[Targeted therapy for pulmonary arterial hypertension in patients without comorbidities]

The 2022 guidelines on pulmonary hypertension from the European Society of Cardiology (ESC) and the European Respiratory Society (ERS) provide therapeutic strategies that account for the variability in the clinical presentation of newly diagnosed patients. We summarize treatment recommendations for pulmonary arterial hypertension (PAH) in patients without significant comorbidities, particularly for idiopathic, hereditary, drug/toxin-induced, or connective tissue disease-associated PAH. In this group of patients, multidimensional assessments for short-term mortality risk guide initial treatment decisions and treatment decisions during follow-up. Upfront dual combination therapy (phosphodiesterase type-5 inhibitor and endothelin receptor antagonist) is recommended for low- and intermediate-risk patients, and triple therapy including a parenteral prostacyclin should be considered in high- or intermediate-high-risk patients. If a low or intermediate-low-risk profile cannot be achieved during therapy, sequential add-on therapy escalation with parenteral prostacyclin or a prostacyclin receptor agonist should be considered, and switching from a phosphodiesterase type-5 inhibitor to a guanylate cyclase stimulator may also be considered.

[General measures and management of pulmonary arterial hypertension]

Care of patients with pulmonary arterial hypertension (PAH) needs a multi-facetet concept and measures, including management of adverse reactions, right heart insufficiency as well as information on pregnancy, travels by air, psychosocial support, physical exercise training and prophylaxis by vaccination.Positive study results led to an higher recommendation of specialized exercise training in pulmonary hypertension. Also, the recommendation on iron substitution was amended according to the current evidence.In the current guidelines, special focus was given to the elaboration of recommendations regarding pregnancy, including patient information, contraception and patient management in case of pregnancy.This article aims to provide an overview on the recommendations of general measuremes, special circumstances and patient management according to the ESC/ERS guidelines. Amendments to the guideline recommendations are given as comments from the authors of this article.

Long-Term Safety, Outcome, and Clinical Effects of Subcutaneous and Intravenous Treprostinil Treatment in Patients with Severe Chronic Pulmonary Arterial Hypertension

BACKGROUND

Current guidelines recommend treatment with parenteral prostacyclin analogs in patients with severe pulmonary arterial hypertension (PAH), who have insufficient response to treatment. Real-life data are sought to help physicians in treatment decisions and clinical care of patients.

OBJECTIVE

This study analyzed safety, clinical effects, and long-term outcomes of subcutaneous (sc) and/or intravenous (iv) treprostinil via different pump systems in consecutive patients with PAH.

METHODS

Thirty-seven patients with severe progressive PAH despite dual combination therapy (20 female, mean age: 52.3 ± 15 years, mean pulmonary vascular resistance: 12.1 ± 5.1 WU) were initiated with add-on treprostinil sc and were routinely clinically assessed. Changes in clinical parameters, adverse events, and outcome were analyzed retrospectively.

RESULTS

In 24 of 37 patients, treprostinil administration was continued iv via implantation of LENUS Pro® pump after 3 ± 1.3 months, 6 patients continued with sc therapy, and 7 discontinued treatment. After 3, 6, 9, and 12 months of treprostinil treatment, patients showed a significant improvement in mean 6-min walk distance and tricuspid annular plane systolic excursion compared to baseline. In 8 of the 24 patients, iv pumps required surgical revision. During a mean follow-up of 2.82 ± 1.95 years, 12 patients died, four received lung transplantation. Transplant-free survival after 1, 2, and 3 years was 85.7%, 69.2%, and 65.3%, respectively.

CONCLUSION

sc treprostinil as add-on to double combination treatment significantly improved exercise capacity and right heart function. In most patients, treprostinil could be continued via more tolerable iv administration approach (LENUS Pro® pump), showing reasonable overall survival with respect to the severity of PAH.

Is iron deficiency caused by BMPR2 mutations or dysfunction in pulmonary arterial hypertension patients?

Iron deficiency is common in idiopathic and heritable pulmonary arterial hypertension patients (I/HPAH). A previous report suggested a dysregulation of the iron hormone hepcidin, which is controlled by BMP/SMAD signaling involving the bone morphogenetic protein receptor 2 (BMPR-II). Pathogenic variants in the BMPR2 gene are the most common cause of HPAH. Their effect on patients' hepcidin levels has not been investigated. The aim of this study was to assess whether iron metabolism and regulation of the iron regulatory hormone hepcidin was disturbed in I/HPAH patients with and without a pathogenic variant in the gene BMPR2 compared to healthy controls. In this explorative, cross-sectional study hepcidin serum levels were quantified by enzyme-linked immunosorbent assay. We measured iron status, inflammatory parameters and hepcidin modifying proteins such as IL6, erythropoietin, and BMP2, BMP6 in addition to BMPR-II protein and mRNA levels. Clinical routine parameters were correlated with hepcidin levels. In total 109 I/HPAH patients and controls, separated into three groups, 23 BMPR2 variant-carriers, 56 BMPR2 noncarriers and 30 healthy controls were enrolled. Of these, 84% had iron deficiency requiring iron supplementation. Hepcidin levels were not different between groups and corresponded to the degree of iron deficiency. The levels of IL6, erythropoietin, BMP2, or BMP6 showed no correlation with hepcidin expression. Hence, iron homeostasis and hepcidin regulation was largely independent from these parameters. I/HPAH patients had a physiologically normal iron regulation and no false elevation of hepcidin levels. Iron deficiency was prevalent albeit independent of pathogenic variants in the BMPR2 gene.

Hypochromic red cells as a prognostic indicator of survival among patients with systemic sclerosis screened for pulmonary hypertension

BACKGROUND

Patients with systemic sclerosis (SSc) are frequently affected by iron deficiency, particularly those with pulmonary hypertension (PH). The first data indicate the prognostic importance of hypochromic red cells (% HRC) > 2% among patients with PH. Hence, the objective of our study was to investigate the prognostic value of % HRC in SSc patients screened for PH.

METHODS

In this retrospective, single-center cohort study, SSc patients with a screening for PH were enrolled. Clinical characteristics and laboratory and pulmonary functional parameters associated with the prognosis of SSc were analyzed using uni- and multivariable analysis.

