Pulmonary Hypertension with Left Heart Disease: Prevalence, Temporal Shifts in Etiologies and Outcome

Development and validation of a diagnostic nomogram in pulmonary hypertension due to left heart disease

BACKGROUND

Pulmonary hypertension (pH) due to left heart disease (pH-LHD) is the most common form of pH in clinical practice.

OBJECTIVES

The purpose of the study is to develop a diagnostic nomogram predictive model combining conventional noninvasive examination and detection indicators.

METHODS

Our study retrospectively included 361 patients with left heart disease (LHD) who underwent right heart catheterization between 2013 and 2020. All patients were randomly divided into a training cohort (253, 70 %) and a validation cohort (108, 30 %). pH was defined as resting mean pulmonary arterial pressure (mPAP) ≥25 mmHg measured by RHC examination. Data dimension reduction and feature selection were used by Lasso regression model. The nomogram was constructed based on multivariable logistic regression.

RESULTS

A total of 175 patients with LHD were diagnosed with pH during their hospitalization, representing 48.5 % of the cohort. The mean age of the overall group was 55.6 years, with 76.7 % being male patients. Excessive resting heart rate, elevated New York Heart Association functional class, increased red blood cell distribution width, right ventricular end-diastolic diameter, and pulmonary artery systolic pressure measured by echocardiography were independently associated with the prevalence of pH-LHD. The inclusion of these 5 variables in the nomogram showed good discrimination (AUC = 0.866 [95 % CI, 0.820-0.911]) and optimal calibration (Hosmer-Lemeshow test, P = 0.791) for the validation cohort.

CONCLUSIONS

The noninvasive nomogram of pH-LHD developed in this study has excellent diagnostic value and clinical applicability, and can more accurately evaluate the presence risk of pH in patients with LHD.

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

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

Post-Capillary Pulmonary Hypertension: Clinical Review

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

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).

Monitoring of Levosimendan Administration in Patients with Pulmonary Hypertension Undergoing Cardiac Surgery and Effect of Two Different Dosing Schemes on Hemodynamic and Echocardiographic Parameters

INTRODUCTION

The perioperative management of patients with pulmonary hypertension (PH) undergoing cardiac surgery represents one of the most challenging clinical scenarios. This fact mainly depends on the relationship existing between PH and right ventricular failure (RVF). Levosimendan (LS) is an inodilator that might be an effective agent in the treatment of PH and RVF. The aim of this study was to examine the impact of the duration of cardiopulmonary bypass (CPB) on the therapeutic drug monitoring of LS and to evaluate the effect of preemptive administration of LS on perioperative hemodynamic and echocardiographic parameters in cardiac surgical patients with preexisting PH.

MATERIALS AND METHODS

In this study, LS was administered in adult patients undergoing cardiac surgery before CPB in order to prevent exacerbation of preexisting PH and subsequent right ventricular dysfunction. Thirty cardiac surgical patients with preoperatively confirmed PH were randomized to receive either 6 μg/kg or 12 μg/kg of LS after the induction of anesthesia. The plasma concentration of LS was measured after CPB. In this study, a low sample volume was used combined with a simple sample preparation protocol. The plasma sample was extracted by protein precipitation and evaporated; then, the analyte was reconstituted and detected using specific and sensitive bioanalytical liquid chromatography with mass spectrometry (LC-MS/MS) methodology. The clinical, hemodynamic, and echocardiographic parameters were registered and evaluated before and after the administration of the drug.

RESULTS

A fast bioanalytical LC-MS/MS methodology (a run time of 5.5 min) was developed for the simultaneous determination of LS and OR-1896, its main metabolite in human plasma. The LC-MS/MS method was linear over a range of 0.1-50 ng/mL for LS and 1-50 ng/mL for its metabolite OR-1896. Measured plasma concentrations of LS were inversely related to the duration of CPB. LS administration before CPB during cardiac surgery was effective in reducing pulmonary artery pressure and improving hemodynamic parameters after CPB, with a more pronounced and durable effect of the drug at the dose of 12 μg/kg. Additionally, administration of LS at a dose of 12 μg/kg in cardiac surgical patients with PH before CPB improved right ventricular function.

CONCLUSION

LS administration decreases pulmonary artery pressure and may improve right ventricular function in patients with PH undergoing cardiac surgery.

