Therapeutic potential of phosphodiesterase type 5 inhibitors in heart failure with preserved ejection fraction and combined post- and pre-capillary pulmonary hypertension

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

New Therapies in Outpatient Pulmonary Medicine

Newer medications and devices, as well as greater understanding of the benefits and limitations of existing treatments, have led to expanded treatment options for patients with lung disease. Treatment advances have led to improved outcomes for patients with asthma, chronic obstructive pulmonary disease, interstitial lung disease, pulmonary hypertension, and cystic fibrosis. The risks and benefits of available treatments are substantially variable within these heterogeneous disease groups. Defining the role of newer therapies mandates both an understanding of these disorders and overall treatment approaches. This section will review general treatment approaches in addition to focusing on newer therapies for these conditions..

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.

Management of Pulmonary Hypertension in the Context of Heart Failure with Preserved Ejection Fraction

PURPOSE OF REVIEW

To review the current evidence and modalities for treating pulmonary hypertension (PH) in heart failure with preserved ejection fraction (HFpEF).

RECENT FINDINGS

In recent years, several therapies have been developed that improve morbidity in HFpEF, though these studies have not specifically studied patients with PF-HFpEF. Multiple trials of therapies specifically targeting the pulmonary vasculature such as phosphodiesterase (PDE) inhibitors, prostacyclin analogs, endothelin receptor antagonists (ERA), and soluble guanylate cyclase stimulators have also been conducted. However, these therapies demonstrated lack of consistency in improving hemodynamics or functional outcomes in PH-HFpEF. There is limited evidence to support the use of pulmonary vasculature-targeting therapies in PH-HFpEF. The mainstay of therapy remains the treatment of the underlying HFpEF condition. There is emerging evidence that newer HF therapies such as sodium-glucose transporter 2 inhibitors and angiotensin-receptor-neprilysin inhibitors are associated with improved hemodynamics and quality of life of patients with PH-HFpEF. There is also a growing realization that more robust phenotyping PH and right ventricular (RV) function may hold promise for therapeutic strategies for patients with PH-HFpEF.

Advance in the pharmacological and comorbidities management of heart failure with preserved ejection fraction: evidence from clinical trials

The prevalence of heart failure with preserved ejection fraction (HFpEF) accounts for approximately 50% of the total heart failure population, and with the aging of the population and the increasing prevalence of hypertension, obesity, and type 2 diabetes (T2DM), the incidence of HFpEF continues to rise and has become the most common subtype of heart failure. Compared with heart failure with reduced ejection fraction, HFpEF has a more complex pathophysiology and is more often associated with hypertension, T2DM, obesity, atrial fibrillation, renal insufficiency, pulmonary hypertension, obstructive sleep apnea, and other comorbidities. HFpEF has generally been considered a syndrome with high phenotypic heterogeneity, and no effective treatments have been shown to reduce mortality to date. Diuretics and comorbidity management are traditional treatments for HFpEF; however, they are mostly empirical due to a lack of clinical evidence in the setting of HFpEF. With the EMPEROR-Preserved and DELIVER results, sodium-glucose cotransporter 2 inhibitors become the first evidence-based therapies to reduce rehospitalization for heart failure. Subgroup analyses of the PARAGON-HF, TOPCAT, and CHARM-Preserved trials suggest that angiotensin receptor-neprilysin inhibitors, spironolactone, and angiotensin II receptor blockers may be beneficial in patients at the lower end of the ejection fraction spectrum. Other potential pharmacotherapies represented by non-steroidal mineralocorticoid receptor antagonists finerenone and antifibrotic agent pirfenidone also hold promise for the treatment of HFpEF. This article intends to review the clinical evidence on current pharmacotherapies of HFpEF, as well as the comorbidities management of atrial fibrillation, hypertension, T2DM, obesity, pulmonary hypertension, renal insufficiency, obstructive sleep apnea, and iron deficiency, to optimize the clinical management of HFpEF.