RESULTS

From 280 SSc patients screened, 171 could be included in the analysis having available data of iron metabolism (81% female, 60 ± 13 years of age, 77% limited cutaneous SSc, 65 manifest PH, and 73 pulmonary fibrosis). The patients were followed for 2.4 ± 1.8 (median 2.4) years. HRC > 2% at baseline was significantly associated with worse survival in the uni- (p = 0.018) and multivariable (p = 0.031) analysis independent from the presence of PH or pulmonary parenchymal manifestations. The combination of HRC > 2% and low diffusion capacity for carbon monoxide (DLCO) ≤ 65% predicted was significantly associated with survival (p < 0.0001).

CONCLUSION

This is the first study reporting that HRC > 2% is an independent prognostic predictor of mortality and can possibly be used as a biomarker among SSc patients. The combination of HRC > 2% and DLCO ≤ 65% predicted could serve in the risk stratification of SSc patients. Larger studies are required to confirm these findings.

Oxygenated hemoglobin as prognostic marker among patients with systemic sclerosis screened for pulmonary hypertension

Oxygenated hemoglobin (OxyHem) in arterial blood may reflect disease severity in patients with systemic sclerosis (SSc). The aim of this study was to analyze the predictive value of OxyHem in SSc patients screened for pulmonary hypertension (PH). OxyHem (g/dl) was measured by multiplying the concentration of hemoglobin with fractional oxygen saturation in arterialized capillary blood. Prognostic power was compared with known prognostic parameters in SSc using uni- and multivariable analysis. A total of 280 SSc patients were screened, 267 were included in the analysis. No signs of pulmonary vascular disease were found in 126 patients, while 141 patients presented with mean pulmonary arterial pressure ≥ 21 mmHg. Interstitial lung disease (ILD) was identified in 70 patients. Low OxyHem ≤ 12.5 g/dl at baseline was significantly associated with worse survival (P = 0.046). In the multivariable analysis presence of ILD, age ≥ 60 years and diffusion capacity for carbon monoxide (DLCO) ≤ 65% were negatively associated with survival. The combination of low DLCO and low OxyHem at baseline could predict PH at baseline (sensitivity 76.1%). This study detected for the first time OxyHem ≤ 12.5 g/dl as a prognostic predictor in SSc patients. Further studies are needed to confirm these results.

Gezielte medikamentöse Therapie der pulmonalarteriellen Hypertonie nach den aktuellen Leitlinien

Dieser Artikel stellt die gezielte Therapie der pulmonalarteriellen Hypertonie (PAH) vor. Die medikamentöse Therapie der PAH hat sich in den letzten Jahren entscheidend verbessert und ermöglicht heute vielen Patienten eine deutliche Verbesserung der körperlichen Belastbarkeit, Lebensqualität und des Langzeitüberlebens. Die neuen ESC/ERS-Leitlinien zur pulmonalen Hypertonie haben die aus vielen neuen Studien entstandenen Evidenzen zusammengetragen, bewertet und den therapeutischen Algorithmus und die Therapieempfehlungen entsprechend angepasst. In dem folgenden Artikel werden die neuen Empfehlungen zur medikamentösen Therapie der PAH zusammengefasst und eingeordnet. Die PAH-Therapie wird wie bisher am Schweregrad der Erkrankung orientiert, der bei Diagnose nach einem 3-Risikostufen-Modell abgeschätzt wird. Neu ist die Anwendung eines 4-stufigen Risikomodells bei der Therapieanpassung im Krankheitsverlauf. In den neuen Leitlinien werden erstmals auch Therapieempfehlungen für Patienten mit PAH und Komorbiditäten gegeben.

Tolerability, safety and survival in patients with severe pulmonary arterial hypertension treated with intravenous epoprostenol (Veletri®): a prospective, 6-months, open label, observational, non-interventional study

BACKGROUND

Epoprostenol AS (Veletri^®), a thermostable epoprostenol formulation, provides better drug stability and improved clinical use compared to previous epoprostenol formulations. This study aims to expand clinical experience in the use of Veletri^®, especially regarding tolerability, safety and survival.

METHODS

Pulmonary arterial hypertension (PAH) patients at high risk despite pretreatment with at least double oral combination therapy and with clinical indication for epoprostenol (Veletri^®) treatment were consecutively included in this prospective, open label, observational, non-interventional study. Clinical data were assessed at baseline, after 3 and 6 months. Adverse events (AEs) and serious adverse events (SAEs) were documented. Survival from initiation of Veletri^® was assessed at last patient out.

RESULTS

Fifteen patients (60 ± 13.7 years, WHO functional class III (n = 10) or IV (n = 5), severely impaired right ventricular function, mean pulmonary arterial pressure 54.8 ± 8.9 mmHg, mean pulmonary vascular resistance 4.4 ± 0.7 (median 3.8) Wood Units) were enrolled and treated with a mean dosage of 7.9 ± 3.9 (median 7.5) ng/kg/min. Eleven patients completed the study (treatment withdrawal n = 1, death n = 3). After a mean follow-up of 19.1 ± 13.5 (median 18.0) months, seven patients died and three were listed for lung transplantation. Seven AEs (nausea n = 3, diarrhea n = 1, flushing n = 2, headaches n = 1) and three SAEs (catheter infection n = 2, catheter occlusion n = 1) were related to Veletri^®. The 1- and 2-year survival rates were 73.3% and 52.4%, respectively.

CONCLUSIONS

The study showed that safety and tolerability of epoprostenol AS (Veletri^®) was comparable to previous prostacyclin formulations and was feasible for most patients. The maximum tolerable dosage was lower than dosages reported in the literature. In future applications/trials the up-titration process should be pushing for higher dosages of epoprostenol in the occurrence of side effects, as the achievement of a high and effective dosage is crucial for the clinical benefit of the patients. Survival was as expected in these prevalent severely impaired patients. Trial registration The study was registered in the EUPAS registry (EUPAS32492).

