic features. Despite a large volume of evidence indicating the relevance of RH function to the clinical syndrome of HF, evidence-based management strategies are lacking. Targeting RH dysfunction in HF should be an objective of future investigations, being an unmet need in the current management of HF.

Pulmonary Hypertension in Patients With Heart Failure With Mid-Range Ejection Fraction

Pulmonary hypertension (PH) is common in patients with heart failure (HF). The role of PH in patients with HF with reduced (HFrEF) and preserved (HFpEF) left ventricular ejection fraction (LVEF) has been extensively characterized during the last years. In contrast, the pathophysiology of HF with mid-range LVEF (HFmrEF), and in particular the role of PH in this context, are largely unknown. There is a paucity of data in this field, and the prevalence of PH, the underlying mechanisms, and the optimal therapy are not well-defined. Although often studied together there is increasing evidence that despite similarities with both HFrEF and HFpEF, HFmrEF also differs from both entities. The present review provides a summary of the current concepts of the mechanisms and clinical impact of PH in patients with HFmrEF, a proposal for the non-invasive and invasive diagnostic approach required to define the pathophysiology of PH and its management, and a discussion of future directions based on insights from mechanistic studies and randomized trials. We also provide an outlook regarding gaps in evidence, future clinical challenges, and research opportunities.

Invasive Hemodynamics in Heart Failure with Preserved Ejection Fraction: Importance of Detecting Pulmonary Vascular Remodeling and Right Heart Function

Heart failure (HF) is an ongoing crisis reaching epidemic proportions worldwide. About 50% of HF patients have a preserved ejection fraction. Invasive hemodynamics have shown varied results in patients who have HF with preserved ejection fraction (HFpEF). This article attempts to summarize the importance of detecting pulmonary vascular remodeling in HFpEF using invasive hemodynamics. Incorporating newer invasive hemodynamic parameters such as diastolic pulmonary gradient, pulmonary arterial compliance, pulmonary vascular resistance, and pulmonary arterial pulsatility index may improve patient selection for studies used in defining advanced therapies and clinical outcomes. Profiling of patients using invasive hemodynamic parameters may lead to better patient selection for clinical research.

Pulmonary hypertension and right ventricular remodeling in HFpEF and HFrEF

Right ventricular function has long been neglected by heart failure specialists. We have now learnt that it is strongly associated with morbidity and mortality in all patients with heart failure, regardless of the degree of left ventricular dysfunction. Importantly, right ventricular function is tightly linked with pulmonary hypertension, and only a thorough understanding of how the right ventricle couples with the pulmonary circulation can provide an improved knowledge of the pathophysiology and possibly a more efficient treatment and a better prognosis in patients with heart failure.

Congestion occurrence and evaluation in acute heart failure scenario: time to reconsider different pathways of volume overload

Although congestion is considered to be the main reason for hospital admission in patients with acute heart failure, a simplistic view considering idro saline retention and total body volume accumulation did not provide convincing data. Clinical congestion occurrence is often the tip of the iceberg of several different mechanisms ranging from increased filling pressure to extravascular fluid accumulation and blood flow redistribution. Therefore, the clinical evaluation is often restricted to a simple physical examination including few and inaccurate signs and symptoms. This superficial approach has led to contradictory data and patients have not been evaluated according to a more realistic clinical scenario. The integration with new diagnostic ultrasonographic and laboratory tools would substantially improve these weaknesses. Indeed, congestion could be assessed by following the most recognized HF subtypes including primitive cardiac defect, presence of right ventricular dysfunction, and organ perfusion. Moreover, there is a tremendous gap regarding the interchangeable concept of fluid retention and redistribution used with a univocal meaning. Overall, congestion assessment should be revised, considering it as either central, peripheral, or both. In this review, we aim to provide different evidence regarding the concept of congestion starting from the most recognized pathophysiological mechanisms of AHF decompensation. We highlight the fact that a better knowledge of congestion is a challenge for future investigation and it could lead to significant advances in HF treatment.

