An electrocardiogram-based AI algorithm for early detection of pulmonary hypertension.

BACKGROUND: Early diagnosis of pulmonary hypertension (PH) is critical for effective treatment and management. We aimed to develop and externally validate an artificial intelligence algorithm that could serve as a PH screening tool, based on analysis of a standard 12-lead electrocardiogram (ECG). METHODS: The PH Early Detection Algorithm (PH-EDA) is a convolutional neural network developed using retrospective ECG voltage-time data, with patients classified as "PH-likely" or "PH-unlikely" (controls) based on right heart catheterisation or echocardiography. In total, 39 823 PH-likely patients and 219 404 control patients from Mayo Clinic were randomly split into training (48%), validation (12%), and test (40%) sets. ECGs taken within 1 month of PH diagnosis (diagnostic dataset) were used to train the PH-EDA at Mayo Clinic. Performance was tested on diagnostic ECGs within the test sets from Mayo Clinic (n=16 175/87 998 PH-likely/controls) and Vanderbilt University Medical Center (VUMC; n=6045/24 256 PH-likely/controls). Performance was also tested on ECGs taken 6-18 months (pre-emptive dataset), and up to 5 years prior to a PH diagnosis at both sites. RESULTS: Performance testing yielded an area under the receiver operating characteristic curve (AUC) of 0.92 and 0.88 in the diagnostic test set at Mayo Clinic and VUMC, respectively, and 0.86 and 0.81, respectively, in the pre-emptive test set. The AUC remained a minimum of 0.79 at Mayo Clinic and 0.73 at VUMC up to 5 years before diagnosis. CONCLUSION: The PH-EDA can detect PH at diagnosis and 6-18 months prior, demonstrating the potential to accelerate diagnosis and management of this debilitating disease.

A claims-based, machine-learning algorithm to identify patients with pulmonary arterial hypertension.

Many patients with pulmonary arterial hypertension (PAH) experience substantial delays in diagnosis, which is associated with worse outcomes and higher costs. Tools for diagnosing PAH sooner may lead to earlier treatment, which may delay disease progression and adverse outcomes including hospitalization and death. We developed a machine-learning (ML) algorithm to identify patients at risk for PAH earlier in their symptom journey and distinguish them from patients with similar early symptoms not at risk for developing PAH. Our supervised ML model analyzed retrospective, de-identified data from the US-based Optum® Clinformatics® Data Mart claims database (January 2015 to December 2019). Propensity score matched PAH and non-PAH (control) cohorts were established based on observed differences. Random forest models were used to classify patients as PAH or non-PAH at diagnosis and at 6 months prediagnosis. The PAH and non-PAH cohorts included 1339 and 4222 patients, respectively. At 6 months prediagnosis, the model performed well in distinguishing PAH and non-PAH patients, with area under the curve of the receiver operating characteristic of 0.84, recall (sensitivity) of 0.73, and precision of 0.50. Key features distinguishing PAH from non-PAH cohorts were a longer time between first symptom and the prediagnosis model date (i.e., 6 months before diagnosis); more diagnostic and prescription claims, circulatory claims, and imaging procedures, leading to higher overall healthcare resource utilization; and more hospitalizations. Our model distinguishes between patients with and without PAH at 6 months before diagnosis and illustrates the feasibility of using routine claims data to identify patients at a population level who might benefit from PAH-specific screening and/or earlier specialist referral.

Derivation of a Risk Score (REVEAL-ECHO) Based on Echocardiographic Parameters of Patients With Pulmonary Arterial Hypertension.

