Randomized, Multicenter Study to Assess the Effects of Different Doses of Sildenafil on Mortality in Adults With Pulmonary Arterial Hypertension.

BACKGROUND: Sildenafil, approved for pulmonary arterial hypertension (PAH), has a recommended adult dose of 20 mg TID, with a previously approved 5-mg TID dose by the US Food and Drug Administration. Safety concerns arose because of common off-label use of higher doses, particularly after pediatric data linked higher doses to increased mortality. To assess this, the Food and Drug Administration mandated a study evaluating the effects of various sildenafil doses on mortality in adults with PAH. METHODS: This randomized, double-blind study compared sildenafil at doses of 5, 20, or 80 mg TID in adults with PAH. The primary objective was noninferiority of 80 mg of sildenafil versus 5 mg for all-cause mortality. Secondary end points included time to clinical worsening and change in 6-minute walk distance at 6 months. Interim analyses were planned at 50% and 75% of the anticipated mortality events. Safety and tolerability were assessed in the intention-to-treat population. RESULTS: The study was halted after the first interim analysis, demonstrating noninferiority for 80 mg of sildenafil versus 5 mg. Of 385 patients enrolled across all dose groups, 78 died. The primary analysis showed a hazard ratio of 0.51 (99.7% CI, 0.22-1.21; P<0.001 for noninferiority) for overall survival comparing 80 mg of sildenafil with 5 mg. Time to clinical worsening favored 80 mg of sildenafil compared with 5 mg (hazard ratio, 0.44 [99.7% CI, 0.22-0.89]; P<0.001). Sildenafil at 80 mg improved 6-minute walk distance from baseline at 6 months compared with 5 mg (least square mean change, 18.9 m [95% CI, 2.99-34.86]; P=0.0201). No significant differences were found between 80 mg of sildenafil and 20 mg in mortality, clinical worsening, and 6-minute walk distance. Adverse event-related drug discontinuations were numerically higher with 80 mg of sildenafil. CONCLUSIONS: Sildenafil at 80 mg was noninferior to sildenafil at 5 mg when examining all-cause mortality in adults with PAH. Secondary efficacy end points favored 80 mg of sildenafil over 5 mg. On the basis of these findings, the Food and Drug Administration recently revoked the approval of 5 mg of sildenafil for adults with PAH, reinforced 20 mg TID as the recommended dose, and now allows dose titration up to 80 mg TID, if needed. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02060487.

Even non-expert radiologists report chronic thromboembolic pulmonary hypertension (CTEPH) on CT pulmonary angiography with high sensitivity and almost perfect agreement.

OBJECTIVES: To assess the diagnostic performance and interobserver agreement of CT pulmonary angiography (CTPA) in the detection of chronic thromboembolic pulmonary hypertension (CTEPH) and its features among radiologists of different levels of experience. MATERIALS AND METHODS: In this retrospective, single-center, single-blinded study, three radiologists with different levels of experience in CT imaging (R1:15 years, R2:6 years, and R3:3 years) evaluated CTPA of 51 patients ultimately diagnosed with CTEPH (European Society of Cardiology guidelines) and 49 patients without CTEPH in random order to assess the presence of CTEPH, its features in the pulmonary artery tree, proximal level of involvement, bronchial artery hypertrophy, mosaic perfusion, and right heart overload. RESULTS: CTPAs of 51 patients with CTEPH (median age, 66 years (IQR 56-72), 28 men) and 49 patients without CTEPH (median age, 65 years (IQR 50-74), 25 men) were evaluated. The sensitivity and specificity for the detection of CTEPH was 100% (all radiologists) and 100% (R1), 96% (R2), and 96% (R3) with almost perfect agreement (κ = 0.95). The sensitivity and specificity for detecting CTEPH by mosaic perfusion would be 89% (95%CI 83-93%) and 81% (74-87%). The level of pulmonary artery involvement was reported with moderate agreement (κ = 0.54, 95%CI 0.40-0.65). Substantial agreement was found in the evaluation of mosaic attenuation (κ = 0.75, 95%CI 0.64-0.84), right heart overload (κ = 0.68, 95%CI 0.56-0.79), and bronchial artery hypertrophy (0.71, 95%CI 0.59-0.82) which were the best predictors of CTEPH (p < 0.0001). CONCLUSIONS: CTPA has high sensitivity and specificity in detecting CTEPH and almost perfect agreement among radiologists of different levels of expertise. CLINICAL RELEVANCE: CT pulmonary angiography can be used as a first-line imaging modality in patients with suspected chronic thromboembolic pulmonary hypertension (CTEPH) even when interpreted by non-CTEPH experts. KEY POINTS: • CT pulmonary angiography has high sensitivity and specificity in detecting chronic thromboembolic pulmonary hypertension (CTEPH) and almost perfect interobserver agreement among radiologists of different levels of expertise. • Substantial agreement exists in the assessment of mosaic attenuation, right heart overload, and bronchial artery hypertrophy, which are the best predictors of CTEPH.

Balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension: a clinical consensus statement of the ESC working group on pulmonary circulation and right ventricular function.

The current treatment algorithm for chronic thromboembolic pulmonary hypertension (CTEPH) as depicted in the 2022 European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines on the diagnosis and treatment of pulmonary hypertension (PH) includes a multimodal approach of combinations of pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA) and medical therapies to target major vessel pulmonary vascular lesions, and microvasculopathy. Today, BPA of >1700 patients has been reported in the literature from centers in Asia, the US, and also Europe; many more patients have been treated outside literature reports. As BPA becomes part of routine care of patients with CTEPH, benchmarks for safe and effective care delivery become increasingly important. In light of this development, the ESC Working Group on Pulmonary Circulation and Right Ventricular Function has decided to publish a document that helps standardize BPA to meet the need of uniformity in patient selection, procedural planning, technical approach, materials and devices, treatment goals, complications including their management, and patient follow-up, thus complementing the guidelines. Delphi methodology was utilized for statements that were not evidence based. First, an anatomical nomenclature and a description of vascular lesions are provided. Second, treatment goals and definitions of complete BPA are outlined. Third, definitions of complications are presented which may be the basis for a standardized reporting in studies involving BPA. The document is intended to serve as a companion to the official ESC/ERS guidelines.

Catheter ablation of atrial fibrillation and atrial tachycardia in patients with pulmonary hypertension: a randomized study.

AIMS: Atrial fibrillation (AF), typical atrial flutter (AFL), and other atrial tachycardias (ATs) are common in patients with pulmonary hypertension. Frequently, several supraventricular arrhythmias are successively observed in individual patients. We investigated the hypothesis of whether more extensive radiofrequency catheter ablation of the bi-atrial arrhythmogenic substrate instead of clinical arrhythmia ablation alone results in superior clinical outcomes in patients with pulmonary arterial hypertension (PH) and supraventricular arrhythmias. METHODS AND RESULTS: Patients with combined post- and pre-capillary or isolated pre-capillary PH and supraventricular arrhythmia indicated to catheter ablation were enrolled in three centres and randomized 1:1 into two parallel treatment arms. Patients underwent either clinical arrhythmia ablation only (Limited ablation group) or clinical arrhythmia plus substrate-based ablation (Extended ablation group). The primary endpoint was arrhythmia recurrence >30 s without antiarrhythmic drugs after the 3-month blanking period. A total of 77 patients (mean age 67 ± 10 years; 41 males) were enrolled. The presumable clinical arrhythmia was AF in 38 and AT in 36 patients, including typical AFL in 23 patients. During the median follow-up period of 13 (interquartile range: 12; 19) months, the primary endpoint occurred in 15 patients (42%) vs. 17 patients (45%) in the Extended vs. Limited ablation group (hazard ratio: 0.97, 95% confidence interval: 0.49-2.0). There was no excess of procedural complications and clinical follow-up events including an all-cause death in the Extended ablation group. CONCLUSION: Extensive ablation, compared with a limited approach, was not beneficial in terms of arrhythmia recurrence in patients with AF/AT and PH. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov; NCT04053361.

Central versus Peripheral CTEPH-Clinical and Hemodynamic Specifications.

