Pulmonary Arterial Hypertension in the Elderly: Peculiar Features and Challenges for a Proper Phenotyping Approach

(1) Introduction. Although pulmonary arterial hypertension (PAH) usually affects young people with a low cardiovascular risk profile, progressive epidemiologic changes have been providing a codified phenotype of elderly subjects with PAH and increased risk predictors for left heart disease. We therefore conducted a systematic review to describe the current knowledge and characteristics of elderly individuals with PAH and further insights concerning their prognostic outcomes and therapeutic response. (2) Methods. A search was conducted in PubMed, Embase, and Cochrane Library for publications evaluating the epidemiology, diagnostic work-up, and treatment of PAH in elderly subjects. (3) Among the 74 publications initially retrieved, 16 full-text articles were selected for the present systematic review. Compared to their younger counterparts, elderly individuals with PAH showed greater clinical deterioration, reduced exercise capacity, and worse prognostic outcomes, as well as less response to PAH-targeted therapy and higher rates of PAH drug discontinuation. (4) Conclusions. Demographic changes over time contributed to define a peculiar PAH phenotype in elderly patients, with an increased burden of cardiovascular comorbidities and distinctive features compared to young patients. Further investigations are needed in order to better clarify the nosologic criteria, and management in this subset population.

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.

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.

Left Heart Disease Phenotype in Elderly Patients with Pulmonary Arterial Hypertension: Insights from the Italian PATRIARCA Registry

Pulmonary arterial hypertension (PAH) in the elderly is often associated with left heart disease (LHD), prompting concerns about the use of pulmonary vasodilators. The PATRIARCA registry enrolled ≥70 year-old PAH or chronic thromboembolic pulmonary hypertension (CTEPH) patients at 11 Italian centers from 1 December 2019 through 15 September 2022. After excluding those with CTEPH, post-capillary PH at the diagnostic right heart catheterization (RHC), and/or incomplete data, 23 (33%) of a total of 69 subjects met the criteria proposed in the AMBITION trial to suspect LHD. Diabetes [9 (39%) vs. 6 (13%), p = 0.01] and chronic kidney disease [14 (61%) vs. 12 (26%), p = 0.003] were more common, and the last RHC pulmonary artery wedge pressure [14 ± 5 vs. 10 ± 3 mmHg, p < 0.001] was higher and pulmonary vascular resistance [5.56 ± 3.31 vs. 8.30 ± 4.80, p = 0.02] was lower in LHD than non-LHD patients. However, PAH therapy was similar, with 13 (57%) and 23 (50%) subjects, respectively, taking two oral drugs. PAH medication patterns remained comparable between LHD and non-LHD patients also when the former [37, 54%] were identified by atrial fibrillation and echocardiographic features of LHD, in addition to the AMBITION criteria. In this real-world snapshot, elderly PAH patients were treated with pulmonary vasodilators, including combinations, despite a remarkable prevalence of a LHD phenotype.

An updated meta-analysis of hemodynamics markers of prognosis in patients with pulmonary hypertension due to left heart disease

Pulmonary hypertension (PH) is associated with a poor prognosis in left heart disease (LHD). We sought to provide an updated analysis on the association of hemodynamic variables, such as pulmonary vascular resistance (PVR), pulmonary artery compliance (PAC), and diastolic pressure gradient (DPG), with prognosis in PH-LHD, through a systematic literature review. Sixteen articles were identified, including 9600 patients with LHD, heterogeneous in terms of age, sex, and etiology of cardiac disease. In this large population, PVR (hazard ratio [HR], 1.07; 95% confidence interval [CI]: 1.05-1.0), DPG (HR, 1.02; 95% CI: 1.01-1.02) and PAC (HR, 0.76; 95% CI: 0.69-0.84) were associated with an increased risk of adverse outcome, albeit with a less solid performance of DPG. Similar results were found when hemodynamic variables were analyzed according to the thresholds commonly applied in clinical practice, or subdividing cohorts according to the underlying LHD. Furthermore, cumulative metanalysis indicated that these results are consistently stable since 2018. Thus, PVR, DPG and PAC have an established prognostic value in PH-LHD. These results are consistent through the years and unlikely to change with further studies.