BACKGROUND: Multiparametric risk assessment tools determine mortality risk in patients with pulmonary arterial hypertension (PAH) by combining invasive and noninvasive variables so management strategies can be tailored to individuals. RESEARCH QUESTION: Can a risk score based on common echocardiographic parameters risk-stratify patients with PAH? STUDY DESIGN AND METHODS: A Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) echocardiographic risk score (REVEAL-ECHO) was derived using retrospective echocardiographic data from 2,400 adult patients with PAH enrolled in the REVEAL registry database. A stepwise Cox regression model identified echocardiographic parameters significantly predictive of survival. Values were assigned to each selected parameter based on survival at 12 months' follow-up (Kaplan-Meier estimates). The REVEAL-ECHO risk score was the sum of individual values. Patients were categorized as having low, intermediate, or high risk based on Kaplan-Meier-predicted 12-month survival. RESULTS: The risk score included four echocardiographic parameters-right ventricular (RV) chamber enlargement, reduced RV systolic function, tricuspid regurgitation severity, and pericardial effusion-and accounted for PAH etiology. Higher REVEAL-ECHO risk scores signaled lower probability of 12-month survival. Statistically significant separation of mortality risk was observed among the risk strata: intermediate vs low (hazard ratio [HR], 1.43; 95% CI, 1.17-1.75; P = .0004) and high vs low (HR, 2.60; 95% CI, 2.19-3.10; P < .0001). Augmentation of the REVEAL Lite 2 risk calculator with REVEAL-ECHO risk scores achieved separation of REVEAL Lite 2 into four risk groups and identified a subgroup of patients with a low REVEAL Lite 2 risk score who were at higher risk (intermediate-low risk) and a subgroup of patients with an intermediate REVEAL Lite 2 risk score who also were at higher risk (intermediate-high risk). INTERPRETATION: A REVEAL-ECHO risk score, derived using four echocardiographic parameters, may discriminate risk further when used as an adjunct to current risk assessment scores. Further validation is required.

Smoking history and pulmonary arterial hypertension: Demographics, onset, and outcomes.

BACKGROUND: Smoking prevalence and its association with pulmonary arterial hypertension (PAH) outcomes have not been described in patients in the United States. METHODS: Using the US-based Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL), the prevalence, demographics, and outcomes in ever- versus never-smokers with PAH were determined. RESULTS: Ever-smoking status was more prevalent in males (61.7%) than in females (42.9%) enrolled in REVEAL. Ever-smokers were older than never-smokers at the time of PAH diagnosis and REVEAL enrollment. The time to first hospitalization, transplant-free survival, and survival did not differ between ever- and never-smokers overall; however, in newly diagnosed males, ever-smoking was associated with earlier death (hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.1-3.0; p = 0.0199), the composite of transplant or death (HR 2.2, 95% CI 1.4-3.6; p = 0.0008), and first hospitalization (HR 1.8, 95% CI 1.2-2.7; p = 0.0063), though smoking exposure (pack-years) did not differ between newly and previously diagnosed males. CONCLUSIONS: REVEAL PAH data demonstrate that smoking prevalence in male PAH patients is disproportionate. The prevalence of cigarette smoking was significantly higher in males than females enrolled in REVEAL. Ever-smoking status was associated with increased age at PAH diagnosis and, in newly diagnosed male PAH patients, earlier time to hospitalization and shorter survival after PAH diagnosis.

Timely PAH Identification in Adults With Repaired Congenital Heart Disease? The ACHD-QuERI Registry Insights.

Background: The Quality Enhancement Research Initiative (QuERI) in adults with congenital heart disease (ACHD) was developed to improve detection of pulmonary arterial hypertension (PAH) after repair of systemic-to-pulmonary arterial shunt lesions. Objectives: This study sought to standardize use of accepted criteria for PAH diagnosis and evaluate utility in at-risk patients with ACHD. Methods: Patients ≥18 years of age with ACHD repaired ≥1 year before enrollment and with additional risk factors for developing PAH were eligible. History, physical examination, electrocardiogram, transthoracic echocardiogram, World Health Organization functional class, and 6-minute walk distance were evaluated at baseline and yearly for 3 years. Pop-up reminders of patient-specific evidence-based recommendations for PAH detection appeared during data entry. Results: Among 217 eligible patients, mean age (enrollment) was 44.0 ± 15.9 years, 72.3% were women, and 82.0% were World Health Organization functional class I. Electrocardiogram was performed in >80% and TTE in >70% of patients annually; capture of required transthoracic echocardiography (TTE) measures and alignment between study- and core-center interpretation improved over time, with more frequent assessment of pulmonary arterial flow acceleration time and documentation of right ventricular outflow tract Doppler notching. Approximately 40% of patients had ≥2 high-risk features for PAH on TTE, but only 7% (6/82) underwent right heart catheterization (RHC). Using current definitions, 2 patients were confirmed by RHC to have a diagnosis of PAH (maximum follow-up 3 years). Conclusions: A structured protocol may improve screening for patients with repaired ACHD at risk of developing PAH. RHC may be underutilized in patients with ACHD with TTE findings suggestive of PAH. (Adult Congenital Heart Disease Registry [QuERI]; NCT01659411).

