Features and Outcomes of Methamphetamine-associated Pulmonary Arterial Hypertension

Effects of congeners of amphetamine on the human heart

Central stimulatory and hallucinogenic drugs of abuse like amphetamine and most congeners of amphetamine can have cardiac harmful effects. These cardiac side effects can lead to morbidities and death. In this paper, we review current knowledge on the direct and indirect effects of these amphetamine congeners on the mammalian heart-more specifically, the isolated human heart muscle preparation. In detail, we address the question of whether and how these drugs affect cardiac contractility and their mechanisms of action. Based on this information, further research areas are defined, and further research efforts are proposed.

Overview of Methamphetamine-Associated Pulmonary Arterial Hypertension

TOPIC IMPORTANCE

The global surge in methamphetamine use is a critical public health concern, particularly due to its robust correlation with methamphetamine-associated pulmonary arterial hypertension (MA-PAH). This association raises urgent alarms about the potential escalation of MA-PAH incidence, posing a significant and imminent challenge to global public health.

REVIEW FINDINGS

This comprehensive review meticulously explores MA-PAH, offering insights into its epidemiology, pathophysiology, clinical presentation, diagnostic intricacies, and management strategies. The pathogenesis, yet to be fully described, involves complex molecular interactions, including alterations in serotonin signaling, reduced activity of carboxylesterase 1, oxidative stress, and dysregulation of pulmonary vasoconstrictors and vasodilators. These processes culminate in the structural remodeling of the pulmonary vasculature, resulting in pulmonary arterial hypertension. MA-PAH exhibits a more severe clinical profile in functional class and hemodynamics compared with idiopathic pulmonary arterial hypertension. Management involves a multifaceted approach, integrating pulmonary vasodilators, cessation of methamphetamine use, and implementing social and rehabilitation programs. These measures aim to enhance patient outcomes and detect potential relapses for timely intervention.

SUMMARY

This review consolidates our understanding of MA-PAH, pinpointing knowledge gaps for future studies. Addressing these gaps is crucial for advancing diagnostic accuracy, unraveling mechanisms, and optimizing treatment for MA-PAH, thereby addressing the evolving landscape of this complex health concern.

Nupr1-mediated vascular smooth muscle cell phenotype transformation involved in methamphetamine induces pulmonary hypertension

AIMS

Nuclear protein 1 (Nupr1) is a multifunctional stress-induced protein involved in the regulation of tumorigenesis, apoptosis, and autophagy. However, its role in pulmonary hypertension (PH) after METH exposure remains unexplored. In this study, we aimed to investigate whether METH can induce PH and describe the role and mechanism of Nupr1 in the development of PH.

METHODS AND RESULTS

Mice were made to induce pulmonary hypertension (PH) upon chronic intermittent treatment with METH. Their right ventricular systolic pressure (RVSP) was measured to assess pulmonary artery pressure. Pulmonary artery morphometry was determined by H&E staining and Masson staining. Nupr1 expression and function were detected in human lungs, mice lungs exposed to METH, and cultured pulmonary arterial smooth muscle cells (PASMCs) with METH treatment. Our results showed that chronic intermittent METH treatment successfully induced PH in mice. Nupr1 expression was increased in the cultured PASMCs, pulmonary arterial media from METH-exposed mice, and METH-ingested human specimens compared with control. Elevated Nupr1 expression promoted PASMC phenotype change from contractile to synthetic, which triggered pulmonary artery remodeling and resulted in PH formation. Mechanistically, Nupr1 mediated the opening of store-operated calcium entry (SOCE) by activating the expression of STIM1, thereby promoting Ca2+ influx and inducing phenotypic conversion of PASMCs.

CONCLUSIONS

Nupr1 activation could promote Ca2+ influx through STIM1-mediated SOCE opening, which promoted METH-induced pulmonary artery remodeling and led to PH formation. These results suggested that Nupr1 played an important role in METH-induced PH and might be a potential target for METH-related PH therapy.

Methamphetamine-associated pulmonary arterial hypertension: data from the national biological sample and data repository for pulmonary arterial hypertension (PAH Biobank)

OBJECTIVE

This study compares the clinical and haemodynamic severity of methamphetamine-associated pulmonary arterial hypertension (MA-PAH) with idiopathic pulmonary arterial hypertension (IPAH) and connective tissue-associated pulmonary arterial hypertension (CTD-PAH). It also examines sex differences in clinical and physiological parameters among those with MA-PAH.

DESIGN

This is a cross-sectional study using clinically derived data from the National Biological Sample and Data Repository for Pulmonary Arterial Hypertension (PAH biobank), a US-based registry, to compare clinical and physiological characteristics between males and females with MA-PAH.

POPULATION

The analysis included 1830 patients enrolled in the PAH biobank, with a diagnosis of MA-PAH (n=42), IPAH (n=1073), or CTD-PAH (n=715).

MAIN OUTCOME MEASURES

The study assessed and compared the clinical and haemodynamic parameters of patients with MA-PAH, IPAH and CTD-PAH.

RESULTS

Among the patients analysed, 42 had MA-PAH, with 69.1% being female. There were no statistically significant differences in functional class among patients with MA-PAH, IPAH and CTD-PAH. The per cent predicted 6-min walk distance (6MWD) was comparable between the three groups. Patients with MA-PAH had similar mean pulmonary artery pressure and pulmonary vascular resistance to patients with IPAH but higher compared with patients with CTD-PAH. Male patients with MA-PAH exhibited a worse functional class and lower per cent predicted 6MWD, but no significant differences in haemodynamic findings were observed between the sexes.

CONCLUSION

There were no differences in haemodynamic between MA-PAH and IPAH but we found that MA-PAH differed from CTD-PAH. The study did not find evidence of sex differences in MA-PAH. Further research is necessary to identify risk factors and underlying mechanisms of MA-PAH, particularly considering the increasing prevalence of methamphetamine use. Such investigations will contribute to the development of effective prevention and treatment strategies for this condition.

Critical care for patients with substance use disorders

PURPOSE OF REVIEW

To examine the impact of substance use disorders (SUDs) on critical illness and the role of critical care providers in treating SUDs. We discuss emerging evidence supporting hospital-based addiction treatment and highlight the clinical and research innovations needed to elevate the standards of care for patients with SUDs in the intensive care unit (ICU) amidst staggering individual and public health consequences.

RECENT FINDINGS

Despite the rapid increase of SUDs in recent years, with growing implications for critical care, dedicated studies focused on ICU patients with SUDs remain scant. Available data demonstrate SUDs are major risk factors for the development and severity of critical illness and are associated with poor outcomes. ICU patients with SUDs experience mutually reinforcing effects of substance withdrawal and pain, which amplify risks and consequences of delirium, and complicate management of comorbid conditions. Hospital-based addiction treatment can dramatically improve the health outcomes of hospitalized patients with SUDs and should begin in the ICU.

SUMMARY

SUDs have a significant impact on critical illness and post-ICU outcomes. High-quality cohort and treatment studies designed specifically for ICU patients with SUDs are needed to define best practices and improve health outcomes in this vulnerable population.