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSION

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

Distinguishing exercise intolerance in early-stage pulmonary hypertension with invasive exercise hemodynamics: Rest VE /VCO2 and ETCO2 identify pulmonary vascular disease

BACKGROUND

Among subjects with exercise intolerance and suspected early-stage pulmonary hypertension (PH), early identification of pulmonary vascular disease (PVD) with noninvasive methods is essential for prompt PH management.

HYPOTHESIS

Rest gas exchange parameters (minute ventilation to carbon dioxide production ratio: VE /VCO2 and end-tidal carbon dioxide: ETCO2 ) can identify PVD in early-stage PH.

METHODS

We conducted a retrospective review of 55 subjects with early-stage PH (per echocardiogram), undergoing invasive exercise hemodynamics with cardiopulmonary exercise test to distinguish exercise intolerance mechanisms. Based on the rest and exercise hemodynamics, three distinct phenotypes were defined: (1) PVD, (2) pulmonary venous hypertension, and (3) noncardiac dyspnea (no rest or exercise PH). For all tests, *p < .05 was considered statistically significant.

RESULTS

The mean age was 63.3 ± 13.4 years (53% female). In the overall cohort, higher rest VE /VCO2 and lower rest ETCO2 (mm Hg) correlated with high rest and exercise pulmonary vascular resistance (PVR) (r ~ 0.5-0.6*). On receiver-operating characteristic analysis to predict PVD (vs. non-PVD) subjects with noninvasive metrics, area under the curve for pulmonary artery systolic pressure (echocardiogram) = 0.53, rest VE /VCO2  = 0.70* and ETCO2  = 0.73*. Based on this, optimal thresholds of rest VE /VCO2  > 40 mm Hg and rest ETCO2  < 30 mm Hg were applied to the overall cohort. Subjects with both abnormal gas exchange parameters (n = 12, vs. both normal parameters, n = 19) had an exercise PVR 5.2 ± 2.6* (vs. 1.9 ± 1.2), mPAP/CO slope with exercise 10.2 ± 6.0* (vs. 2.9 ± 2.0), and none included subjects from the noncardiac dyspnea group.

CONCLUSIONS

In a broad cohort of subjects with suspected early-stage PH, referred for invasive exercise testing to distinguish mechanisms of exercise intolerance, rest gas exchange parameters (VE /VCO2  > 40 mm Hg and ETCO2  < 30 mm Hg) identify PVD.

Pulmonary Arterial Hypertension and Adverse Outcomes after Kidney Transplantation: A Systematic Review and Meta-Analysis

Pulmonary arterial hypertension (PH) has a high prevalence in chronic kidney disease (CKD) patients, especially those undergoing kidney transplantation (KT). We aimed to systematically review and calculate the pooled effect size of the literature evaluating the association between pre-existing PH documented by transthoracic echocardiography (TTE) or invasively and adverse outcomes following KT. The primary composite outcome extracted from the included studies was represented by the mortality from any cause following KT and delayed graft function (DGF), graft dysfunction, or graft failure. The secondary outcomes were represented by individual components of the primary composite outcome. Twelve studies meeting the inclusion criteria were selected. The main finding is that pre-existing PH was associated with increased mortality and a higher rate of DGF, kidney graft dysfunction, or failure in KT recipients. The effect remained significant for all outcomes irrespective of PH evaluation, invasively or using TTE. Consequently, patients with PH defined only by TTE were at higher risk of death, DGF, or graft failure. Our findings support the routine assessment of PH in patients on the KT waitlist. PH might represent an extensively available and valuable tool for risk stratification in KT patients. These data should be confirmed in large prospective clinical trials.

A predictive model for dilated cardiomyopathy with pulmonary hypertension

Aims

Dilated cardiomyopathy (DCM) is defined as a serious cardiac disorder caused by the presence of left ventricular dilatation and contractile dysfunction in the absence of severe coronary artery disease and abnormal loading conditions. The incidence of cardiac death is markedly higher in patients with DCM with pulmonary hypertension (PH) than in DCM patients without PH. No previous studies have constructed a predictive model to predict PH in patients with DCM.