CMR Measures of Left Atrial Volume Index and Right Ventricular Function Have Prognostic Value in Chronic Thromboembolic Pulmonary Hypertension

Providing prognostic information is important when counseling patients and planning treatment strategies in chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this study was to assess the prognostic value of gold standard imaging of cardiac structure and function using cardiac magnetic resonance imaging (CMR) in CTEPH. Consecutive treatment-naive patients with CTEPH who underwent right heart catheterization and CMR between 2011 and 2017 were identified from the ASPIRE (Assessing-the-Specturm-of-Pulmonary-hypertensIon-at-a-REferral-center) registry. CMR metrics were corrected for age and sex where appropriate. Univariate and multivariate regression models were generated to assess the prognostic ability of CMR metrics in CTEPH. Three hundred and seventy-five patients (mean+/-standard deviation: age 64+/-14 years, 49% female) were identified and 181 (48%) had pulmonary endarterectomy (PEA). For all patients with CTEPH, left-ventricular-stroke-volume-index-%predicted (LVSVI%predicted) (p = 0.040), left-atrial-volume-index (LAVI) (p = 0.030), the presence of comorbidities, incremental shuttle walking test distance (ISWD), mixed venous oxygen saturation and undergoing PEA were independent predictors of mortality at multivariate analysis. In patients undergoing PEA, LAVI (p < 0.010), ISWD and comorbidities and in patients not undergoing surgery, right-ventricular-ejection-fraction-%predicted (RVEF%pred) (p = 0.040), age and ISWD were independent predictors of mortality. CMR metrics reflecting cardiac function and left heart disease have prognostic value in CTEPH. In those undergoing PEA, LAVI predicts outcome whereas in patients not undergoing PEA RVEF%pred predicts outcome. This study highlights the prognostic value of imaging cardiac structure and function in CTEPH and the importance of considering left heart disease in patients considered for PEA.

Pulmonary Hypertension in the Context of Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is the most common form of heart failure and frequently is associated with pulmonary hypertension (PH). HFpEF associated with PH may be difficult to distinguish from precapillary forms of PH, although this distinction is crucial because therapeutic pathways are divergent for the two conditions. A comprehensive and systematic approach using history, clinical examination, and noninvasive and invasive evaluation with and without provocative testing may be necessary for accurate diagnosis and phenotyping. After diagnosis, HFpEF associated with PH can be subdivided into isolated postcapillary pulmonary hypertension (IpcPH) and combined postcapillary and precapillary pulmonary hypertension (CpcPH) based on the presence or absence of elevated pulmonary vascular resistance. CpcPH portends a worse prognosis than IpcPH. Despite its association with reduced functional capacity and quality of life, heart failure hospitalizations, and higher mortality, therapeutic options focused on PH for HFpEF associated with PH remain limited. In this review, we aim to provide an updated overview on clinical definitions and hemodynamically characterized phenotypes of PH, pathophysiologic features, therapeutic strategies, and ongoing challenges in this patient population.

Under Pressure: Right Heart Catheterization and Provocative Testing for Diagnosing Pulmonary Hypertension

Pulmonary hypertension (PH) is a heterogenous disorder involving multiple pathophysiological processes that ultimately affect the vasculature within the lungs. Right heart catheterization (RHC) continues to be the benchmark for diagnosing PH. The use of provocation techniques during RHC can help sub-characterize the type of PH and thus assist in developing appropriate treatment strategies for the management of each PH subtype. This review examines proven and novel approaches for evaluating the pulmonary vasculature during RHC and aspires to provide an accurate, clinically relevant framework for using RHC to diagnose and manage PH. Further improvement in standardized protocols will help optimize the application of RHC in patients with PH.

Management of Pulmonary Hypertension in Left Heart Disease

Pulmonary hypertension due to left heart diseases (PH-LHD) is the most prevalent form of pulmonary hypertension. It frequently complicates heart failure with reduced ejection fraction (HFrEF) or preserved ejection fraction (HFpEF) and negatively impacts prognosis, particularly when a precapillary component is present.