Impairment of Inspiratory Muscle Function after COVID-19

<b><i>Background:</i></b> Persistent symptoms after acute coronavirus-disease-2019 (COVID-19) are common, and there is no significant correlation with the severity of the acute disease. In long-COVID (persistent symptoms &#x3e;4 weeks after acute COVID-19), respiratory symptoms are frequent, but lung function testing shows only mild changes that do not explain the symptoms. Although COVID-19 may lead to an impairment of the peripheral nervous system and skeletal muscles, respiratory muscle function has not been examined in this setting. <b><i>Methods:</i></b> In this study, we assessed the severity of dyspnea (NYHA-function class) in long-COVID patients and analyzed its association with body mass index (BMI), FEV1, forced vital capacity, other parameters of body plethysmography, diffusing capacity for carbon monoxide (DLCO), arterial blood gases, and inspiratory muscle function, assessed by airway occlusion pressure (P0.1) and maximal inspiratory pressure (PImax) in two respiratory clinics in Germany between Oct 2020 and Aug 2021. <b><i>Results:</i></b> A total of 116 patients were included in the study. The mean age was 50.2 ± 14.5 years; BMI, 26.7 ± 5.87 kg/m²; NYHA class I, 19%; II, 27%; III, 41%; and IV, 14%. While lung function values and computed tomography or conventional X-ray of the chest were in the normal range, inspiratory muscle function was markedly impaired. P01 was elevated to 154 ± 83%predicted and PImax was reduced to 41 ± 25%predicted. PImax reduction was strongly associated with the severity of dyspnea but independent of BMI, time after acute COVID-19 and most of the other parameters. <b><i>Conclusions:</i></b> This study shows that in long-COVID patients, respiratory symptoms may be mainly caused by reduced inspiratory muscle strength. Assessment of PImax and P0.1 might better explain dyspnea than classical lung function tests and DLCO. A prospective study is needed to confirm these results.

Prognostic meaning of right ventricular function and output reserve in patients with systemic sclerosis

Background

The objective of this study was to investigate the prognostic impact of right ventricular (RV) function at rest and during exercise in patients with systemic sclerosis (SSc) presenting for a screening for pulmonary hypertension (PH).

Methods

In this study, data from SSc patients who underwent routinely performed examinations for PH screening including echocardiography and right heart catheterization at rest and during exercise were analysed. Uni- and multivariable analyses were performed to identify prognostic parameters.

Results

Out of 280 SSc patients screened for PH, 225 were included in the analysis (81.3% female, mean age 58.1±13.0 years, 68% limited cutaneous SSc, WHO-FC II–III 74%, 24 manifest PH). During the observation period of 3.2±2.7 (median 2.6) years 35 patients died. Tricuspid annular plane systolic excursion (TAPSE) at rest <18 mm (p=0.001), RV output reserve as increase of cardiac index (CI) during exercise <2 l/min (p<0.0001), RV pulmonary vascular reserve (Δ mean pulmonary artery pressure/Δ cardiac output) ≥3 mmHg/l/min (p<0.0001), peak CI <5.5 l/min/m² (p=0.001), pulmonary arterial compliance <2 ml/mmHg (p=0.002), TAPSE/systolic pulmonary arterial pressure (sPAP) ratio ≤0.6 ml/mmHg (p<0.0001) and echocardiographic qualitative RV function at rest (p<0.0001) significantly predicted worse survival. In the multivariable analysis TAPSE/sPAP ratio and diffusion capacity for carbon monoxide ≤65% were identified as independent prognostic predictors and had 75% sensitivity and 69% specificity to predict future development of pulmonary vascular disease (PVD) during follow-up.

Conclusions

This study demonstrates that assessment of RV function at rest and during exercise may provide crucial information to identify SSc patients who are at a high risk of poor outcome and for the development of PH and/or PVD.

POS0885 HYPOCHROMIC ERYTHROCYTES AS PROGNOSTIC INDICATOR OF SURVIVAL AMONG PATIENTS WITH SYSTEMIC SCLEROSIS SCREENED FOR PULMONARY HYPERTENSION

Background

Iron deficiency is frequent among patients with systemic sclerosis (SSc), particularly among those with pulmonary hypertension (PH). First data indicate prognostic importance of hypochromic erythrocytes (HRC) >2% among patients with PH1. Hence, the aim of this study was to investigate the predictive value of HRC in SSc patients screened for PH.

Objectives

The objective of this study was to investigate the predictive value of HRC in SSc patients screened for PH.

Methods

In this retrospective, single-center cohort study SSc patients screened for PH were included. Clinical characteristics, laboratory and pulmonary functional parameters associated with the prognosis of SSc were analysed using uni- and multivariable analysis.

Results

A total of 280 SSc patients were screened, 171 were included in the analysis having complete data of iron metabolism (79% female, 61.0±12.9 years of age, 73.2% limited cutaneous SSc, 56 manifest PH and 112 pulmonary fibrosis). The patients were followed for 2.4±1.8 (median 2.4) years. HRC >2% at baseline was significantly associated with worse survival in the uni- (p=0.018) and multivariable analysis (p<0.0001). Overall 34.5% of the patients suffered from iron deficiency and 22% received iron substitution during follow-up. HRC >2% was identified as independent predictor of mortality, for patients with and without pulmonary manifestations of SSc.

Conclusion

This study detected for the first time that HRC >2% is an independent prognostic predictor and can possibly be used as a biomarker among SSc-patients. Further studies are needed to confirm these results.

References

[1]Xanthouli P, Theobald V, Benjamin N, Marra AM, D’Agostino A, Egenlauf B, Shaukat M, Ding C, Cittadini A, Bossone E, Kögler M, Grünig E, Muckenthaler MU, Eichstaedt CA. Prognostic impact of hypochromic erythrocytes in patients with pulmonary arterial hypertension. Respir Res. 2021 Nov 9;22(1):288. doi: 10.1186/s12931-021-01884-9.