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

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

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

Pulmonary hypertension associated with left heart disease (PH-LHD) corresponds to group two of pulmonary hypertension according to clinical classification. Haemodynamically, this group includes isolated post-capillary pulmonary hypertension (IpcPH) and combined post- and pre-capillary pulmonary hypertension (CpcPH). PH-LHD is defined by an mPAP > 20 mmHg and a PAWP > 15 mmHg, pulmonary vascular resistance (PVR) with a cut-off value of 2 Wood Units (WU) is used to differentiate between IpcPH and CpcPH. A PVR greater than 5 WU indicates a dominant precapillary component. PH-LHD is the most common form of pulmonary hypertension, the leading cause being left heart failure with preserved (HFpEF) or reduced ejection fraction (HFmrEF, HFrEF), valvular heart disease and, less commonly, congenital heart disease. The presence of pulmonary hypertension is associated with increased symptom burden and poorer outcome across the spectrum of left heart disease. Differentiating between group 1 pulmonary hypertension with cardiac comorbidities and PH-LHD, especially due to HFpEF, is a particular challenge. Therapeutically, no general recommendation for the use of PDE5 inhibitors in HFpEF-associated CpcPH can be made at this time. There is currently no reliable rationale for the use of PAH drugs in IpcPH, nor is therapy with endothelin receptor antagonists or prostacyclin analogues recommended for all forms of PH-LHD.

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.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pulmonary hypertension associated with left heart disease

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

Clinical features do not identify risk of progression from isolated postcapillary pulmonary hypertension to combined pre- and postcapillary pulmonary hypertension

Pulmonary hypertension is a common sequelae of left heart failure and may present as isolated postcapillary pulmonary hypertension (Ipc-PH) or combined pre- and postcapillary pulmonary hypertension (Cpc-PH). Clinical features associated with progression from Ipc-PH to Cpc-PH have not yet been described. We extracted clinical data from patients who underwent right heart catheterizations (RHC) on two separate occasions. Ipc-PH was defined as mean pulmonary pressure >20 mmHg, pulmonary capillary wedge pressure >15 mmHg, and pulmonary vascular resistance (PVR) < 3 WU. Progression to Cpc-PH required an increase in PVR to ≥3 WU. We performed a retrospective cohort study with repeated assessments comparing subjects that progressed to Cpc-PH to subjects that remained with Ipc-PH. Of 153 patients with Ipc-PH at baseline who underwent a repeat RHC after a median of 0.7 years (IQR 0.2, 2.1), 33% (50/153) had developed Cpc-PH. In univariate analysis comparing the two groups at baseline, body mass index (BMI) and right atrial pressure were lower, while the prevalence of moderate or worse mitral regurgitation (MR) was higher among those who progressed. In age- and sex-adjusted multivariable analysis, only BMI (OR 0.94, 95% CI 0.90-0.99, p = 0.017, C = 0.655) and moderate or worse MR (OR 3.00, 95% CI 1.37-6.60, p = 0.006, C = 0.654) predicted progression, but with poor discriminatory power. This study suggests that clinical features alone cannot distinguish patients at risk for development of Cpc-PH and support the need for molecular and genetic studies to identify biomarkers of progression.

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

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

Combined pre- and post-capillary pulmonary hypertension in left heart disease

Patients with heart failure (HF) often have pulmonary hypertension (PH), which is mainly post-capillary; however, some of them also develop a pre-capillary component. The exact mechanisms leading to combined pre- and post-capillary PH are not yet clear, but the phenomenon seems to start from a passive transmission of increased pressure from the left heart to the lungs, and then continues with the remodeling of both the alveolar and vascular components through different pathways. More importantly, it is not yet clear which patients are predisposed to develop the disease. These patients have some characteristics similar to those with idiopathic pulmonary arterial hypertension (e.g., young age and frequent incidence in female gender), but they share cardiovascular risk factors with patients with HF (e.g., obesity and diabetes), with both reduced and preserved ejection fraction. Thanks to echocardiography parameters and newly introduced scores, more tools are available to distinguish between idiopathic pulmonary arterial hypertension and combined PH and to guide patients' management. It may be hypothesized to treat patients in whom the pre-capillary component is predominant with specific therapies such as those for idiopathic pulmonary arterial hypertension; however, no adequately powered trials of PH-specific treatment are available in combined PH. Early evidence of clinical benefit has been proven in some trials on phosphodiesterase type 5 inhibitors, while data on prostacyclin analogues, endothelin-1 receptor antagonists, and soluble guanylate cyclase stimulators are still controversial.