PH-LHD is distinctive from pulmonary arterial hypertension (PAH) even though both conditions may share some common characteristics. In addition, the mechanisms involved in the development of a precapillary component are yet to be fully clarified, in particular in PH due to HFpEF.

Several studies have been exploring PAH pathways as potential therapies for PH-LHD, but no PAH-approved drug has demonstrated efficacy in PH-LHD. Rather, some classes of drugs, such as endothelin-receptor antagonists or prostacycline-analogues, have been found to be harmful in patients with HF. Therefore, at present, the only established treatments for PH-LHD are those that target the heart as recommended in the international guidelines for HF. Based on current knowledge, off-label prescription of PAH-approved drugs in PH-LHD patients must be strongly discouraged.

Nonresponse to Acute Vasodilator Challenge and Prognosis in Heart Failure With Pulmonary Hypertension

BACKGROUND

An acute vasodilator challenge is recommended in patients with heart failure and pulmonary hypertension during heart transplant evaluation. The aim of the study was to assess which hemodynamic parameters are associated with nonresponsiveness to the challenge.

METHODS AND RESULTS

This study is a retrospective analysis of 402 patients with heart failure with pulmonary hypertension who underwent right heart catheterization and a pulmonary vasodilator challenge. Among the 140 who fulfilled the transplant guidelines eligibility criteria for the vasodilator challenge, 38 were responders and 102 nonresponders. At multivariable analysis, a diastolic blood pressure of <70 mm Hg, pulmonary vascular resistance of >5 Woods units, and pulmonary artery compliance of <1.2 mL/mm Hg were independently associated with poor response to vasodilator challenge (all P < .001). The presence of any 2 of these 3 conditions was associated with a 90% probability of being a nonresponder. The covariate-adjusted hemodynamic predictors of death in the entire population were a low baseline systolic blood pressure (P = .0017) and a low baseline right ventricular stroke work index (P = .0395).

CONCLUSIONS

In patients with heart failure and pulmonary hypertension, low pulmonary arterial compliance, high pulmonary vascular resistance, and low diastolic blood pressure predict the nonresponsiveness to acute vasodilator challenge whilst a poor right ventricular function predicts a dismal prognosis.

The Biological Bases of Group 2 Pulmonary Hypertension

Pulmonary hypertension (PH) is a potentially fatal condition with a prevalence of around 1% in the world population and most commonly caused by left heart disease (PH-LHD). Usually, in PH-LHD, the increase of pulmonary pressure is only conditioned by the retrograde transmission of the left atrial pressure. However, in some cases, the long-term retrograde pressure overload may trigger complex and irreversible biomechanical and biological changes in the pulmonary vasculature. This latter clinical entity, designated as combined pre- and post-capillary PH, is associated with very poor outcomes. The underlying mechanisms of this progression are poorly understood, and most of the current knowledge comes from the field of Group 1-PAH. Treatment is also an unsolved issue in patients with PH-LHD. Targeting the molecular pathways that regulate pulmonary hemodynamics and vascular remodeling has provided excellent results in other forms of PH but has a neutral or detrimental result in patients with PH-LHD. Therefore, a deep and comprehensive biological characterization of PH-LHD is essential to improve the diagnostic and prognostic evaluation of patients and, eventually, identify new therapeutic targets. Ongoing research is aimed at identify candidate genes, variants, non-coding RNAs, and other biomarkers with potential diagnostic and therapeutic implications. In this review, we discuss the state-of-the-art cellular, molecular, genetic, and epigenetic mechanisms potentially involved in PH-LHD. Signaling and effective pathways are particularly emphasized, as well as the current knowledge on -omic biomarkers. Our final aim is to provide readers with the biological foundations on which to ground both clinical and pre-clinical research in the field of PH-LHD.