Methods

Data from 218 DCM patients (68.3% man; mean age 57.33) were collected. Patients were divided into low, intermediate and high PH‐risk groups based on the echocardiographic assessment at the tricuspid regurgitation peak velocity (TRV) in conjunction with the presence of echocardiographic signs from at least two different categories. Basic information, vital signs, comorbidities and biochemical data of each patient were determined. The impact of each parameter on PH probability was analysed by univariable and multivariable analyses, the data from which were employed to establish a predictive model. Finally, the discriminability, calibration ability and clinical efficacy of the model were verified for both the modelling group and the external validation group.

Results

We successfully applied a history of chronic obstructive pulmonary disease (COPD) or chronic bronchitis, systolic murmur (SM) at the tricuspid area, SM at the apex and brain natriuretic peptide (BNP) level to establish a model for predicting PH probability in DCM. The model was proven to have high accuracy and good discriminability (area under the receiver operating characteristic curve 0.889), calibration ability and clinical application value.

Conclusions

A model for predicting PH probability in patients with DCM was successfully established. The new model is reliable for predicting PH probability in DCM and has good clinical applicability.

Therapeutic Challenges and Emerging Treatment Targets for Pulmonary Hypertension in Left Heart Disease

Pulmonary hypertension (PH) attributable to left heart disease (LHD) is believed to be the most common form of PH and is strongly associated with increased mortality and morbidity in this patient population. Specific therapies for PH‐LHD have not yet been identified and the use of pulmonary artery hypertension‐targeted therapies in PH‐LHD are not recommended. Endothelin receptor antagonists, phosphodiesterase‐5 inhibitors, guanylate cyclase stimulators, and prostacyclins have all been studied in PH‐LHD with conflicting results. Understanding the mechanisms underlying PH‐LHD could potentially provide novel therapeutic targets. Fibrosis, oxidative stress, and metabolic syndrome have been proposed as pathophysiological components of PH‐LHD. Genetic associations have also been identified, offering additional mechanisms with biological plausibility. This review summarizes the evidence and challenges for treatment of PH‐LHD and focuses on underlying mechanisms on the horizon that could develop into potential therapeutic targets for this disease.

The effect of transcatheter aortic valve implantation on pulmonary artery pressures in a patient suffering from chronic heart failure: a case report

BACKGROUND

Pulmonary hypertension (PH) is most commonly caused by left-sided heart disease and may negatively affect the long-term prognosis and quality of life of patients with chronic heart failure (CHF). CardioMEMS (Micro-Electro-Mechanical-System) allows physicians to monitor pulmonary artery (PA) pressures remotely and optimize heart failure treatment based on haemodynamic parameters, which provides further insight into the effect of valvular interventions.

CASE SUMMARY

We present a case of a 61-year-old male patient with an ischaemic cardiomyopathy, poor LV function, moderate to severe mitral regurgitation, and severe aortic valve regurgitation in refractory heart failure. Right heart catheterization and CardioMEMS monitoring revealed severe pulmonary hypertension with mean PA pressures of 55 mmHg and a mean pulmonary capillary wedge pressure of 21 mmHg despite up titration of heart failure medication and sildenafil. Pulmonary and systemic causes of pulmonary hypertension were excluded. After heart team consensus, the patient underwent transcatheter aortic valve implantation (TAVI) which resulted in normalization of PA pressures and a significant improvement of functional performance.

DISCUSSION

To the best of our knowledge, this is the first case report describing the direct effects of TAVI on continuous PA pressures in a patient with poor LV function and severe aortic regurgitation. Elective TAVI appeared to be safe and very effective in reverting severe pulmonary hypertension. Most strikingly, drug interventions could not affect the elevated pulmonary pressures, but TAVI corrected the aortic valve insufficiency with normalization of left-sided pulmonary hypertension.

