Phenotypes in Pulmonary Hypertension.

The clinical classification of pulmonary hypertension (PH) has guided diagnosis and treatment of patients with PH for several decades. Discoveries relating to underlying mechanisms, pathobiology, and responses to treatments for PH have informed the evolution in this clinical classification to describe the heterogeneity in PH phenotypes. In more recent years, advances in imaging, computational science, and multi-omic approaches have yielded new insights into potential phenotypes and sub-phenotypes within the existing clinical classification. Identification of novel phenotypes in pulmonary arterial hypertension (PAH) with unique molecular profiles, for example, could lead to new precision therapies. Recent phenotyping studies have also identified groups of patients with PAH that more closely resemble patients with left heart disease (group 2 PH) and lung disease (group 3 PH), which has important prognostic and therapeutic implications. Within group 2 and group 3 PH, novel phenotypes have emerged that reflect a persistent and severe pulmonary vasculopathy that is associated with worse prognosis but still distinct from PAH. In group 4 PH (chronic thromboembolic pulmonary disease) and sarcoidosis (group 5 PH) the current approach to patient phenotyping integrates clinical, hemodynamic and imaging characteristics to guide treatment but applications of multi-omic approaches to sub-phenotyping in these areas are sparse. The next iteration of the PH clinical classification is likely to reflect several emerging PH phenotypes and improve the next generation of prognostication tools, clinical trial design, and improve treatment selection in clinical practice.

Medical Emergencies in Pulmonary Hypertension.

The management of acute medical emergencies in patients with pulmonary hypertension (PH) can be challenging. Patients with preexisting PH can rapidly deteriorate due to right ventricular decompensation when faced with acute physiological challenges that would usually be considered low-risk scenarios. This review considers the assessment and management of acute medical emergencies in patients with PH, encompassing both pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), acknowledging these comprise the more severe groups of PH. Management protocols are described in a systems-based approach. Respiratory emergencies include pulmonary embolism, airways disease, and pneumonia; cardiac emergencies including arrhythmia and chest pain with acute myocardial infarction are discussed, alongside PH-specific emergencies such as pulmonary artery dissection and extrinsic coronary artery compression by a dilated proximal pulmonary artery. Other emergencies including sepsis, severe gastroenteritis with dehydration, syncope, and liver failure are also considered. We propose management recommendations for medical emergencies based on available evidence, international guidelines, and expert consensus. We aim to provide advice to the specialist alongside the generalist, and emergency doctors, nurses, and acute physicians in nonspecialist centers. A multidisciplinary team approach is essential in the management of patients with PH, and communication with local and specialist PH centers is paramount. Close hemodynamic monitoring during medical emergencies in patients with preexisting PH is vital, with early referral to critical care recommended given the frequent deterioration and high mortality in this setting.

Phosphodiesterase 5 inhibitor treatment and survival in interstitial lung disease pulmonary hypertension: A Bayesian retrospective observational cohort study.

BACKGROUND AND OBJECTIVE: Pulmonary hypertension is a life-limiting complication of interstitial lung disease (ILD-PH). We investigated whether treatment with phosphodiesterase 5 inhibitors (PDE5i) in patients with ILD-PH was associated with improved survival. METHODS: Consecutive incident patients with ILD-PH and right heart catheterisation, echocardiography and spirometry data were followed from diagnosis to death, transplantation or censoring with all follow-up and survival data modelled by Bayesian methods. RESULTS: The diagnoses in 128 patients were idiopathic pulmonary fibrosis (n = 74, 58%), hypersensitivity pneumonitis (n = 17, 13%), non-specific interstitial pneumonia (n = 12, 9%), undifferentiated ILD (n = 8, 6%) and other lung diseases (n = 17, 13%). Final outcomes were death (n = 106, 83%), transplantation (n = 9, 7%) and censoring (n = 13, 10%). Patients treated with PDE5i (n = 50, 39%) had higher mean pulmonary artery pressure (median 38 mm Hg [interquartile range, IQR: 34, 43] vs. 35 mm Hg [IQR: 31, 38], p = 0.07) and percentage predicted forced vital capacity (FVC; median 57% [IQR: 51, 73] vs. 52% [IQR: 45, 66], p=0.08) though differences did not reach significance. Patients treated with PDE5i survived longer than untreated patients (median 2.18 years [95% CI: 1.43, 3.04] vs. 0.94 years [0.69, 1.51], p = 0.003) independent of all other prognostic markers by Bayesian joint-modelling (HR 0.39, 95% CI: 0.23, 0.59, p < 0.001) and propensity-matched analyses (HR 0.38, 95% CI: 0.22, 0.58, p < 0.001). Survival difference with treatment was significantly larger if right ventricular function was normal, rather than abnormal, at presentation (+2.55 years, 95% CI: -0.03, +3.97 vs. +0.98 years, 95% CI: +0.47, +2.00, p = 0.04). CONCLUSION: PDE5i treatment in ILD-PH should be investigated by a prospective randomized trial.

Percutaneous oxygenated right ventricular assist device for pulmonary embolism: A case series.