Using a knowledge translation program to facilitate guideline- and evidence-based patient management: the PAH-QuERI Extension Program.

The Pulmonary Arterial Hypertension-Quality Enhancement Research Initiative Extension Program was designed to support physicians' adherence to pulmonary arterial hypertension (PAH) guidelines. Guidelines were followed in >95% of patients with functional class (FC) II/III, but for only 28.6% of FC IV patients (Month 36). Low adherence was driven by FC IV patients' preference to avoid parenteral treatment.

Development and Validation of an Abridged Version of the REVEAL 2.0 Risk Score Calculator, REVEAL Lite 2, for Use in Patients With Pulmonary Arterial Hypertension.

BACKGROUND: Achievement of low-risk status is a treatment goal in pulmonary arterial hypertension (PAH). Risk assessment often is performed using multiparameter tools, such as the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) risk calculator. Risk calculators that assess fewer variables without compromising validity may expedite risk assessment in the routine clinic setting. We describe the development and validation of REVEAL Lite 2, an abridged version of REVEAL 2.0. RESEARCH QUESTION: Can a simplified version of the REVEAL 2.0 risk assessment calculator for patients with PAH be developed and validated? STUDY DESIGN AND METHODS: REVEAL Lite 2 includes six noninvasive variables-functional class (FC), vital signs (systolic BP [SBP] and heart rate), 6-min walk distance (6MWD), brain natriuretic peptide (BNP)/N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and renal insufficiency (by estimated glomerular filtration rate [eGFR])-and was validated in a series of analyses (Kaplan-Meier, concordance index, Cox proportional hazard model, and multivariate analysis). RESULTS: REVEAL Lite 2 approximates REVEAL 2.0 at discriminating low, intermediate, and high risk for 1-year mortality in patients in the REVEAL registry. The model indicated that the most highly predictive REVEAL Lite 2 parameter was BNP/NT-proBNP, followed by 6MWD and FC. Even if multiple, less predictive variables (heart rate, SBP, eGFR) were missing, REVEAL Lite 2 still discriminated among risk groups. INTERPRETATION: REVEAL Lite 2, an abridged version of REVEAL 2.0, provides a simplified method of risk assessment that can be implemented routinely in daily clinical practice. REVEAL Lite 2 is a robust tool that provides discrimination among patients at low, intermediate, and high risk of 1-year mortality. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00370214; URL: www.clinicaltrials.gov.

Risk assessment in patients with functional class II pulmonary arterial hypertension: Comparison of physician gestalt with ESC/ERS and the REVEAL 2.0 risk score.

BACKGROUND: Accurate and regular risk assessment is important for evaluation and treatment of pulmonary arterial hypertension (PAH) patients, including those with functional class (FC) II symptoms, a population considered at low risk for disease progression. Risk assessment methods include subjective and objective evaluations. Multiparametric assessments include tools based on the European Society of Cardiology/European Respiratory Society (ESC/ERS) guidelines (COMPERA and FPHR methods, respectively) and the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL; REVEAL 2.0 tool). To better understand risk status determination in FC II patients, we compared physician-reported risk assessments with objective multiparameter assessment tools. METHODS: This retrospective chart analysis included PAH patients with FC II symptoms receiving monotherapy or dual therapy. Physicians were surveyed (via telephone) to obtain an assessment of patient risk using their typical methodology, which might have been informed by objective risk assessment. Patient risk was then calculated independently using COMPERA, FPHR and REVEAL 2.0 tools. Factors associated with incongruent risk assessment were identified. RESULTS: Of the 153 patients, 41%, 46%, and 13% were classified as low, intermediate, and high risk, respectively, by physicians. Concordance between physician gestalt and objective methods ranged from 43%-54%. Among patients considered as low risk by physician gestalt, 4%-28% were categorized as high risk using objective methods. The most common physician factor associated with incongruent risk assessment was less frequent echocardiography during follow-up (every 7-12 months vs. every 3 months; p = 0.01). CONCLUSIONS: More than half of FC II PAH patients were classified as intermediate/high risk using objective multiparameter assessments. Incorporating objective risk-assessment algorithms into clinical practice may better inform risk assessment and treatment strategies.

Impact of race on survival in pulmonary arterial hypertension: Results from the REVEAL registry.