Persistent Pulmonary Hypertension in Corrected Valvular Heart Disease: Hemodynamic Insights and Long-Term Survival

Background The determinants and consequences of pulmonary hypertension after successfully corrected valvular heart disease remain poorly understood. We aim to clarify the hemodynamic bases and risk factors for mortality in patients with this condition. Methods and Results We analyzed long-term follow-up data of 222 patients with pulmonary hypertension and valvular heart disease successfully corrected at least 1 year before enrollment who had undergone comprehensive hemodynamic and imaging characterization as per the SIOVAC (Sildenafil for Improving Outcomes After Valvular Correction) clinical trial. Median (interquartile range) mean pulmonary pressure was 37 mm Hg (32-44 mm Hg) and pulmonary artery wedge pressure was 23 mm Hg (18-26 mm Hg). Most patients were classified either as having combined precapillary and postcapillary or isolated postcapillary pulmonary hypertension. After a median follow-up of 4.5 years, 91 deaths accounted for 4.21 higher-than-expected mortality in the age-matched population. Risk factors for mortality were male sex, older age, diabetes mellitus, World Health Organization functional class III and higher pulmonary vascular resistance-either measured by catheterization or approximated from ultrasound data. Higher pulmonary vascular resistance was related to diabetes mellitus and smaller residual aortic and mitral valve areas. In turn, the latter correlated with prosthetic nominal size. Six-month changes in the composite clinical score and in the 6-minute walk test distance were related to survival. Conclusions Persistent valvular heart disease-pulmonary hypertension is an ominous disease that is almost universally associated with elevated pulmonary artery wedge pressure. Pulmonary vascular resistance is a major determinant of mortality in this condition and is related to diabetes mellitus and the residual effective area of the corrected valve. These findings have important implications for individualizing valve correction procedures. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT00862043.

Pulmonary Hypertension Due to Left Heart Disease-A Practical Approach to Diagnosis and Management

Pulmonary hypertension (PH) due to left heart disease (LHD) is a frequent complication of heart failure (HF) and is associated with exercise intolerance, poor quality of life, increased risk of hospitalisations, and reduced overall survival. Since the recent Sixth World Symposium on Pulmonary Hypertension in 2018, there have been significant changes in the hemodynamic definitions and clinical classification of PH-LHD. PH-LHD can be subdivided into (1) isolated postcapillary PH (IpcPH) and (2) combined precapillary and postcapillary PH (CpcPH). This categorisation of PH-LHD is important because CpcPH shares certain pathophysiologic, clinical, and hemodynamic characteristics with pulmonary arterial hypertension and is associated with worse outcomes compared with IpcPH. A systematic approach using clinical history and noninvasive investigations is required in the diagnosis of PH-LHD. Right heart catheterisation with and without provocative testing is performed in expert centres and is indicated in selected individuals. Although the definition of IpcPH and CpcPH is based on measurements made with right heart catheterisation, distinguishing between these two entities is not always necessary. Despite strong evidence for medical therapy in patients with pulmonary arterial hypertension, those options have limited benefit in PH-LHD. Expert PH centres in Canada have been established to provide ongoing care for the more complex patient subgroups.

Midterm postoperative prognosis of patients with severe left heart valvular disease combined with moderate or severe pulmonary hypertension treated with treprostinil

BACKGROUND

To investigate the midterm postoperative prognosis of patients with severe left heart valvular disease combined with moderate or severe pulmonary hypertension (PAH) using subcutaneous injection of treprostinil.

METHODS

A retrospective study was conducted on 61 patients with severe left heart valvular disease combined with moderate or severe PAH who had undergone mechanical mitral and/or aortic valve replacement from April 2018 to October 2018. The patients were divided into the treprostinil group and the conventional treatment group according to whether they received treprostinil. The patients were assessed by SwanGanz catheterization, echocardiography, the 6-min walk test (6-MWT), the Borg dyspnoea score and the SF-36 questionnaire.

RESULTS

Compared with the preoperative data, the mPAP measured by SwanGanz catheterization, the results of the 6-MWT and the Borg score were significantly improved in both groups during the 1 year follow-up (P < 0.05). Regarding the comparison between the groups, the results in group T were significantly better than those in group C, including the results of the 6-MWT and the general health, vitality and mental health of SF-36 during the 1 year follow-up (P < 0.05).

CONCLUSIONS

Continuous subcutaneous infusion of treprostinil was not capable of decreasing pulmonary pressures in patients with severe left heart valvular disease combined with moderate or severe PAH during 1 year follow-up, although which some of our data suggest that might improve the symptoms and quality of life of these patients.

