COMPERA 2.0: a refined four-stratum risk assessment model for pulmonary arterial hypertension.

BACKGROUND: Risk stratification plays an essential role in the management of patients with pulmonary arterial hypertension (PAH). The current European guidelines propose a three-stratum model to categorise risk as low, intermediate or high, based on the expected 1-year mortality. However, with this model, most patients are categorised as intermediate risk. We investigated a modified approach based on four risk categories, with intermediate risk subdivided into intermediate-low and intermediate-high risk. METHODS: We analysed data from the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA), a European pulmonary hypertension registry, and calculated risk at diagnosis and first follow-up based on World Health Organization functional class, 6-min walk distance (6MWD) and serum levels of brain natriuretic peptide (BNP) or N-terminal pro-BNP (NT-proBNP), using refined cut-off values. Survival was assessed using Kaplan-Meier analyses, log-rank testing and Cox proportional hazards models. RESULTS: Data from 1655 patients with PAH were analysed. Using the three-stratum model, most patients were classified as intermediate risk (76.0% at baseline and 63.9% at first follow-up). The refined four-stratum risk model yielded a more nuanced separation and predicted long-term survival, especially at follow-up assessment. Changes in risk from baseline to follow-up were observed in 31.1% of the patients with the three-stratum model and in 49.2% with the four-stratum model. These changes, including those between the intermediate-low and intermediate-high strata, were associated with changes in long-term mortality risk. CONCLUSIONS: Modified risk stratification using a four-stratum model based on refined cut-off levels for functional class, 6MWD and BNP/NT-proBNP was more sensitive to prognostically relevant changes in risk than the original three-stratum model.

A model for estimating the health economic impact of earlier diagnosis of chronic thromboembolic pulmonary hypertension.

BACKGROUND: Diagnostic delay of chronic thromboembolic pulmonary hypertension (CTEPH) exceeds 1 year, contributing to higher mortality. Health economic consequences of late CTEPH diagnosis are unknown. We aimed to develop a model for quantifying the impact of diagnosing CTEPH earlier on survival, quality-adjusted life-years (QALYs) and healthcare costs. MATERIAL AND METHODS: A Markov model was developed to estimate lifelong outcomes, depending on the degree of delay. Data on survival and quality of life were obtained from published literature. Hospital costs were assessed from patient records (n=498) at the Amsterdam UMC - VUmc, which is a Dutch CTEPH referral center. Medication costs were based on a mix of standard medication regimens. RESULTS: For 63-year-old CTEPH patients with a 14-month diagnostic delay of CTEPH (median age and delay of patients in the European CTEPH Registry), lifelong healthcare costs were estimated at EUR 117 100 for a mix of treatment options. In a hypothetical scenario of maximal reduction of current delay, improved survival was estimated at a gain of 3.01 life-years and 2.04 QALYs. The associated cost increase was EUR 44 654, of which 87% was due to prolonged medication use. This accounts for an incremental cost-utility ratio of EUR 21 900/QALY. CONCLUSION: Our constructed model based on the Dutch healthcare setting demonstrates a substantial health gain when CTEPH is diagnosed earlier. According to Dutch health economic standards, additional costs remain below the deemed acceptable limit of EUR 50 000/QALY for the particular disease burden. This model can be used for evaluating cost-effectiveness of diagnostic strategies aimed at reducing the diagnostic delay.

Risk assessment in medically treated chronic thromboembolic pulmonary hypertension patients.

Abbreviated versions of the risk stratification strategy of the European Society of Cardiology (ESC)/European Respiratory Society (ERS) pulmonary hypertension guidelines have been recently validated in patients with pulmonary arterial hypertension. We aimed to investigate their prognostic value in medically treated chronic thromboembolic pulmonary hypertension (CTEPH) patients from the COMPERA registry, which collects six variables of interest (World Health Organization Functional Class, 6-min walk distance, brain natriuretic peptide, right atrial pressure, cardiac index and mixed venous oxygen saturation).We included patients with at least one follow-up visit, no pulmonary endarterectomy and at least three of the six variables available, and classified the patients into low-, intermediate- and high-risk groups. As a secondary analysis, the number of noninvasive low-risk criteria was counted. The association between risk assessment and survival was evaluated.Data from inclusion and follow-up (median 7 months) visits were available for 561 and 231 patients, respectively. Baseline 1- and 5-year survival estimates were significantly different (p<0.0001) in the baseline low-risk (98.6% and 88.3%, respectively), intermediate-risk (94.9% and 61.8%, respectively) and high-risk (75.5% and 32.9%, respectively) cohorts. Follow-up data were even more discriminative, with 100%, 92% and 69% 1-year survival, respectively. The number of low-risk noninvasive criteria was also associated with survival.These analyses suggest that the ESC/ERS risk assessment may be applicable in patients with medically treated CTEPH.