BACKGROUND: Prior research has suggested that the prevalence and outcomes of pulmonary arterial hypertension (PAH) may vary by race or ethnicity. However, these studies have been limited by small sample size or methodological techniques relying on epidemiologic data. The purpose of this study is to evaluate the relationship between race/ethnicity and survival in a large U.S.-based prospective multicenter registry. METHODS: Patients in the Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL), a 5-year observational study of Group 1 PAH, were categorized by race/ethnicity. Baseline hemodynamic characteristics, clinical characteristics, and medication use was described. The relationship between race/ethnicity and outcome was evaluated by Kaplan-Meier and Cox proportional hazards modeling techniques. Left-truncation analysis, which adjusted for time from diagnosis to study enrollment, was used to minimize the effect of survivor bias. RESULTS: This analysis included 3,046 patients; 2,202 identified as white, 393 as black, 263 as Hispanic, 100 as Asian or Pacific Islander, and 88 as other. Unadjusted Kaplan-Meier survival analysis indicated that white patients had the lowest survival rates. After adjusting for variables of prognostic impact, race/ethnicity was no longer significantly associated with survival. Other results showed that black patients were more likely to have connective tissue disease-associated PAH, Hispanic patients were more likely to have portopulmonary hypertension, and Asian patients were more likely to have congenital heart disease-associated PAH. CONCLUSIONS: Analysis of the REVEAL registry did not find race/ethnicity to be a significant predictor of mortality. This is the largest analysis to date evaluating the role of race/ethnicity on outcomes in PAH.

Approaching Higher Dimension Imaging Data Using Cluster-Based Hierarchical Modeling in Patients with Heart Failure Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is a major cause of morbidity and mortality, accounting for the majority of heart failure (HF) hospitalization. To identify the most complementary predictors of mortality among clinical, laboratory and echocardiographic data, we used cluster based hierarchical modeling. Using Stanford Translational Research Database, we identified patients hospitalized with HFpEF between 2005 and 2016 in whom echocardiogram and NT-proBNP were both available at the time of admission. Comprehensive echocardiographic assessment including left ventricular longitudinal strain (LVLS), right ventricular function and right ventricular systolic pressure (RVSP) was performed. The outcome was defined as all-cause mortality. Among patients identified, 186 patients with complete echocardiographic assessment were included in the analysis. The cohort included 58% female, with a mean age of 78.7 ± 13.5 years, LVLS of -13.3 ± 2.5%, an estimated RVSP of 38 ± 13 mmHg. Unsupervised cluster analyses identified six clusters including ventricular systolic-function cluster, diastolic-hemodynamic cluster, end-organ function cluster, vital-sign cluster, complete blood count and sodium clusters. Using a stepwise hierarchical selection from each cluster, we identified NT-proBNP (standard hazard ratio [95%CI] = 1.56 [1.17-2.08]) and RVSP (1.37 [1.09-1.78]) as independent correlates of outcome. When adding these parameters to the well validated Get with the Guideline Heart Failure risk score, the Chi-square was significantly improved (p = 0.01). In conclusion, NT-proBNP and RVSP were independently predictive in HFpEF among clinical, imaging, and biomarker parameters. Cluster-based hierarchical modeling may help identify the complementally predictive parameters in small cohorts with higher dimensional clinical data.

Predicting Survival in Patients With Pulmonary Arterial Hypertension: The REVEAL Risk Score Calculator 2.0 and Comparison With ESC/ERS-Based Risk Assessment Strategies.

BACKGROUND: Pulmonary arterial hypertension is a progressive, fatal disease. Published treatment guidelines recommend treatment escalation on the basis of regular patient assessment with the goal of achieving or maintaining low-risk status. Various strategies are available to determine risk status. This analysis describes an update of the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) risk calculator (REVEAL 2.0) and compares it with recently published European Society of Cardiology/Respiratory Society guideline-derived risk assessment strategies. METHODS: A subpopulation from the US-based registry REVEAL that survived ≥ 1 year postenrollment (baseline for this cohort) was analyzed. For REVEAL 2.0, point values and cutpoints were reassessed, and new variables were evaluated. The Kaplan-Meier method was used to estimate survival at 12 months postbaseline; discrimination was quantified using the c-statistic. Mortality estimates and discrimination were compared between REVEAL 2.0 and Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA) and French Pulmonary Hypertension Registry (FPHR) risk assessment strategies. For this comparison, a three-category REVEAL 2.0 score was computed in which patients were classified as low-, intermediate-, or high-risk. RESULTS: REVEAL 2.0 demonstrated similar discrimination as the original calculator in this subpopulation (c-statistic = 0.76 vs 0.74), provided excellent separation of risk among the risk categories, and predicted clinical worsening as well as mortality in patients who were followed ≥ 1 year. The REVEAL 2.0 three-category score had greater discrimination (c-statistic = 0.73) than COMPERA (c-statistic = 0.62) or FPHR (c-statistic = 0.64). Compared with REVEAL 2.0, COMPERA and FPHR both underestimated and overestimated risk. CONCLUSIONS: REVEAL 2.0 demonstrates greater risk discrimination than the COMPERA and FPHR risk assessment strategies in patients enrolled in REVEAL. After external validation, the REVEAL 2.0 calculator can assist clinicians and patients in making informed treatment decisions on the basis of individual risk profiles. TRIAL REGISTRY: ClinicalTrials.gov; No. NCT00370214; URL: www.clinicaltrials.gov.