Disclosure of Interests

Panagiota Xanthouli Speakers bureau: MSD and OMT, outside the submitted work, Ojan Gordjani: None declared, Christina Eichstaedt: None declared, Nicola Benjamin Speakers bureau: Actelion pharmaceuticals, Bayer HealthCare and MSD., Benjamin Egenlauf Speakers bureau: Actelion, MSD, Bayer and OMT outside the submitted work, Satenik Harutyunova Speakers bureau: Bayer, MSD, Actelion and GSK, outside the submitted work., Alberto Marra Speakers bureau: Bayer/MSD outside the submitted work, Vivienne Theobald: None declared, Nicklas Milde: None declared, Christian Nagel Speakers bureau: Actelion, MSD, Boehringer, Novartis, Bayer, and AstraZeneca, Norbert Blank Speakers bureau: MSD, GSK, Actelion and Bayer Vital., Consultant of: MSD, GSK, Actelion and Bayer Vital., Hanns-Martin Lorenz Speakers bureau: AbbVie, BMS, Pfizer, Cellgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, AstraZeneca, and Lilly (less than $10,000 each) and research support from AbbVie, MSD, BMS, Cellgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, AstraZeneca, Lilly, Baxter, SOBI, Biogen, Actelion, Bayer Vital, Shire, Octapharm, Sanofi, Hexal, Mundipharm, and Thermo Fisher, Consultant of: AbbVie, BMS, Pfizer, Cellgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, AstraZeneca, and Lilly (less than $10,000 each) and research support from AbbVie, MSD, BMS, Cellgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, AstraZeneca, Lilly, Baxter, SOBI, Biogen, Actelion, Bayer Vital, Shire, Octapharm, Sanofi, Hexal, Mundipharm, and Thermo Fisher, Ekkehard Grünig Speakers bureau: Actelion, Bayer AG, and MSD; grants from GSK, Novartis, and United Therapeutics; and personal fees from SCOPE, OrPha Swiss GmbH, and Zurich Heart House, Consultant of: Actelion, Bayer AG, and MSD; grants from GSK, Novartis, and United Therapeutics; and personal fees from SCOPE, OrPha Swiss GmbH, and Zurich Heart House

AB0687 Prognostic meaning of right ventricular function and reserve in patients with systemic sclerosis

Background

The delay of the diagnosis of pulmonary hypertension (PH) in patients with systemic sclerosis (SSc) leads to severe impairment of survival.

Objectives

The objective of this study was to investigate the prognostic impact of right ventricular (RV) function at rest and during exercise on survival in patients with SSc presenting for screening for PH.

Methods

Data from SSc patients who underwent routinely performed examinations for PH screening including echocardiography and right heart catheterization at rest and during exercise were analyzed. Uni- and multivariable analyses were performed to identify prognostic parameters in SSc and to compare them to known prognostic predictors.

Results

Out of 285 SSc patients screened for PH, 225 patients (81.3% female, mean age 58.1±13.0 years, 68% limited cutaneous SSc, WHO-FC II-III 74%, 24 manifest PH) were included in the analysis. During an observation period of 3.2±2.7 (median 2.6) years 35 patients died. Tricuspid annular plane systolic excursion ≤18 mm (p=0.0004), increase of cardiac index (CI) during exercise ≤ 2 l/min (p=0.0002), RV output reserve >3 mmHg/l/min (p=0.001), peak CI ≤ 5.5l/min (p=0.01), pulmonary arterial compliance >2 ml/mmHg (p=0.0005) and qualitative RV function at rest (p<0.0001) significantly predicted survival. In the multivariable analysis, RV function at rest, diffusion capacity for carbon monoxide < 65% predicted and CI increase <2 l/min/m2 were identified as independent prognostic predictors and had >70% sensitivity and specificity to predict development of pulmonary vascular disease (PVD) during follow-up.

Conclusion

This study demonstrates that assessment of RV function at rest and during exercise may provide crucial information to identify SSc patients who are at a high risk of an impaired survival and development of PVD.

References

[1]Brown ZR, et al. Screening for pulmonary arterial hypertension in systemic sclerosis: Now or never!. Eur J Rheumatol. 2020;7(Suppl 3):S187-S192.

Disclosure of Interests

Panagiota Xanthouli Speakers bureau: MSD and OMT, outside the submitted work, Julia Miazgowski: None declared, Nicola Benjamin Speakers bureau: Actelion pharmaceuticals, Bayer HealthCare and MSD outside the submitted work., Ojan Gordjani: None declared, Benjamin Egenlauf Speakers bureau: Actelion, MSD, Bayer and OMT (less than $10,000 each)., Satenik Harutyunova Speakers bureau: Bayer, MSD, Actelion and GSK, outside the submitted work., Rebekka Seeger: None declared, Alberto Marra Speakers bureau: MSD, Norbert Blank Speakers bureau: MSD, GSK, Actelion and Bayer Vital., Hanns-Martin Lorenz Speakers bureau: AbbVie, BMS, Pfizer, Cellgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, AstraZeneca, and Lilly (less than $10,000 each) and research support from AbbVie, MSD, BMS, Cellgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, AstraZeneca, Lilly, Baxter, SOBI, Biogen, Actelion, Bayer Vital, Shire, Octapharm, Sanofi, Hexal, Mundipharm, and Thermo Fisher, Consultant of: AbbVie, BMS, Pfizer, Cellgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, AstraZeneca, and Lilly (less than $10,000 each) and research support from AbbVie, MSD, BMS, Cellgene, Medac, GSK, Roche, Chugai, Novartis, UCB, Janssen-Cilag, AstraZeneca, Lilly, Baxter, SOBI, Biogen, Actelion, Bayer Vital, Shire, Octapharm, Sanofi, Hexal, Mundipharm, and Thermo Fisher, Ekkehard Grünig Speakers bureau: Actelion, Bayer AG, and MSD; grants from GSK, Novartis, and United Therapeutics; and personal fees from SCOPE, OrPha Swiss GmbH, and Zurich Heart House, Consultant of: Actelion, Bayer AG, and MSD; grants from GSK, Novartis, and United Therapeutics; and personal fees from SCOPE, OrPha Swiss GmbH, and Zurich Heart House, Christina Eichstaedt: None declared

Effect of Supervised Training Therapy on Pulmonary Arterial Compliance and Stroke Volume in Severe Pulmonary Arterial Hypertension and Inoperable or Persistent Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

Pulmonary arterial compliance (PAC) is a prognostic parameter in pulmonary arterial hypertension (PAH) reflecting the elasticity of the pulmonary vessels.

OBJECTIVES

The objective of this post hoc analysis of a prospective randomized controlled trial (RCT) was to assess the effect of exercise training on PAC and stroke volume (SV) in patients with PAH and persistent/inoperable chronic thromboembolic pulmonary hypertension (CTEPH).

METHOD

From the previous RCT, 43 out of 87 patients with severe PAH (n = 29) and CTEPH (n = 14) had complete haemodynamic examinations at baseline and after 15 weeks by right heart catheterization and were analysed (53% female, 79% World Health Organization functional class III/IV, 58% combination therapy, 42% on supplemental oxygen therapy, training group n = 24, and control group n = 19). Medication remained unchanged for all patients.