Assessment of Right Ventricular Function in the Research Setting: Knowledge Gaps and Pathways Forward. An Official American Thoracic Society Research Statement.

BACKGROUND: Right ventricular (RV) adaptation to acute and chronic pulmonary hypertensive syndromes is a significant determinant of short- and long-term outcomes. Although remarkable progress has been made in the understanding of RV function and failure since the meeting of the NIH Working Group on Cellular and Molecular Mechanisms of Right Heart Failure in 2005, significant gaps remain at many levels in the understanding of cellular and molecular mechanisms of RV responses to pressure and volume overload, in the validation of diagnostic modalities, and in the development of evidence-based therapies. METHODS: A multidisciplinary working group of 20 international experts from the American Thoracic Society Assemblies on Pulmonary Circulation and Critical Care, as well as external content experts, reviewed the literature, identified important knowledge gaps, and provided recommendations. RESULTS: This document reviews the knowledge in the field of RV failure, identifies and prioritizes the most pertinent research gaps, and provides a prioritized pathway for addressing these preclinical and clinical questions. The group identified knowledge gaps and research opportunities in three major topic areas: 1) optimizing the methodology to assess RV function in acute and chronic conditions in preclinical models, human studies, and clinical trials; 2) analyzing advanced RV hemodynamic parameters at rest and in response to exercise; and 3) deciphering the underlying molecular and pathogenic mechanisms of RV function and failure in diverse pulmonary hypertension syndromes. CONCLUSIONS: This statement provides a roadmap to further advance the state of knowledge, with the ultimate goal of developing RV-targeted therapies for patients with RV failure of any etiology.

Serial assessment of right ventricular systolic function in patients with precapillary pulmonary hypertension using simple echocardiographic parameters: A comparison with cardiac magnetic resonance imaging.

BACKGROUND: Although cardiac magnetic resonance imaging (CMRI) is the gold standard for the (serial) assessment of right ventricular (RV) function, the technique has several drawbacks: CMRI is relatively expensive, has a limited availability, and the analyses are time consuming. Echocardiography (echo) can overcome several of these issues. The aim of this study was to compare simple echo-derived parameters of RV systolic function with CMRI-derived RV ejection fraction (RVEF) in patients with precapillary pulmonary hypertension (PH) and to determine which echo parameters best followed the change in CMRI-derived-RVEF during follow-up. METHODS: CMRI and echo were performed in 96 precapillary PH patients. In 38 patients a second set of a CMRI and echo were available. Retrospectively, echo-derived right ventricular fractional area change (RVFAC), tricuspid annulus plane systolic excursion (TAPSE), fractional transversal (FTWM), and longitudinal wall motion (FLWM) were assessed and compared with CMRI-derived-RVEF. Furthermore, the changes in RVFAC, TAPSE, FTWM, and FLWM during follow-up were compared with the change in CMRI-derived-RVEF. RESULTS: All four echo parameters were significantly correlated to CMRI-derived-RVEF. The strongest relationship was seen between CMRI-derived-RVEF and RVFAC (r2=0.567). However, sensitivity for predicting a deterioration in CMRI-derived RVEF was poor for all four echo-derived parameters (ranging from 33% to 56%). CONCLUSIONS: Although RVFAC, TAPSE, FTWM, and FLWM were significantly correlated to CMRI-derived-RVEF, all four echo parameters showed a low sensitivity for predicting a deterioration in CMRI-derived RVEF during follow-up. Therefore, RVFAC, TAPSE, FTWM, and FLWM are not suitable parameters for the serial assessment of RV systolic function in patients with precapillary PH.

Assessment of right ventricular responses to therapy in pulmonary hypertension.

Irrespective of its cause, pulmonary hypertension (PH) leads to an increase in pulmonary vascular resistance (PVR). Failing adaption of the right ventricle (RV) to the increased afterload is the main cause of death in PH patients and therefore monitoring RV function during treatment is essential. However, consensus on the optimal method for serial assessment of RV function is lacking and therefore the major clinical trials on PH-specific therapies have not provided clear answers with respect to the response of the RV to treatment. This short review will give an overview of the most important load-dependent and load-independent parameters for assessing RV response to therapy in PH patients.