Use of supplemental oxygen in patients with pulmonary arterial hypertension in REVEAL.

BACKGROUND: Supplemental low-flow oxygen is recommended by treatment guidelines as supportive therapy for patients with pulmonary arterial hypertension (PAH), based largely on expert opinion. Reduced diffusing capacity of lung carbon monoxide (DLCO) is associated with increased mortality in PAH. Reduced DLCO is also associated with relative hypoxemia, making the effects of supplemental oxygen use of particular interest in this sub-population. METHODS: Patients in the Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL), a 5-year observational study of Group 1 PAH, were categorized by presence or absence of supplemental oxygen use and by degree of DLCO reduction. Kaplan-Meier survival estimates were calculated by group. RESULTS: Of 3,046 patients, 57% used supplemental oxygen and 43% did not. Supplemental oxygen users had worse prognostic factors and more PAH-specific medication use. Of the 424 patients with severe DLCO reduction (<40% of predicted), 76% used oxygen and 24% did not. Patients with severe DLCO reduction who used supplemental oxygen had a significantly lower risk of all-cause mortality than those who did not (hazard ratio 0.56; 95% confidence interval 0.39 to 0.83; p = 0.0033). This was true for newly diagnosed and previously diagnosed patients. There was no relationship between oxygen use and outcomes in patients with no, mild, or moderate DLCO reduction. CONCLUSIONS: In this observational study, the risk of death was significantly lower for patients with severe DLCO reduction who received supplemental oxygen compared with those who did not. A randomized trial is warranted to further investigate the relationship between supplemental oxygen use and outcomes in PAH.

Hypoxia Upregulates Estrogen Receptor ß in Pulmonary Artery Endothelial Cells in a HIF-1α-Dependent Manner.

17ß-Estradiol (E2) attenuates hypoxia-induced pulmonary hypertension (HPH) through estrogen receptor (ER)-dependent effects, including inhibition of hypoxia-induced endothelial cell proliferation; however, the mechanisms responsible for this remain unknown. We hypothesized that the protective effects of E2 in HPH are mediated through hypoxia-inducible factor 1α (HIF-1α)-dependent increases in ERß expression. Sprague-Dawley rats and ERα or ERß knockout mice were exposed to hypobaric hypoxia for 2-3 weeks. The effects of hypoxia were also studied in primary rat or human pulmonary artery endothelial cells (PAECs). Hypoxia increased expression of ERß, but not ERα, in lungs from HPH rats as well as in rat and human PAECs. ERß mRNA time dependently increased in PAECs exposed to hypoxia. Normoxic HIF-1α/HIF-2α stabilization increased PAEC ERß, whereas HIF-1α knockdown decreased ERß abundance in hypoxic PAECs. In turn, ERß knockdown in hypoxic PAECs increased HIF-2α expression, suggesting a hypoxia-sensitive feedback mechanism. ERß knockdown in hypoxic PAECs also decreased expression of the HIF inhibitor prolyl hydroxylase 2 (PHD2), whereas ERß activation increased PHD2 and decreased both HIF-1α and HIF-2α, suggesting that ERß regulates the PHD2/HIF-1α/HIF-2α axis during hypoxia. Whereas hypoxic wild-type or ERα knockout mice treated with E2 demonstrated less pulmonary vascular remodeling and decreased HIF-1α after hypoxia compared with untreated hypoxic mice, ERß knockout mice exhibited increased HIF-2α and an attenuated response to E2 during hypoxia. Taken together, our results demonstrate a novel and potentially therapeutically targetable mechanism whereby hypoxia, via HIF-1α, increases ERß expression and the E2-ERß axis targets PHD2, HIF-1α, and HIF-2α to attenuate HPH development.