The role of mechanotransduction in heart failure pathobiology-a concise review

This review evaluates the role of mechanotransduction (MT) in heart failure (HF) pathobiology. Cardiac functional and structural modifications are regulated by biomechanical forces. Exposing cardiomyocytes and the myocardial tissue to altered biomechanical stress precipitates changes in the end-diastolic wall stress (EDWS). Thereby various interconnected biomolecular pathways, essentially mediated and orchestrated by MT, are launched and jointly contribute to adapt and remodel the myocardium. This cardiac MT-mediated feedback decisively determines the primary cardiac cellular and tissue response, the sort (concentric or eccentric) of hypertrophy/remodeling, to mechanical and/or hemodynamic alterations. Moreover, the altered EDWS affects the diastolic myocardial properties independent of the systolic function, and elevated EDWS causes diastolic dysfunction. The close interconnection between MT pathways and the cell nucleus, the genetic endowment, principally allows for the wide variety of phenotypic appearances. However, demographic, environmental features, comorbidities, and also the genetic make-up may modulate the phenotypic result. Cardiac MT takes a fundamental and superordinate position in the myocardial adaptation and remodeling processes in all HF categories and phenotypes. Therefore, the effects of MT should be integrated in all our scientific, clinical, and therapeutic considerations.

Prognostic Significance of an Early Echocardiographic Evaluation of Right Ventricular Dimension and Function in Acute Heart Failure

OBJECTIVE

Sparse and contradictory data are available on the prognostic role of an early echocardiographic examination in patients with acute decompensated heart failure (ADHF). We planned a prospective study to illustrate which early echocardiographic parameter would be better related to prognosis in such patients.

METHODS

In a consecutive series of patients with ADHF with either reduced (n=209) or preserved (n=172) left ventricular ejection fraction (LVEF), a complete echocardiographic examination was performed within 12 hours of admission. The endpoint of the study was death or rehospitalization at 6 months from hospital discharge.

RESULTS

After 6 months from discharge, 73 died and 96 were rehospitalized due to cardiovascular causes. In multivariable analysis, a right ventricular end-diastolic diameter (RVEDD) >40 mm (P = .02), a tricuspid annular plane systolic excursion (TAPSE) <19 mm (P= .004), and an inferior vena cava diameter >22 mm (P = .02) were associated with 6-month events. LVEF and LV diastolic function were not predictive of events. Pulmonary artery systolic pressure (PASP) >45 mmHg and TAPSE/PASP <0.425 were associated with prognosis in univariate but not in multivariable analysis. Conversely, the TAPSE/RVEDD ratio (dichotomized at its median value of 0.461) was an independent predictor of outcome in multivariable analysis (P< .001).

CONCLUSIONS

In patients hospitalized for ADHF, early echocardiographic identification of right ventricular dilatation and dysfunction predicts a poor outcome better than LV systolic and/or diastolic dysfunction.

The impact of left ventricular ejection fraction on heart failure patients with pulmonary hypertension

BACKGROUND

The most common cause of pulmonary hypertension (PH) in developed countries is left heart disease (LHD, group 2 PH). The development of PH in heart failure (HF) patients is indicative of worse outcomes.

OBJECTIVE

The aim of this study was to evaluate the long term outcomes of HF patients with PH in a national long-term registry.

METHODS

Study included 9 cardiology centers across Israel between 01/2013-01/2015, with a 12-month clinical follow-up and 24-month mortality follow-up. Patients were age ≥18 years old with HF and pre-inclusion PH due to left heart disease determined by echocardiography [estimated systolic pulmonary arterial pressure (SPAP) ≥ 50 mmHg]. Patients were categorized into 3 groups: HF with reduced (HFrEF < 40%), mid-range (HFmrEF 40-49%), and preserved (HFpEF ≥ 50%) ejection fraction.

RESULTS

The registry included 372 patients, with high prevalence of cardiovascular risk factors. Median HF duration was 4 years and 65% were in severe HF New York Heart Association (NYHA) classification ≥3. Mean systolic pulmonary artery pressure (SPAP) was 62 ± 11 mmHg. During 2-years of follow-up, 54 patients (15%) died. Univariable predictors of mortality included NYHA grade 3-4, chronic renal failure, and SPAP ≥ 65 mmHg. Severe PH was associated with mortality in HFpEF, but not HFmrEF or HFrEF, and remained significant after multivariable adjustment with an adjusted hazard ratio of 2.99, (95%CI 1.29-6.91, p = 0.010).

CONCLUSIONS

The combination of HFpEF with severe PH was independently associated with increased mortality. Currently, HFpEF patients are included with group 2 PH patients. Defining HFpEF with severe PH as a sub-class may be more appropriate, as these patients are at increased risk and deserve special consideration.