RESULTS

Low-dose exercise training at 4-7 days/week significantly improved PAC (training group 0.33 ± 0.65 mL/mm Hg vs. control group -0.06 ± 1.10 mL/mm Hg; mean difference 0.39 mL/mm Hg, 95% confidence interval [CI] 0.15-0.94 mL/mm Hg; p = 0.004) and SV (training group 9.9 ± 13.4 mL/min vs. control group -4.2 ± 11.0 mL/min; mean difference 14.2 mL, 95% CI 6.5-21.8 mL; p < 0.001) in the training versus control group. Furthermore, exercise training significantly improved cardiac output and pulmonary vascular resistance at rest, peak oxygen consumption, and oxygen pulse.

CONCLUSIONS

Our findings suggest that supervised exercise training may improve right ventricular function and PAC at the same time. Further prospective studies are needed to evaluate these findings.

Supervised Exercise Training in Patients with Chronic Thromboembolic Pulmonary Hypertension as Early Follow-Up Treatment after Pulmonary Endarterectomy: A Prospective Cohort Study

BACKGROUND

Data on exercise training in chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary endarterectomy (PEA) as well as data on clinical and haemodynamic changes shortly after PEA are lacking.

OBJECTIVE

The objective of this prospective study was to analyse the safety, feasibility, and the effectiveness of combined supervised inpatient rehabilitation in patients with CTEPH directly after PEA.

METHODS

CTEPH patients started a 19-week rehabilitation program (3 weeks as inpatients and continued at home for another 16 weeks) with supervised exercise training as follow-up treatment shortly after PEA. Haemodynamics were assessed by right heart catheterisation before PEA and 22 weeks after PEA. Non-invasive assessments as transthoracic echocardiography and 6-min walking distance (6MWD) were performed before PEA and after 3 (that is, beginning of rehabilitation), 6, and 22 weeks following PEA. Adverse events were recorded throughout the study.

RESULTS

Forty-five CTEPH patients were included (49% female, 57.6 ± 12.4 years old, 60% WHO functional class III). Rehabilitation was started 3.3 ± 0.9 weeks after PEA. Exercise training was well tolerated in all patients without severe side effects. Haemodynamics measured by right heart catheterisation significantly improved from pre-PEA to 22 weeks post-PEA in cardiac output (+1.2 ± 1.5 L/min, 33.4%, p = 0.001) and mean pulmonary arterial pressure (-19 ± 13 mm Hg, -39.6%, p < 0.0001). Right heart size measured by echocardiography, 6MWD, quality of life, and oxygen saturation significantly improved not only within the first 3 weeks after PEA but also during the following 19 weeks of exercise training.

CONCLUSIONS

Supervised exercise training was feasible as early follow-up treatment after PEA. Further controlled studies are needed to discriminate the effects of PEA and early follow-up rehabilitation.

TRIAL REGISTRATION

The study was registered at clinicaltrials.gov (NCT01393327) on July 13, 2011. The study start date was January 2010, and completion date was December 2013.

Risk stratification and prognostic factors in patients with pulmonary arterial hypertension and comorbidities a cross-sectional cohort study with survival follow-up

BACKGROUND

The objective of this study was to analyze prognostic factors and risk stratification in patients with pulmonary arterial hypertension (PAH) and comorbidities.

METHODS

Patients with invasively diagnosed PAH were included in the analysis. Comorbidities were clinically diagnosed as proposed in the 6th World Symposium of pulmonary hypertension. Uni- and multivariate analysis were employed for identification of factors predicting survival and time to first clinical worsening (TTCW). Risk stratification was based on parameters from ESC/ERS-guidelines 2015.

RESULTS

In total 142 patients were enrolled in the study, 90 of them were diagnosed as PAH without and 52 with comorbidities. All patients received targeted PAH therapy and were followed for 3.3 ± 2.4 years. In PAH patients without comorbidities survival and TTCW were significantly associated with reduced 6-min walking distance (6MWD), elevated N-terminal pro brain natriuretic peptide (NT-proBNP), WHO-functional class (WHO-FC) and right atrial (RA) area. In the multivariate analysis, 6MWD was an independent predictor for survival (p = 0.002) and WHO-FC for TTCW (p = 0.001). In patients with PAH and comorbidities these parameters had no significant association with survival and TTCW. Average risk score was significantly associated with survival (p = 0.001) and TTCW (p = 0.013) in PAH but not in PAH with comorbidities (both p > 0.05; figure 1).

CONCLUSION

Risk stratification based on ESC/ERS-guidelines could only be confirmed in patients without comorbidities, but not in patients with PAH and comorbidities. The data of this study suggest, that a different risk stratification needs to be applied to PAH patients with comorbidities. Further studies are needed to confirm these results.

TRIAL REGISTRATION

Not applicable, retrospective registry.

Myeloproliferative Diseases as Possible Risk Factor for Development of Chronic Thromboembolic Pulmonary Hypertension-A Genetic Study

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease which is often caused by recurrent emboli. These are also frequently found in patients with myeloproliferative diseases. While myeloproliferative diseases can be caused by gene defects, the genetic predisposition to CTEPH is largely unexplored. Therefore, the objective of this study was to analyse these genes and further genes involved in pulmonary hypertension in CTEPH patients. A systematic screening was conducted for pathogenic variants using a gene panel based on next generation sequencing. CTEPH was diagnosed according to current guidelines. In this study, out of 40 CTEPH patients 4 (10%) carried pathogenic variants. One patient had a nonsense variant (c.2071A>T p.Lys691*) in the BMPR2 gene and three further patients carried the same pathogenic variant (missense variant, c.1849G>T p.Val617Phe) in the Janus kinase 2 (JAK2) gene. The latter led to a myeloproliferative disease in each patient. The prevalence of this JAK2 variant was significantly higher than expected (p < 0.0001). CTEPH patients may have a genetic predisposition more often than previously thought. The predisposition for myeloproliferative diseases could be an additional risk factor for CTEPH development. Thus, clinical screening for myeloproliferative diseases and genetic testing may be considered also for CTEPH patients.