Pulmonary hypertension due to left heart disease with pulmonary arterial wedge pressure ≤15 mm Hg

BACKGROUND

Pulmonary hypertension due to left heart disease (PH-LHD) is the most prevalent type of pulmonary hypertension (PH). The hemodynamic diagnostic standard of pulmonary arterial wedge pressure (PAWP) >15 mm Hg that is traditionally recommended by guidelines is being challenged.

METHODS

To address this problem, we analyzed the data of 154 patients with PH-LHD admitted to our center from April 2013 to March 2018. Pharmacological or nonpharmacological treatment of underlying left heart disease was offered to all 154 patients.

RESULTS

In total, there were 24 patients (15.6%) with PAWP ≤15 mm Hg. Comparison of echocardiography and right heart catheterization parameters between the two groups (PAWP >15 mm Hg and PAWP ≤15 mm Hg) showed that the group with PAWP ≤15 mm Hg had smaller left ventricular diameter, higher cardiac output, lower pressure and higher oxygen saturation in the pulmonary artery, right atrium, right ventricle, and superior vena cava. No significant difference was found regarding dilated cardiomyopathy, diabetes mellitus, hypertension, atrial fibrillation, and left heart valvular disease, but a significant difference was found for coronary heart disease (higher morbidity in group with PAWP ≤15 mm Hg) between the two groups.

CONCLUSION

We found that 15.6% of the patients with PH-LHD under pharmacological or nonpharmacological treatment had PAWP ≤15 mm Hg. These results suggest that the diagnostic criterion of PAWP and the characteristics for this group of patients should be further investigated.

Pulmonary Artery Denervation as an Innovative Treatment for Pulmonary Hypertension With and Without Heart Failure

Pulmonary hypertension (PH) is categorized into 5 groups based on etiology. The 2 most prevalent forms are pulmonary arterial hypertension (PAH) and PH due to left heart disease (PH-LHD). Therapeutic options do exist for PAH to decrease symptoms and improve functional capacity; however, the mortality rate remains high and clinical improvements are limited. PH-LHD is the most common cause of PH; however, no treatment exists and the use of PAH-therapies is discouraged. Pulmonary artery denervation (PADN) is an innovative catheter-based ablation technique targeting the afferent and efferent fibers of a baroreceptor reflex in the main pulmonary artery (PA) trunk and its bifurcation. This reflex is involved in the elevation of the PA pressure seen in PH. Since 2013, both animal trials and human trials have shown the efficacy of PADN in improving PAH, including improved hemodynamic parameters, increased functional capacity, decreased PA remodeling, and much more. PADN has been shown to decrease the rate of rehospitalization, PH-related complications, and death, and is an overall safe procedure. PADN has also been shown to be effective for PH-LHD. Additional therapeutic mechanisms and benefits of PADN are discussed along with new PADN techniques. PADN has shown efficacy and safety as a potential treatment option for PH.

Pulmonary Hypertension in an Oncologic Intensive Care Unit

Pulmonary hypertension (PH) is the condition of elevated pressures in the pulmonary circulation. PH can develop acutely in patients with critical illness such as acute respiratory distress syndrome, sepsis, massive pulmonary embolism, left ventricular dysfunction, or after surgery. In a cancer patient, unique etiologies such as myeloproliferative disorders, tyrosine kinase inhibitors, or tumor emboli may result in PH. Early recognition and treatment of the causative condition may reverse acute PH or return chronic PH to its baseline status. Progression of the disease or its decompensation due to infection, a thromboembolic event, or other triggers can lead to admission to an intensive care unit. Regardless of etiology, the development or worsening of PH may precipitate hypoxemia, hemodynamic instability, or right ventricular failure, which can be challenging to manage or even fatal. In select cases, rapid institution of advanced treatment modalities may be warranted. This chapter reviews the etiology, epidemiology, pathophysiology, clinical features, diagnosis, and prognosis of PH and presents a comprehensive analysis of PH and right heart failure management strategies in the critical care setting. In particular, a unique perspective on oncologically relevant PH is provided.

