Performance of the REVEAL model in WHO Group 2 to 5 pulmonary hypertension: Application beyond pulmonary arterial hypertension

A prognostic model for systemic lupus erythematosus-associated pulmonary arterial hypertension: CSTAR-PAH cohort study

BACKGROUND

Pulmonary arterial hypertension is a major cause of death in systemic lupus erythematosus, but there are no tools specialized for predicting survival in systemic lupus erythematosus-associated pulmonary arterial hypertension.

RESEARCH QUESTION

To develop a practical model for predicting long-term prognosis in patients with systemic lupus erythematosus-associated pulmonary arterial hypertension.

METHODS

A prognostic model was developed from a multicenter, longitudinal national cohort of consecutively evaluated patients with systemic lupus erythematosus-associated pulmonary arterial hypertension. The study was conducted between November 2006 and February 2020. All-cause death was defined as the endpoint. Cox regression and least absolute shrinkage and selection operators were used to fit the model. Internal validation of the model was assessed by discrimination and calibration using bootstrapping.

RESULTS

Of 310 patients included in the study, 81 (26.1%) died within a median follow-up of 5.94 years (interquartile range 4.67-7.46). The final prognostic model included eight variables: modified World Health Organization functional class, 6-min walking distance, pulmonary vascular resistance, estimated glomerular filtration rate, thrombocytopenia, mild interstitial lung disease, N-terminal pro-brain natriuretic peptide/brain natriuretic peptide level, and direct bilirubin level. A 5-year death probability predictive algorithm was established and validated using the C-index (0.77) and a satisfactory calibration curve. Risk stratification was performed based on the predicted probability to improve clinical decision-making.

CONCLUSIONS

This new risk stratification model for systemic lupus erythematosus-associated pulmonary arterial hypertension may provide individualized prognostic probability using readily obtained clinical risk factors. External validation is required to demonstrate the accuracy of this model's predictions in diverse patient populations.

Use of Handheld Ultrasound to Estimate Right Atrial Pressure in a Pulmonary Hypertension Clinic

RATIONALE

Point-of-care ultrasonography is an invaluable asset for inpatient decision-making. Whether handheld ultrasound can be utilized in the outpatient management of pulmonary hypertension (PH) is unknown.

OBJECTIVES

We investigated whether a handheld ultrasound estimate of right atrial pressure correlates with B-type natriuretic peptide (BNP) and clinical outcome over time in PH outpatients.

METHODS

This prospective study included outpatients in a PH Comprehensive Care Center clinic who had a same-day BNP level. We used a handheld ultrasound to measure inferior vena cava (IVC) size and collapsibility, which were used to estimate right atrial pressure (eRAP) and categorize it as normal, intermediate, or high. Correlation analysis was used to compare these ultrasound measurements to BNP at baseline and over time. Cox regression was used to determine if these measurements were associated with time to clinical worsening.

RESULTS

Ninety patients (60% Group 1 PH) were enrolled. Patients with an intermediate or high eRAP category at baseline had higher BNP levels than patients with normal eRAP. For every transition in eRAP category (e.g. from normal to intermediate) between clinic visits, BNP changed by an average of 155 pg/mL (95% CI 84 to 227). Higher baseline eRAP category was independently associated with more than two-fold increased risk for clinical worsening (HR 2.44, 95% CI 1.47-4.07).

CONCLUSIONS

Right atrial pressure estimated by portable handheld ultrasound correlates with BNP at baseline and serially over time. Furthermore, eRAP is independently associated with clinical worsening. The use of portable handheld ultrasound to estimate right atrial pressure should be considered in PH clinics. Clinical trial registered at clinicaltrials.gov (NCT02873039).