Flow rate variance of a fully implantable pump for the delivery of intravenous treprostinil in pulmonary arterial hypertension

Implantable infusion pumps might improve the convenience and safety of intravenous treprostinil for pulmonary arterial hypertension. The LENUS Pro® pump (approved in Europe) has a fixed flow rate. Based on 126 pumps and 2853 refills, we retrospectively analyzed the actual flow rate from 09/2010 to 09/2018. A relevant flow rate variance is evident after three years; therefore, flow rate monitoring and dose adjustment are mandatory.

Haemodynamic phenotypes and survival in patients with systemic sclerosis: the impact of the new definition of pulmonary arterial hypertension

BACKGROUND

In this study, we investigated the impact of the new haemodynamic definition of pulmonary arterial hypertension (PAH) as proposed by the 6th PH World Symposium on phenotypes and survival in patients with systemic sclerosis (SSc).

METHODS

In SSc patients who were prospectively and consecutively screened for PAH including right heart catheterisation in Heidelberg or Zurich, haemodynamic and clinical variables have been reassessed according to the new PAH definition. Patients have been followed for 3.7±3.7 (median 3.4) years; Kaplan-Meier survival analysis was performed. Patients with significant lung or left heart disease were excluded from comparative analyses.

RESULTS

The final dataset included 284 SSc patients, 146 patients (49.2%) had mean pulmonary arterial pressure (mPAP) ≤20 mm Hg, 19.3% had mPAP 21-24 mm Hg and 29.4% had mPAP ≥25 mm Hg. In the group of mildly elevated mPAP, only four patients (1.4% of the whole SSc cohort) had pulmonary vascular resistance (PVR) values ≥3 Wood Units (WU) and could be reclassified as manifest SSc-APAH. Twenty-eight (9.8%) patients with mPAP of 21-24 mm Hg and PVR ≥2 WU already presented with early pulmonary vascular disease with decreased 6 min walking distance (6MWD) (p<0.001), TAPSE (p=0.004) and pulmonary arterial compliance (p<0.001). A PVR ≥2 WU was associated with reduced long-term survival (p=0.002). PVR and 6MWD were independent prognostic predictors in multivariate analysis.

CONCLUSION

The data of this study show that a PVR threshold ≥3 WU is too high to enable an early diagnosis of PAH. A PVR threshold ≥2 WU was already associated with pulmonary vascular disease, significantly reduced survival and would be more appropriate in SSc patients with mild PAH.

Early treatment with ambrisentan of mildly elevated mean pulmonary arterial pressure associated with systemic sclerosis: a randomized, controlled, double-blind, parallel group study (EDITA study)

Objective

The objective of this randomized, placebo-controlled, double-blind, parallel group, trial was to assess the effect of ambrisentan on mean pulmonary arterial pressure (mPAP) in patients with systemic sclerosis (SSc) and mildly elevated pulmonary hypertension (PH).

Methods

Thirty-eight SSc patients with mildly elevated mPAP at rest between 21 and 24 mmHg and/or > 30 mmHg during low-dose exercise were randomly assigned to treatment with either ambrisentan 5–10 mg/day or placebo. Right heart catheterization and further clinical parameters were assessed at baseline and after 6 months. The primary endpoint was the difference of mPAP change at rest between groups.

Results

After 6 months, the two groups did not differ in the primary endpoint (ambrisentan mPAP − 1 ± 6.4 mmHg vs. placebo − 0.73 ± 3.59 mmHg at rest, p = 0.884). However, three patients from the placebo group but none of the ambrisentan group progressed to SSc-associated pulmonary arterial hypertension. Furthermore, ambrisentan treatment showed significant improvements in the secondary endpoints cardiac index (CI) and pulmonary vascular resistance (PVR) at rest (CI 0.36 ± 0.66 l/min/m² vs. − 0.31 ± 0.71 l/min/m², p = 0.010; PVR − 0.70 ± 0.78 WU vs. 0.01 ± 0.71 WU, p = 0.012) and during exercise (CI 0.7 ± 0.81 l/min/m² vs. − 0.45 ± 1.36 l/min/m², p = 0.015; PVR − 0.84 ± 0.48 WU vs. − 0.0032 ± 0.34 WU, p < 0.0001).

Conclusion

This is the first randomized, double-blind, placebo-controlled study testing the effect of ambrisentan in patients with mildly elevated mPAP and/or exercise PH. The primary endpoint change in mPAP did only tendentially improve in the ambrisentan group, but the significant improvement of other hemodynamic parameters points to a possible benefit of ambrisentan and will be helpful to design future trials.

Trial registration

www.ClinicalTrials.gov, unique identifier NCT: NCT02290613, registered 14^th of November 2014.

P3676Hemodynamic phenotypes in systemic sclerosis patients screened for pulmonary hypertension (PH): impact of the new definition of PH

Background

Patients with systemic sclerosis (SSc) are at high risk of developing concomitant pulmonary hypertension (PH) which has a crucial impact on the patients' symptoms, quality of life and prognosis.

Purpose

The aim of this study was to analyse the impact of the new hemodynamic definition of precapillary PH as proposed at the 2018 World Symposium on PH in Nice in patients with SSc. Although recent data suggest that PVR >2 WU could be considered as abnormal in the new definition a conservative cut-off value of PVR ≥3 WU has been used.

Methods

SSc-patients were screened for PH using clinical assessments as WHO-functional class, 6 minute walking distance and right heart catheterisation. Patients were divided into hemodynamic subgroups according to their mean pulmonary arterial pressure (mPAP) values with mPAP ≤20 mmHg, 21–24 mmHg and ≥25 mmHg. These subgroups were further divided according to their pulmonary vascular resistance (PVR) with PVR <3 WU or ≥3 WU.

Results

One-hundred-twenty-two patients (79% female, age 57.6±12.7 years, 6MWD 439.5±98.1 meters, 70% diffuse cutaneous SSc, 30% limited cutaneous SSc, 53% WHO-FC II, 25% WHO-FC III) who were prospectively screened for PH were included in the analysis (Figure 1). Among them 26 had a symptomatic manifest PH using the cut-off value of mPAP ≥25 mmHg. Only half of this group presented with PVR ≥3 WU, the others had PVR <3 WU. Eight of these 26 PH-patients presented with PH due to left heart disease. Out of 21 patients with mildly elevated mPAP 21–24 mmHg, two (10%) met the new definition criteria of PH (pulmonary arterial wedge pressure <15 mmHg, mPAP 23 and 24 mmHg, PVR 3.0 and 3.2 WU, CI 2.2 L/min/m2 both, WHO-FC II both, respectively). Out of 75 patients with mPAP <21 mmHg, three presented with PVR ≥3 WU.