Nrf2 protects against methamphetamine-induced nephrotoxicity by mitigating oxidative stress and autophagy in mice

Methamphetamine (MA) is a widely abused drug that can cause kidney damage. However, the molecular mechanism remains unclear. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor that regulates resistance to oxidative and proteotoxic stress. In this study, we investigated the role of Nrf2 in MA-induced renal injury in mice. Nrf2 was pharmacologically activated and genetically knocked-out in mice. The animal model of MA-induced nephrotoxicity was established by injecting MA (2 mg/kg) intraperitoneally twice a day for 5 days. Histopathological alterations were shown in the MA-exposed kidneys. MA significantly increased renal function biomarkers and kidney injury molecule-1 (KIM-1) levels. MA decreased superoxide dismutase activity and increased malondialdehyde levels. Autophagy-related factors (LC3 and Beclin 1) were elevated in MA-treated mice. Furthermore, Nrf2 increased in the MA-exposed kidneys. Activation of Nrf2 may attenuate histopathological changes in the kidneys of MA-treated mice. Pre-administration of Nrf2 agonist significantly decreased KIM-1 expression, oxidative stress, and autophagy in the kidneys after MA toxicity. In contrast, Nrf2 knockout mice treated with MA lost renal tubular morphology. Nrf2 deficiency increased KIM-1 expression, oxidative stress, and autophagy in the MA-exposed kidneys. Our results demonstrate that Nrf2 may protect against MA-induced nephrotoxicity by mitigating oxidative stress and autophagy.

Methamphetamine increases force of contraction in isolated human atrial preparations through the release of noradrenaline

We measured the cardiac contractile effects of the sympathomimetic amphetamine-like drug methamphetamine alone and in the presence of cocaine or propranolol in human atrial preparations. For a more comprehensive analysis, we also examined the effects of methamphetamine in preparations from the left and right atria of mice and, for comparison, analyzed the cardiac effects of amphetamine itself. In human atrial preparations, methamphetamine and amphetamine increased the contractile force, the relaxation rate, and the rate of tension development, and shortened the time to maximum tension and the time to relaxation. Likewise, in mice preparations, methamphetamine and amphetamine increased the contractile force in the left atrium and increased the beating rate in the right atrium. The effect in human atrial preparations started at 1µM, therefore methamphetamine was less effective and potent than isoproterenol in increasing contractile force. These positive inotropic effects of methamphetamine were greatly attenuated by 10µM cocaine and abolished by 10µM propranolol. The inotropic effects of methamphetamine in human atrial preparations were associated with, and are believed to be mediated at least in part by, an increase in the phosphorylation state of the inhibitory subunit of troponin. In conclusion, the sympathomimetic central stimulant drug methamphetamine (as well as amphetamine) increased contractile force and protein phosphorylation, presumably through a release of noradrenaline in isolated human atrial preparations. Thus, methamphetamine acts as an indirect sympathomimetic in the human atrium.

HIV and Drug Use: A Tale of Synergy in Pulmonary Vascular Disease Development

Over the past two decades, with the advent and adoption of highly active anti-retroviral therapy, HIV-1 infection, a once fatal and acute illness, has transformed into a chronic disease with people living with HIV (PWH) experiencing increased rates of cardio-pulmonary vascular diseases including life-threatening pulmonary hypertension. Moreover, the chronic consequences of tobacco, alcohol, and drug use are increasingly seen in older PWH. Drug use, specifically, can have pathologic effects on the cardiovascular health of these individuals. The "double hit" of drug use and HIV may increase the risk of HIV-associated pulmonary arterial hypertension (HIV-PAH) and potentiate right heart failure in this population. This article explores the epidemiology and pathophysiology of PAH associated with HIV and recreational drug use and describes the proposed mechanisms by which HIV and drug use, together, can cause pulmonary vascular remodeling and cardiopulmonary hemodynamic compromise. In addition to detailing the proposed cellular and signaling pathways involved in the development of PAH, this article proposes areas ripe for future research, including the influence of gut dysbiosis and cellular senescence on the pathobiology of HIV-PAH. © 2023 American Physiological Society. Compr Physiol 13:4659-4683, 2023.

Usefulness of genetics for clinical reclassification and refinement of prognostic stratification in pulmonary arterial hypertension

INTRODUCTION AND OBJECTIVES

Risk stratification in pulmonary arterial hypertension (PAH) is essential to provide more aggressive treatment for patients at higher risk. Nevertheless, recently introduced simplified prognostic tools neglect the genetic background. Additionally, pulmonary veno-oclusive disease (PVOD) has never been considered in risk assessment strategies.

METHODS

We analyzed consecutive patients in the Spanish registry of PAH (REHAP) genetically tested, between 2011 and 2022. We applied the 4-strata COMPERA 2.0 model, comparing these results with an amplified score including genetics. Cox regression models were compared using Harrel c-statistics. The application of the model was specifically tested in PVOD before inclusion.

RESULTS

We identified 298 patients tested genetically among the group of idiopathic, familial, drug-induced PAH and PVOD patients in the REHAP registry. When we analyzed only patients with all available variables of interest at baseline (World Health Organization functional class, 6-minute walk test, B-type natriuretic peptide or N-terminal pro-B-type natriuretic peptide) and included in the 4-strata model (n=142), after a median follow-up of 58.2 months, 17.6% of patients died and 11.3% underwent lung transplant. The application of the 4-strata model in our population demonstrated a good prognostic capacity (Harrel c of 0.689), which was not improved by the introduction of genetics (c-index 0.690). This last model showed a tendency for a better identification of patients at intermediate-low and intermediate-high risk, and no differences between intermediate-high and high-risk strata.

CONCLUSIONS

In this work, the addition of genetics to the COMPERA 4-strata model achieved a similar global prognostic capacity but changed the identification of different risk strata in a cohort of young genetically tested patients.

Circulating markers of inflammation and angiogenesis and clinical outcomes across subtypes of pulmonary arterial hypertension

BACKGROUND

Subtypes of pulmonary arterial hypertension (PAH) differ in both fundamental disease features and clinical outcomes. Angiogenesis and inflammation represent disease features that may differ across subtypes and are of special interest in connective tissue disease-associated PAH (CTD-PAH). We compared inflammatory and angiogenic biomarker profiles across different etiologies of PAH and related them to clinical outcomes.

METHODS

Participants with idiopathic PAH, CTD-PAH, toxin-associated PAH (tox-PAH), or congenital heart disease-associated PAH (CHD-PAH) were enrolled into a prospective observational cohort. Baseline serum concentrations of 33 biomarkers were related to 3-year mortality, echocardiogram, REVEAL score, and 6-minute walk distance (6MWD). Findings were validated using plasma proteomic data from the UK PAH Cohort Study.

RESULTS

One hundred twelve patients were enrolled: 45 idiopathic, 27 CTD-PAH, 20 tox-PAH, and 20 CHD-PAH. Angiogenic and inflammatory biomarkers were distinctly elevated within the CTD-PAH cohort. Six biomarkers were associated with mortality within the entire PAH cohort: interleukin-6 (IL-6, HR:1.6, 95% CI:1.18-2.18), soluble fms-like tyrosine kinase 1 (sFlt-1, HR:1.35, 95% CI:1.02-1.80), placental growth factor (PlGF, HR:1.55, 95% CI:1.07-2.25), interferon gamma-induced protein 10 (IP-10, HR:1.44, 95% CI:1.04-1.99), tumor necrosis factor-beta (TNF-β, HR:1.81, 95% CI:1.11-2.95), and NT-proBNP (HR:2.19, 95% CI:1.52-3.14). Only IL-6 and NT-proBNP remained significant after controlling for multiple comparisons. IL-6, IP-10, and sFlt-1 significantly associated with mortality in CTD-PAH, but not non-CTD-PAH subgroups. In the UK cohort, IP-10, PlGF, TNF-β, and NT-proBNP significantly associated with 5-year survival.