Baseline and Serial Brain Natriuretic Peptide Level Predicts 5-Year Overall Survival in Patients With Pulmonary Arterial Hypertension: Data From the REVEAL Registry.

BACKGROUND: Plasma brain natriuretic peptide (BNP) level is a prognostic biomarker in pulmonary arterial hypertension (PAH). Its impact on long-term overall survival (OS) was investigated in the Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL), a 5-year observational, multicenter, US registry of patients with PAH. METHODS: Patients were ≥ 18 years of age, met right heart catheterization criteria at rest, had World Health Organization group I PAH, and had BNP measurement at enrollment. Optimal BNP threshold was obtained via receiver operating characteristic curve analysis. OS was compared in patients with low (≤ 340 pg/mL) vs high (> 340 pg/mL) BNP at baseline; changes between baseline and last assessment were also examined. Patients were categorized based on baseline (low or high) and follow-up (low or high) BNP values; hazard ratios (HRs) for OS were estimated and compared using Cox regression. RESULTS: Overall, 1,426 patients were analyzed. Mortality risk was significantly higher in patients with baseline high vs low BNP (HR, 3.6; 95% CI, 3.0-4.2). BNP change analysis at ≤ 1 year postenrollment demonstrated that the low-low group had the lowest and the high-high group had the highest 5-year mortality risk (HR, 0.23; 95% CI, 0.19-0.27). Changes in BNP score also correlated with change of risk of death. CONCLUSIONS: Baseline BNP threshold of 340 pg/mL strongly predicted survival up to 5 years in patients with PAH. A BNP reduction at 1 year since enrollment was associated with decreased mortality risk, whereas an increase in BNP at 1 year was associated with an increased mortality risk, supporting BNP as a surrogate marker of PAH survival.

Impact of declining renal function on outcomes in pulmonary arterial hypertension: A REVEAL registry analysis.

BACKGROUND: Renal dysfunction is associated with abnormal cardiopulmonary hemodynamics, in-hospital death and poor survival in patients with pulmonary arterial hypertension (PAH), and thus it may be a prognostic biomarker. In our analysis we assess the relationship between change in estimated glomerular filtration rate (eGFR) and outcomes in PAH patients in the Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL). METHODS: Overall 2,368 patients were classified into chronic kidney disease (CKD) stages based on baseline eGFR: normal or Stages 1 or 2 (n = 1,699); Stage 3a (n = 399); Stage 3b (n = 196); and Stages 4 or 5 (n = 74). We evaluated the relationship between baseline CKD stage and survival, as well as the composite end-point of survival and freedom from all-cause hospitalization. The relationships between change in eGFR at ≥1 year and these clinical end-points were also evaluated. RESULTS: Patients with a ≥10% decline in eGFR from baseline over ≥1 year had a significantly increased risk of death (hazard ratio 1.66; p < 0.0001) and the composite of all-cause hospitalization and death (hazard ratio 1.33; p = 0.002). This decline predicted survival independently of changes in 6-minute walk distance and functional class. However, a ≥10% increase in eGFR was not significantly associated with either end-point. CONCLUSION: In REVEAL, a ≥10% decline in eGFR over ≥1 year independently predicted poorer survival. Thus, eGFR may be a simple and economical biomarker in PAH.

Health Disparities in Patients with Pulmonary Arterial Hypertension: A Blueprint for Action. An Official American Thoracic Society Statement.

BACKGROUND: Health disparities have a major impact in the quality of life and clinical care received by minorities in the United States. Pulmonary arterial hypertension (PAH) is a rare cardiopulmonary disorder that affects children and adults and that, if untreated, results in premature death. The impact of health disparities in the diagnosis, treatment, and clinical outcome of patients with PAH has not been systematically investigated. OBJECTIVES: The specific goals of this research statement were to conduct a critical review of the literature concerning health disparities in PAH, identify major research gaps and prioritize direction for future research. METHODS: Literature searches from multiple reference databases were performed using medical subject headings and text words for pulmonary hypertension and health disparities. Members of the committee discussed the evidence and provided recommendations for future research. RESULTS: Few studies were found discussing the impact of health disparities in PAH. Using recent research statements focused on health disparities, the group identified six major study topics that would help address the contribution of health disparities to PAH. Representative studies in each topic were discussed and specific recommendations were made by the group concerning the most urgent questions to address in future research studies. CONCLUSIONS: At present, there are few studies that address health disparities in PAH. Given the potential adverse impact of health disparities, we recommend that research efforts be undertaken to address the topics discussed in the document. Awareness of health disparities will likely improve advocacy efforts, public health policy and the quality of care of vulnerable populations with PAH.

