Validation of the Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL) pulmonary hypertension prediction model in a unique population and utility in the prediction of long-term survival

Prognostic Value of Serial Risk Stratification in Adult and Pediatric Pulmonary Arterial Hypertension: A Systematic Review

BACKGROUND

In pulmonary arterial hypertension, it is recommended to base therapeutic decisions on risk stratification. This systematic review aims to report the prognostic value of serial risk stratification in adult and pediatric pulmonary arterial hypertension and to explore the usability of serial risk stratification as treatment target.

METHODS AND RESULTS

Electronic databases PubMed, Embase, and Web of Science were searched up to January 30, 2023, using terms associated with pulmonary arterial hypertension, pediatric pulmonary hypertension, and risk stratification. Observational studies and clinical trials describing risk stratification at both baseline and follow-up were included. Sixty five studies were eligible for inclusion, including only 2 studies in a pediatric population. C-statistic range at baseline was 0.31 to 0.77 and improved to 0.30 to 0.91 at follow-up. In 53% of patients, risk status changed (42% improved, 12% worsened) over 168 days (interquartile range, 137-327 days; n=22 studies). The average proportion of low-risk patients increased from 18% at baseline to 36% at a median follow-up of 244 days (interquartile range, 140-365 days; n=40 studies). In placebo-controlled drug studies, risk statuses of the intervention groups improved more and worsened less compared with the placebo groups. Furthermore, a low-risk status, but also an improved risk status, at follow-up was associated with a better outcome. Similar results were found in the 2 pediatric studies.

CONCLUSIONS

Follow-up risk stratification has improved prognostic value compared with baseline risk stratification, and change in risk status between baseline and follow-up corresponded to a change in survival. These data support the use of serial risk stratification as treatment target in pulmonary arterial hypertension.

Blocking Sigmar1 exacerbates methamphetamine-induced hypertension

AIM

Methamphetamine (METH) chronic exposure is an important risk factor for hypertension development. However, the mechanisms behind METH-induced hypertension remain unclear. Therefore, we aimed to reveal the potential mechanisms underlying METH-induced hypertension.

METHODS AND RESULTS

We structured the mouse hypertension model by METH, and observed that METH-treated mice have presented vascular remodeling (large-and small-size arteries) with collagen deposit around the vessel and increasing blood pressure (BP) and Sigma1 receptor (Sigmar1) in vascular tissue. We hypothesized that Sigmar1 is crucial in METH-induced hypertension and vascular remodeling. Sigmar1 knockout (KO) mice and antagonist (BD1047) pretreated mice exposed to METH for six-week showed higher BP and more collagen deposited around vessels than wild-type (WT) mice exposed to METH for six-week, in contrast, mice pretreated with Sigmar1 agonist (PRE-084) had unchanged BP and perivascular collagen despite the six-week METH exposure. Furthermore, we found that METH exposure induced vascular smooth muscle cells (VSMCs) and mesenchymal stem cells to differentiate into the myofibroblast-like cell and secrete collagen into surrounding vessels. Mechanically, Sigmar1 can suppress the COL1A1 expression by blocking the classical fibrotic TGF-β/Smad2/3 signaling pathway in METH-exposed VSMCs and mesenchymal stem cells.

CONCLUSION

Our results suggest that Sigmar1 is involved in METH-induced hypertension and vascular fibrosis by blocking the activation of the TGF-β/Smad2/3 signaling pathway. Accordingly, Sigmar1 may be a novel therapeutic target for METH-induced hypertension and vascular fibrosis.

Risk stratification, prognosis, and survival in a pulmonary arterial hypertension cohort in Latin America. A multicenter study

BACKGROUND

Pulmonary arterial hypertension (PAH) guidelines suggest that achieving a low-risk profile should be the treatment goal. Our aim was to assess a risk assessment strategy based on three non-invasive variables from the ESC/ERS 2015 guidelines in a Latin American cohort.

METHODS

92 incident patients (mean [SD] age 47, 77% female, 53% idiopathic PAH) were included in this retrospective, multicenter study. Patients were stratified at baseline and at early follow-up, within the first year, using three non-invasive variables (WHO functional class, 6-minute walking distance, BNP/NT-proBNP) from the ESC/ERS 2015 risk assessment instrument. Median (IQR) follow-up was 3.11 years (3.01 years).