Pre-Operative Sildenafil for Patients With Pulmonary Hypertension Undergoing Mitral Valve Surgery: A Systematic Review and Meta-Analysis

Background

Pulmonary hypertension is a usual complication of long-standing mitral valve disease. Perioperative pulmonary hypertension is a risk factor for right ventricular failure and is an important cause of morbidity and mortality in patients with pulmonary hypertension undergoing mitral valve surgery. Phosphodiesterase-5 inhibitors particularly sildenafil citrate have proven clinical benefit for pulmonary arterial hypertension but have shown discordant results in group 2 pulmonary hypertension patients. We sought to determine the effect of pre-operative sildenafil on the intra-operative hemodynamic parameters of these patients.

Methods

Studies were included if they satisfied the following criteria: 1) Randomized controlled trials; 2) Adult patients with pulmonary hypertension scheduled for elective mitral valve surgery; and 3) Reported data on changes in pre-, intra-, and post-operative hemodynamic parameters. Using PUBMED, Clinical Key, Science Direct, and Cochrane databases, a search for eligible studies was conducted from September 1 to December 31, 2018. The quality of each study was evaluated using the Cochrane Risk of Bias Tool. The primary outcome of interest is on the effect of pre-operative sildenafil on the improvement of intra-operative hemodynamic parameters such as systolic pulmonary artery pressure (sPAP), mean pulmonary arterial pressure, mean arterial pressure, pulmonary and systemic vascular resistances. We also investigated its effect on the post-operative mortality, length of cardiopulmonary bypass time, ventilation time, and inotrope support requirement. Review Manager 5.3 was utilized to perform analysis of random effects for continuous outcomes.

Results

We identified three studies involving 153 patients with pulmonary hypertension undergoing mitral valve surgery, showing that among those who received pre-operative sildenafil there is a significant decrease in intra-operative systolic pulmonary arterial pressure (mean difference -11.19 (95% confidence interval (CI), -20.23 to -2.15), P < 0.05) and post-operative sPAP (mean difference -13.67 (95% CI, - 19.56 to - 7.78), P < 0.05) without significantly affecting the mean arterial pressure (mean difference 1.94 (95% CI, -5.49 to 9.37), P < 0.05). The systemic and pulmonary vascular resistances were not affected as well.

Conclusions

Administration of pre-operative sildenafil to patients with pulmonary hypertension undergoing mitral valve surgery decreases intra-operative and post-operative systolic pulmonary arterial pressure without significantly affecting other systemic hemodynamic parameters.

Sildenafil for improving outcomes in patients with corrected valvular heart disease and persistent pulmonary hypertension: a multicenter, double-blind, randomized clinical trial

Aims

We aimed to determine whether treatment with sildenafil improves outcomes of patients with persistent pulmonary hypertension (PH) after correction of valvular heart disease (VHD).

Methods and results

The sildenafil for improving outcomes after valvular correction (SIOVAC) study was a multricentric, randomized, parallel, and placebo-controlled trial that enrolled stable adults with mean pulmonary artery pressure ≥ 30 mmHg who had undergone a successful valve replacement or repair procedure at least 1 year before inclusion. We assigned 200 patients to receive sildenafil (40 mg three times daily, n = 104) or placebo (n = 96) for 6 months. The primary endpoint was the composite clinical score combining death, hospital admission for heart failure (HF), change in functional class, and patient global self-assessment. Only 27 patients receiving sildenafil improved their composite clinical score, as compared with 44 patients receiving placebo; in contrast 33 patients in the sildenafil group worsened their composite score, as compared with 14 in the placebo group [odds ratio 0.39; 95% confidence interval (CI) 0.22–0.67; P < 0.001]. The Kaplan–Meier estimates for survival without admission due to HF were 0.76 and 0.86 in the sildenafil and placebo groups, respectively (hazard ratio 2.0, 95% CI = 1.0–4.0; log-rank P = 0.044). Changes in 6-min walk test distance, natriuretic peptides, and Doppler-derived systolic pulmonary pressure were similar in both groups.

Conclusion

Treatment with sildenafil in patients with persistent PH after successfully corrected VHD is associated to worse clinical outcomes than placebo. Off-label usage of sildenafil for treating this source of left heart disease PH should be avoided.

The trial is registered with ClinicalTrials.gov, number NCT00862043.