CONCLUSION

Levels of angiogenic and inflammatory biomarkers are elevated in CTD-PAH, compared with other etiologies of PAH, and may correlate with clinical outcomes including mortality.

Methamphetamine-associated pulmonary arterial hypertension

PURPOSE OF REVIEW

Methamphetamine use is increasing in popularity globally, and chronic users suffer from various drug toxicities, including the development of pulmonary arterial hypertension. Although it was previously thought to be a possible cause of pulmonary arterial hypertension, as of the sixth World Symposium on Pulmonary Hypertension, methamphetamine use is now recognized as a definite cause of pulmonary arterial hypertension. This review will discuss the history of methamphetamine use, the link between methamphetamine use and pulmonary arterial hypertension, and the clinical characteristics of patients with pulmonary hypertension from methamphetamine use.

RECENT FINDINGS

The mechanism by which methamphetamine abuse leads to pulmonary hypertension is unclear. However, recent studies have suggested that reduced expression of carboxylesterase 1 may be implicated due to maladaptation to the environmental injury of methamphetamine abuse. Based on the report of two recent cohort studies, patients with methamphetamine-associated pulmonary arterial hypertension have a worse functional class, less favorable hemodynamics, impaired health-related quality of life, increased health-care utilization, and attenuated survival, as compared to those with idiopathic pulmonary arterial hypertension.

SUMMARY

Future studies are needed to better understand the mechanism by which methamphetamine use leads to pulmonary arterial hypertension. Methamphetamine-associated pulmonary arterial hypertension likely represents a more advanced disease state than idiopathic pulmonary arterial hypertension, however, it is treated less aggressively in clinical practice.

Clinical Correlates and Outcomes of Methamphetamine-Associated Cardiovascular Diseases in Hospitalized Patients in California

Background

Methamphetamine misuse affects 27 million people worldwide and is associated with cardiovascular disease (CVD); however, risk factors for CVD among users have not been well studied.

Methods and Results

We studied hospitalized patients in California, captured by the Healthcare Cost and Utilization Project database, between 2005 and 2011. We studied the association between methamphetamine use and CVD (pulmonary hypertension, heart failure, stroke, and myocardial infarction). Among 20 249 026 persons in the Healthcare Cost and Utilization Project, 66 199 used methamphetamines (median follow‐up 4.58 years). Those who used were more likely younger (33 years versus 45 years), male (63.3% versus 44.4%), smoked, misused alcohol, and had depression and anxiety compared with nonusers. Methamphetamine use was associated with the development of heart failure (hazard ratio [HR], 1.53 [95% CI, 1.45–1.62]) and pulmonary hypertension (HR, 1.42 [95% CI, 1.26–1.60]). Among users, male sex (HR, 1.73 [95% CI, 1.37–2.18]) was associated with myocardial infarction. Chronic kidney disease (HR, 2.38 [95% CI, 1.74–3.25]) and hypertension (HR, 2.26 [95% CI, 2.03–2.51]) were strong risk factors for CVD among users. When compared with nonuse, methamphetamine use was associated with a 32% significant increase in CVD, alcohol abuse with a 28% increase, and cocaine use with a 47% increase in CVD.

Conclusions

Methamphetamine use has a similar magnitude of risk of CVD compared with alcohol and cocaine. Prevention and treatment could be focused on those with chronic kidney disease, hypertension, and mental health disorders.

Prediction of Patient Outcomes through Social Determinants of Health: The Pulmonary Hypertension Association Registry (PHAR) Evaluation

Outcomes of patients with pulmonary arterial hypertension (PAH) may be associated with social determinants of health (SDOH) and other baseline patient characteristics. At present, there is no prognostic model to predict important patient outcomes in PAH based on SDOH. Utilizing information from the Pulmonary Hypertension Association Registry (PHAR), we derive a model (PHAR Evaluation or PHARE) to predict an important composite patient outcomes based on SDOH and other patient characteristics. Baseline data regarding SDOH from adult patients with PAH enrolled in the PHAR between 2015 and March 23, 2020, were included for analysis. We performed repeated measures logistic regression modeling with dichotomous outcome data (0 for no events, 1 for one or more events) to derive the PHARE. Here, 1275 consecutive adult patients enrolled in the PHAR from 47 participating centers were included. Variables included in our model are race, gender, ethnicity, household income, level of education, age, body mass index, drug use, alcohol use, marital status, and type of health insurance. Interaction effect between variables was analyzed and several interactions were also included in the PHARE. The PHARE shows a c‐statistic of 0.608 (p < 0.0001) with 95% confidence intervals (0.583, 0.632). Using SDOH and baseline characteristics from the PHAR, the PHARE correlates with our composite patient outcome. Further work evaluating the role of SDOH in prognostic modeling of PAH is indicated.

Sex Differences in Pulmonary Hypertension

Pulmonary hypertension (PH) includes multiple diseases that share as common characteristic an elevated pulmonary artery pressure and right ventricular involvement. Sex differences are observed in practically all causes of PH. The most studied type is pulmonary arterial hypertension (PAH) which presents a gender bias regarding its prevalence, prognosis, and response to treatment. Although this disease is more frequent in women, once affected they present a better prognosis compared to men. Even if estrogens seem to be the key to understand these differences, animal models have shown contradictory results leading to the birth of the estrogen paradox. In this review we will summarize the evidence regarding sex differences in experimental animal models and, very specially, in patients suffering from PAH or PH from other etiologies.

Early Onset Cardiovascular Disease from Cocaine, Amphetamines, Alcohol, and Marijuana

Cardiovascular disease (CVD), a disease typically associated with aging and the definitive leading cause of death worldwide, now threatens the young and middle-aged populations. Recreational abuse of alcohol, marijuana, cocaine and amphetamine-type stimulants has been an escalating public health problem for decades, but now use of these substances has become a significant contributor to early onset CVD. While this remains a global phenomenon, the epicenter of substance abuse is rooted in North America where it has been exacerbated by the COVID-19 pandemic. For the first time in history, the United States (US) crossed 100,000 overdose-related deaths in a calendar year. Sadly, Canada's recreational drug abuse problem closely mirrors that of the US. This is indicative of the larger public health crisis unfolding, as we now know that these substances are cardiotoxic and are contributing to the rising levels of premature chronic CVD, including hypertension, arrhythmias, heart failure, stroke, myocardial infarction, arterial dissection, sudden cardiac death and early mortality.