Validation of the REVEAL Prognostic Models in Systemic Lupus Erythematosus-Associated Pulmonary Arterial Hypertension

No previous studies have investigated the predictive performance of the Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management (REVEAL) prognostic equation and simplified risk score calculator in patients with systemic lupus erythematosus-associated pulmonary arterial hypertension (SLE-PAH). We aimed to validate these prediction tools in an external cohort of patients with SLE-PAH. In this study, the validation cohort consisted of patients with SLE-PAH registered in a prospective, multicenter, nationwide database between November 2006 and May2016. The follow-up of patients was censored at 1 year. Discrimination, calibration, model fit, and risk stratification of the REVEAL prognostic equation and simplified risk score calculator were validated. As a result, a total of 306 patients with SLE-PAH were included. The 1-year overall survival rate was 91.5%. The C-index of the prognostic equation was 0.736, demonstrating reasonably good discrimination, and it was greater than that for the simplified risk score calculator (0.710). The overall calibration slope was 0.83, and the Brier score was 0.079. The risk of renal insufficiency and World Health Organization Functional Class III (WHO FC III) were underestimated, and the risk assigned to a heart rate >92 bpm in the REVEAL prognostic models was not observed in our validation cohort. Both model discrimination and calibration were poor in the very high-risk group. In conclusion, the REVEAL models exhibit good discriminatory ability when predicting 1-year overall survival in patients with SLE-PAH. Findings from both models should be interpreted with caution in cases of renal insufficiency, WHO FC III, and heart rate >92 bpm.

Cardiac magnetic resonance imaging as a prognostic biomarker in treatment-naïve pulmonary hypertension

PURPOSE

Targeted treatment for pulmonary arterial hypertension (PAH), diagnosed via right heart catheterization (RHC), has been shown to improve morbidity and mortality. Identifying characteristics that predict clinical worsening has been challenging. We sought to evaluate the role of cardiac Magnetic Resonance Imaging (CMR) as a predictor of clinical worsening in a cohort of treatment-naïve pulmonary hypertension (PH) patients.

METHODS

We performed a retrospective single center analysis of all adults with newly diagnosed treatment-naïve PH between January 1st 2013 and January 1st 2019. Patients with World Health Organization (WHO)-Group I PAH or WHO-Group II/III PH disease, who underwent both CMR (Signa Horizon 1.5 T, General Electric, Milwaukee, WI and Siemens Espree 1.5 T, Munich, Germany) and RHC testing prior to targeted PAH treatment, were included for analysis. Cox proportional hazards models were constructed.

RESULTS

A total of 38 patients, of which 12 (32 %) experienced the primary outcome of clinical worsening. were included in the final analysis, Patients with clinical worsening were significantly more likely to have RV dysfunction by CMR (including lower RV ejection fraction (HR 0.93, p = 0.007) and more RV dilation (HR 1.02, p = 0.005-0.021)) and RHC (including worse pulmonary vascular resistance (HR 1.32, p < 0.001)), even after adjustment for disease severity. Both CMR and RHC measures of RV dysfunction were found to be equally effective in predicting clinical worsening, regardless of PH etiology.

CONCLUSIONS

In treatment-naïve PH patients, including those with WHO-Group II/III disease, both CMR and RHC measures independently and significantly predicted clinical worsening, even after adjustment for disease severity.

Right atrial to left atrial volume index ratio is associated with increased mortality in patients with pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) is characterized by increased pulmonary vascular resistance leading to right heart failure. Elevated right atrial (RA) pressure reflects right ventricular (RV) pressure overload and is an established risk factor for mortality in PH. We hypothesized that PH patients with an increased ratio of RA to LA volume index (RAVI/LAVI), would have increased mortality.

METHODS

We evaluated the association of RAVI/LAVI with mortality in 124 patients seen at a single academic center's PH clinic after adjusting for the REVEAL risk score, an established risk score in PH. LA and RA volume indices were measured in the four-and two-chamber views by two independent researchers. Multivariable logistic regression was used to model the independent association of RAVI/LAVI with survival.

RESULTS

Among 124 patients (mean age 62 ± 12.7 years, 68.6% female), each unit increase in RAVI/LAVI was associated with a nearly twofold increase in mortality (OR: 1.91, 95% CI: 1.20-3.04). In a multivariable logistic regression, each unit increase in RAVI/LAVI was associated with a nearly twofold increase in mortality (OR: 1.73, 95% CI: 1.003-2.998). Furthermore, RAVI/LAVI in the highest quartile (>1.42) was significantly associated with elevated right atrial pressure (RAP) to pulmonary artery wedge pressure ratio (RAP/PAWP) (0.76 ± 0.41, P = 0.02) compared with the lowest quartile (<0.77), suggesting an interaction between invasive hemodynamic data, atrial structural changes, and mortality in PH.