Accurate assessment of load-independent right ventricular systolic function in patients with pulmonary hypertension.

BACKGROUND: End-systolic elastance (E(es)), a load-independent measure of ventricular function, is of clinical interest for studies of the right ventricle (RV) in patients with pulmonary arterial hypertension (PAH). The objective of this study was to determine whether, in PAH patients, E(es) can be estimated from mean pulmonary artery pressure (mPAP) and end-systolic volume (ESV) only. METHODS: Right heart catheterization was used to measure mPAP. Maximal isovolumic pressure (P(iso)) was estimated from RV pressure curves with the so-called single-beat method. Cardiac magnetic resonance imaging (MRI) was used to assess RV end-diastolic and end-systolic volumes (EDV and ESV). E(es) was then calculated as: E(es) = (P(iso)-mPAP) / (EDV-ESV), and as E(es,V0 = 0) = mPAP/ESV (simplified method, with V0 = 0, is negligible volume at zero pressure). Right ventricular volume at zero pressure (V(0)) was then defined as the intercept of the end-systolic pressure-volume relation (single-beat method) with the horizontal axis. RESULTS: E(es,V0 = 0) was significantly lower compared with E(es) (0.61 vs 1.34 mm Hg/ml, respectively, p<0.01). A modified Bland-Altman analysis showed a contractility-dependent difference between E(es,V0 = 0) and E(es). Moreover, V(0) ranged from-8 up to 171 ml, and a moderate and good correlation was found between V(0) and EDV, and V(0) and ESV, respectively (r = 0.65 and r = 0.87, p< 0.01). CONCLUSIONS: These findings show that V(0) is dependent on RV dilation. Therefore, the assumption that V(0) is negligible in PAH is incorrect. Consequently, for an accurate assessment of load-independent RV systolic function, RV volumes and pressure curves are required.

A multicentre study on the reliability of qualitative and quantitative nail-fold videocapillaroscopy assessment.

OBJECTIVE: To investigate the inter- and intra-observer reliability of both qualitative and quantitative parameters used in the assessment of nail-fold capillaroscopy images. METHODS: Fifty mosaic nail-fold images of healthy controls (n = 10), patients with primary RP (n = 10) and SSc (n = 30) were assessed in random order by two blinded observers on two occasions at centres in Sweden, UK and The Netherlands. Each image was therefore scored by six observers twice. RESULTS: Inter- and intra-observer reliability of quantitative parameters showed substantial to almost perfect agreement [inter- and intra-observer weighted κ's for the number of widened capillaries was 0.75 and 0.87 and giant capillaries was 0.84 and 0.92, intra-class correlation coefficients (ICCs) for capillary density was 0.87 and 0.92 and total loop width was 0.94 and 0.98, respectively]. Qualitative parameters including architecture, avascularity, haemorrhage, crossed, ramified and bushy capillaries showed moderate to substantial inter-observer reproducibility (weighted κ ranging from 0.47 to 0.73), and substantial intra-observer repeatability (weighted κ ranging from 0.71 to 0.80), whereas the scoring of tortuous and bizarre capillaries showed poor inter-observer and substantial intra-observer agreement (inter-observer weighted κ's was 0.39 and 0.21 and intra-observer weighted κ's was 0.68 and 0.76, respectively). CONCLUSION: All quantitative and certain qualitative parameters are highly reliable in terms of inter- and intra-observer agreement. A combination of parameters with the highest reliability should be incorporated into future capillaroscopic scoring systems in studies of prediction and monitoring of SSc spectrum disorders.

Epoprostenol in pulmonary arterial hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a devastating disease leading to right heart failure and death in a relatively young patient population. In recent years novel PAH specific therapies have become available. OBJECTIVE: To determine the place of epoprostenol in current PAH treatment strategies. METHODS: An extensive Medline search was performed to evaluate the use of epoprostenol in PAH. Data from both human and animal studies were reviewed. RESULTS/CONCLUSION: Epoprostenol is an effective and potent treatment in pulmonary arterial hypertension and has greatly improved survival, exercise capacity, PAH symptoms, pulmonary haemodynamics and disease progression. A main disadvantage is that it can only be delivered through a continuous intravenous pump infusion.