Clinical and hemodynamic factors in predicting response to fluid challenge during right heart catheterization

Fluid challenge during right heart catheterization has been used for unmasking pulmonary hypertension (PH) related to left-sided heart disease. We evaluated the clinical and hemodynamic factors affecting the response to fluid challenge and investigated the role of fluid challenge in the classification and management of PH patients. We reviewed the charts of 67 patients who underwent fluid challenge with a baseline pulmonary arterial wedge pressure (PAWP) of ≤ 18 mmHg. A positive fluid challenge (PFC) was defined as an increase in PAWP to > 18 mmHg after 500 mL saline infusion. Clinical characteristics and echocardiographic and hemodynamic parameters were compared between PFC and negative fluid challenge (NFC). PFC was associated with female sex, increased BMI, and hypertension. A greater rise in PAWP was observed in PFC (6.8 ± 2.3 vs. 3.8 ± 2.7 mmHg, P = 0.001). A larger increase in PAWP correlated with a lower transpulmonary gradient (r = –0.42, P < 0.001), diastolic pulmonary gradient (r = –0.42, P < 0.001), and pulmonary vascular resistance (r = –0.38, P < 0.001). We found 100% of the patients with PFC were classified as WHO group 2 PH compared to 49% of the NFC patients (P < 0.001). Fewer patients with PFC were started on advanced PH therapies and more were discharged from PH clinic. A PFC and the magnitude of PAWP increase after saline loading are associated with parameters related to left heart disease. In our population, fluid challenge appeared to influence the classification of PH and whether patients are started on therapy or discharged from clinic.

A diagnostic algorithm for pulmonary hypertension due to left heart disease in resource-limited settings: can busy clinicians adopt a simple, practical approach?

Pulmonary hypertension (PH) has progressively moved from an orphan disease to a significant global health problem with a major disease burden in limited7hyphen;resource countries, where over 97% of patients live. The aetiologies of PH differ between high- and low-income nations, but PH due to left heart disease is credited to be the most frequent contemporary form. Although a straightforward diagnosis of PH requires the use of right heart catheterisation (RHC), access to equipment for RHC is a deterrent. Furthermore, the risk associated with RHC limits its uptake to a selection of specialised centres. Moreover, the rigour and clinical reasoning for diagnosis in clinical medicine is rapidly changing and revealing that PH can complicate a diverse range of medical conditions needing other explorations. In this article, we provide for the busy clinician, a simplified diagnostic algorithm for PH that is relevant for making a correct early diagnosis and limiting the impact of PH.

Pathophysiology and Diagnosis of Pulmonary Hypertension Due to Left Heart Disease

Pulmonary hypertension due to left heart disease (PH-LHD) is the most common type of pulmonary hypertension, although an accurate prevalence is challenging. PH-LHD includes PH due to systolic or diastolic left ventricular dysfunction, mitral or aortic valve disease and congenital left heart disease. In recent years a new and distinct phenotype of “combined post-capillary and pre-capillary PH,” based on diastolic pulmonary gradient and pulmonary vascular resistance, has been recognized. The roles of right ventricular dysfunction and pulmonary vascular compliance in PH-LHD have also been elucidated recently and they appear to have significant clinical implications. Echocardiography continues to play a seminal role in diagnosis of PH-LHD and heart failure with preserved LV ejection fraction, as it can identify valve disease and help to distinguish PH-LHD from pre-capillary PH. Right, and occasionally left heart catheterization, remains the gold-standard for diagnosis and phenotyping of PH-LHD, although Cardiac Magnetic Resonance Imaging is emerging as a useful alternative tool in non-invasive diagnostic and prognostic assessment of PH-LHD. In this review, the latest evidence for more recent advances will be discussed, including the role of fluid challenge and exercise during cardiac catheterization to unravel occult post-capillary and the role of vasoreactivity testing. The use of many or all of these diagnostic techniques will undoubtedly provide key information about sub-groups of patients with PH-LHD that might benefit from medical therapy previously considered to be only suitable for pulmonary arterial hypertension.