Diversity of hemodynamic types in connective tissue disease associated pulmonary hypertension: more than a subgroup of pulmonary arterial hypertension

Objective

Connective tissue disease associated pulmonary hypertension (CTD-PH) is classified as a subgroup of WHO group 1 PH, also called pulmonary arterial hypertension (PAH). However, not all CTD-PH fit hemodynamic definition of PAH. This study investigates the diversity of hemodynamic types of CTD-PH, their differences in clinical characteristics and outcomes.

Method

We performed a retrospective cohort study. CTD-PH patients were enrolled and divided into WHO group1 PH, WHO group 2 PH and hyperdynamic PH (mPAP > 20 mmHg, PVR < 3WU, PAWP < 15 mmHg) according to hemodynamics obtained by right heart catheterization. Patients with severe lung diseases, heart failure with reduced ejection fraction, pulmonary embolism, and hepatic cirrhosis were excluded. Baseline characteristics, autoantibodies, cardiac function, echocardiogram parameters, hemodynamics and survival rates were compared.

Result

A total of 202 CTD-PH patients were included, 138 in WHO group 1 PH, 33 in WHO group 2 PH and 31 in hyperdynamic PH. We found hyperdynamic PH is less severe, presenting lower NT-proBNP level, better WHO function class, lower mPAP and PVR, higher cardiac output, and less cardiac remodeling. Incidence of anti-RNP was significantly lower in patients with elevated PAWP. Short-term survival was worse in WHO group 2 PH, yet 5-year survival rates didn’t differ between groups.

Conclusion

Considering diversity in hemodynamic types, CTD-PH is more than a subgroup of PAH. Different types of CTD-PH present different clinical phenotypes and outcome. Phenotyping PH in CTD-PH patients is important.

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

AIM

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Right Heart Function in Cardiorenal Syndrome

PURPOSE OF REVIEW

Since CRS is critically dependent on right heart function and involved in interorgan crosstalk, assessment and monitoring of both right heart and kidney function are of utmost importance for clinical outcomes. This systematic review aims to comprehensively report on novel diagnostic and therapeutic paradigms that are gaining importance for the clinical management of the growing heart failure population suffering from CRS.

RECENT FINDINGS

Cardiorenal syndrome (CRS) in patients with heart failure is associated with poor outcome. Although systemic venous congestion and elevated central venous pressure have been recognized as main contributors to CRS, they are often neglected in clinical practice. The delicate hemodynamic balance in CRS is particularly determined by the respective status of the right heart. The consideration of hemodynamic and CRS profiles is advantageous in tailoring treatment for better preservation of renal function. Assessment and monitoring of right heart and renal function by known and emerging tools like renal Doppler ultrasonography or new biomarkers may have direct clinical implications.

Strategizing Drug Therapies in Pulmonary Hypertension for Improved Outcomes

Pulmonary hypertension (PH) is characterized by a resting mean pulmonary artery pressure (PAP) of 20 mmHg or more and is a disease of multiple etiologies. Of the various types of PH, pulmonary arterial hypertension (PAH) is characterized by elevated resistance in the pulmonary arterial tree. It is a rare but deadly disease characterized by vascular remodeling of the distal pulmonary arteries. This paper focuses on PAH diagnosis and management including current and future treatment options. Over the last 15 years, our understanding of this progressive disease has expanded from the concept of vasoconstrictive/vasodilatory mismatch in the pulmonary arterioles to now a better appreciation of the role of genetic determinants, numerous cell signaling pathways, cell proliferation and apoptosis, fibrosis, thrombosis, and metabolic abnormalities. While knowledge of its pathophysiology has expanded, the majority of the treatments available today still modulate the same three vasodilatory pathways that have been targeted for over 30 years (endothelin, nitric oxide, and prostacyclin). While modifying these pathways may help improve symptoms and quality of life, none of these directly modify the underlying disease pathogenesis. However, there are now studies ongoing with new drugs that can prevent or reverse these underlying causes of PAH. This review discusses the evidence base for the current treatment algorithms for PAH, as well as discusses novel therapies in development.