CONCLUSIONS

Increased RAVI/LAVI in PH is associated with decreased survival and accounts for atrial structural remodeling related to invasive hemodynamics. These findings support further study of this index in predicting outcomes in PH.

Diagnostic and Prognostic Implications of Exercise Treadmill and Rest First-Pass Radionuclide Angiography in Patients With Pulmonary Hypertension

PURPOSE

Pulmonary hypertension (PH) is characterized by abnormally increased pulmonary vascular pressure, leading to deteriorated right ventricular function and premature death. Pulmonary mean transit time (PMTT) and biventricular function response to exercise in first-pass radionuclide angiography (FP-RNA) may provide early detection and timely disease monitoring of PH. This study aimed to investigate the diagnostic and prognostic values of this imaging modality in PH patients.

METHODS

Left and right ventricular ejection fraction (LVEF/RVEF) and PMTT at rest and immediately after exercise treadmill test were measured by FP-RNA in 77 consecutive patients with clinical presentations suggestive of PH (aged 46 ± 15 years, 33 men), mostly with symptoms of unexplained progressive dyspnea. These parameters, along with other clinical variables, were correlated with right-sided heart catheterization data and clinical outcomes.

RESULTS

Fifty patients (64.9%) were diagnosed as having definite PH. Besides higher N-terminal pro-B-type natriuretic peptide levels, right atrial pressure, and pulmonary vascular resistance, PH patients had significantly longer PMTT, lower LVEF after exercise and rest, and lower poststress RVEF (all P < 0.05), compared with non-PH subjects. Moreover, PH patients exhibited stress-induced right ventricular dysfunction and stationary poststress PMTT. Poststress PMTT and echocardiography had comparable diagnostic utility (area under the curve, 0.80 vs 0.84, respectively). Eighteen patients died during a median follow-up period of 380 days. Failure of exercise treadmill test, lower peak heart rate response, and stress/rest LVEF ratio of less than 90% using exercise treadmill FP-RNA were independent predictors of mortality in PH patients.

CONCLUSIONS

Exercise treadmill and rest FP-RNA provided diagnostic value and had prognostic implications in patients with PH.

Echocardiographic predictors of mortality in patients with pulmonary hypertension and cardiopulmonary comorbidities

OBJECTIVE

We aimed to identify the echocardiographic measures associated with survival in a patient population with a high prevalence of co-morbid cardiovascular and pulmonary disease that have significantly elevated estimated pulmonary artery systolic pressures (ePASP).

BACKGROUND

Pulmonary hypertension (PH) is a clinical feature of several cardiopulmonary diseases that are prevalent among elderly. While certain echocardiographic parameters have been shown to be important in the prognosis in specific PH groups, the prognostic relevance of echocardiographic characteristics in a cohort with multiple cardiopulmonary comorbidities is unclear.

METHODS

We retrospectively identified 152 patients with ePASP > 60 mmHg by echocardiography over a five year period (6/2006-11/2011) and followed until 4/2013. Candidate clinical and echocardiographic characteristics suggestive of PH severity were compared between deceased and surviving subpopulations. Cox proportional hazard modeling was used to identify echocardiographic predictors of death adjusted for age and clinical characteristics.

RESULTS

This was a predominantly elderly (age 78.8 ± 10.2 years), male (98.7%) cohort with several cardiopulmonary comorbidities. Overall mortality was high (69.7%, median survival 129 days). After adjusting for age and clinical characteristics, decreased right ventricular (RV) systolic function assessed by tricuspid annular plane systolic excursion (HR 0.56, 95% CI 0.33-0.96, p = 0.034) and increased RV thickness (HR: 4.34, 95% CI: 1.49-12.59, p = 0.007) were independently associated with mortality. In contrast, left ventricular systolic function, left ventricular diastolic parameters, ePASP, or echo-derived pulmonary vascular resistance (PVR) were not associated with increased mortality.

CONCLUSION

In a cohort of patients with PH and high prevalence of cardio-pulmonary comorbidities, RV systolic function and hypertrophy are associated with mortality and may be the most relevant echocardiographic markers for prognosis.

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.