Pulmonary vascular disease in the setting of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is defined as clinical features of heart failure, ideally with biomarker evidence such as elevated plasma natriuretic peptide levels, in the setting of an ejection fraction (EF) greater than 50% and imaging evidence of diastolic left ventricular dysfunction [1,2]. In the absence of cardiac imaging or invasive hemodynamics, this is a clinical syndrome that is often indistinguishable from heart failure with reduced ejection fraction (HFrEF). HFpEF and HFrEF present with a cadre of comparable signs and symptoms including jugular venous distention, pulmonary rales on auscultation, breathlessness, orthopnea, exercise intolerance, exertional dyspnea, fatigue and peripheral edema. HFpEF accounts for at least half of all diagnoses of heart failure [1,2]. Pulmonary hypertension (PH) is a common complication of HFpEF that is linked to worse disease morbidity and mortality. In fact, mortality has been linked to increases in the intrinsic pulmonary vascular resistance in the setting of increased left ventricular end diastolic pressure, characterized hemodynamically by rises in the transpulmonary pressure gradient, pulmonary vascular resistance or diastolic pressure gradient. Despite being the most common form of PH, there are no approved therapies for the treatment of PH secondary to HFpEF. This review will summarize the hemodynamic classifications of PH in the setting of HFpEF, mechanisms of disease, the potential contribution of pulmonary vascular disease to poor outcomes in patients with HFpEF, and new approaches to therapy.

Insights into the pulmonary vascular complications of heart failure with preserved ejection fraction

Pulmonary hypertension in the setting of heart failure with preserved ejection fraction (PH-HFpEF) is a growing public health problem that is increasing in prevalence. While PH-HFpEF is defined by a high mean pulmonary artery pressure, high left ventricular end-diastolic pressure and a normal ejection fraction, some HFpEF patients develop PH in the presence of pulmonary vascular remodelling with a high transpulmonary pressure gradient or pulmonary vascular resistance. Ageing, increased left atrial pressure and stiffness, mitral regurgitation, as well as features of metabolic syndrome, which include obesity, diabetes and hypertension, are recognized as risk factors for PH-HFpEF. Qualitative studies have documented that patients with PH-HFpEF develop more severe symptoms than those with HFpEF and are associated with more significant exercise intolerance, frequent hospitalizations, right heart failure and reduced survival. Currently, there are no effective therapies for PH-HFpEF, although a number of candidate drugs are being evaluated, including soluble guanylate cyclase stimulators, phosphodiesterase type 5 inhibitors, sodium nitrite and endothelin receptor antagonists. In this review we attempt to provide an updated overview of recent findings pertaining to the pulmonary vascular complications in HFpEF in terms of clinical definitions, epidemiology and pathophysiology. Mechanisms leading to pulmonary vascular remodelling in HFpEF, a summary of pre-clinical models of HFpEF and PH-HFpEF, and new candidate therapeutic strategies for the treatment of PH-HFpEF are summarized.

Heart Failure With Preserved Ejection Fraction - Time for a Paradigm Shift Beyond Diastolic Function

At present, heart failure with preserved ejection fraction (HFpEF) is a commonly accepted condition in HF patients. In contrast to HF with reduced EF (HFrEF), HFpEF is strongly associated with aging, and vascular, metabolic, neurohormonal, and systemic inflammatory comorbidities. Two major hypotheses explain the pathophysiology of HFpEF (stages C,D in the American College of Cardiology Foundation/American Heart Association HF staging system): (1) impaired active relaxation and increased passive stiffness of the left ventricular (LV) myocardium during diastole (left atrial [LA]-LV coupling); and (2) LV and arterial stiffening during systole (LV-arterial coupling). Cardiac structural and functional abnormalities can be evaluated using non-invasive measures, such as 2-D, flow velocity Doppler, and tissue Doppler echocardiography, to estimate LV filling pressure and afterload mismatch. The clinical application of 2-D speckle-tracking echocardiography (2D-STE) is feasible for earlier diagnosis of functional abnormalities of the LA, LV, and elastic arteries in asymptomatic patients with cardiovascular risk factors (stages A,B). The goal of this review is to highlight the role of 2D-STE to detect impairment of LA-LV-arterial coupling beyond diastolic function earlier, because it may provide important information on the pathophysiology and prevention of HFpEF.