Background and Objectives: Chronic thromboembolic pulmonary hypertension (CTEPH) is a chronic progressive disease, resulting from persistent arterial obstruction combined with small-vessel remodeling. Central and peripheral CTEPH are distinguished, according to the dominant lesion's location. This is important for surgical or percutaneous interventional assessment or for medical treatment. Material and Methods: Eighty-one patients (51 male/30 female) with confirmed CTEPH were analyzed, while the CENTRAL type included 51 patients (63%) and the PERIPHERAL type 30 patients (37%). Results: A significant difference in CENTRAL type vs. PERIPHERAL type was determined in gender (male 72.5% vs. 46.7%; p = 0.0198). No difference was found in age, functional status, or echocardiographic parameters. Invasive hemodynamic parameters showed a significant difference in mean pulmonary arterial pressure (46 vs. 58 mmHg; p = 0.0002), transpulmonary gradient (34 vs. 47 mmHg; p = 0.0005), and cardiac index (2.04 vs. 2.5 L.min.m2; p = 0.02) but not in pulmonary vascular resistance. Risk factors showed a significant difference only in acute pulmonary embolism (93.8% vs. 60%; p = 0.0002) and malignancy (2% vs. 13.3%; p = 0.0426). Conclusions: Our study showed hemodynamic differences between CENTRAL type vs. PERIPHERAL type CTEPH with a worse hemodynamic picture in CENTRAL form. This may indicate a different pathophysiological response and/or possible additional influences contributing especially to the peripheral pulmonary bed affection.

ERS statement on chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism, either symptomatic or not. The occlusion of proximal pulmonary arteries by fibrotic intravascular material, in combination with a secondary microvasculopathy of vessels <500 µm, leads to increased pulmonary vascular resistance and progressive right heart failure. The mechanism responsible for the transformation of red clots into fibrotic material remnants has not yet been elucidated. In patients with pulmonary hypertension, the diagnosis is suspected when a ventilation/perfusion lung scan shows mismatched perfusion defects, and confirmed by right heart catheterisation and vascular imaging. Today, in addition to lifelong anticoagulation, treatment modalities include surgery, angioplasty and medical treatment according to the localisation and characteristics of the lesions.This statement outlines a review of the literature and current practice concerning diagnosis and management of CTEPH. It covers the definitions, diagnosis, epidemiology, follow-up after acute pulmonary embolism, pathophysiology, treatment by pulmonary endarterectomy, balloon pulmonary angioplasty, drugs and their combination, rehabilitation and new lines of research in CTEPH.It represents the first collaboration of the European Respiratory Society, the International CTEPH Association and the European Reference Network-Lung in the pulmonary hypertension domain. The statement summarises current knowledge, but does not make formal recommendations for clinical practice.

Atrial fibrillation and atrial tachycardia in patients with chronic thromboembolic pulmonary hypertension treated with pulmonary endarterectomy.

Atrial fibrillation (AF) and atrial tachycardia (AT) are frequently observed in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who were treated with pulmonary endarterectomy (PEA). Their prevalence and impact on prognosis of patients are not known. We analysed the prevalence of AF/AT and the clinical outcome in 197 patients with CTEPH treated with PEA (median age 62; interquartile range 53-68 years; 62% males). The prevalence of AF/AT was 29% (57 patients). Compared to patients without arrhythmia, the subjects with AF/AT were older [60 (50-67) vs. 62 (57-70) years], manifested an increased size of the left atrium [39 (35-44) vs. 45 (40-50) mm], had a reduced 6-min walking distance [411 (321-506) vs. 340 (254-460) m], and higher pulmonary artery systolic pressure after PEA [38 (30-47) vs. 45 (38-71) mmHg], all results with P-value <0.05. During the follow-up with a median 4.2 (1.6-6.3) years, 45 (23%) patients died. In a multivariate Cox regression model only the male gender [hazard ratio (HR) 2.27, 95% confidence interval (CI) 1.15-4.50], a reduced 6-min walking distance (HR 3.67, 95% CI 1.74-7.73), and an increased New York Heart Association class (HR 8.56, 95% CI 4.17-17.60) were associated with mortality (P < 0.05). The prevalence of AF/AT in patients with CTEPH treated with PEA is high. Arrhythmias are associated with reduced functional capacity but not with mortality.

The left atrial substrate plays a significant role in the development of complex atrial tachycardia in patients with precapillary pulmonary hypertension.