Heart Failure with Preserved Ejection Fraction and Pulmonary Hypertension: Focus on Phosphodiesterase Inhibitors

Pulmonary hypertension (PH) is common in patients with heart failure with preserved ejection fraction (HFpEF). A chronic increase in mean left atrial pressure leads to passive remodeling in pulmonary veins and capillaries and modest PH (isolated postcapillary PH, Ipc-PH) and is not associated with significant right ventricular dysfunction. In approximately 20% of patients with HFpEF, "precapillary" alterations of pulmonary vasculature occur with the development of the combined pre- and post-capillary PH (Cpc-PH), pertaining to a poor prognosis. Current data indicate that pulmonary vasculopathy may be at least partially reversible and thus serves as a therapeutic target in HFpEF. Pulmonary vascular targeted therapies, including phosphodiesterase (PDE) inhibitors, may have a valuable role in the management of patients with PH-HFpEF. In studies of Cpc-PH and HFpEF, PDE type 5 inhibitors were effective in long-term follow-up, decreasing pulmonary artery pressure and improving RV contractility, whereas studies of Ipc-PH did not show any benefit. Randomized trials are essential to elucidate the actual value of PDE inhibition in selected patients with PH-HFpEF, especially in those with invasively confirmed Cpc-PH who are most likely to benefit from such treatment.

[Treatment of patients with heart failure and preserved ejection fraction: reliance on clinical phenotypes]

The article discusses the problem of improving the effectiveness of treatment of heart failure with preserved left ventricular ejection fraction (HFpEF). The relative "failure" of early studies with renin-angiotensin-aldosterone system inhibitors was largely due to the lack of understanding that patients with HFpEF represent a heterogeneous group with various etiological factors and pathogenetic mechanisms of the disease. Therefore, the so-called personalized approach should be used in the treatment of these patients. This approach is based on the identification of clearly defined disease phenotypes, each characterized by a set of demographic, pathogenetic, and clinical characteristics. Based on the literature and own experience, the authors consider four main phenotypes of HFpEF: 1) phenotype with brain natriuretic peptide "deficiency" syndrome associated with moderate/severe left ventricular hypertrophy; 2) cardiometabolic phenotype; 3) phenotype with mixed pulmonary hypertension and right ventricular failure; and 4) cardiac amyloidosis phenotype. In the treatment of patients with phenotype 1, it seems preferable to use the valsartan + sacubitril (possibly in combination with spironolactone) combination treatment; with phenotype 2, the empagliflozin treatment is the best; with phenotype 3, the phosphodiesterase type 5 inhibitor sildenafil; and with phenotype 4, transthyretin stabilizers. Certain features of different phenotypes overlap and may change as the disease progresses. Nevertheless, the isolation of these phenotypes is advisable to prioritize the choice of drug therapy. Thus, the diuretic treatment (preferably torasemide) should be considered in the presence of congestion, regardless of the HFpEF phenotype; the valsartan + sacubitril and spironolactone treatment is appropriate not only in the shortage of brain natriuretic peptide but also in the presence of concentric left ventricular hypertrophy (except for the amyloidosis phenotype); and the treatment with empagliflozin and statins may be considered in all situations where pro-inflammatory mechanisms are involved.

Right ventricular and cyclic guanosine monophosphate signalling abnormalities in stages B and C of heart failure with preserved ejection fraction

Aims

Identifying early right ventricular (RV) dysfunction and impaired vasodilator reserve is challenging in heart failure with preserved ejection fraction (HFpEF). We hypothesized that cardiac magnetic resonance (CMR)‐based exercise imaging and serial cyclic guanosine monophosphate (cGMP) measurements can identify dynamic RV‐arterial uncoupling and responsiveness to pulmonary vasodilators at early stages of the HFpEF syndrome.