Pathophysiological Mapping of Experimental Heart Failure: Left and Right Ventricular Remodeling in Transverse Aortic Constriction Is Temporally, Kinetically and Structurally Distinct

A growing proportion of heart failure (HF) patients present with impairments in both ventricles. Experimental pressure-overload (i.e., transverse aortic constriction, TAC) induces left ventricle (LV) hypertrophy and failure, as well as right ventricle (RV) dysfunction. However, little is known about the coordinated progression of biventricular dysfunction that occurs in TAC. Here we investigated the time course of systolic and diastolic function in both the LV and RV concurrently to improve our understanding of the chronology of events in TAC. Hemodynamic, histological, and morphometric assessments were obtained from the LV and RV at 2, 4, 9, and 18 weeks post-surgery. Results: Systolic pressures peaked in both ventricles at 4 weeks, thereafter steadily declining in the LV, while remaining elevated in the RV. The LV and RV followed different structural and functional timelines, suggesting the patterns in one ventricle are independent from the opposing ventricle. RV hypertrophy/fibrosis and pulmonary arterial remodeling confirmed a progressive right-sided pathology. We further identified both compensation and decompensation in the LV with persistent concentric hypertrophy in both phases. Finally, diastolic impairments in both ventricles manifested as an intricate progression of multiple parameters that were not in agreement until overt systolic failure was evident. Conclusion: We establish pulmonary hypertension was secondary to LV dysfunction, confirming TAC is a model of type II pulmonary hypertension. This study also challenges some common assumptions in experimental HF (e.g., the relationship between fibrosis and filling pressure) while addressing a knowledge gap with respect to temporality of RV remodeling in pressure-overload.

Treatment of pulmonary hypertension with left heart disease: a concise review

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure ≥ 25 mmHg, as determined by right heart catheterization. Pulmonary arterial hypertension (PAH) can no longer be considered an orphan disease given the increase in awareness and availability of new drugs. PH carries with it a dismal prognosis and leads to significant morbidity and mortality. Symptoms can range from dyspnea, fatigue and chest pain to right ventricular failure and death. PH is divided into five groups by the World Health Organization (WHO), based on etiology. The most common cause of PH in developed countries is left heart disease (group 2), owing to the epidemic of heart failure (HF). The data regarding prevalence, diagnosis and treatment of patients with group 2 PH is unclear as large, prospective, randomized controlled trials and standardized protocols do not exist. Current guidelines do not support the use of PAH-specific therapy in patients with group 2 PH. Prostacyclins, endothelin receptor antagonists, phosphodiesterase-5 inhibitors and guanylate cyclase stimulators have been tried in treatment of patients with HF and/or group 2 PH with mixed results. This review summarizes and critically appraises the evidence for diagnosis and treatment of patients with group 2 PH/HF and suggests directions for future research.

Pulmonary Hypertension secondary to Left Heart Disease

Pulmonary Hypertension (PH) related to Left Heart Disease (LHD) is the most common form of PH, accounting for more than two third of all PH cases. The hemodynamic abnormalities seen in PHLHD are complex, and there are currently minimal evidence-based recommendations for the management of PH-LHD. While it is accepted that PH in the context of left heart disease is a marker of worse prognosis, it remains unclear whether its primary treatment is beneficial or harmful. In this article, we discuss the prevalence and significance of PH in patients with Heart Failure (HF) with Reduced Ejection Fraction (HFrEF) as well as HF with Preserved Ejection Fraction (HFpEF), and those with valvular heart disease and provide insights into the complex pathophysiology of cardiopulmonary interrelationship in individuals with PH due to left heart disease. Furthermore, we provide a framework for diagnostic testing and an approach to optimal management of these complex patients based on current European Society of Cardiology (ESC) guidelines.

Poor survival in patients with scleroderma and pulmonary hypertension due to heart failure with preserved ejection fraction