RESULTS

At baseline assessment, 25% of patients were at low risk, 61.9% at intermediate-risk, and 13% at high-risk. At early follow-up (median 9.5 months), 56.5% of patients were at low-risk, 40.2% at intermediate-risk, and 3.2% at high-risk (p<0.001 vs. baseline). According to risk stratification at early follow-up, one, three and five-year overall survival was 100% in the low-risk group (no deaths at five-year follow-up), and 100%, 84% (95% CI: 72-98%), and 66% (95% CI: 48-90%) respectively in the intermediate-risk group, p = 0.0003. Mortality in the high-risk patients at early follow-up was 1/3 (33.3%). One, three, and five-year event-free survival (death or transplant or first hospitalization due to worsening PAH) based on early follow-up risk assessment was higher in the low-risk group, p = 0.0003.

CONCLUSION

Our study validates a risk assessment strategy based on three non-invasive variables and confirms that early achievement of a low-risk profile should be the treatment goal.

Development and validation of prediction models for hypertension risks: A cross-sectional study based on 4,287,407 participants

Objective

To develop an optimal screening model to identify the individuals with a high risk of hypertension in China by comparing tree-based machine learning models, such as classification and regression tree, random forest, adaboost with a decision tree, extreme gradient boosting decision tree, and other machine learning models like an artificial neural network, naive Bayes, and traditional logistic regression models.

Methods

A total of 4,287,407 adults participating in the national physical examination were included in the study. Features were selected using the least absolute shrinkage and selection operator regression. The Borderline synthetic minority over-sampling technique was used for data balance. Non-laboratory and semi-laboratory analyses were carried out in combination with the selected features. The tree-based machine learning models, other machine learning models, and traditional logistic regression models were constructed to identify individuals with hypertension, respectively. Top features selected using the best algorithm and the corresponding variable importance score were visualized.

Results

A total of 24 variables were finally included for analyses after the least absolute shrinkage and selection operator regression model. The sample size of hypertensive patients in the training set was expanded from 689,025 to 2,312,160 using the borderline synthetic minority over-sampling technique algorithm. The extreme gradient boosting decision tree algorithm showed the best results (area under the receiver operating characteristic curve of non-laboratory: 0.893 and area under the receiver operating characteristic curve of semi-laboratory: 0.894). This study found that age, systolic blood pressure, waist circumference, diastolic blood pressure, albumin, drinking frequency, electrocardiogram, ethnicity (uyghur, hui, and other), body mass index, sex (female), exercise frequency, diabetes mellitus, and total bilirubin are important factors reflecting hypertension. Besides, some algorithms included in the semi-laboratory analyses showed less improvement in the predictive performance compared to the non-laboratory analyses.

Conclusion

Using multiple methods, a more significant prediction model can be built, which discovers risk factors and provides new insights into the prediction and prevention of hypertension.

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.

Prediction Models and Scores in Pulmonary Hypertension: A Review

BACKGROUND

Pulmonary arterial hypertension (PAH) is a serious disease with increased morbidity and mortality. The need for an individualized patient treatment approach necessitates the use of risk assessment in PAH patients. That may include a range of hemodynamic, clinical, imaging and biochemical parameters derived from clinical studies and registry data.

OBJECTIVE

In the current systematic review, we summarize the available data on risk prognostic models and scores in PAH and we explore the possible concordance amongst different risk stratification tools in PAH.

METHODS

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines aided the performance of this systematic review. Eligible studies were identified through a literature search in the electronic databases PubMed, Science Direct, Google Scholar and Cochrane with the use of various combinations of MeSH and non-MeSH terms, with a focus on PAH.

RESULTS

Overall, 25 studies were included in the systematic review; out of them, 9 were studies deriving prognostic equations and risk scores and 16 were validating studies of an existing score. The majority of risk stratification scores use hemodynamic data for the assessment of prognosis, while others also include clinical and demographic variables in their equations. The risk discrimination in the overall PAH population was adequate, especially in differentiating the low versus high-risk patients, but their discrimination ability in the intermediate groups remained lower. Current ESC/ERS proposed risk stratification score utilizes a limited number of parameters with prognostic significance, whose prognostic ability has been validated in European patient populations.

CONCLUSION

Despite improvement in risk estimation of prognostic tools of the disease, PAH morbidity and mortality remain high, necessitating the need for the risk scores to undergo periodic re-evaluation and refinements to incorporate new data into predictors of disease progression and mortality and, thereby, maintain their clinical utility.

Validation of the REVEAL Prognostic Equation and Risk Score Calculator in Incident Systemic Sclerosis-Associated Pulmonary Arterial Hypertension

OBJECTIVE

A prognostic equation and risk score calculator derived from the Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL) are being used to predict 1-year survival in patients with pulmonary arterial hypertension (PAH), but little is known about the performance of these REVEAL survival prediction tools in systemic sclerosis (SSc)-associated PAH (SSc-PAH).