Methods and results

Patients with HFpEF (n = 16), impaired left ventricular relaxation due to concentric remodelling (LVCR, n = 7), and healthy controls (n = 8) underwent CMR at rest and during supine bicycle exercise with simultaneous measurements of central haemodynamics and circulating cGMP levels, before and after oral administration of 50 mg sildenafil. At rest, mean pulmonary artery pressures (mPAP) were higher in HFpEF, compared with LVCR and controls (27 ± 2, 18 ± 1, and 11 ± 1, respectively; P = 0.01), whereas biventricular volumes, heart rate, and stroke volume were similar. During exercise, LVCR and HFpEF had a greater increase in the ratio of mPAP over cardiac output than controls (5.50 ± 0.77 and 6.34 ± 0.86 vs. 2.24 ± 0.55 in controls, P = 0.005). The ratio of peak exercise to rest RV end‐systolic pressure‐volume, a surrogate of RV contractility, was significantly reduced in LVCR and HFpEF (2.32 ± 0.17 and 1.56 ± 0.08 vs. 3.49 ± 0.35 in controls, P < 0.001) and correlated with peak exercise VO₂ (R² = 0.648, P < 0.001). cGMP levels increased with exercise across the HFpEF spectrum (P < 0.05 vs. baseline), except when postcapillary pulmonary hypertension was present at rest (P = 0.73 vs. baseline). A single sildenafil administration failed to increase circulating cGMP levels and did not improve RV performance.

Conclusion

Exercise CMR identifies impaired RV‐arterial coupling at an early stage of HFpEF. Circulating cGMP levels phenocopy the haemodynamic spectrum in HFpEF but fail to increase after phosphodiesterase type 5 inhibition, endorsing the need for alternative interventions to increase cGMP signalling in HFpEF.

Pulmonale Hypertonie und Rechtsherzinsuffizienz

Pulmonale Hypertonie (PH) beschreibt einen hämodynamischen Zustand, der durch eine Druckerhöhung im kleinen Kreislauf charakterisiert ist und der insbesondere bei älteren Patienten häufig zu beobachten ist. In Abhängigkeit der Ätiologie differenziert die klinische Klassifikation der pulmonalen Hypertonie 5 Hauptgruppen. Unabhängig von der zugrunde liegenden Ursache führt eine PH zu einer chronischen Rechtsherzbelastung und Rechtsherzinsuffizienz. Aktuelle Studien zeigen, dass bereits eine moderate Erhöhung des pulmonalarteriellen Druckes sowie des pulmonalvaskulären Widerstands prognoserelevant sind. Im Einzelfall ist die konsequente differenzialdiagnostische Abklärung einer PH essenziell, da sich die Behandlungsoptionen je nach zugrunde liegender Ursache grundlegend unterscheiden.

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.

Impact of targeted pulmonary arterial hypertension therapy in patients with combined post- and precapillary pulmonary hypertension

BACKGROUND

Combined post- and precapillary pulmonary hypertension (CpcPH) portends poor outcomes in pulmonary hypertension related to left heart disease (PH-LHD). While recent evidence does not support the use of targeted pulmonary arterial hypertension (PAH) therapy in PH-LHD, there is a lack of clinical data on their use in CpcPH. We evaluated the outcomes in patients with CpcPH treated with PAH therapies.

METHODS

Retrospectively, 50 patients meeting hemodynamic criteria of CpcPH and started on PAH-targeted drugs were identified. Fifty age- and gender-matched PAH patients were chosen as controls. We evaluated the change in 6-minute walk distance, World Health Organization functional class (FC), tricuspid annular plane systolic excursion, BNP or NT-proBNP, and pulmonary artery systolic pressure at 3, 6, 12, and 24 months of follow-up.