Echocardiographic assessment of pulmonary hypertension: a guideline protocol from the British Society of Echocardiography

Pulmonary hypertension is defined as a mean arterial pressure of ≥25 mmHg as confirmed on right heart catheterisation. Traditionally, the pulmonary arterial systolic pressure has been estimated on echo by utilising the simplified Bernoulli equation from the peak tricuspid regurgitant velocity and adding this to an estimate of right atrial pressure. Previous studies have demonstrated a correlation between this estimate of pulmonary arterial systolic pressure and that obtained from invasive measurement across a cohort of patients. However, for an individual patient significant overestimation and underestimation can occur and the levels of agreement between the two is poor. Recent guidance has suggested that echocardiographic assessment of pulmonary hypertension should be limited to determining the probability of pulmonary hypertension being present rather than estimating the pulmonary artery pressure. In those patients in whom the presence of pulmonary hypertension requires confirmation, this should be done with right heart catheterisation when indicated. This guideline protocol from the British Society of Echocardiography aims to outline a practical approach to assessing the probability of pulmonary hypertension using echocardiography and should be used in conjunction with the previously published minimum dataset for a standard transthoracic echocardiogram.

Evolving use of natriuretic peptide receptor type-C as part of strategies for the treatment of pulmonary hypertension due to left ventricle heart failure

Pulmonary hypertension (PH) due to left ventricular heart failure (LV-HF) is a disabling and life-threatening disease for which there is currently no single marketed pharmacological agent approved. Despite recent advances in the pathophysiological understanding, there is as yet no prospect of cure, and the majority of patients continue to progress to right ventricular failure and die. There is, therefore an urgent unmet need to identify novel pharmacological agents that will prevent or reverse the increase in pulmonary artery pressures while enhancing cardiac performance in PH due to LV-HF. In the present article, we first focused on the Natriuretic Peptide Receptor type C (NPR-C) based therapeutic strategies aimed at lowering pulmonary artery pressure. Second, we reviewed potential NPR-C therapeutic strategies to reverse or least halt the detrimental effects of diastolic dysfunction and impaired nitic oxide signalling pathways, as well as possibilities for neurohumoral modulation.

Pulmonary Hypertension in Aortic and Mitral Valve Disease

In patients with aortic and/or mitral valve disease the presence of pulmonary hypertension (PH) indicates a decompensated state of the disease with left ventricular and left atrial dysfunction and exhausted compensatory mechanism, i.e., a state of heart failure. Pulmonary hypertension in this context is the consequence of the backwards transmission of elevated left atrial pressure. In this form of PH, pulmonary vascular resistance is initially normal (isolated post-capillary PH). Depending on the extent and chronicity of left atrial pressure elevation additional pulmonary vascular remodeling may occur (combined pre- and post-capillary PH). Mechanical interventions for the correction of valve disease often but not always reduce pulmonary pressures. However, the reduction in pulmonary pressures is often modest, and persistent PH in these patients is common and a marker of poor prognosis. In the present review we discuss the pathophysiology and clinical impact of PH in patients with aortic and mitral valve disease, the comprehensive non-invasive and invasive diagnostic approach required to define treatment of PH, and recent insights from mechanistic studies, registries and randomized studies, and we provide an outlook regarding gaps in evidence, future clinical challenges, and research opportunities in this setting.

Gallic acid attenuates pulmonary fibrosis in a mouse model of transverse aortic contraction-induced heart failure

Gallic acid, a trihydroxybenzoic acid found in tea and other plants, attenuates cardiac hypertrophy, fibrosis, and hypertension in animal models. However, the role of gallic acid in heart failure remains unknown. In this study, we show that gallic acid administration prevents heart failure-induced pulmonary fibrosis. Heart failure induced in mice, 8weeks after transverse aortic constriction (TAC) surgery, was confirmed by echocardiography. Treatment for 2weeks with gallic acid but not furosemide prevented cardiac dysfunction in mice. Gallic acid significantly inhibited TAC-induced pathological changes in the lungs, such as increased lung mass, pulmonary fibrosis, and damaged alveolar morphology. It also decreased the expression of fibrosis-related genes, including collagen types I and III, fibronectin, connective tissue growth factor (CTGF), and phosphorylated Smad3. Further, it inhibited the expression of epithelial-mesenchymal transition (EMT)-related genes, such as N-cadherin, vimentin, E-cadherin, SNAI1, and TWIST1. We suggest that gallic acid has therapeutic potential for the treatment of heart failure-induced pulmonary fibrosis.