Non-invasive stroke volume assessment in patients with pulmonary arterial hypertension: left-sided data mandatory.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is an emerging modality in the diagnosis and follow-up of patients with pulmonary arterial hypertension (PAH). Derivation of stroke volume (SV) from the pulmonary flow curves is considered as a standard in this respect. Our aim was to investigate the accuracy of pulmonary artery (PA) flow for measuring SV. METHODS: Thirty-four PAH patients underwent both CMR and right-sided heart catheterisation. CMR-derived SV was measured by PA flow, left (LV) and right ventricular (RV) volumes, and, in a subset of nine patients also by aortic flow. These SV values were compared to the SV obtained by invasive Fick method. RESULTS: For SV by PA flow versus Fick, r = 0.71, mean difference was -4.2 ml with limits of agreement 26.8 and -18.3 ml. For SV by LV volumes versus Fick, r = 0.95, mean difference was -0.8 ml with limits of agreement of 8.7 and -10.4 ml. For SV by RV volumes versus Fick, r = 0.73, mean difference -0.75 ml with limits of agreement 21.8 and -23.3 ml. In the subset of nine patients, SV by aorta flow versus Fick yielded r = 0.95, while in this subset SV by pulmonary flow versus Fick yielded r = 0.76. For all regression analyses, p < 0.0001. CONCLUSION: In conclusion, SV from PA flow has limited accuracy in PAH patients. LV volumes and aorta flow are to be preferred for the measurement of SV.

Assessment of the pulmonary volume pulse in idiopathic pulmonary arterial hypertension by means of electrical impedance tomography.

BACKGROUND: Electrical impedance tomography (EIT) is a non-invasive imaging technique which can be used to measure the blood volume changes in the pulmonary vascular bed during the cardiac cycle. STUDY OBJECTIVES: This study was performed to evaluate the differences in the EIT signal of the pulmonary vascular bed between healthy subjects and patients with idiopathic pulmonary arterial hypertension (IPAH), who are known to have a remodelled pulmonary vascular bed. PATIENTS AND METHODS: Twenty-one patients (17 females, 4 males) with IPAH and 30 healthy controls (5 females, 25 males) were measured. EIT measurements were performed in duplicate, on the same day as right heart catheterization to obtain haemodynamic data. The maximal impedance change during systole (Delta Z(sys)) was used as a measure of the pulmonary volume pulse and expressed in arbitrary units (AU). Total lung capacity, spirometric values and diffusion capacity for carbon monoxide were measured as well. RESULTS: Mean Delta Z(sys) was 215 +/- 58 x 10(-2) AU (95% CI 193 x 10(-2) to 236 x 10(-2)) in the healthy subjects and 78 +/- 27 x 10(-2) AU (95% CI 66 x 10(-2) to 91 x 10(-2)) in the IPAH patient group (p < 0.0001). No significant correlation was found between Delta Z(sys) and any of the haemodynamic or lung function data. CONCLUSION: The impedance pulsation of the pulmonary vascular bed is reduced in IPAH in comparison with controls, indicating a reduced volume pulse. This might represent the reduced cross section area, as well as the reduced compliance and number of the pulmonary vessels in these patients.

Cost-effectiveness of early intervention: comparison between intraluminal bronchoscopic treatment and surgical resection for T1N0 lung cancer patients.

BACKGROUND: For patients with early-stage lung cancer (ESLC) and severe comorbidities, the cost-effectiveness of early intervention may be reduced by screening and treatment-related morbidity and mortality in addition to the risk for non-cancer-related deaths. OBJECTIVES: The use of bronchoscopic treatment (BT) for centrally located ESLC as minimally invasive technique has raised questions whether this approach will be more cost-effective than standard surgical resection in the above-mentioned cohort of patients. METHODS: The cost-effectiveness of BT of 32 medically inoperable patients with intraluminal tumor has been compared to a matched control group of surgically treated stage IA cancer patients. RESULTS: Median follow-up after BT for ESLC has been 5 years (range 2-10) versus 6.7 years (range 2-10) for the surgical group. Five patients (16%) developed subsequent primaries/local recurrences after BT versus 4 (12.5%) in the surgical group. The respective percentages of actual survival during follow-up have been 50 and 41%, non-lung-cancer-related death 22 and 31% and lung-cancer-related death 28% in both groups, respectively. So far, the average costs per individual for early management by BT have been Euro 22,638 by surgery, and total expenses have been Euro 209,492 and Euro 724,403, respectively. CONCLUSIONS: Despite the worse initial health status of patients treated with BT, actual survival rates and costs for early intervention underscore the superior cost-effectiveness of BT as early intervention in properly selected individuals with ESLC in the central airways.