METHODS

Prospectively gathered data from the Johns Hopkins Pulmonary Hypertension Program and Pulmonary Hypertension Assessment and Recognition of Outcome in Scleroderma Registries were used to evaluate the predictive accuracy of the REVEAL models for predicting the probability of 1-year survival in patients with SSc-PAH. Model discrimination was assessed by comparison of the Harrell's C-index, model fit was assessed using multivariable regression techniques, and model calibration was assessed by comparing predicted to observed survival estimates.

RESULTS

The validation cohort consisted of 292 SSc-PAH patients with a 1-year survival rate of 87.4%. The C-index for predictive accuracy of the REVEAL prognostic equation (0.734, 95% confidence interval [95% CI] 0.652-0.816) and for the risk score (0.743, 95% CI 0.663-0.823) demonstrated good discrimination, comparable to that in the model development cohort. The calibration slope was 0.707 (95% CI 0.400-1.014), indicating that the overall model fit was marginal (P = 0.06). The magnitude of risk assigned to low distance on the 6-minute walk test (6MWD) and elevated serum levels of brain natriuretic peptide (BNP) was lower in the validation cohort than was originally seen in the REVEAL derivation cohort. Model calibration was poor, particularly for the highest risk groups.

CONCLUSION

In predicting 1-year survival in patients newly diagnosed as having SSc-PAH, the REVEAL prognostic equation and risk score provide very good discrimination but poor calibration. REVEAL prediction scores should be interpreted with caution in newly diagnosed SSc-PAH patients, particularly those with higher predicted risk of poor 1-year survival resulting from a low 6MWD or a high BNP serum level.

Pulmonary Arterial Hypertension

This article provides an overview of pulmonary arterial hypertension (PAH), beginning with the initial pathologic recognition of pulmonary hypertension more than 100 years ago and progressing to the current diagnostic categorization of PAH. It reviews the epidemiology, pathophysiology, genetics, and modern treatment of PAH. The article discusses several important recent studies that have highlighted the importance of new management strategies, including serial risk assessment and combination pharmacotherapy.

Prognostic relevance of the right ventricular myo-mechanical index (RV-MMI) in patients with precapillary pulmonary hypertension

Objective

The aim of the prospective New-RV study was to evaluate a parameter for non-invasive quantification of right ventricular (RV) dysfunction in patients with precapillary pulmonary hypertension (PH) that yields prognostic information and is applicable in daily clinical routine.

Methods

Sixty-five consecutive patients with precapillary PH under guideline conform therapy (43 women, 22 men) underwent clinical assessment, serological testing, as well as a comprehensive transthoracic echocardiography including strain imaging and a detailed assessment of RV haemodynamics.

Results

The mean follow-up time was 844 days. Sixteen patients died during clinical follow-up. Right ventricular myo-mechanical index (RV-MMI) was calculated by right atrial size, mean RV pressure gradient and strain imaging of the RV free wall, and was measurable in all examinations. RV-MMI was tested for its diagnostic accuracy (sensitivity of 88% and specificity of 73% for an optimal cut-off value of ≤0.31 mm Hg^*%; area under the curve=0.85), as well as its predictive value (HR=3.3, 95% CI 1.6 to 7.0, p<0.001), and was compared in detail with established parameters. RV-MMI and N-terminal pro-brain natriuretic peptide (NTproBNP)were independent predictors of survival (HR=2.9, 95% CI 1.4 to 6.2, p=0.006; and HR=2.6, 95% CI 1.5 to 4.6, p=0.001, respectively).

Conclusion

In a cohort of patients with precapillary PH, the RV-MMI differentiates the outcome of patients better than other available non-invasive parameters of RV function by preload and afterload adjusted quantification.

Trial registration number

NCT01230294.

Tolerability and clinical efficacy of inhaled treprostinil in patients with group 1 pulmonary arterial hypertension

Background

Treprostinil is a prostacyclin analogue that directly vasodilates pulmonary and systemic arterial vascular beds. The United States Food and Drug Administration approved inhaled treprostinil in July 2009 for the treatment of group 1 pulmonary arterial hypertension. Inhaled treprostinil avoids issues with continuous infusion prostanoids. This study describes a single institutional experience with inhaled treprostinil.