Silencing the Tlr4 Gene Alleviates Methamphetamine-Induced Hepatotoxicity by Inhibiting Lipopolysaccharide-Mediated Inflammation in Mice

Methamphetamine (METH) is a stimulant drug. METH abuse induces hepatotoxicity, although the mechanisms are not well understood. METH-induced hepatotoxicity was regulated by TLR4-mediated inflammation in BALB/c mice in our previous study. To further investigate the underlying mechanisms, the wild-type (C57BL/6) and Tlr4^−/− mice were treated with METH. Transcriptomics of the mouse liver was performed via RNA-sequencing. Histopathological changes, serum levels of metabolic enzymes and lipopolysaccharide (LPS), and expression of TLR4-mediated proinflammatory cytokines were assessed. Compared to the control, METH treatment induced obvious histopathological changes and significantly increased the levels of metabolic enzymes in wild-type mice. Furthermore, inflammatory pathways were enriched in the liver of METH-treated mice, as demonstrated by expression analysis of RNA-sequencing data. Consistently, the expression of TLR4 pathway members was significantly increased by METH treatment. In addition, increased serum LPS levels in METH-treated mice indicated overproduction of LPS and gut microbiota dysbiosis. However, antibiotic pretreatment or silencing Tlr4 significantly decreased METH-induced hepatic injury, serum LPS levels, and inflammation. In addition, the dampening effects of silencing Tlr4 on inflammatory pathways were verified by the enrichment analysis of RNA-sequencing data in METH-treated Tlr4^−/− mice compared to METH-treated wild-type mice. Taken together, these findings implied that Tlr4 silencing, comparable to antibiotic pretreatment, effectively alleviated METH-induced hepatotoxicity by inhibiting LPS-TLR4-mediated inflammation in the liver.

Sex differences in methamphetamine use disorder perused from pre-clinical and clinical studies: Potential therapeutic impacts

Methamphetamine (METH) use, and misuse are associated with severe socioeconomic consequences. METH users develop tolerance, lose control over drug taking behaviors, and suffer frequent relapses even during treatment. The clinical course of METH use disorder is influenced by multifactorial METH-induced effects on the central and peripheral nervous systems. Although these METH-induced consequences are observed in humans of all ages, races, and sexes, sexual dimorphism in these outcomes have been observed in both pre-clinical and clinical settings. In this review, we have provided a detailed presentation of the sex differences reported in human and animal studies. We have therefore presented data that identified the influences of sex on METH pharmacokinetics, METH-induced changes in behaviors, cognitive processes, structural changes in the brain, and the effects of the drug on neurotransmitter systems and molecular mechanisms. Finally, we highlighted the potential significance of sex as a critical variable that should be considered when planning the development of new pharmacotherapeutic approaches against MEH use disorder in humans.

Loss of cAbl Tyrosine Kinase in Pulmonary Arterial Hypertension Causes Dysfunction of Vascular Endothelial Cells

Pulmonary arterial hypertension (PAH) is a progressive and fatal disease characterized by the dysfunction of pulmonary endothelial cells (ECs) and obstructive vascular remodeling. The non-receptor tyrosine kinase c-Abelson (cAbl) plays central roles in regulating cell-cycle arrest, apoptosis, and senescence after cellular stress. We hypothesized that cAbl is down-activated in experimental and human PAH, thus leading to reduced DNA integrity and angiogenic capacity of pulmonary ECs from PAH patients (PAH-ECs). We found cAbl and phosphorylated cAbl levels to be lower in the endothelium of remodeled pulmonary vessels in the lungs of PAH patients than controls. Similar observations were obtained for the lungs of sugen+hypoxia (SuHx) and monocrotaline (MCT) rats with established pulmonary hypertension. These in situ abnormalities were also replicated in vitro, with cultured PAH-ECs displaying lower cAbl expression and activity and an altered DNA damage response and capacity of tube formation. Downregulation of cAbl by RNA-interference in Control-ECs or its inhibition with dasatinib resulted in genomic instability and the failure to form tubes, whereas upregulation of cAbl with DPH reduced DNA damage and apoptosis in PAH-ECs. Finally, we establish the existence of crosstalk between cAbl and bone morphogenetic protein receptor type II (BMPRII). This work identifies the loss of cAbl signaling as a novel contributor to pulmonary EC dysfunction associated with PAH.

Mortality in Pulmonary Arterial Hypertension in the Modern Era: Early Insights From the Pulmonary Hypertension Association Registry

Background Current mortality data for pulmonary arterial hypertension (PAH) in the United States are based on registries that enrolled patients prior to 2010. We sought to determine mortality in PAH in the modern era using the PHAR (Pulmonary Hypertension Association Registry). Methods and Results We identified all adult patients with PAH enrolled in the PHAR between September 2015 and September 2020 (N=935). We used Kaplan-Meier survival analysis and Cox proportional hazards models to assess mortality at 1, 2, and 3 years. Patients were stratified based on disease severity by 3 validated risk scores. In treatment-naïve patients, we compared survival based on initial treatment strategy. The median age was 56 years (44-68 years), and 76% were women. Of the 935 patients, 483 (52%) were ≤6 months from PAH diagnosis. There were 121 deaths (12.9%) during a median follow-up time of 489 days (281-812 days). The 1-, 2-, and 3-year mortality was 8% (95% CI, 6%-10%), 16% (95% CI, 13%-19%), and 21% (95% CI, 17%-25%), respectively. When stratified into low-, intermediate-, and high-risk PAH, the mortality at 1, 2, and 3 years was 1%, 4% to 6%, and 7% to 11% for low risk; 7% to 8%, 11% to 16%, and 18% to 20% for intermediate risk; and 12% to 19%, 22% to 38%, and 28% to 55% for high risk, respectively. In treatment-naïve patients, initial combination therapy was associated with better 1-year survival (adjusted hazard ratio, 0.43 [95% CI, 0.19-0.95]; P=0.037). Conclusions Mortality in the intermediate- and high-risk patients with PAH remains unacceptably high in the PHAR, suggesting the importance for early diagnosis, aggressive use of available therapies, and the need for better therapeutics.

Diagnosis and Treatment of Pulmonary Arterial Hypertension: A Review

IMPORTANCE

Pulmonary arterial hypertension (PAH) is a subtype of pulmonary hypertension (PH), characterized by pulmonary arterial remodeling. The prevalence of PAH is approximately 10.6 cases per 1 million adults in the US. Untreated, PAH progresses to right heart failure and death.

OBSERVATIONS

Pulmonary hypertension is defined by a mean pulmonary artery pressure greater than 20 mm Hg and is classified into 5 clinical groups based on etiology, pathophysiology, and treatment. Pulmonary arterial hypertension is 1 of the 5 groups of PH and is hemodynamically defined by right heart catheterization demonstrating a mean pulmonary artery pressure greater than 20 mm Hg, a pulmonary artery wedge pressure of 15 mm Hg or lower, and a pulmonary vascular resistance of 3 Wood units or greater. Pulmonary arterial hypertension is further divided into subgroups based on underlying etiology, consisting of idiopathic PAH, heritable PAH, drug- and toxin-associated PAH, pulmonary veno-occlusive disease, PAH in long-term responders to calcium channel blockers, and persistent PH of the newborn, as well as PAH associated with other medical conditions including connective tissue disease, HIV, and congenital heart disease. Early presenting symptoms are nonspecific and typically consist of dyspnea on exertion and fatigue. Currently approved therapy for PAH consists of drugs that enhance the nitric oxide-cyclic guanosine monophosphate biological pathway (sildenafil, tadalafil, or riociguat), prostacyclin pathway agonists (epoprostenol or treprostinil), and endothelin pathway antagonists (bosentan and ambrisentan). With these PAH-specific therapies, 5-year survival has improved from 34% in 1991 to more than 60% in 2015. Current treatment consists of combination drug therapy that targets more than 1 biological pathway, such as the nitric oxide-cyclic guanosine monophosphate and endothelin pathways (eg, ambrisentan and tadalafil), and has shown demonstrable improvement in morbidity and mortality compared with the previous conventional single-pathway targeted monotherapy.