Acute right ventricular (RV) failure following massive pulmonary embolism (PE) can have significant hemodynamic consequences and is the mode of death. Temporary mechanical circulatory support can provide tissue perfusion required while thrombectomy or lysis-aimed therapies act to relieve the thrombotic obstruction. Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) has conventionally been the first line MCS. A more selective approach to RV support has been advocated in the form of an extracorporeal right ventricular assist device (RVAD) as it mitigates some of the shortcomings of V-A ECMO. We present the first case series of four patients who received fully percutaneous RVAD, with an integrated oxygenator forming an Oxy-RVAD, for selective right heart support following massive PE, including the application of single-access dual-lumen right atrium to pulmonary artery cannula. All patients achieved RV recovery and were successfully weaned from oxy-RVAD support within 5-10 days demonstrating the feasibility of selective percutaneous right heart support in managing these challenging patients.

The Effect of Borderline Pulmonary Hypertension on Survival in Chronic Lung Disease.

BACKGROUND: The impact of the new "borderline" hemodynamic class for pulmonary hypertension (PH) (mean pulmonary artery pressure [mPAP], 21-24 mm Hg and pulmonary vascular resistance, [PVR], ≥3 wood units, [WU]) in chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) is unclear. OBJECTIVES: The aim of this study was to assess the effect of borderline PH (BLPH) on survival in COPD and ILD patients. METHOD: Survival was analyzed from retrospective data from 317 patients in 12 centers (Italy, Spain, UK) comparing four hemodynamic groups: the absence of PH (NoPH; mPAP <21 mm Hg or 21-24 mm Hg and PVR <3 WU), BLPH (mPAP 21-24 mm Hg and PVR ≥3 WU), mild-moderate PH (MPH; mPAP 25-35 mm Hg and cardiac index [CI] ≥2 L/min/m2), and severe PH (SPH; mPAP ≥35 mm Hg or mPAP ≥25 mm Hg and CI <2 L/min/m2). RESULTS: BLPH affected 14% of patients; hemodynamic severity did not predict survival when COPD and ILD patients were analyzed together. However, survival in the ILD cohort for any PH level was worse than in NoPH (3-year survival: NoPH 58%, BLPH 32%, MPH 28%, SPH 33%, p = 0.002). In the COPD cohort, only SPH had reduced survival compared to the other groups (3-year survival: NoPH 82%, BLPH 86%, MPH 87%, SPH 57%, p = 0.005). The mortality risk correlated significantly with mPAP in ILD (hazard ratio [HR]: 2.776, 95% CI: 2.057-3.748, p < 0.001) and notably less in COPD patients (HR: 1.015, 95% CI: 1.003-1.027, p = 0.0146). CONCLUSIONS: In ILD, any level of PH portends worse survival, while in COPD, only SPH presents a worse outcome.

Sarcoidosis associated pulmonary hypertension: an update.

PURPOSE OF REVIEW: Sarcoidosis associated pulmonary hypertension (SAPH) is a well-recognised complication, associated with a seven-fold increase in mortality. This comprehensive review will summarise these recent developments and proposes the use of a phenotype-based management approach in SAPH. RECENT FINDINGS: Recent registry-based studies have highlighted the adverse outcomes associated with SAPH and shown that reduced 6-min walk distance and diffusion capacity for carbon monoxide are predictive of poor prognosis. There is increasing interest in methods for early detection of SAPH, although whether early diagnosis impacts on survival remains uncertain. The pathophysiology underpinning SAPH is complex and often incorporates multiple mechanisms. Once the diagnosis is confirmed, understanding the underlying phenotypes of SAPH is key to providing the most effective management plan. There is some evidence that treating patients with precapillary PH with pulmonary vasodilators may improve some haemodynamic and quality life measures. However, more work is needed to determine whether mortality is affected. SUMMARY: SAPH is associated with worsened survival. A range of phenotypes are recognised in SAPH. Multimodality risk assessment in patients with SAPH is likely to be important and is an area that requires further work. Published evidence for pulmonary vasodilator therapies in SAPH with a Pulmonary arterial hypertension-like phenotype is encouraging so far, but multiple confounding factors affects the quality of the evidence. The role of immunosuppressive agents for improving pulmonary pressures is unclear. Urgent controlled trials are needed.

Perioperative management of patients with pulmonary hypertension undergoing non-cardiothoracic, non-obstetric surgery: a systematic review and expert consensus statement.

BACKGROUND: The risk of complications, including death, is substantially increased in patients with pulmonary hypertension (PH) undergoing anaesthesia for surgical procedures, especially in those with pulmonary arterial hypertension (PAH) and chronic thromboembolic PH (CTEPH). Sedation also poses a risk to patients with PH. Physiological changes including tachycardia, hypotension, fluid shifts, and an increase in pulmonary vascular resistance (PH crisis) can precipitate acute right ventricular decompensation and death. METHODS: A systematic literature review was performed of studies in patients with PH undergoing non-cardiac and non-obstetric surgery. The management of patients with PH requiring sedation for endoscopy was also reviewed. Using a framework of relevant clinical questions, we review the available evidence guiding operative risk, risk assessment, preoperative optimisation, and perioperative management, and identifying areas for future research. RESULTS: Reported 30 day mortality after non-cardiac and non-obstetric surgery ranges between 2% and 18% in patients with PH undergoing elective procedures, and increases to 15-50% for emergency surgery, with complications and death usually relating to acute right ventricular failure. Risk factors for mortality include procedure-specific and patient-related factors, especially markers of PH severity (e.g. pulmonary haemodynamics, poor exercise performance, and right ventricular dysfunction). Most studies highlight the importance of individualised preoperative risk assessment and optimisation and advanced perioperative planning. CONCLUSIONS: With an increasing number of patients requiring surgery in specialist and non-specialist PH centres, a systematic, evidence-based, multidisciplinary approach is required to minimise complications. Adequate risk stratification and a tailored-individualised perioperative plan is paramount.