BACKGROUND: Atrial fibrillation (AF) and related atrial tachyarrhythmias (AT), including type I atrial flutter (AFL) are frequently observed in patients with pulmonary hypertension (PH). Their relationship to hemodynamic changes, atrial size, and ventricular function are still not fully verified. METHODS: We retrospectively studied hemodynamic data, echocardiographic findings and arrhythmia incidence in 814 patients with invasively diagnosed precapillary PH (aged 59 ± 14 years; 46% males). Patients with combined or post-capillary PH were excluded. RESULTS: AF / AT were identified in 225 (28%) of all the study population. Compared to the subgroup without arrhythmia, patients with AF / AT had elevated right atrial pressure (11 ± 5 vs. 9 ± 5 mmHg), wedge pressure (11 ± 3 vs. 10 ± 3), a more enlarged right atrium (50 ± 12 vs. 47 ± 11 mm) and an increased left atrial diameter in the parasternal long axis projection, p <  0.05 for all comparisons. In the multivariate model, the left atrial size, patient age, arterial hypertension, diabetes and type of PH were associated with AF / AT occurrence, p <  0.05. Patients with type I AFL were more frequently male (39 (80%) vs. 62 (42%)), were younger (61 ± 11 vs. 67 ± 10 years), had increased pulmonary artery mean pressure (50 ± 12 vs. 45 ± 12 mmHg), less advanced left atrial dilatation (38 ± 10 vs. 42 ± 7 mm), and a more enlarged right atrium (56 ± 12 vs. 48 ± 11) as compared to subjects with AF or other AT, p <  0.05. CONCLUSIONS: The evidence of elevated wedge pressure and the enlargement of the left atrium especially in patients with AF suggest a parallel involvement of the left atrial substrate in arrhythmia formation despite invasively confirmed evidence of purely isolated precapillary PH. Substantial differences were noticed between patients with type I AFL and the remaining patients with other arrhythmia types.

Surgical treatment of chronic thromboembolic pulmonary hypertension.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease characterized by a mean pulmonary artery pressure that exceeds 25 mm Hg and is caused by intraluminal thrombi organisation, stenosis and occlusions of pulmonary artery and its branches and peripheral vascular remodelation. It is a chronic complication of acute pulmonary embolism. The obstruction of pulmonary artery branches increases pulmonary vascular resistance (PVR) and this leads to the right ventricular overload and right-sided heart failure. The treatment of choice is surgical pulmonary endarterectomy (PEA), a procedure that is performed in deep hypothermic cardiac arrest. The only center that specializes into the surgical treatment of patients with CTEPH in the Czech Republic is the Complex Cardiovascular Centre at the General Teaching Hospital in Prague. Between years 2004-2017 there were 314 patients opera-ted (including 50 patients from Slovakia, where this treatment is not available). Patients with peripheral type of CTEPH, who are not indicated for operation and also patients with residual pulmonary hypertension after PEA can be indicated for specific vasodilatation therapy. In indicated cases the treatment may involve the balloon angioplasty or lung transplantation.

SERAPHIN haemodynamic substudy: the effect of the dual endothelin receptor antagonist macitentan on haemodynamic parameters and NT-proBNP levels and their association with disease progression in patients with pulmonary arterial hypertension.

Aims: The effect of macitentan on haemodynamic parameters and NT-proBNP levels was evaluated in pulmonary arterial hypertension (PAH) patients in the SERAPHIN study. Association between these parameters and disease progression, assessed by the primary endpoint (time to first morbidity/mortality event), was explored. Methods and results: Of the 742 randomized patients, 187 with right heart catheterization at baseline and month 6 participated in a haemodynamic sub-study. Prespecified endpoints included change from baseline to month 6 in cardiac index (CI), right atrial pressure (RAP), mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), mixed-venous oxygen saturation, and NT-proBNP. Exploratory analyses examined associations between CI, RAP, and NT-proBNP and disease progression using the Kaplan-Meier method and Cox regression models. Macitentan improved CI, RAP, mPAP, PVR and NT-proBNP vs. placebo at month 6. Absolute levels of CI, RAP and NT-proBNP at baseline and month 6, but not their changes, were associated with morbidity/mortality events. Patients with CI > 2.5 L/min/m2, RAP < 8 mmHg, or NT-proBNP < 750 fmol/ml at month 6 had a lower risk of morbidity/mortality than those not meeting these thresholds (HR 0.49, 95% CL 0.28-0.86; HR 0.72, 95% CL 0.42-1.22; and HR 0.22, 95% CL 0.15-0.33, respectively). Conclusions: For all treatment groups, baseline and month 6 values of CI, RAP, and NT-proBNP, but not their changes, were associated with morbidity/mortality events, confirming their relevance in predicting disease progression in patients with PAH. By improving those parameters, macitentan increased the likelihood of reaching threshold values associated with lower risk of morbidity/mortality.