CONCLUSIONS AND RELEVANCE

Pulmonary arterial hypertension affects an estimated 10.6 per 1 million adults in the US and, without treatment, typically progresses to right heart failure and death. First-line therapy with drug combinations that target multiple biological pathways are associated with improved survival.

Methamphetamine induces intestinal injury by altering gut microbiota and promoting inflammation in mice

Methamphetamine (METH) is a psychostimulant abused worldwide. Its abuse induces intestinal toxicity. Moreover, the gut microbiota is altered by drugs, which induces intestinal injury. Whether gut microbiota mediates METH-induced intestinal toxicity remains to be validated. In the present study, wild-type and TLR4^-/- mice were treated with METH. Gut microbiota was determined using 16S rRNA gene sequencing. Transcriptomics of the intestinal mucosa was performed by RNA-Sequencing. Blood levels of pro-inflammatory cytokines and lipopolysaccharide (LPS), the intestinal barrier, and inflammation were also assessed. METH treatment weakened the intestinal barrier and increased pro-inflammatory cytokines and LPS levels in the blood. Moreover, METH treatment significantly decreased the diversity of probiotics but increased the abundance of pathogenic gut microbiota, contributing to the over-production of LPS and disruption of intestinal barrier. Inflammatory pathways were enriched in the intestinal mucosa of METH-treated mice by KEGG analysis. Consistently, activation of the TLR4 pathway was determined in METH-treated mice, which confirmed intestinal inflammation. However, pretreatment with antibiotics or Tlr4 silencing significantly alleviated METH-induced gut microbiota dysbiosis, LPS over-production, intestinal inflammation, and disruption of the intestinal barrier. These findings suggested that the gut microbiota and LPS-mediated inflammation took an important role in METH-induced intestinal injury. Taken together, these findings suggest that METH-induced intestinal injury is mediated by gut microbiota dysbiosis and LPS-associated inflammation.

A second hit? Pulmonary arterial hypertension, BMPR2 mutation and exposure to prescription‐amphetamines

The second hit hypothesis in pulmonary hypertension refers to the development of pulmonary vascular disease in individuals at risk, after an additional exposure or “hit” to factors with potential injury to the pulmonary circulation, such as drugs or toxins. We here present a case of severe pulmonary hypertension diagnosed during the third trimester of pregnancy, in a patient with familial history of pulmonary hypertension, found to have a heterozygous mutation in the BMPR2 gene, who also had chronic exposure to prescription amphetamines. We hypothesize that exposure to prescription amphetamines could act as a second hit of pulmonary vascular injury in individuals at risk of pulmonary vascular disease.

Hemodynamic Effects of Methamphetamine and General Anesthesia

Design

A retrospective analysis of all anesthetic records at our institution over a two-year period was performed. Setting. Operating room cases under balanced anesthesia. Patients. All patients with ASA class I or II, who did not have trauma or were initially admitted to ICU, aged 18–65, without preexisting cardiac, renal, or pulmonary disease. Patients were divided into three groups: those acutely positive for methamphetamine within 48 hours of surgery (n = 137), those positive for methamphetamine between 48 hours and 7 days of surgery (n = 69), and randomly selected controls who were negative for methamphetamine within 7 days of surgery (n = 159). Measurements. Intraoperative hemodynamic instability was defined as either a drop of more than 40% in MAP for greater than 5 minutes or requirement for significant amount of vasopressors. Main Results. Among the patients who were acutely positive for methamphetamine within 24 hours, 31.4% met the criteria for hemodynamic instability within the first hour of general anesthesia, compared to 26.1% of the subacutely positive patients and 6.3% of controls (p < 0.0001). This was despite lower doses of anesthetic medications in the acutely and subacutely positive groups.

Conclusion

Patients who present to the operating room with a positive urine drug screen for amphetamines within 2 days of surgery are at increased risk of hemodynamic instability. Postponing surgery up to 7 days somewhat decreases this risk, but not to the levels of patients who do not use methamphetamines.

Prenatal methamphetamine-impact on the mother and child-a review

Methamphetamine (MA) is the second most commonly used illicit drug in the world, after cannabis. There are limited data on the outcomes of pregnant MA users but there is rapidly emerging evidence to suggest that they are more vulnerable, marginalized and impoverished compared with other drug-using mothers. MA use during pregnancy is associated with worse pregnancy outcomes and significantly higher rates of co-existing health and psychosocial problems. Newborn infants exposed to MA are at increased risk of perinatal complications, present differently at birth to infants exposed to other drugs of dependency such as opioids and have poorer neurological adaptation and feeding difficulties. Sparse literature from neuroimaging and cohort studies suggests that the neurocognitive deficits in MA exposed children persist, even into adulthood. Current clinical practice guidelines for the care of substance exposed pregnant women are opioid-centric with little attention paid to the consequences of prenatal MA exposure.

Pulmonary Arterial Hypertension: Emerging Principles of Precision Medicine across Basic Science to Clinical Practice

Pulmonary arterial hypertension (PAH) is an enigmatic and deadly vascular disease with no known cure. Recent years have seen rapid advances in our understanding of the molecular underpinnings of PAH, with an expanding knowledge of the molecular, cellular, and systems-level drivers of disease that are being translated into novel therapeutic modalities. Simultaneous advances in clinical technology have led to a growing list of tools with potential application to diagnosis and phenotyping. Guided by fundamental biology, these developments hold the potential to usher in a new era of personalized medicine in PAH with broad implications for patient management and great promise for improved outcomes.

Clinical Differences and Outcomes between Methamphetamine-associated and Idiopathic Pulmonary Arterial Hypertension in the Pulmonary Hypertension Association Registry