RESULTS

After adjusting for age and gender, there was no improvement in World Health Organization FC in CpcPH over 2 years (odds ratio of change to FC I/II 1.01, 95% CI: 0.98-1.04). There was no significant improvement in 6-minute walk distance (β coefficient 0.21, 95% CI: -0.98 to 1.4), reduction in BNP/NT-proBNP (β coefficient -12.16, 95% CI: -30.68 to 6.37), increase in tricuspid annular plane systolic excursion (β coefficient 0.074, 95% CI: 0.010-0.139), or decrease in pulmonary artery systolic pressure (0.996, 95% CI: 0.991-1.011) in CpcPH with therapy. There was higher mortality in CpcPH compared to PAH on treatment (24% vs 4%, P = .003).

CONCLUSIONS

There were no improvements in symptoms, exercise capacity, or echocardiographic parameters with PAH-targeted therapy in CpcPH. Further studies into potential treatments benefiting this population are needed.

Effect of sildenafil on right ventricular performance in an experimental large-animal model of postcapillary pulmonary hypertension

Right ventricle (RV) dysfunction is a main determinant of morbidity and mortality in postcapillary pulmonary hypertension (PH). However, currently there are not available therapies. Since reduced nitric oxide (NO) availability and cyclic guanylate monophosphate (cGMP) levels are central in this disease, therapies targeting the NO pathway might have a beneficial effect on RV performance. In this regard, sildenafil has shown contradictory results. Our objective was to evaluate the effect of sildenafil on RV performance in an experimental pig model of postcapillary PH induced by a fixed banding of the venous pulmonary confluent. Animals were evaluated by right heart catheterization and cardiac magnetic resonance before randomization and after 8 weeks on sildenafil (n = 8) or placebo (n = 8), and myocardial tissues were analyzed with histology and molecular biology. At the end of the study, animals receiving sildenafil showed better RV performance as compared with those on placebo (improvement in RV ejection fraction of 7.3% ± 5.8% versus -0.6% ± 5.0%, P= 0.021) associated with less apoptotic cells and gene expression related with reduced oxidative stress and increased anti-inflammatory activity in the myocardium. No differences were observed in pulmonary hemodynamics. In conclusion, in a translational large animal model of chronic postcapillary PH, sildenafil improved RV systolic function independently of afterload. Further research with pharmacological approaches able to manipulate the NO-cGMP axis are needed to confirm this potential cardioprotective effect.

Pulmonary hypertension associated with left-sided heart failure

PURPOSE OF REVIEW

Pulmonary hypertension is a common phenomenon in heart failure patients that is highly relevant for morbidity and outcome. Although postcapillary in nature, the pathophysiology of pulmonary hypertension in patients with heart failure with reduced or preserved ejection fraction is complex, and decisions about management strategies remain challenging.

RECENT FINDINGS

Recently, the hemodynamic definitions and subclassification of postcapillary pulmonary hypertension have been revisited. The distinction between isolated postcapillary pulmonary hypertension (IpcPH) and combined post and precapillary pulmonary hypertension (CpcPH) and their definition are essential. Novel data on the prognostic impact of hemodynamic variables and right ventricular function highlight the importance of cardiopulmonary interaction in patients with left-sided heart failure (LHF). Furthermore, the impact of management strategies including medical therapy, remote hemodynamic monitoring, and interventional approaches on hemodynamics and outcome has recently been investigated. Here, we critically review recent developments and future considerations in this field, and highlight distinct treatment strategies targeting the underlying left heart condition, the pulmonary circulation, and/or impaired right ventricular function.

SUMMARY

Detailed hemodynamic characterization and proper phenotyping are essential for prognostication and the management of patients with pulmonary hypertension associated with LHF, both in clinical practice and when addressing research questions.

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

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

Phosphodiesterase 5 inhibitor sildenafil in patients with heart failure with preserved ejection fraction and combined pre- and postcapillary pulmonary hypertension: a randomized open-label pilot study

BACKGROUND

Heart failure with preserved ejection fraction (HFpEF) is frequently complicated by pulmonary hypertension (PH). A pulmonary vascular contribution could be considered as a substantial therapeutic target in HFpEF and PH and combined pre- and postcapillary PH (Cpc-PH).

