Frequency and prognostic significance of hemoptysis in pediatric pulmonary arterial hypertension

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.

Prevalence, incidence, and survival of pulmonary arterial hypertension: A systematic review for the global burden of disease 2020 study

Pulmonary arterial hypertension (PAH) is characterized by increased resistance in the pulmonary arterioles as a result of remodeled blood vessels. We sought all available epidemiologic data on population‐based prevalence, incidence, and 1‐year survival of PAH as part of the Global Burden of Disease Study. We performed a systematic review searching Global Index Medicus (GIM) for keywords related to PAH between 1980 and 2021 and identified population‐representative sources of prevalence, incidence, and mortality for clinically diagnosed PAH. Of 6772 articles identified we found 65 with population‐level data: 17 for prevalence, 17 for incidence, and 58 reporting case fatality. Reported prevalence ranged from 0.37 cases/100,000 persons in a referral center of French children to 15 cases/100,000 persons in an Australian study. Reported incidence ranged from 0.008 cases/100,000 person‐years in Finland, to 1.4 cases/100,000 person‐years in a retrospective chart review at a clinic in Utah, United States. Reported 1‐year survival ranged from 67% to 99%. All studies with sex‐specific estimates of prevalence or incidence reported higher levels in females than males. Studies varied in their size, study design, diagnostic criteria, and sampling procedures. Reported PAH prevalence, incidence, and mortality varied by location and study. Prevalence ranged from 0.4 to 1.4 per 100,000 persons. Harmonization of methods for PAH registries would improve efforts at disease surveillance. Results of this search contribute to ongoing efforts to quantify the global burden of PAH.

Lung transplantation for pediatric pulmonary arterial hypertension-quo vadis?

In children with pulmonary arterial hypertension, lung transplantation illustrates a feasible treatment option once pharmacological therapy is exhausted. Timing of listing for lung transplantation in children remains difficult since hemodynamic deterioration often occurs abruptly and the time on the waiting list is usually hard to predict. Clear contraindications for lung transplantation are recent history of malignancies as well as irreversible end-organ failure. Generally, patients with pulmonary arterial hypertension in the absence of structural cardiac defects can safely undergo bilateral lung transplantation, combined heart-lung transplantation remains a procedure with a higher perioperative risk and should only be performed in selected cases with irreversible structural defects. Donor selection in recent years shows donors with extended criteria as well as lobar transplantation with good outcome, having the positive effect of broadening of the donor pool. Bridging to lung transplantation with veno-arterial ECMO treatment is feasible and has a good outcome in experienced transplant centers. Surgical considerations should include the risk of hemodynamic decompensation upon anesthesia induction and the need for extracorporeal support pre-, intra- and postoperative. Lung transplantation should be performed on veno-arterial ECMO support with either peripheral (>20 kg) or central cannulation (<20 kg). The surgical transplantation procedure includes the bronchial anastomosis as well as anastomoses of the pulmonary artery and the left atrium. Postoperative prolonged veno-arterial ECMO treatment for the immediate postoperative period allows for left ventricular remodeling given the new hemodynamic circumstances with lower pulmonary vascular resistance. Standard triple immunosuppression in most lung transplant programs currently includes steroids, mycophenolate mofetil and tacrolimus. Survival after pediatric lung transplantation for IPAH is comparable to pediatric lung transplants for other underlying diseases with a 1-year survival of approx. 80% and a 5-year survival of 64-65%. Therefore, evolving techniques in the field of lung transplantation led to overall improved survival prospects in children with end-stage pulmonary vascular disease.

Platelet and coagulation disorders in newly diagnosed patients with pulmonary arterial hypertension

There is a complex and not fully elucidated association between pulmonary arterial hypertension (PAH) and coagulation disorders. The goal of this study was to evaluate platelet function, coagulation and fibrinolysis in PAH patients at diagnosis, before PAH-specific treatment initiation. We enrolled 20 healthy controls and 30 PAH patients (20 with connective tissue disease (CTD-PAH) and 10 idiopathic (iPAH)). None of the participants was on any antiplatelet or anticoagulation therapy. Blood samples from PAH patients were collected during the initial right heart catheterization. All subjects were assessed with platelet function analyzer-100 (PFA-100), epinephrine (Epi) and ADP-induced light transmission aggregometry (LTA), thromboelastometry (ROTEM) and endogenous thrombin potential (ETP). Our results showed that Epi and ADP-LTA values were significantly lower in newly diagnosed PAH patients compared to controls. Disaggregation was present in 73% of patients, a characteristic not seen in healthy individuals. In ROTEM assay, CT and CFT measurements were significantly higher and a angle lower compared to controls. ETP testing revealed significantly reduced outcomes in AUC, Cmax and Tmax. When CTD-PAH and iPAH patient groups were compared, iPAH ADP-LTA values were significantly decreased compared to CTD-PAH. In conclusion, newly diagnosed PAH patients presented with decreased platelet aggregation, clot propagation and thrombin generation, along with delayed initiation of the coagulation process. These hemostatic deficits could indicate an "exhaustion" of the coagulation process that could be caused by endothelial dysfunction and chronic activation of the procoagulant pathways. Further studies are warranted to confirm these laboratory findings and assess their potential clinical significance.