Rationale: Single-center studies demonstrated that methamphetamine use is associated with pulmonary arterial hypertension (Meth-APAH). We used the Pulmonary Hypertension Association Registry to evaluate the national distribution of Meth-APAH and to compare its impact on patient-reported and clinical outcomes relative to idiopathic PAH.Objectives: To determine if patients with Meth-APAH differ from those with idiopathic PAH in demographics, regional distribution in the United States, hemodynamics, health-related quality of life, PAH-specific treatment, and health care use.Methods: The Pulmonary Hypertension Association Registry is a U.S.-based prospective cohort of patients new to care at a Pulmonary Hypertension Care Center. The registry collects baseline demographics, clinical parameters, and repeated measures of health-related quality of life, World Health Organization functional class, 6-minute walk distance, therapy, and health care use. Repeated measures of functional class, health-related quality of life, type of therapy, emergency department visits, and hospitalizations were compared using generalized estimating equations.Results: Of 541 participants included, 118 had Meth-APAH; 83% of Meth-APAH arose in the western United States. The Meth-APAH group was younger and had a poorer socioeconomic status and lower cardiac index than the idiopathic PAH group, despite no difference in mean pulmonary artery pressure or pulmonary vascular resistance. The Meth-APAH group had a more advanced functional class in longitudinal models (0.22 points greater; 95% confidence interval [CI], 0.07 to 0.37) and worse PAH-specific (emPHasis-10) health-related quality of life (-5.4; 95% CI, -8.1 to -2.8). There was no difference in dual combination therapy; however, participants with Meth-APAH were less likely to be initiated on triple therapy (odds ratio [OR], 0.43; 95% CI, 0.24 to 0.77) or parenteral therapy (OR, 0.10; 95% CI, 0.04 to 0.24). Participants with Meth-APAH were more likely to seek care in the emergency department (incidence rate ratio, 2.30; 95% CI, 1.71 to 3.11) and more likely to be hospitalized (incidence rate ratio, 1.42; 95% CI, 1.10 to 1.83).Conclusions: Meth-APAH represents a unique clinical phenotype of PAH, most common in the western United States. It accounts for a notable proportion of PAH in expert centers. Assessment for methamphetamine use is necessary in patients with PAH.

Methamphetamine-Associated Heart Failure Hospitalizations Across the United States: Geographic and Social Disparities

Background Although methamphetamine abuse is associated with the development of heart failure (HF), nationwide data on methamphetamine-associated HF (MethHF) hospitalizations are limited. This study evaluates nationwide HF hospitalizations associated with substance abuse to better understand MethHF prevalence trends and the clinical characteristics of those patients. Methods and Results This cross-sectional period-prevalence study used hospital discharge data from the National Inpatient Sample to identify adult primary HF hospitalizations with a secondary diagnosis of abuse of methamphetamines, cocaine, or alcohol in the United States from 2002 to 2014. All 2014 MethHF admissions were separated by regional census division to evaluate geographical distribution. Demographics, payer information, and clinical characteristics of MethHF hospitalizations were compared with all other HF hospitalizations. Total nationwide MethHF hospitalizations increased from 547 in 2002 to 6625 in 2014 with a predominance on the West Coast. Methamphetamine abuse was slightly more common among primary HF hospitalizations compared with all-cause hospitalizations (7.4 versus 6.4 per 1000; Cohen h=0.012; P<0.001). Among HF hospitalizations, patients with MethHF were younger (mean age, 48.9 versus 72.4 years; Cohen d=1.93; P<0.001), more likely to be on Medicaid (59.4% versus 8.8%; Cohen h=1.16; P<0.001) or uninsured (12.0% versus 2.6%; Cohen h=0.36; P<0.001), and more likely to present to urban hospitals (43.8% versus 28.3%; Cohen h=0.32; P<0.001) than patients with non-methamphetamine associated HF. Patients with MethHF had higher rates of psychiatric comorbidities and were more likely to leave the hospital against medical advice. Conclusions MethHF hospitalizations have significantly increased in the United States, particularly on the West Coast. Coordinated public health policies and systems of care are needed to address this rising epidemic.

Pulmonary Arterial Hypertension: Diagnosis, Treatment, and Novel Advances

The diagnosis and management of pulmonary arterial hypertension (PAH) includes several advances, such as a broader recognition of extrapulmonary vascular organ system involvement, validated point-of-care clinical assessment tools, and focus on the early initiation of multiple pharmacotherapeutics in appropriate patients. Indeed, a principal goal in PAH today is an early diagnosis for prompt initiation of treatment to achieve a minimal symptom burden; optimize the patient's biochemical, hemodynamic, and functional profile; and limit adverse events. To accomplish this end, clinicians must be familiar with novel risk factors and the revised hemodynamic definition for PAH. Fresh insights into the role of developmental biology (i.e., perinatal health) may also be useful for predicting incident PAH in early adulthood. Emergent or underused approaches to PAH management include a novel TGF-β ligand trap pharmacotherapy, remote pulmonary arterial pressure monitoring, next-generation imaging using inert gas-based magnetic resonance and other technologies, right atrial pacing, and pulmonary arterial denervation. These and other PAH state of the art advances are summarized here for the wider pulmonary medicine community.

Association between Leflunomide and Pulmonary Hypertension

Rationale: Pulmonary hypertension (PH) has been described in patients treated with leflunomide. Objectives: To assess the association between leflunomide and PH. Methods: We identified incident cases of PH in patients treated with leflunomide from the French PH Registry and through the pharmacoVIGIlAnce in Pulmonary ArTerial Hypertension (VIGIAPATH) program between September 1999 to December 2019. PH etiology, clinical, functional, radiologic, and hemodynamic characteristics were reviewed at baseline and follow-up. A pharmacovigilance disproportionality analysis using the World Health Organization's global database was conducted. We then investigated the effect of leflunomide on human pulmonary endothelial cells. Data are expressed as median (min-max). Results: Twenty-eight patients treated with leflunomide before PH diagnosis was identified. A total of 21 (75%) had another risk factor for PH and 2 had two risk factors. The median time between leflunomide initiation and PH diagnosis was 32 months (1-120). Right heart catheterization confirmed precapillary PH with a cardiac index of 2.37 L⋅min^-1 ⋅m^-2 (1.19-3.1) and elevated pulmonary vascular resistance at 9.63 Wood Units (3.6-22.1) without nitric oxide reversibility. Five patients (17.9%) had no other risk factor for PH besides exposure to leflunomide. No significant hemodynamic improvement was observed after leflunomide withdrawal. The pharmacovigilance disproportionality analysis using the World Health Organization's database revealed a significant overrepresentation of leflunomide among reported pulmonary arterial hypertension-adverse drug reactions. In vitro studies showed the dose-dependent toxicity of leflunomide on human pulmonary endothelial cells. Conclusions: PH associated with leflunomide is rare and usually associated with other risk factors. The pharmacovigilance analysis suggests an association reinforced by experimental data.

Cor Pulmonale from Concomitant Human Immunodeficiency Virus Infection and Methamphetamine Use

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HIV and frequent methamphetamine use are two known risk factors for PAH development.

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HIV and methamphetamine are both associated with higher rates of mortality in PAH.

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Echocardiography is an effective noninvasive modality for assessing PAH severity.

Excipient-Induced Pulmonary Vascular Disease: An Underrecognized and Deadly Complication of Opioid Addiction

Despite widespread public health concern regarding opioid misuse and overuse, there is a paucity of literature on the acute and chronic pulmonary vascular and cardiac implications of excipient lung disease. This case series describes the clinical presentation of five adult patients who experienced profound pulmonary hypertension and right heart failure in the setting of confirmed or suspected crushed opioid injection at a single academic center between 2012 and 2019. The clinical characteristics and right heart catheterization data presented in these cases demonstrate the acute intravascular effects of the intravenous injection of crushed opioids and potential for hemodynamic collapse. Moreover, these cases suggest that survivors of acute excipient lung disease may develop chronic pulmonary vascular disease. Further studies are needed to explore the epidemiology and outcomes of oral opioid-induced intravascular excipient lung disease to increase awareness of this life-threatening complication among health care professionals and guide treatment and prevention measures.