Pulmonary hypertension due to heart failure with preserved ejection fraction (PH-HFpEF) has been poorly studied in patients with systemic sclerosis (SSc). We sought to compare clinical characteristics and survival of SSc patients with PH-HFpEF (SSc-PH-HFpEF) versus pulmonary arterial hypertension (SSc-PAH). We hypothesized that patients with SSc-PH-HFpEF have a similar poor overall prognosis compared with patients with SSc-PAH when matched for total right ventricular load. The analysis included 117 patients with SSc-PH (93 with SSc-PAH versus 24 with SSc-PH-HFpEF) enrolled prospectively in the Johns Hopkins PH Registry. We examined baseline demographics and hemodynamics at diagnostic right heart catheterization (RHC), two-dimensional echocardiographic characteristics, six-minute walking distance (6MWD), treatment modalities, and laboratory values (serum NT-proBNP, creatinine, uric acid, and sodium), and assessed survival. Demographics and clinical features were similar between the two groups. Baseline RHC showed significantly higher pulmonary and right heart pressures in the SSc-PH-HFpEF compared with the SSc-PAH group. Trans-pulmonary gradient (TPG), however, was equally elevated without significant difference between the groups. SSc-PH-HFpEF patients had left atrial enlargement on echocardiography compared with SSc-PAH patients. No significant differences were found between groups for 6MWD, NT-proBNP, and other laboratory values. Although overall median survival time was 4.6 years with no difference in mortality rate between the two groups (SSc-PH-HFpEF versus SSc-PAH: 75% versus 59%; P = 0.26), patients with SSc-PH-HFpEF had a twofold increased risk of death compared with SSc-PAH patients after adjusting for hemodynamics. Concomitant intrinsic pulmonary vascular disease and HFpEF likely contribute to very poor survival in patients with SSc-PH-HFpEF.

"From right to left": The role of right heart catheterization in the diagnosis and management of left heart diseases

Pulmonary hypertension (PH), second only to left heart diseases (LHD), is a frequent problem in clinical practice. At the same time, left heart diseases represent the most common cause of pulmonary hypertension, and the occurrence of PH in patients with chronic heart failure is usually associated with worse functional class, and prognosis. Right heart catheterization (RHC) is the "gold standard" in the diagnosis and differentiation of PH. It is also essential in the process of qualifying for a heart transplantation. Therefore, right heart catheterization should be performed in expert centers by experienced operators and according to a strict protocol to ensure the reliability and reproducibility of results. Recommendations for pulmonary hypertension due to left heart disease are based on the European Society of Cardiology (ESC) guidelines designed in cooperation with the European Respiratory Society (ERS) and the International Society for Heart and Lung Transplantation (ISHL). The new ESC guidelines for pulmonary hypertension published in 2015 have improved the diagnostic and therapeutic process in patients with left heart diseases.

The diastolic pulmonary gradient does not predict survival in patients with pulmonary hypertension due to left heart disease

OBJECTIVES

This study sought to evaluate if diastolic pulmonary gradient (DPG) can predict survival in patients with pulmonary hypertension due to left heart disease (PH-LHD).

BACKGROUND

Patients with combined post- and pre-capillary PH-LHD have worse prognosis than those with passive pulmonary hypertension. The transpulmonary gradient (TPG) and pulmonary vascular resistance (PVR) have commonly been used to identify high-risk patients. However, these parameters have significant shortcomings and do not always correlate with pulmonary vasculature remodeling. Recently, it has been suggested that DPG may be better a marker, yet its prognostic ability in patients with cardiomyopathy has not been fully assessed.

METHODS

A retrospective cohort of 1,236 patients evaluated for unexplained cardiomyopathy at Johns Hopkins Hospital was studied. All patients underwent right heart catheterization and were followed until death, cardiac transplantation, or the end of the study period (mean time 4.4 years). The relationships between DPG, TPG, or PVR and survival in subjects with PH-LHD (n = 469) were evaluated with Cox proportional hazards regression and Kaplan-Meier analyses.

RESULTS

DPG was not significantly associated with mortality (hazard ratio [HR]: 1.02, p = 0.10) in PH-LHD whereas elevated TPG and PVR predicted death (HR: 1.02, p = 0.046; and HR: 1.11, p = 0.002, respectively). Similarly, DPG did not differentiate survivors from non-survivors at any selected cut points including a DPG of 7 mm Hg.

CONCLUSIONS

In this retrospective study of patients with cardiomyopathy and PH-LHD, an elevated DPG was not associated with worse survival.