Long-Term Outcome of Patients With Chronic Thromboembolic Pulmonary Hypertension: Results From an International Prospective Registry.

BACKGROUND: Chronic thromboembolic pulmonary hypertension, a rare complication of acute pulmonary embolism, is characterized by fibrothrombotic obstructions of large pulmonary arteries combined with small-vessel arteriopathy. It can be cured by pulmonary endarterectomy, and can be clinically improved by medical therapy in inoperable patients. A European registry was set up in 27 centers to evaluate long-term outcome and outcome correlates in 2 distinct populations of operated and not-operated patients who have chronic thromboembolic pulmonary hypertension. METHODS AND RESULTS: A total of 679 patients newly diagnosed with chronic thromboembolic pulmonary hypertension were prospectively included over a 24-month period. Estimated survival at 1, 2, and 3 years was 93% (95% confidence interval [CI], 90-95), 91% (95% CI, 87-93), and 89% (95% CI, 86-92) in operated patients (n=404), and only 88% (95% CI, 83-91), 79% (95% CI, 74-83), and 70% (95% CI, 64-76) in not-operated patients (n=275). In both operated and not-operated patients, pulmonary arterial hypertension-targeted therapy did not affect survival estimates significantly. Mortality was associated with New York Heart Association functional class IV (hazard ratio [HR], 4.16; 95% CI, 1.49-11.62; P=0.0065 and HR, 4.76; 95% CI, 1.76-12.88; P=0.0021), increased right atrial pressure (HR, 1.34; 95% CI, 0.95-1.90; P=0.0992 and HR, 1.50; 95% CI, 1.20-1.88; P=0.0004), and a history of cancer (HR, 3.02; 95% CI, 1.36-6.69; P=0.0065 and HR, 2.15; 95% CI, 1.18-3.94; P=0.0129) in operated and not-operated patients, respectively. Additional correlates of mortality were bridging therapy with pulmonary arterial hypertension-targeted drugs, postoperative pulmonary hypertension, surgical complications, and additional cardiac procedures in operated patients, and comorbidities such as coronary disease, left heart failure, and chronic obstructive pulmonary disease in not-operated patients. CONCLUSIONS: The long-term prognosis of operated patients currently is excellent and better than the outcome of not-operated patients.

RESPITE: switching to riociguat in pulmonary arterial hypertension patients with inadequate response to phosphodiesterase-5 inhibitors.

A proportion of pulmonary arterial hypertension (PAH) patients do not reach treatment goals with phosphodiesterase-5 inhibitors (PDE5i). RESPITE investigated the safety, feasibility and benefit of switching from PDE5i to riociguat in these patients.RESPITE was a 24-week, open-label, multicentre, uncontrolled study. Patients in World Health Organization (WHO) functional class (FC) III, with 6-min walking distance (6MWD) 165-440 m, cardiac index <3.0 L·min-1·m-2 and pulmonary vascular resistance >400 dyn·s·cm-5 underwent a 1-3 day PDE5i treatment-free period before receiving riociguat adjusted up to 2.5 mg maximum t.i.d Exploratory end-points included change in 6MWD, WHO FC, N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and safety.Of 61 patients enrolled, 51 (84%) completed RESPITE. 50 (82%) were receiving concomitant endothelin receptor antagonists. At week 24, mean±sd 6MWD had increased by 31±63 m, NT-proBNP decreased by 347±1235 pg·mL-1 and WHO FC improved in 28 patients (54%). 32 patients (52%) experienced study drug-related adverse events and 10 (16%) experienced serious adverse events (2 (3%) study drug-related, none during the PDE5i treatment-free period). Six patients (10%) experienced clinical worsening, including death in two (not study drug-related).In conclusion, selected patients with PAH may benefit from switching from PDE5i to riociguat, but this strategy needs to be further studied.

Sildenafil dosed concomitantly with bosentan for adult pulmonary arterial hypertension in a randomized controlled trial.