The Adverse Effects of Prenatal METH Exposure on the Offspring: A Review

Abuse of methamphetamine (METH), an illicit psychostimulant, is a growing public health issue. METH abuse during pregnancy is on the rise due to its stimulant, anorectic, and hallucinogenic properties. METH can lead to multiple organ toxicity in adults, including neurotoxicity, cardiovascular toxicity, and hepatotoxicity. It can also cross the placental barrier and have long-lasting effects on the fetus. This review summarizes neurotoxicity, cardiovascular toxicity, hepatotoxicity, toxicity in other organs, and biomonitoring of prenatal METH exposure, as well as the possible emergence of sensitization associated with METH. We proposed the importance of gut microbiota in studying prenatal METH exposure. There is rising evidence of the adverse effects of METH exposure during pregnancy, which are of significant concern.

Pulmonary Arterial Hypertension Secondary to Drugs and Toxins

Pulmonary arterial hypertension secondary to drugs and toxins is an important subgroup of group 1 pulmonary hypertension associated with significant morbidity and mortality. Many drugs and toxins have emerged as risk factors for pulmonary arterial hypertension, which include anorexigens, illicit agents, and several US Food and Drug Administration-approved therapeutic medications. Drugs and toxins are classified as possible or definite risk factors for pulmonary arterial hypertension. This article reviews agents that have been implicated in the development of pulmonary arterial hypertension, their pathologic mechanisms, and methods to prevent the next deadly outbreak of drug- and toxin-induced pulmonary arterial hypertension.

Opioid use disorder and health service utilization among COVID-19 patients in the US: A nationwide cohort from the Cerner Real-World Data

BACKGROUND

Both opioid use and COVID-19 affect respiratory and pulmonary health, potentially putting individuals with opioid use disorders (OUD) at risk for complications from COVID-19. We examine the relationship between OUD and subsequent hospitalization, length of stay, risk for invasive ventilator dependence (IVD), and COVID-19 mortality.

METHODS

Multivariable logistic and exponential regression models using electronic health records data from the Cerner COVID-19 De-Identified Data Cohort from January through June 2020.

FINDINGS

Out of 52,312 patients with COVID-19, 1.9% (n=1,013) had an OUD. COVID-19 patients with an OUD had higher odds of hospitalization (aOR=3.44, 95% CI=2.81-4.21), maximum length of stay ( e β ^ =1.16, 95% CI=1.09-1.22), and odds of IVD (aOR=1.26, 95% CI=1.06-1.49) than patients without an OUD, but did not differ with respect to COVID-19 mortality. However, OUD patients under age 45 exhibited greater COVID-19 mortality (aOR=3.23, 95% CI=1.59-6.56) compared to patients under age 45 without an OUD. OUD patients using opioid agonist treatment (OAT) exhibited higher odds of hospitalization (aOR=5.14, 95% CI=2.75-10.60) and higher maximum length of stay ( e β ^ =1.22, 95% CI=1.01-1.48) than patients without OUDs; however, risk for IVD and COVID-19 mortality did not differ. OUD patients using naltrexone had higher odds of hospitalization (aOR=32.19, 95% CI=4.29-4,119.83), higher maximum length of stay ( e β ^ =1.59, 95% CI=1.06-2.38), and higher odds of IVD (aOR=3.15, 95% CI=1.04-9.51) than patients without OUDs, but mortality did not differ. OUD patients who did not use treatment medication had higher odds of hospitalization (aOR=4.05, 95% CI=3.32-4.98), higher maximum length of stay ( e β ^ =1.14, 95% CI=1.08-1.21), and higher odds of IVD (aOR=1.25, 95% CI=1.04-1.50) and COVID-19 mortality (aOR=1.31, 95% CI=1.07-1.61) than patients without OUDs.

INTERPRETATION

This study suggests people with OUD and COVID-19 often require higher levels of care, and OUD patients who are younger or not using medication treatment for OUDs are particularly vulnerable to death due to COVID-19.

Pediatric Pulmonary Hypertension: Definitions, Mechanisms, Diagnosis, and Treatment

Pediatric pulmonary hypertension (PPH) is a multifactorial disease with diverse etiologies and presenting features. Pulmonary hypertension (PH), defined as elevated pulmonary artery pressure, is the presenting feature for several pulmonary vascular diseases. It is often a hidden component of other lung diseases, such as cystic fibrosis and bronchopulmonary dysplasia. Alterations in lung development and genetic conditions are an important contributor to pediatric pulmonary hypertensive disease, which is a distinct entity from adult PH. Many of the causes of pediatric PH have prenatal onset with altered lung development due to maternal and fetal conditions. Since lung growth is altered in several conditions that lead to PPH, therapy for PPH includes both pulmonary vasodilators and strategies to restore lung growth. These strategies include optimal alveolar recruitment, maintaining physiologic blood gas tension, nutritional support, and addressing contributing factors, such as airway disease and gastroesophageal reflux. The outcome for infants and children with PH is highly variable and largely dependent on the underlying cause. The best outcomes are for neonates with persistent pulmonary hypertension (PPHN) and reversible lung diseases, while some genetic conditions such as alveolar capillary dysplasia are lethal. © 2021 American Physiological Society. Compr Physiol 11:2135-2190, 2021.

Sex-dependent right ventricular hypertrophic gene changes after methamphetamine treatment in mice

Methamphetamine (MA) abuse is associated with the development of pulmonary arterial hypertension (PAH) and subsequent right ventricular failure. A recent clinical study demonstrated that female sex is a major risk factor for MA-induced PAH. The mechanisms associated with increased prevalence and severity of MA-induced PAH in females are still unclear. We hypothesized that MA may promote changes in gene expression in the right ventricle contributing to the development and/or worsening of PAH in females. Male and female C57BL/6 mice were treated with either MA or vehicle. Right and left ventricular systolic pressures (RVSP and LVSP, respectively) were assessed and tissue samples were collected for gene expression and histology. LVSP and RVSP were not affected by MA in either males or females. Right ventricular hypertrophy was significantly increased by MA in females but it was not affected by MA in males. In the female mice, MA-induced right ventricular hypertrophy was associated with increased expression of brain natriuretic peptide gene and members of the TGF-β receptor signaling pathway such as TGF-β receptor-1, smad3 and smad7. In male mice, there were no changes in right ventricular gene expression. Our results suggest that MA caused right ventricular hypertrophy in female mice, but not in males and that this was associated with an increase in hypertrophic genes. The right ventricular hypertrophy was not dependent on increased RVSP suggesting a direct effect of MA on the right ventricle. If this translates to PAH patients, it might explain the poor outcome observed in MA-associated female PAH patients.

Characterization and treatment challenges of pulmonary hypertension in methamphetamine users

The World Health Organization pulmonary hypertension classification scheme provides a framework for evaluation and management of patients with pulmonary vascular disease. Methamphetamine is a recreational stimulant which causes cardiac and pulmonary vascular toxicity. We discuss three cases of methamphetamine users who presented with left ventricular systolic failure but on heart failure therapy developed features more consistent with pulmonary arterial hypertension (PAH) or combined pre-capillary and post-capillary pulmonary hypertension. All three were started on PAH treatment and showed clinical improvement in symptoms. These cases illustrate the difficulty with treating methamphetamine users with pulmonary hypertension who have been left out of randomized controlled trials. Consideration should be given to creating a clinical registry for patients with methamphetamine associated pulmonary hypertension to assist with best treatment strategies.