Riociguat for pulmonary arterial hypertension associated with congenital heart disease

Objective

The Pulmonary Arterial hyperTENsion sGC-stimulator Trial-1 (PATENT-1) was a randomised, double-blind, placebo-controlled phase III trial evaluating riociguat in patients with pulmonary arterial hypertension (PAH). PATENT-2 was an open-label long-term extension to PATENT-1. Here, we explore the efficacy and safety of riociguat in the subgroup of patients with persistent/recurrent PAH after correction of congenital heart disease (PAH-CHD) from the PATENT studies.

Methods

In PATENT-1, patients received riociguat (maximum 2.5 or 1.5 mg three times daily) or placebo for 12 weeks; efficacy assessments included change from baseline to study end in 6-min walking distance (6MWD; primary), pulmonary vascular resistance (PVR), N-terminal of the prohormone of brain natriuretic peptide (NT-proBNP), WHO functional class (WHO FC) and time to clinical worsening. In PATENT-2, eligible patients from PATENT-1 received long-term riociguat (maximum 2.5 mg three times daily); the primary assessment was safety and tolerability. All PAH-CHD patients had a corrected cardiac defect.

Results

In PATENT-1, riociguat increased mean±SD 6MWD from baseline to week 12 by 39±60 m in patients with PAH-CHD versus 0±42 m for placebo. Riociguat also improved several secondary variables versus placebo, including PVR (−250±410 vs −66±632 dyn·s/cm⁵), NT-proBNP (−164±317 vs −46±697 pg/mL) and WHO FC (21%/79%/0% vs 8%/83%/8% improved/stabilised/worsened). One patient experienced clinical worsening (riociguat 1.5 mg group). Riociguat was well tolerated. In PATENT-2, riociguat showed sustained efficacy and tolerability in patients with PAH-CHD at 2 years.

Conclusions

Riociguat was well tolerated in patients with PAH-CHD and improved clinical outcomes including 6MWD, PVR, WHO FC and NT-proBNP.

Trial registration number

The clinical trials numbers are NCT00810693 for PATENT-1 and NCT00863681 for PATENT-2.

Isolated pulmonary artery arising from a duct: a single-center review of diagnostic and therapeutic strategies

OBJECTIVE

Isolated pulmonary artery of ductal origin (IPADO) is a rare disease with diverse presentations. Diagnostic and therapeutic approaches vary widely given the low incidence. Reporting additional cases may help inform medical decision making.

METHODS

We reviewed diagnostic data--including echocardiography, catheterization, and MRI--and outcomes for all patients with IPADO at our institution.

RESULTS

Thirty-seven patients who met inclusion criteria were identified. The mean age at diagnosis was 3 months (range, 1 day-45 years). In 11 patients, the duct supplying the IPADO was patent (ie, patent ductus arteriosis [PDA]); the duct had closed (ligamentum) in the other 26 patients. When performed, catheterization delineated the anatomy in 90% (100% if PDA) versus 54% with magnetic resonance imaging. Patients with a PDA were more likely to undergo intervention (100% vs 58%, P=.02) and had earlier first intervention (1 vs 20 months; P<.001). Patients diagnosed at age≤6 months were more likely to undergo intervention (86% vs 50%; P=.03) and unifocalization (81% vs 44%; P=.04), and had greater IPADO flow at follow-up (40% vs 14%; P<.001). Patients who underwent any intervention had greater IPADO flow than those without intervention (38% vs 0%).

CONCLUSIONS

Early IPADO diagnosis is important in long-term outcome. However, successful interventions can be performed on older patients. Diagnosis relies on angiography but magnetic resonance imaging may play an increasingly important role. Although initial intervention depends on individual factors, the ultimate goal should be early unifocalization.