METHODS

We enrolled 50 patients with HFpEF and Cpc-PH who were determined by echocardiography to have pulmonary artery systolic pressure (PASP) > 40 mmHg, pulmonary vascular resistance > 3 Wood units, and/or transpulmonary gradient > 15 mmHg.

RESULTS

The patients were assigned to the phosphodiesterase 5 (PDE5) inhibitor sildenafil group (25 mg TID for 3 months followed by 50 mg TID for 3 months; n = 30) or the control group (n = 20). In the sildenafil group after 6 months, the 6-min walk distance increased by 50 m (95% CI, 36 to 64 m); substantial improvement in NYHA functional class and exercise capacity during diastolic stress test were revealed; decreases in early mitral inflow to mitral annulus relaxation velocities ratio by 2.4 (95% CI, - 3.3 to - 1.4) and PASP by 17.0 mmHg (95% CI, 20.4 to 13.5) were observed; right ventricular systolic function (M-mode tricuspid annular plane systolic excursion) increased by 0.42 cm (95% CI, 0.32 to 0.52 cm; P < 0.01 for all). No changes occurred in the control group.

CONCLUSIONS

In a subset of patients with HFpEF and Cpc-PH assessed by echocardiography, PDE5 inhibition was associated with an improvement in exercise capacity, pulmonary haemodynamic parameters, and right ventricular function. The role of sildenafil needs to be considered in randomized trials in selected patients with HFpEF with invasively confirmed Cpc-PH.

TRIAL REGISTRATION

Russian National Information System of Research, Development and Technology Data of Civilian Usage (NIS, https://rosrid.ru), registration number 01201257849 . Registered 20 April 2012. This manuscript adheres to the CONSORT guidelines.

Mechanisms of diabetic cardiomyopathy and potential therapeutic strategies: preclinical and clinical evidence

The pathogenesis and clinical features of diabetic cardiomyopathy have been well-studied in the past decade, but effective approaches to prevent and treat this disease are limited. Diabetic cardiomyopathy occurs as a result of the dysregulated glucose and lipid metabolism associated with diabetes mellitus, which leads to increased oxidative stress and the activation of multiple inflammatory pathways that mediate cellular and extracellular injury, pathological cardiac remodelling, and diastolic and systolic dysfunction. Preclinical studies in animal models of diabetes have identified multiple intracellular pathways involved in the pathogenesis of diabetic cardiomyopathy and potential cardioprotective strategies to prevent and treat the disease, including antifibrotic agents, anti-inflammatory agents and antioxidants. Some of these interventions have been tested in clinical trials and have shown favourable initial results. In this Review, we discuss the mechanisms underlying the development of diabetic cardiomyopathy and heart failure in type 1 and type 2 diabetes mellitus, and we summarize the evidence from preclinical and clinical studies that might provide guidance for the development of targeted strategies. We also highlight some of the novel pharmacological therapeutic strategies for the treatment and prevention of diabetic cardiomyopathy.

Pulmonary Hypertension Due to Left Heart Disease

Pulmonary hypertension (PH) due to left heart disease (LHD) is the most common type of PH and is defined as mean pulmonary artery systolic pressure of >20 mm Hg and pulmonary capillary wedge pressure >15 mm Hg during right heart catheterization. LHD may lead to elevated left atrial pressure alone, which in the absence of intrinsic pulmonary vascular disease will result in PH without changes in pulmonary vascular resistance. Persistent elevation in left atrial pressure may, however, also be associated with subsequent pulmonary vascular remodeling, vasoconstriction, and an increase in pulmonary vascular resistance. Hence, there are 2 subgroups of PH due to LHD, isolated postcapillary PH and combined post- and precapillary PH, with these groups have differing clinical implications. Differentiation of pulmonary arterial hypertension and PH due to LHD is critical to guide management planning; however, this may be challenging. Older patients, patients with metabolic syndrome, and patients with imaging and clinical features consistent with left ventricular dysfunction are suggestive of LHD etiology rather than pulmonary arterial hypertension. Hemodynamic measures such as diastolic pressure gradient, transpulmonary gradient, and pulmonary vascular resistance may assist to differentiate pre- from postcapillary PH and offer prognostic insights. However, these are influenced by fluid status and heart failure treatment. Pulmonary arterial hypertension therapies have been trialed in the treatment with concerning results reflecting disease heterogeneity, variation in inclusion criteria, and mixed end point criteria. The aim of this review is to provide an updated definition, discuss possible pathophysiology, clinical aspects, and the available treatment options for PH due to LHD.