Clinical Characteristics and Management of Methamphetamine-Associated Cardiomyopathy: State-of-the-Art Review

Methamphetamine‐associated cardiomyopathy (MACM) is an increasingly recognized disease entity in the context of a rapidly spreading methamphetamine epidemic. MACM may afflict individuals with a wide range of ages and socioeconomic backgrounds. Presentations can vary greatly and may involve several complications unique to the disease. Given the public health significance of this disease, there is a relative dearth of consensus material to guide clinicians in understanding, diagnosing, and managing MACM. This review therefore aims to: (1) describe pathologic mechanisms of methamphetamine as they pertain to the development, progression, and prognosis of MACM, and the potential to recover cardiac function; (2) summarize existing data from epidemiologic studies and case series in an effort to improve recognition and diagnosis of the disease; (3) guide short‐ and long‐term management of MACM with special attention to expected or potential sequelae of the disease; and (4) highlight pivotal unanswered questions in need of urgent investigation from a public health perspective.

High geographic prevalence of pulmonary artery hypertension: associations with ethnicity, drug use, and altitude

While estimates of pulmonary arterial hypertension incidence and prevalence commonly range from 1-3/million and 15-25/million, respectively, clinical experience at our institution suggested much higher rates. We sought to describe the disease burden of pulmonary arterial hypertension in the geographic area served by our Pulmonary Hypertension Clinic and compare it to the REVEAL registry. Our secondary objectives were to document pulmonary arterial hypertension prevalence in minorities underrepresented in REVEAL (Hispanics and Native Americans) and to address the association of pulmonary arterial hypertension with exposure to drugs and moderately increased residential altitude in this population. Retrospective review of pulmonary arterial hypertension clinic patients alive during 2016 identified 154 patients. Hispanic patients made up 35.7% of the cohort, a much greater percentage than REVEAL, p < .001 but smaller than the percentage of Hispanic patients (48.4%) in geographic area served by the clinic. Pulmonary arterial hypertension due to drug exposure was more common and idiopathic pulmonary arterial hypertension was less common than in REVEAL (p < .001). Overall, pulmonary arterial hypertension incidence was 14 cases per million, greater than the REVEAL registry, odds ratio 6.3 (95% CI: 4.2-9.5), (p < .001). Annual period prevalence of pulmonary arterial hypertension was 93 cases per million, also greater than the REVEAL, odds ratio = 7.5 (95% CI: 6.4-8.8) and remained greater when the clinic cohort was constrained to patients with hemodynamic severity comparable to REVEAL, odds ratio = 3.8 (95% CI: 3.0-4.6), (p < .001). There was a strong association between pulmonary arterial hypertension prevalence and residence at altitude > 4000 ft, odds ratio = 26.6 (95% CI: 8.5-83.5), p < .001; however, this was potentially confounded by pulmonary arterial hypertension treatment referral patterns. These findings document a much higher local pulmonary arterial hypertension incidence and prevalence than previously reported in REVEAL. While population ethnicity differed markedly from REVEAL, the disease burden was not driven by these differences. The possible association of moderately increased residential altitude with pulmonary arterial hypertension warrants further evaluation.

Circulating NEDD9 is increased in pulmonary arterial hypertension: A multicenter, retrospective analysis

BACKGROUND

Pulmonary arterial hypertension (PAH) is a highly morbid disease characterized by elevated pulmonary vascular resistance (PVR) and pathogenic right ventricular remodeling. Endothelial expression of the prometastatic protein NEDD9 is increased in fibrotic PAH arterioles, and NEDD9 inhibition decreases PVR in experimental PAH. We hypothesized that circulating NEDD9 is increased in PAH and informs the clinical profile of patients.

METHODS

Clinical data and plasma samples were analyzed retrospectively for 242 patients from 5 referral centers (2010-2017): PAH (n = 139; female 82%, 58 [48-67] years), non-PAH pulmonary hypertension (PH) (n = 54; female 56%, 63.4 ± 12.2 years), and dyspnea non-PH controls (n = 36; female 75%, 54.2 ± 14.0 years).

RESULTS

Compared with controls, NEDD9 was increased in PAH by 1.82-fold (p < 0.0001). Elevated NEDD9 correlated with PVR in idiopathic PAH (ρ = 0.42, p < 0.0001, n = 54), connective tissue disease (CTD)-PAH (ρ = 0.53, p < 0.0001, n = 53), and congenital heart disease-PAH (ρ = 0.68, p < 0.0001, n = 10). In CTD-PAH, NEDD9 correlated with 6-minute walk distance (ρ = -0.35, p = 0.028, n = 39). In contrast to the PAH biomarker N-terminal pro-brain natriuretic peptide (n = 38), NEDD9 correlated inversely with exercise pulmonary artery wedge pressure and more strongly with right ventricular ejection fraction (ρ = -0.41, p = 0.006, n = 45) in a mixed population. The adjusted hazard ratio for lung transplant-free survival was 1.12 (95% confidence interval [CI], 1.02-1.22, p = 0.01) and 1.75 (95% CI, 1.12-2.73, p = 0.01) per 1 ng/ml and 5 ng/ml increase in plasma NEDD9, respectively, by Cox proportional hazard model.

CONCLUSIONS

In PAH, plasma NEDD9 is increased and associates with key prognostic variables. Prospective studies that include hard end points are warranted to validate NEDD9 as a novel PAH biomarker.

Sex, Gender, and Sex Hormones in Pulmonary Hypertension and Right Ventricular Failure

Pulmonary hypertension (PH) encompasses a syndrome of diseases that are characterized by elevated pulmonary artery pressure and pulmonary vascular remodeling and that frequently lead to right ventricular (RV) failure and death. Several types of PH exhibit sexually dimorphic features in disease penetrance, presentation, and progression. Most sexually dimorphic features in PH have been described in pulmonary arterial hypertension (PAH), a devastating and progressive pulmonary vasculopathy with a 3-year survival rate <60%. While patient registries show that women are more susceptible to development of PAH, female PAH patients display better RV function and increased survival compared to their male counterparts, a phenomenon referred to as the "estrogen paradox" or "estrogen puzzle" of PAH. Recent advances in the field have demonstrated that multiple sex hormones, receptors, and metabolites play a role in the estrogen puzzle and that the effects of hormone signaling may be time and compartment specific. While the underlying physiological mechanisms are complex, unraveling the estrogen puzzle may reveal novel therapeutic strategies to treat and reverse the effects of PAH/PH. In this article, we (i) review PH classification and pathophysiology; (ii) discuss sex/gender differences observed in patients and animal models; (iii) review sex hormone synthesis and metabolism; (iv) review in detail the scientific literature of sex hormone signaling in PAH/PH, particularly estrogen-, testosterone-, progesterone-, and dehydroepiandrosterone (DHEA)-mediated effects in the pulmonary vasculature and RV; (v) discuss hormone-independent variables contributing to sexually dimorphic disease presentation; and (vi) identify knowledge gaps and pathways forward. © 2020 American Physiological Society. Compr Physiol 10:125-170, 2020.