Traffic exposures, air pollution and outcomes in pulmonary arterial hypertension: a UK cohort study analysis.

While traffic and air pollution exposure is associated with increased mortality in numerous diseases, its association with disease severity and outcomes in pulmonary arterial hypertension (PAH) remains unknown.Exposure to particulate matter with a 50% cut-off aerodynamic diameter ≤2.5 µm (PM2.5), nitrogen dioxide (NO2) and indirect measures of traffic-related air pollution (distance to main road and length of roads within buffer zones surrounding residential addresses) were estimated for 301 patients with idiopathic/heritable PAH recruited in the UK National Cohort Study of Idiopathic and Heritable PAH. Associations with transplant-free survival and pulmonary haemodynamic severity at baseline were assessed, adjusting for confounding variables defined a prioriHigher estimated exposure to PM2.5 was associated with higher risk of death or lung transplant (unadjusted hazard ratio (HR) 2.68 (95% CI 1.11-6.47) per 3 µg·m-3; p=0.028). This association remained similar when adjusted for potential confounding variables (HR 4.38 (95% CI 1.44-13.36) per 3 µg·m-3; p=0.009). No associations were found between NO2 exposure or other traffic pollution indicators and transplant-free survival. Conversely, indirect measures of exposure to traffic-related air pollution within the 500-1000 m buffer zones correlated with the European Society of Cardiology/European Respiratory Society risk categories as well as pulmonary haemodynamics at baseline. This association was strongest for pulmonary vascular resistance.In idiopathic/heritable PAH, indirect measures of exposure to traffic-related air pollution were associated with disease severity at baseline, whereas higher PM2.5 exposure may independently predict shorter transplant-free survival.

The CRASH report: emergency management dilemmas facing acute physicians in patients with pulmonary arterial hypertension.

Treatment of acute emergencies in patients with pulmonary arterial hypertension (PAH) can be challenging. In the UK and Ireland, management of adult patients with PAH is centred in eight nationally designated pulmonary hypertension (PH) centres. However, many patients live far from these centres and physicians in local hospitals are often required to manage PAH emergencies. A committee of physicians from nationally designated PH centres identified the 'most common' emergency clinical scenarios encountered in patients with PAH. Thereafter, a review of the literature was performed centred on these specified topics and a management approach was developed based on best available evidence and expert consensus. Management protocols were developed on the following PAH emergencies: chest pain (including myocardial ischaemia), right ventricular failure, arrhythmias, sepsis, haemoptysis ('CRASH'), as well as considerations relevant to surgery, anaesthesia and pregnancy. Emergencies are not uncommon in PAH. While expertise in PAH management is essential, all physicians involved in acute care should be aware of the principles of acute management of PAH emergencies. A multidisciplinary approach is necessary, with physicians from tertiary PH centres supporting care locally and planning safe transfer of patients to PH centres when appropriate.

Pulmonary tumour thrombotic microangiopathy.

PURPOSE OF REVIEW: Pulmonary tumour thrombotic microangiopathy (PTTM) describes tumour cell microemboli with occlusive fibrointimal remodelling in small pulmonary arteries, veins and lymphatics. Progressive vessel occlusion ultimately results in pulmonary hypertension, which is often severe and rapid in onset. PTTM is associated with carcinomas, notably gastric carcinoma, with vascular endothelial growth factor and platelet-derived growth factor (PDGF) signalling implicated in driving the intimal remodelling. PTTM is a rare cause of pulmonary hypertension, but given that up to a quarter of autopsy specimens from patients dying of carcinoma show evidence for PTTM, it is probably underdiagnosed. RECENT FINDINGS: Until recently, prognosis in PTTM was universally abysmal from weeks to a few months. Diagnostic utilities include aspiration of tumour cells at wedged right heart catheterization, high-resolution computed tomography (HRCT) findings and computed tomography-positron emission tomography (CT-PET), although definitive diagnosis requires histological analysis. Reports of PTTM treated with a combination of targeted pulmonary vasodilator therapies, anticoagulation, specific chemotherapy and PDGF inhibition, for example using imatinib, suggest that these approaches can prolong survival. SUMMARY: PTTM is increasingly recognized as an important cause of pulmonary hypertension, often in patients presenting with new-onset pulmonary hypertension and as yet undiagnosed malignancy. Prospects of survival are improving with targeted combination therapy, and early recognition and diagnosis are likely to be the key factors to improve outcome.