Methods

This was a retrospective review of group 1 pulmonary arterial hypertension patients receiving inhaled treprostinil from July 2009 through September 2015. Patient demographics, vital signs, prognostic indicators, pulmonary arterial hypertension assessments, treprostinil dosing, pulmonary arterial hypertension medications, and physician assessment were collected. Prognostic indicators and the physician assessment were used to assess treatment response. A modified Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL) risk score was calculated prior to and after initiation of inhaled treprostinil.

Results

The mean time on inhaled treprostinil for the 16 patients was 21 ± 17 months. A total of 31% discontinued treatment. The New York Heart Association Functional Class, right ventricular size, and right ventricular function improved after inhaled treprostinil. Directional improvement in B-type natriuretic peptide, 6-minute walk distance, right arterial pressure and mean pulmonary artery pressure were also observed. The mean modified REVEAL risk score (RRS) was 7 ± 3 at baseline. The RRS decreased in 7 of the 11 patients that improved and remained stable in 2 patients.

Conclusion

The majority of patients in this consecutive series receiving inhaled treprostinil tolerated treatment. Most patients remained on therapy for over 12 months. Clinical assessments of disease severity all changed directionally toward improvement and the overall risk assessment was improved or stable in 56% by the RRS.

Managing the Patient With Pulmonary Arterial Hypertension and Methamphetamine Use: A Practical Perspective for the Clinician

Pulmonary arterial hypertension (PAH) is a serious, chronic, progressive cardiopulmonary disease. PAH is associated with several concomitant conditions, as well as drugs and toxins.12 Methamphetamine abuse is likely associated with the development of PAH.3 Methamphetamine abuse is epidemic in the United States and abroad, with rates of new users escalating since 2012. There are over 100,000 new users annually as young as 12 years old. Treating a patient with a history of methamphetamine abuse poses many challenges for a clinician, including nonadherence, therapeutic treatment selection, complex psychosocial issues, and relapse or continued drug abuse. Patients with methamphetamine-associated PAH (Meth-APAH) have higher mortality rates when compared to idiopathic PAH.3 Having a better understanding of the complexities of addiction and working with a multidisciplinary team that includes a social worker to provide care and counseling to these patients can improve their trajectory. In this article, we will offer insight and background into methamphetamine abuse and addiction, as well as discuss a practical approach for clinicians in treating a patient with Meth-APAH, based on the literature, as well as our personal experiences at University of California, San Francisco Medical Center.

Low-density lipoprotein cholesterol and survival in pulmonary arterial hypertension

Low-density lipoprotein cholesterol(LDL-C) is a well established metabolic marker of cardiovascular risk, however, its role in pulmonary arterial hypertension (PAH) has not been determined. Therefore we assessed whether LDL-C levels are altered in PAH patients, if they are associated with survival in this group and whether pulmonary hypertension (PH) reversal can influence LDL-C levels. Consecutive 46 PAH males and 94 females were age matched with a representative sample of 1168 males and 1245 females, respectively. Cox regression models were used to assess the association between LDL-C and mortality. The effect of PH reversal on LDL-C levels was assessed in 34 patients with chronic thromboembolic pulmonary hypertension (CTEPH) undergoing invasive treatment. LDL-C was lower in both PAH (2.6 ± 0.8 mmol/l) and CTEPH (2.7 ± 0.7 mmol/l) patients when compared to controls (3.2 ± 1.1 mmol/l, p < 0.001). In PAH patients lower LDL-C significantly predicted death (HR:0.44/1 mmol/l, 95%CI:0.26-0.74, p = 0.002) after a median follow-up time of 33(21-36) months. In the CTEPH group, LDL-C increased (from 2.6[2.1-3.2] to 4.0[2.8-4.9]mmol/l, p = 0.01) in patients with PH reversal but remained unchanged in other patients (2.4[2.2-2.7] vs 2.3[2.1-2.5]mmol/l, p = 0.51). We concluded that LDL-C level is low in patients with PAH and is associated with an increased risk of death. Reversal of PH increases LDL-C levels.

Validation of two predictive models for survival in pulmonary arterial hypertension

The French Pulmonary Hypertension Network (FPHN) registry and the Registry to Evaluate Early And Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL) have developed predictive models for survival in pulmonary arterial hypertension (PAH). In this collaboration, we assess the external validity (or generalisability) of the FPHN ItinérAIR-HTAP predictive equation and the REVEAL risk score calculator.

Validation cohorts approximated the eligibility criteria defined for each model. The REVEAL cohort comprised 292 treatment-naïve, adult patients diagnosed <1 year prior to enrolment with idiopathic, familial or anorexigen-induced PAH. The FPHN cohort comprised 1737 patients with group 1 PAH.