Exercise intolerance in heart failure: The important role of pulmonary hypertension

NEW FINDINGS

What is the topic of this review? This review concerns the negative impact of pulmonary hypertension (PH) on the pulmonary haemodynamic and gas exchange responses to exercise, considering the mechanisms by which PH plays a role in exercise intolerance in heart failure (HF) patients. What advances does it highlight? The hallmark limited pulmonary vascular 'reserve' and impaired pulmonary gas exchange responses to exercise in HF are worsened by the development of PH; these are key determinants of exercise intolerance. Even HF patients who present with 'normal' pulmonary vascular function experience exercise-induced PH, which plays a role in exercise intolerance.

ABSTRACT

Patients with heart failure universally complain of exertional intolerance, but the underlying cause(s) of this intolerance may differ between patients with different disease phenotypes. Exercise introduces an impressive stress to the lungs, where elevations in venous return and cardiac output engender substantial increases in pulmonary blood volume and flow. Relative to healthy individuals, the pulmonary vascular reserve to accept this increase in pulmonary perfusion is compromised in heart failure, with a growing body of evidence suggesting that the development of pulmonary hypertension (PH), and in particular a precapillary component of PH, worsens the pulmonary haemodynamic response to exercise in these patients. Characterized by an exaggerated increase in pulmonary arterial pressure and an elevation in pulmonary vascular resistance, this dysfunctional pulmonary haemodynamic response plays a role in exercise intolerance, probably through an impairment of right ventricular function, underperfusion of the pulmonary circulation and a subsequent reduction in systemic blood flow and oxygen delivery. The hallmark abnormalities in ventilatory and pulmonary gas exchange that accompany heart failure, including a greater ventilatory equivalent for carbon dioxide, are also worsened by the development of PH. This raises the possibility that measures of exercise pulmonary gas exchange might help to 'describe' underlying PH in heart failure; however, several fundamental issues and questions need to be addressed before such gas exchange measures could truly be considered efficacious measures used to differentiate the type of PH and track the severity of PH in heart failure. exercise intolerance, heart failure, pulmonary gas exchange, pulmonary haemodynamics, pulmonary hypertension.

Pulmonary hypertension in HFpEF and HFrEF: Pathophysiology, diagnosis, treatment approaches

Pulmonary hypertension (PH) is a frequent hemodynamic condition that is highly prevalent in patients with heart failure and reduced (HFrEF) or preserved ejection fraction (HFpEF). Irrespective of left ventricular EF, the presence of PH and right ventricular (RV) dysfunction are highly relevant for morbidity and mortality in patients with heart failure. While elevated left-sided filling pressures and functional mitral regurgitation primarily lead to post-capillary PH, current guidelines and recommendations distinguish between isolated post-capillary PH (IpcPH) and combined post- and pre-capillary PH (CpcPH), the latter being defined by a pulmonary vascular resistance (PVR) of ≥3 Wood units. Here, we describe the pathophysiology and clinical relevance of these distinct entities, and report on the diagnostic work-up including remote pulmonary artery pressure (PAP) monitoring. Furthermore, we highlight strategies to manage PH and improve RV function in heart failure, which may include optimized management of HFrEF and HFpEF (medical and interventional), sufficient volume control, catheter-based mitral valve repair, and-in selected cases-targeted PH therapy. In this context, we also highlight gaps in evidence and the need for further research.