Overview of systemic sclerosis patients

Conclusions

The new definition of precapillary pulmonary hypertension may on the one hand allow detecting an additional 10% of PH patients with mild elevated mPAP. On the other hand, eight of 13 patients (62%), who met the former definition of pulmonary arterial hypertension, would be classified as “normal” due to a lack of increase in PVR according to the new definition. The data of this study suggest that for SSc-patients the cut-off value of mPAP >20 mmHg is useful, but the criteria of PVR ≥3 WU may be too strict.

Further studies with larger sample sizes will be needed to better characterise these hemodynamic subgroups and to define the extent of pulmonary vascular disease and treatability.

Reduced Right Ventricular Output Reserve in Patients With Systemic Sclerosis and Mildly Elevated Pulmonary Artery Pressure

OBJECTIVE

This prospective study was undertaken to evaluate right ventricular function and pulmonary arterial compliance (PAC; ratio of stroke volume to pulse pressure) at rest and during exercise in patients with systemic sclerosis (SSc) with normal mean pulmonary artery pressure (PAP), patients with SSc with mildly elevated mean PAP, and patients with SSc with manifest pulmonary hypertension (PH).

METHODS

Patients with SSc (n = 112) underwent clinical assessment and right-sided heart catheterization at rest and during exercise and were divided into 3 groups according to their resting mean PAP values: normal mean PAP (≤20 mm Hg), mildly elevated mean PAP (21-24 mm Hg), and PH (mean PAP ≥25 mm Hg). Results were compared between groups by analysis of variance followed by post hoc Student's t-test.

RESULTS

Compared to patients with normal mean PAP, patients with mildly elevated mean PAP had a lower 6-minute walking distance (P = 0.008), lower cardiac index (P = 0.027) and higher pulmonary vascular resistance (P = 0.0002) during exercise, and lower PAC at rest (P = 0.016) and different stages of exercise (P = 0.033 for 25W and P = 0.024 for 75W).

CONCLUSION

The results of this study suggest that impaired 6-minute walking distance in SSc patients with mildly elevated mean PAP might be caused by reduced PAC during exercise and reduced right ventricular output reserve, presumably due to impaired coupling between the right ventricle and the pulmonary vasculature. These findings provide further evidence of the clinical relevance of mildly elevated mean PAP in patients with SSc.

Right ventricular size and function under riociguat in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (the RIVER study)

BACKGROUND

Riociguat is a soluble guanylate cyclase stimulator approved for pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTPEH). The objective of this study was to evaluate right heart size and function assessed by echocardiography during long term treatment with riociguat.

METHODS

Patients who started riociguat treatment (1.0-2.5 mg tid) within the trials phase II, PATENT, PATENTplus, EAS, CHEST and continued treatment for 3-12 months were included in this study. Echocardiography was analysed off-line at baseline, after 3, 6 and 12 months by investigators who were blinded to clinical data. Last and baseline observation carried forward method (LOCF, BOCF) were performed as sensitivity analysis.

RESULTS

Seventy-one patients (45% PAH, 55% CTEPH; 53.5% female; 60 ± 13 years, mean pulmonary arterial pressure 46 ± 10 mmHg, mean PVR 700 ± 282dynes·sec·cm-5) were included. After 6 months, RA and RV area, RV thickness tricuspid regurgitation velocity showed a significant reduction. After 12 months, patients receiving riociguat therapy showed a significant reduction in right atrial (- 2.6 ± 4.4 cm2, 95% CI -3.84, - 1.33; p < 0.001, n = 49) and right ventricular (RV) area (- 3.5 ± 5.2 cm2, 95% CI -5.1, - 1.9; p < 0.001; n = 44), RV thickness (- 0.76 ± 2.2 mm, 95% CI -1.55, 0.03; n = 32), and a significant increase in TAPSE (2.95 ± 4.78 mm, 95% CI 1.52, 4.39; n = 45) and RV fractional area change (8.12 ± 8.87 mm, 95% CI 4.61, 11.62; n = 27). Both LOCF and BOCF showed similar results but lower effect sizes.

CONCLUSION

Patients under long-term treatment with riociguat show significantly reduced right heart size and improved RV function in PAH and CTEPH. Further controlled prospective studies are needed to confirm these results.

Right heart size and function significantly correlate in patients with pulmonary arterial hypertension - a cross-sectional study

BACKGROUND

The objective of this study was to assess, whether right atrial (RA) and ventricular (RV) size is related to RV pump function at rest and during exercise in patients with pulmonary arterial hypertension (PAH).

METHODS

We included 54 patients with invasively diagnosed PAH that had been stable on targeted medication. All patients underwent clinical assessments including right heart catheterization and echocardiography at rest and during exercise. RV output reserve was defined as increase of cardiac index (CI) from rest to peak exercise (∆CI_exercise). Patients were classified according to the median of RA and RV-area. RV pump function and further clinical parameters were compared between groups by student's t-test. Uni- and multivariate Pearson correlation analyses were performed.

RESULTS

Patients with larger RA and/or RV-areas (above a median of 16 and 20cm², respectively) showed significantly lower ∆CI_exercise, higher mean pulmonary arterial pressure, pulmonary vascular resistance at rest and NT-proBNP levels. Furthermore, patients with higher RV-areas presented with a significantly lower RV stroke volume and pulmonary arterial compliance at peak exercise than patients with smaller RV-size. RV area was identified as the only independent predictor of RV output reserve.

CONCLUSION

RV and RA areas represent valuable and easily accessible indicators of RV pump function at rest and during exercise. Cardiac output reserve should be considered as an important clinical parameter. Prospective studies are needed for further evaluation.

