Primary pulmonary hypertension. The American experience

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.

Pulmonary hypertension in children and adolescents with sickle cell disease

The prevalence of pulmonary hypertension (PHTN) in the pediatric sickle cell disease (SCD) population is not known despite its high prevalence in adult patients. Our hypothesis was that increased pulmonary artery pressures (PAPs) would be found in SCD children and adolescents, especially those with a history of pulmonary complications: acute chest syndrome, obstructive sleep apnea, asthma, and reactive airway disease. Fifty-two SCD children, 23 of whom had underlying pulmonary disease, were screened for PHTN, which was defined as a tricuspid regurgitant jet velocity (TRV) of at least 2.5 m/s. Twenty-four (46.15%) SCD patients had increased PAP (i.e., TRV > or =2.5 m/s), and 6 (11.5%) had significant PHTN (i.e., TRV > or =3.0 m/s). Pulmonary disease was marginally associated with PHTN (odds ratio 2.80 and confidence interval 0.88 to 8.86; p = 0.0795). As in adult SCD patients with PHTN, this complication was correlated with the degree of hemolysis as manifested by significantly higher lactate dehydrogenase and bilirubin, lower hemoglobin and hematocrit levels, and a strong association with Hb-SS phenotype. However, after statistical adjustment for age and sex, increased serum LDH was not associated with the development of PHTN. Further studies are needed to clarify the prevalence and mechanisms of PHTN in pediatric and adolescent patients with SCD.

Pulmonary hypertension in older adults

Pulmonary hypertension is a frequently encountered problem in older patients. True idiopathic pulmonary arterial hypertension can also be seen and requires careful exclusion in older patients. Institution of therapies must be tempered with an appreciation of individual comorbidities and functional limitations that may affect patients' ability to comply and benefit from the complex treatments available for pulmonary arterial hypertension. This article reviews the existing data on the various forms of pulmonary hypertension presenting in older patients and on appropriate therapy in this challenging population.

Autopsy findings of heart and lungs in a patient with primary pulmonary hypertension associated with use of fenfluramine and phentermine

A 36-year-old woman (height, 157 cm; weight, 117 kg; body mass index, 47.5) received fenfluramine and phentermine (fen-phen) for 7 months, and pulmonary hypertension subsequently developed. Her pulmonary arterial pressure was 56 mm Hg, and echocardiography showed right ventricular dilatation and hypokinesia. Cardiopulmonary arrest developed during right-heart catheterization, and she died 3 days later. At autopsy, right ventricular dilatation with fibroproliferative tricuspid valve was identified. The pulmonary arteries, including the main arteries and elastic arteries to the arterioles, revealed fibroproliferative plaque; the latter was more severe and more prominent in the upper lobes than in the lower lobes. Combined cardiac valvular disease and pulmonary hypertension appear to occur frequently in patients receiving fen-phen, and more autopsy cases of patients with a history of fen-phen usage are warranted to document the frequency of combined cardiac valvular disease and pulmonary hypertension in the United States.

Pulmonary hypertension in chronic liver disease

Pulmonary hypertension develops in approximately 2% of patients with portal hypertension. Diagnosis is often difficult and requires a high degree of clinical suspicion. Treatment of patients with portal and pulmonary hypertension is limited, and mean survival following diagnosis is approximately 15 months. The effect of liver transplantation on the natural history of disease is discussed.