BACKGROUND: Few controlled clinical trials exist to support oral combination therapy in pulmonary arterial hypertension (PAH). METHODS: Patients with PAH (idiopathic [IPAH] or associated with connective tissue disease [APAH-CTD]) taking bosentan (62.5 or 125 mg twice daily at a stable dose for ≥3 months) were randomized (1:1) to sildenafil (20 mg, 3 times daily; n = 50) or placebo (n = 53). The primary endpoint was change from baseline in 6-min walk distance (6MWD) at week 12, assessed using analysis of covariance. Patients could continue in a 52-week extension study. An analysis of covariance main-effects model was used, which included categorical terms for treatment, baseline 6MWD (<325 m; ≥325 m), and baseline aetiology; sensitivity analyses were subsequently performed. RESULTS: In sildenafil versus placebo arms, week-12 6MWD increases were similar (least squares mean difference [sildenafil-placebo], -2.4 m [90% CI: -21.8 to 17.1 m]; P = 0.6); mean ± SD changes from baseline were 26.4 ± 45.7 versus 11.8 ± 57.4 m, respectively, in IPAH (65% of population) and -18.3 ± 82.0 versus 17.5 ± 59.1 m in APAH-CTD (35% of population). One-year survival was 96%; patients maintained modest 6MWD improvements. Changes in WHO functional class and Borg dyspnoea score and incidence of clinical worsening did not differ. Headache, diarrhoea, and flushing were more common with sildenafil. CONCLUSIONS: Sildenafil, in addition to stable (≥3 months) bosentan therapy, had no benefit over placebo for 12-week change from baseline in 6MWD. The influence of PAH aetiology warrants future study. TRIAL REGISTRATION: ClinicalTrials.gov NCT00323297 (registration date: May 5, 2006).

Riociguat in patients with chronic thromboembolic pulmonary hypertension: results from an early access study.

BACKGROUND: Following positive results from the Phase III CHEST-1 study in patients with inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH), the Phase IIIb CTEPH early access study (EAS) was designed to assess the safety and tolerability of riociguat in real-world clinical practice, as well as to provide patients with early access to riociguat before launch. Riociguat is approved for the treatment of inoperable and persistent/recurrent CTEPH. METHODS: We performed an open-label, uncontrolled, single-arm, early access study in which 300 adult patients with inoperable or persistent/recurrent CTEPH received riociguat adjusted from 1 mg three times daily (tid) to a maximum of 2.5 mg tid. Patients switching from unsatisfactory prior pulmonary arterial hypertension (PAH)-targeted therapy (n = 84) underwent a washout period of at least 3 days before initiating riociguat. The primary aim was to assess the safety and tolerability of riociguat, with World Health Organization functional class and 6-min walking distance (6MWD) as exploratory efficacy endpoints. RESULTS: In total, 262 patients (87%) completed study treatment and entered the safety follow-up (median treatment duration 47 weeks). Adverse events were reported in 273 patients (91%). The most frequently reported serious adverse events were syncope (6%), right ventricular failure (3%), and pneumonia (2%). There were five deaths, none of which was considered related to study medication. The safety and tolerability of riociguat was similar in patients switched from other PAH-targeted therapies and those who were treatment naïve. In patients with data available, mean ± standard deviation 6MWD had increased by 33 ± 42 m at Week 12 with no clinically relevant differences between the switched and treatment-naïve subgroups. CONCLUSIONS: Riociguat was well tolerated in patients with CTEPH who were treatment naïve, and in those who were switched from other PAH-targeted therapies. No new safety signals were observed. TRIAL REGISTRATION: ClinicalTrials.org NCT01784562 . Registered February 4, 2013.

Riociguat for the treatment of chronic thromboembolic pulmonary hypertension.

BACKGROUND: Riociguat, a member of a new class of compounds (soluble guanylate cyclase stimulators), has been shown in previous clinical studies to be beneficial in the treatment of chronic thromboembolic pulmonary hypertension. METHODS: In this phase 3, multicenter, randomized, double-blind, placebo-controlled study, we randomly assigned 261 patients with inoperable chronic thromboembolic pulmonary hypertension or persistent or recurrent pulmonary hypertension after pulmonary endarterectomy to receive placebo or riociguat. The primary end point was the change from baseline to the end of week 16 in the distance walked in 6 minutes. Secondary end points included changes from baseline in pulmonary vascular resistance, N-terminal pro-brain natriuretic peptide (NT-proBNP) level, World Health Organization (WHO) functional class, time to clinical worsening, Borg dyspnea score, quality-of-life variables, and safety. RESULTS: By week 16, the 6-minute walk distance had increased by a mean of 39 m in the riociguat group, as compared with a mean decrease of 6 m in the placebo group (least-squares mean difference, 46 m; 95% confidence interval [CI], 25 to 67; P<0.001). Pulmonary vascular resistance decreased by 226 dyn·sec·cm(-5) in the riociguat group and increased by 23 dyn·sec·cm(-5) in the placebo group (least-squares mean difference, -246 dyn·sec·cm(-5); 95% CI, -303 to -190; P<0.001). Riociguat was also associated with significant improvements in the NT-proBNP level (P<0.001) and WHO functional class (P=0.003). The most common serious adverse events were right ventricular failure (in 3% of patients in each group) and syncope (in 2% of the riociguat group and in 3% of the placebo group). CONCLUSIONS: Riociguat significantly improved exercise capacity and pulmonary vascular resistance in patients with chronic thromboembolic pulmonary hypertension. (Funded by Bayer HealthCare; CHEST-1 and CHEST-2 ClinicalTrials.gov numbers, NCT00855465 and NCT00910429, respectively.)