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Pulmonary hypertension due to left heart disease

Pulmonary hypertension (PH) due to left heart disease is the most common cause of pulmonary hypertension in the western world. It is classified as WHO PH group II. Different pathophysiologic abnormalities may take place in this condition, including pulmonary venous congestion and vascular remodeling. Despite the high prevalence of WHO group 2 PH, the major focus of research on PH over the past decade has been on WHO group 1 pulmonary arterial hypertension (PAH). Few investigators have focused on WHO group 2 PH; consequently, the pathophysiology of this condition remains poorly understood, and no specific therapy is available. Clinical and translational studies in this area are much needed and have the potential to positively affect large numbers of patients. In this review, we provide a detailed discussion upon the pathophysiology of the disease, the recent updates in classification, and the diagnostic and therapeutic algorithms.

Predictors of hospitalisations for heart failure and mortality in patients with pulmonary hypertension associated with left heart disease: a systematic review

OBJECTIVES

Left heart disease (LHD) is the main cause of pulmonary hypertension (PH), but little is known regarding the predictors of adverse outcome of PH associated with LHD (PH-LHD). We conducted a systematic review to investigate the predictors of hospitalisations for heart failure and mortality in patients with PH-LHD.

DESIGN

Systematic review.

DATA SOURCES

PubMed MEDLINE and SCOPUS from inception to August 2013 were searched, and citations identified via the ISI Web of Science.

STUDY SELECTION

Studies that reported on hospitalisation and/or mortality in patients with PH-LHD were included if the age of participants was greater than 18 years and PH was diagnosed using Doppler echocardiography and/or right heart catheterisation. Two reviewers independently selected studies, assessed their quality and extracted relevant data.

RESULTS

In all, 45 studies (38 from Europe and USA) were included among which 71.1% were of high quality. 39 studies were published between 2003 and 2013. The number of participants across studies ranged from 46 to 2385; the proportion of men from 21% to 91%; mean/median age from 63 to 82 years; and prevalence of PH from 7% to 83.3%. PH was consistently associated with increased mortality risk in all forms of LHD, except for aortic valve disease where findings were inconsistent. Six of the nine studies with data available on hospitalisations reported a significant adverse effect of PH on hospitalisation risk. Other predictors of adverse outcome were very broad and heterogeneous including right ventricular dysfunction, functional class, left ventricular function and presence of kidney disease.

CONCLUSIONS

PH is almost invariably associated with increased mortality risk in patients with LHD. However, effects on hospitalisation risk are yet to be fully characterised; while available evidence on the adverse effects of PH have been derived essentially from Caucasians.

Pulmonary hypertension due to left heart diseases

Pulmonary hypertension (PH), a common complication of left heart diseases (LHD), negatively impacts symptoms, exercise capacity, and outcome. Although the true prevalence of PH-LHD is unknown, a subset of patients might present significant PH that cannot be explained by a passive increase in left-sided filling pressures. The term "out-of-proportion" PH has been used to identify that population without a clear definition, which has been found less than ideal and created confusion. We propose a change in terminology and a new definition of PH due to LHD. We suggest to abandon "out-of-proportion" PH and to distinguish "isolated post-capillary PH" from "post-capillary PH with a pre-capillary component" on the basis of the pressure difference between diastolic pulmonary artery pressure and pulmonary artery wedge pressure. Although there is no validated treatment for PH-LHD, we provide insights into management and discuss completed and randomized trials in this condition. Finally, we provide recommendations for future clinical trials to establish safety and efficacy of novel compounds to target this area of unmet medical need.

Pressure reflection in the pulmonary circulation by echocardiography in patients with left heart disease indicates reactive pulmonary hypertension

OBJECTIVES

The two hemodynamic profiles in left heart disease (LHD) with pulmonary hypertension (PH), passive PH with increased pulmonary venous pressure and reactive PH with increased pulmonary vascular resistance (PVR > 3 Wood units, WU), are difficult to distinguish non-invasively. We hypothesized that echocardiographic signs of pressure reflection (PR) in the pulmonary circulation can be used to diagnose reactive PH.

MATERIAL AND METHODS

The study comprised 122 patients divided into three groups: patients without PH (No PH, n = 61), patients with LHD, PH and normal PVR (passive PH, n = 29) and patients with LHD, PH and increased PVR (reactive PH, n = 32). Echocardiography and right heart catheterization were performed within 24 h. Three parameters were selected related to PR [the acceleration of flow in the right ventricular outflow tract (RVOT), the interval and the augmentation of pressure between peak RVOT flow and peak RV pressure]. Cutoff values aiming at ruling in (high positive likelihood ratio, PLR) and ruling out (low negative likelihood ratio, NLR) increased PVR were determined using receiver operator characteristic (ROC) curves.