Load Adaptability in Patients With Pulmonary Arterial Hypertension.

Right ventricular (RV) adaptation to pressure overload is a major prognostic factor in patients with pulmonary arterial hypertension (PAH). The objectives were first to define the relation between RV adaptation and load using allometric modeling, then to compare the prognostic value of different indices of load adaptability in PAH. Both a derivation (n = 85) and a validation cohort (n = 200) were included. Load adaptability was assessed using 3 approaches: (1) surrogates of ventriculo-arterial coupling (e.g., RV area change/end-systolic area), (2) simple ratio of function and load (e.g., tricuspid annular plane systolic excursion/right ventricular systolic pressure), and (3) indices assessing the proportionality of adaptation using allometric pressure-function or size modeling. Proportional hazard modeling was used to compare the hazard ratio for the outcome of death or lung transplantation. The mean age of the derivation cohort was 44 ± 11 years, with 80% female and 74% in New York Heart Association class III or IV. Mean pulmonary vascular resistance index (PVRI) was 24 ± 11 with a wide distribution (1.6 to 57.5 WU/m2). Allometric relations were observed between PVRI and RV fractional area change (R2 = 0.53, p < 0.001) and RV end-systolic area indexed to body surface area right ventricular end-systolic area index (RVESAI) (R2 = 0.29, p < 0.001), allowing the derivation of simple ratiometric load-specific indices of RV adaptation. In right heart parameters, RVESAI was the strongest predictor of outcomes (hazard ratio per SD = 1.93, 95% confidence interval 1.37 to 2.75, p < 0.001). Although RVESAI/PVRI0.35 provided small incremental discrimination on multivariate modeling, none of the load-adaptability indices provided stronger discrimination of outcome than simple RV adaptation metrics in either the derivation or the validation cohort. In conclusion, allometric modeling enables quantification of the proportionality of RV load adaptation but offers small incremental prognostic value to RV end-systolic dimension in PAH.

Right Heart End-Systolic Remodeling Index Strongly Predicts Outcomes in Pulmonary Arterial Hypertension: Comparison With Validated Models.

BACKGROUND: Right ventricular (RV) end-systolic dimensions provide information on both size and function. We investigated whether an internally scaled index of end-systolic dimension is incremental to well-validated prognostic scores in pulmonary arterial hypertension. METHODS AND RESULTS: From 2005 to 2014, 228 patients with pulmonary arterial hypertension were prospectively enrolled. RV end-systolic remodeling index (RVESRI) was defined by lateral length divided by septal height. The incremental values of RV free wall longitudinal strain and RVESRI to risk scores were determined. Mean age was 49±14 years, 78% were female, 33% had connective tissue disease, 52% were in New York Heart Association class ≥III, and mean pulmonary vascular resistance was 11.2±6.4 WU. RVESRI and right atrial area were strongly connected to the other right heart metrics. Three zones of adaptation (adapted, maladapted, and severely maladapted) were identified based on the RVESRI to RV systolic pressure relationship. During a mean follow-up of 3.9±2.4 years, the primary end point of death, transplant, or admission for heart failure was reached in 88 patients. RVESRI was incremental to risk prediction scores in pulmonary arterial hypertension, including the Registry to Evaluate Early and Long-Term PAH Disease Management score, the Pulmonary Hypertension Connection equation, and the Mayo Clinic model. Using multivariable analysis, New York Heart Association class III/IV, RVESRI, and log NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) were retained (χ2, 62.2; P<0.0001). Changes in RVESRI at 1 year (n=203) were predictive of outcome; patients initiated on prostanoid therapy showed the greatest improvement in RVESRI. Among right heart metrics, RVESRI demonstrated the best test-retest characteristics. CONCLUSIONS: RVESRI is a simple reproducible prognostic marker in patients with pulmonary arterial hypertension.