Macitentan and morbidity and mortality in pulmonary arterial hypertension.

BACKGROUND: Current therapies for pulmonary arterial hypertension have been adopted on the basis of short-term trials with exercise capacity as the primary end point. We assessed the efficacy of macitentan, a new dual endothelin-receptor antagonist, using a primary end point of morbidity and mortality in a long-term trial. METHODS: We randomly assigned patients with symptomatic pulmonary arterial hypertension to receive placebo once daily, macitentan at a once-daily dose of 3 mg, or macitentan at a once-daily dose of 10 mg. Stable use of oral or inhaled therapy for pulmonary arterial hypertension, other than endothelin-receptor antagonists, was allowed at study entry. The primary end point was the time from the initiation of treatment to the first occurrence of a composite end point of death, atrial septostomy, lung transplantation, initiation of treatment with intravenous or subcutaneous prostanoids, or worsening of pulmonary arterial hypertension. RESULTS: A total of 250 patients were randomly assigned to placebo, 250 to the 3-mg macitentan dose, and 242 to the 10-mg macitentan dose. The primary end point occurred in 46.4%, 38.0%, and 31.4% of the patients in these groups, respectively. The hazard ratio for the 3-mg macitentan dose as compared with placebo was 0.70 (97.5% confidence interval [CI], 0.52 to 0.96; P=0.01), and the hazard ratio for the 10-mg macitentan dose as compared with placebo was 0.55 (97.5% CI, 0.39 to 0.76; P<0.001). Worsening of pulmonary arterial hypertension was the most frequent primary end-point event. The effect of macitentan on this end point was observed regardless of whether the patient was receiving therapy for pulmonary arterial hypertension at baseline. Adverse events more frequently associated with macitentan than with placebo were headache, nasopharyngitis, and anemia. CONCLUSIONS: Macitentan significantly reduced morbidity and mortality among patients with pulmonary arterial hypertension in this event-driven study. (Funded by Actelion Pharmaceuticals; SERAPHIN ClinicalTrials.gov number, NCT00660179.).

Riociguat for the treatment of chronic thromboembolic pulmonary hypertension: a long-term extension study (CHEST-2).

Riociguat is a soluble guanylate cyclase stimulator approved for the treatment of inoperable and persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH). In the 16-week CHEST-1 study, riociguat showed a favourable benefit-risk profile and improved several clinically relevant end-points in patients with CTEPH. The CHEST-2 open-label extension evaluated the long-term safety and efficacy of riociguat. Eligible patients from CHEST-1 received riociguat individually adjusted up to a maximum dose of 2.5 mg three times daily. The primary objective was the safety and tolerability of riociguat; exploratory efficacy end-points included 6-min walking distance (6MWD) and World Health Organization (WHO) functional class (FC). Overall, 237 patients entered CHEST-2 and 211 (89%) were ongoing at this interim analysis (March 2013). The safety profile of riociguat in CHEST-2 was similar to CHEST-1, with no new safety signals. Improvements in 6MWD and WHO FC observed in CHEST-1 persisted for up to 1 year in CHEST-2. In the observed population at 1 year, mean±sd 6MWD had changed by +51±62 m (n=172) versus CHEST-1 baseline (n=237), and WHO FC had improved/stabilised/worsened in 47/50/3% of patients (n=176) versus CHEST-1 baseline (n=236). Long-term riociguat had a favourable benefit-risk profile and apparently showed sustained benefits in exercise and functional capacity for up to 1 year.

Incident and prevalent cohorts with pulmonary arterial hypertension: insight from SERAPHIN.