RESULTS

The proportions of the patients with PH and PVR > 3 WU were 50% and 29%. Twenty-one percent had both increased pulmonary capillary wedge pressure and PVR. The area under the ROC curve for the PR parameters was 0.82-0.89. The PLR with ruling in cutoff values ranged from 4.7 to 9.4. The NLR with ruling out cutoff values ranged from 0.20 to 0.12.

CONCLUSIONS

Echocardiographic assessment of PR in patients with LHD can be used to identify or exclude reactive PH.

Pulmonary hypertension in Saudi Arabia: A single center experience

CONTEXT

Several international studies have described the epidemiology of pulmonary hypertension (PH). However, information about the incidence and prevalence of PH in Saudi Arabia is unknown.

AIMS

To report cases of PH and compare the demographic and clinical characteristics of PH due to various causes in a Saudi population.

METHODS

Newly diagnosed cases of PH [defined as mean pulmonary artery pressure >25 mmHg at right heart cauterization (RHC)] were prospectively collected at a single tertiary care hospital from January 2009 and June 2012. Detailed demographic and clinical data were collected at the time of diagnosis, along with hemodynamic parameters.

RESULTS

Of the total 264 patients who underwent RHC, 112 were identified as having PH. The mean age at diagnosis was 55.8 ± 15.8 years, and there was a female preponderance of 72.3%. About 88 (78.6%) of the PH patients were native Saudis and 24 (21.4%) had other origins. Twelve PH patients (10.7%) were classified in group 1 (pulmonary arterial hypertension), 7 (6.2%) in group 2 (PH due to left heart disease), 73 (65.2%) in group 3 (PH due to lung disease), 4 (3.6%) in group 4 (chronic thromboembolic PH), and 16 (14.3%) in group 5 (PH due to multifactorial mechanisms). PH associated with diastolic dysfunction was noted in 28.6% of group 2 patients, 31.5% of group 3 patients, and 25% of group 5 patients.

CONCLUSIONS

These results offer the first report of incident cases of PH across five groups in Saudi Arabia.

Diagnostic accuracy of cardiovascular magnetic resonance imaging of right ventricular morphology and function in the assessment of suspected pulmonary hypertension results from the ASPIRE registry

BACKGROUND

Cardiovascular Magnetic Resonance (CMR) imaging is accurate and reproducible for the assessment of right ventricular (RV) morphology and function. However, the diagnostic accuracy of CMR derived RV measurements for the detection of pulmonary hypertension (PH) in the assessment of patients with suspected PH in the clinic setting is not well described.

METHODS

We retrospectively studied 233 consecutive treatment naïve patients with suspected PH including 39 patients with no PH who underwent CMR and right heart catheterisation (RHC) within 48 hours. The diagnostic accuracy of multiple CMR measurements for the detection of mPAP ≥ 25 mmHg was assessed using Fisher's exact test and receiver operating characteristic (ROC) analysis.

RESULTS

Ventricular mass index (VMI) was the CMR measurement with the strongest correlation with mPAP (r = 0.78) and the highest diagnostic accuracy for the detection of PH (area under the ROC curve of 0.91) compared to an ROC of 0.88 for echocardiography calculated mPAP. Late gadolinium enhancement, VMI ≥ 0.4, retrograde flow ≥ 0.3 L/min/m² and PA relative area change ≤ 15% predicted the presence of PH with a high degree of diagnostic certainty with a positive predictive value of 98%, 97%, 95% and 94% respectively. No single CMR parameter could confidently exclude the presence of PH.

CONCLUSION

CMR is a useful alternative to echocardiography in the evaluation of suspected PH. This study supports a role for the routine measurement of ventricular mass index, late gadolinium enhancement and the use of phase contrast imaging in addition to right heart functional indices in patients undergoing diagnostic CMR evaluation for suspected pulmonary hypertension.