General measures and supportive therapy for pulmonary arterial hypertension: Updated recommendations from the Cologne Consensus Conference 2018

In the summer of 2016, delegates from the German Respiratory Society, the German Society of Cardiology and the German Society of Pediatric Cardiology met in Cologne, Germany, to define consensus-based practice recommendations for the management of patients with pulmonary arterial hypertension (PAH). These recommendations were built on the 2015 European Pulmonary Hypertension guidelines aiming at their practical implementation, considering country-specific issues, and including new evidence, where available. To this end, a number of working groups was initiated, one of which was specifically dedicated to general measures (i.e. physical activity/supervised rehabilitation, pregnancy/contraception, elective surgery, infection prevention, psychological support, travel) and supportive therapy (i.e. anticoagulants, diuretics, oxygen, cardiovascular medications, anaemia/iron deficiency, arrhythmias) for PAH. While the European guidelines provide detailed recommendations for the use of targeted PAH therapies as well as supportive care, detailed treatment decisions in routine clinical care may be challenging, and the relevance of supportive care is often not sufficiently considered. In addition, new evidence became available, thus requiring a thorough reevaluation of specific recommendations. The detailed results and recommendations of the working group on general measures and supportive therapy for PAH, which were last updated in the spring of 2018, are summarized in this article.

Incidence of pulmonary hypertension and determining factors in patients with systemic sclerosis

The objective of this study was to evaluate the incidence of pulmonary hypertension (PH) and determining factors in patients with systemic sclerosis (SSc) and a diffusing capacity of the lung for carbon monoxide (D_LCO) <60% predicted.In this bicentric, prospective cohort study, patients with SSc were clinically assessed at baseline and after 3 years, including right heart catheterisation (RHC). Analysis of determining factors for the development of PH was performed using univariate and multivariate analyses.96 patients with a mean pulmonary arterial pressure (mPAP) <25 mmHg at baseline were followed for 2.95±0.7 years (median 3 years). Of these, 71 had a second RHC; 18 of these 71 patients (25.3%) developed PH, and five (7%) developed SSc-associated pulmonary arterial hypertension. For patients with an mPAP of 21-24 mmHg at baseline, the likelihood of presenting with PH as opposed to normal pressures on follow-up was significantly higher (p=0.026). Pulmonary vascular resistance, tricuspid regurgitation velocity, diffusion capacity and the size of the inferior vena cava at baseline were independent predictors for the development of PH during follow-up.In a selected cohort of SSc patients with a D_LCO <60%, pulmonary pressures appeared to rise progressively during follow-up. In this population, it was possible to identify manifest PH in almost 25% of patients using prospective RHC during follow-up. Therefore, regular clinical assessment including RHC might be useful in patients with SSc.

Plasma Drug Concentrations in Patients with Pulmonary Arterial Hypertension on Combination Treatment

BACKGROUND

Combination therapy with the phosphodiesterase type 5 inhibitors (PDE-5i) sildenafil or tadalafil and the endothelin receptor antagonists (ERA) bosentan, ambrisentan, or macitentan may cause mutual pharmacokinetic interactions in patients with pulmonary arterial hypertension (PAH).

OBJECTIVE

The objective of this study was to analyze plasma drug concentrations in PAH patients receiving different combination treatments.

METHODS

PAH patients receiving a stable combination treatment with ERA and PDE-5i with targeted dosage for at least 1 month were routinely assessed, including clinical parameters and plasma drug concentrations. Concentrations were normalized considering dose and time from last medication intake and presented as multiples of the expected mean (MoM) of the respective monotherapies.

RESULTS

A total of 125 PAH patients (84 female, 41 male, 57% idiopathic/heritable) were included. Sildenafil and tadalafil concentrations were lowest in combination with bosentan (MoM 0.44 ± 0.42, 95% confidence interval [CI] 0.30-0.57, and MoM 0.89 ± 0.53, 95% CI 0.50-1.28, respectively) compared to the combination with ambrisentan (MoM 1.3 ± 0.97, 95% CI 0.86-1.73, and MoM 1.67 ± 0.63, 95% CI 1.40-1.94, respectively) and macitentan (MoM 1.16 ± 0.87, 95% CI 0.86-1.46, and MoM 1.59 ± 0.99, 95% CI 0.80-2.38, respectively). The combination of sildenafil and bosentan led to more than twice the expected bosentan concentrations in 53.8%. Patients switching from sildenafil-bosentan to macitentan showed a significant increase in sildenafil concentrations (p < 0.001).

CONCLUSIONS

Only the combination with macitentan or ambrisentan led to targeted mean PDE-5i plasma concentrations and should therefore be preferred to combination with bosentan. Sildenafil-bosentan showed the strongest interaction, with low sildenafil and high bosentan concentrations. The study was not powered to analyze whether lower PDE-5i concentrations cause unsatisfying clinical response. However, plasma concentrations within a targeted range are desirable and may become of increasing importance.

EIF2AK4 mutation as "second hit" in hereditary pulmonary arterial hypertension

Background

Mutations in the eukaryotic translation initiation factor 2α kinase 4 (EIF2AK4) gene have recently been identified in recessively inherited veno-occlusive disease. In this study we assessed if EIF2AK4 mutations occur also in a family with autosomal dominantly inherited pulmonary arterial hypertension (HPAH) and incomplete penetrance of bone morphogenic protein receptor 2 (BMPR2) mutations.

Methods

Clinical examinations in a family with 10 members included physical examination, electrocardiogram, (stress)-echocardiography and lung function. Manifest PAH was confirmed by right heart catheterisation in three affected subjects. Genetic analysis was performed using a new PAH-specific gene panel analysis with next generation sequencing of all known PAH and further candidate genes. Identified variants were confirmed by Sanger sequencing.

Results

All living family members with manifest HPAH carried two pathogenic heterozygous mutations: a frame shift mutation in the BMPR2 gene and a novel splice site mutation in the EIF2AK4 gene. Two family members who carried the BMPR2 mutation only did not develop manifest HPAH.

Conclusions

This is the first study suggesting that EIF2AK4 can also contribute to autosomal dominantly inherited HPAH. Up to now it has only been identified in a recessive form of HPAH. Only those family members with a co-occurrence of two mutations developed manifest HPAH. Thus, the EIF2AK4 and BMRPR2 mutations support the “second hit” hypothesis explaining the variable penetrance of HPAH in this family. Hence, the assessment of all known PAH genes in families with a known mutation might assist in predictions about the clinical manifestation in so far non-affected mutation carriers.