In SERAPHIN, a long-term, randomised, controlled trial (NCT00660179) in pulmonary arterial hypertension (PAH), macitentan significantly reduced the risk of morbidity/mortality and PAH-related death/hospitalisation. We evaluated disease progression and the effect of macitentan in treatment-naïve incident and prevalent cohorts.Patients allocated to placebo, or macitentan 3 mg or 10 mg were classified by time from diagnosis to enrolment as incident (≤6 months; n=110) or prevalent (>6 months; n=157). The risk of morbidity/mortality and PAH-related death/hospitalisation was determined using Cox regression.The risk of morbidity/mortality (Kaplan-Meier estimates at month 12: 54.4% versus 26.7%; p=0.006) and PAH-related death/hospitalisation (Kaplan-Meier estimates at month 12: 47.3% versus 19.9%; p=0.006) were significantly higher for incident versus prevalent patients receiving placebo, respectively. There was no significant difference in the risk of all-cause death between incident and prevalent cohorts (p=0.587). Macitentan 10 mg significantly reduced the risk of morbidity/mortality and PAH-related death/hospitalisation versus placebo in incident and prevalent cohorts.Incident patients had a higher risk for PAH progression compared with prevalent patients but not a higher risk of death. Macitentan delayed disease progression in both incident and prevalent PAH patients.

Epidemiology and long-term survival of pulmonary arterial hypertension in the Czech Republic: a retrospective analysis of a nationwide registry.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a severe and progressive disease characterized by increased pulmonary vascular resistance, ultimately leading to right heart failure and death. Epidemiological data from national registries are growing worldwide, but are still unavailable in Eastern Europe. METHODS: A PAH registry was initiated in January 2007 using a nationwide network of echocardiographic centers and four diagnostic centers that specialize in PAH. All patients aged above 18 years, diagnosed with PAH and monitored between January 2000 and December 2007 were included. Patients diagnosed with PAH between January and December 2007 were classified as incident. The survival analyses were performed up to the end of 2010. Prognostic factors at the time of diagnosis were identified using uni- and multivariable Cox proportional hazard models. RESULTS: Overall, 191 patients were included (100 prevalent cases, 91 incident cases). Patients were predominantly female (n = 125) and had a mean age of 51.9 ± 16.9 years. Incident patients were significantly older at the time of diagnosis than prevalent patients (p < 0.001). Most patients (60.7%) had idiopathic PAH; 20.4% had PAH associated with congenital heart disease and 11.4% had PAH associated with connective tissue disease. Estimates of prevalence and incidence of PAH in adults were 22.4 cases per million and 10.7 cases per million per year, respectively. The 1-, 2- and 3-year survival rates in the incident PAH cohort were 89% (95% confidence intervals [CI] 83-95%), 78% (95% CI 70-87%) and 74% (95% CI 65-83%), respectively. Lower survival rates were significantly associated with higher age (hazard ratio [HR] 6.6 95% CI 1.4-30.9) and lower creatinine clearance (HR 3.3 95% CI 1.1-9.7). CONCLUSION: This is the first study in Eastern Europe to describe the prevalence, incidence and survival of patients with PAH from a national representative registry. This registry from the Czech Republic highlights that diagnosis of PAH is frequently made late in the disease continuum when patients have significant functional impairment.

[Development of interest of pulmonary hypertension in the Czech Republic]. / Vývoj klinického zájmu o plicní hypertenzi v Ceské republice.

Development of clinical interest on the pulmonary hypertension is associated with the development of cardiac catheterization. The first measurement of cardiac output during right heart catheterization was performed by Otto Klein, who worked at the German University in Prague right after Forssmann´s pioneering act. The invention of the floating balloon catheter is connected with the name of William Ganz, who was born in Kosice and studied medicine in Prague. Some medical centres in Prague, known as Prague School of Pulmonary Circulation have dedicated to the issue of pulmonary hypertension since the 60s of last century. From their initiative was established the European Society of Breathing Pathophysiology and between the year 1969 and 1999 were regularly held in Prague international conferences dedicated to pulmonary circulation. In clinical practice has dominated interest on treatable forms of chronic pulmonary hypertension - pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) in past 15 years. Therapy of PAH patients is concentrated in 3 specialized centres in the Czech Republic. The care of CTEPH patients is provided in Cardiocentre of General Faculty Hospital in Prague. Surgical treatment is provided to Slovak patients as well.