Application of FPHN parameters to REVEAL and REVEAL risk scores to FPHN demonstrated estimated hazard ratios that were consistent between studies and had high probabilities of concordance (hazard ratios of 0.72, 95% CI 0.64–0.80, and 0.73, 95% CI 0.70–0.77, respectively).

The REVEAL risk score calculator and FPHN ItinérAIR-HTAP predictive equation showed good discrimination and calibration for prediction of survival in the FPHN and REVEAL cohorts, respectively, suggesting prognostic generalisability in geographically different PAH populations. Once prospectively validated, these may become valuable tools in clinical practice.

Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD): explanation and elaboration

The TRIPOD (Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis) Statement includes a 22-item checklist, which aims to improve the reporting of studies developing, validating, or updating a prediction model, whether for diagnostic or prognostic purposes. The TRIPOD Statement aims to improve the transparency of the reporting of a prediction model study regardless of the study methods used. This explanation and elaboration document describes the rationale; clarifies the meaning of each item; and discusses why transparent reporting is important, with a view to assessing risk of bias and clinical usefulness of the prediction model. Each checklist item of the TRIPOD Statement is explained in detail and accompanied by published examples of good reporting. The document also provides a valuable reference of issues to consider when designing, conducting, and analyzing prediction model studies. To aid the editorial process and help peer reviewers and, ultimately, readers and systematic reviewers of prediction model studies, it is recommended that authors include a completed checklist in their submission. The TRIPOD checklist can also be downloaded from www.tripod-statement.org.

Prognostic implications of serial risk score assessments in patients with pulmonary arterial hypertension: a Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL) analysis

BACKGROUND

Data from the Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL) were used previously to develop a risk score calculator to predict 1-year survival. We evaluated prognostic implications of changes in the risk score and individual risk-score parameters over 12 months.

METHODS

Patients were grouped by decreased, unchanged, or increased risk score from enrollment to 12 months. Kaplan-Meier estimates of subsequent 1-year survival were made based on change in the risk score during the initial 12 months of follow-up. Cox regression was used for multivariable analysis.

RESULTS

Of 2,529 patients in the analysis cohort, the risk score was decreased in 800, unchanged in 959, and increased in 770 at 12 months post-enrollment. Six parameters (functional class, systolic blood pressure, heart rate, 6-minute walk distance, brain natriuretic peptide levels, and pericardial effusion) each changed sufficiently over time to improve or worsen risk scores in ≥5% of patients. One-year survival estimates in the subsequent year were 93.7%, 90.3%, and 84.6% in patients with a decreased, unchanged, and increased risk score at 12 months, respectively. Change in risk score significantly predicted future survival, adjusting for risk at enrollment. Considering follow-up risk concurrently with risk at enrollment, follow-up risk was a much stronger predictor, although risk at enrollment maintained a significant effect on future survival.

CONCLUSIONS

Changes in REVEAL risk scores occur in most patients with pulmonary arterial hypertension over a 12-month period and are predictive of survival. Thus, serial risk score assessments can identify changes in disease trajectory that may warrant treatment modifications.

Performance of the REVEAL pulmonary arterial hypertension prediction model using non-invasive and routinely measured parameters

BACKGROUND

The REVEAL model for pulmonary arterial hypertension (PAH) uses 19 predictors to calculate a 1-year survival probability and can be repeated over time. It is currently unclear which of the 19 variables are the most essential for serial REVEAL score calculation. We aimed to identify high-yield predictors in the REVEAL score and hypothesized that the model could be simplified considerably without compromising performance.

METHODS

REVEAL scores were calculated in a cohort of 140 PAH patients (Full REVEAL Model). Scores were then recalculated excluding all right heart catheterization and pulmonary function test data (Simple Model) and again using only PAH type, New York Heart Association class, brain natriuretic peptide, renal function and right atrial pressure by echocardiogram (Clinical Model). The models were then tested for the ability to predict 1-year outcomes and the performance of the models was compared.

RESULTS

The c indices of the models to predict 1-year survival were not statistically different from one another (Full REVEAL Model: 0.765; Simple Model: 0.759; Clinical Model: 0.745; p = 0.92). For the composite outcome of survival or freedom from lung transplant at 1 year, the models were again not statistically different from one another (c indices: Full REVEAL Model: 0.805; Simple Model: 0.809; Clinical Model: 0.785; p = 0.73).

CONCLUSIONS

The original, Full REVEAL Model appeared to have comparable performance after selectively limiting the number of predictors. There is opportunity to re-evaluate large-registry PAH data to identify a limited number of high-yield variables and to develop a simplified, clinical model.