Influence of echo time on pulmonary ventilation and perfusion derived by phase-resolved functional lung (PREFUL) MRI using multi-echo ultrashort echo time acquisition.

Non-contrast enhanced 1H magnetic resonance imaging (MRI) is promising for ventilation/perfusion (V/Q) assessment of the lung but the influence of the echo time (TE) on V/Q parameters is lacking. Therefore, the purpose of this study was to investigate the influence of different TEs on pulmonary V/Q parameters derived by phase-resolved functional lung (PREFUL) MRI using a multi-echo ultrashort TE (UTE) acquisition. A 2D multi-echo UTE sequence with radial center out readout and tiny golden angle increment was developed. Forty-eight participants were enrolled in this study: 25 healthy subjects, six patients with asthma, and 17 patients with pulmonary fibrosis. Participants underwent two acquisitions of 2D multi-echo UTE MRI with three TEs per acquisition (TE1-6: 0.07, 0.82, 1.72, 2.47, 3.37, and 4.12 ms). Regional ventilation (RVent), flow-volume loop cross-correlation metric (FVL-CM), and normalized perfusion-weighted signal (QN) maps were calculated. V/Q defect percentages (VDP/QDP) were determined. To assess repeatability, the measurement was repeated in healthy subjects. Median and interquartile range of RVent, FVL-CM, QN, VDP, and QDP were calculated. To assess significant differences between parameters obtained at different TEs, Friedman's test and Dunnett's test were performed. Pearson correlation coefficients between RVent derived at TE1 and the difference in RVent between TE2,3 and TE1 were calculated. For repeatability assessment, coefficient of variation (CoV) and intraclass correlation coefficient (ICC) were determined. Significant differences were found comparing V/Q parameters obtained at TE3-6 compared to TE1. CoV increased with TE. For ICC, values between 0.35 (QDP at TE1) and 0.83 (VDPRVent at TE2) were obtained for T1,2. Statistically significant differences for ventilation and perfusion parameters derived by PREFUL were found for TE3-6 compared to TE1. All V/Q parameters were well repeatable for TE1-2. With increasing TE and respiratory volume, RVent shows a T2*-dependency leading to biased ventilation assessment compared to TE1.

Changes in REVEAL Lite 2 risk status are associated with long-term outcomes in patients with pulmonary arterial hypertension: A post-hoc analysis of the GRIPHON study.

BACKGROUND: Mortality risk assessment informs clinical management of pulmonary arterial hypertension (PAH). The Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) Lite 2 is a simplified risk calculator discriminating 1-year mortality risk. METHODS: This post-hoc analysis of the phase 3 GRIPHON study assessed changes in REVEAL Lite 2 risk score with selexipag versus placebo and whether changes were prognostic or predictive of time to first morbidity/mortality (M/M) event. RESULTS: REVEAL Lite 2 risk category discriminated M/M risk (landmark concordance indices: 0.68-0.76, selexipag; 0.65-0.70, placebo). Across baseline risk categories, hazard ratios supported a lower risk of M/M events with selexipag versus placebo: low, 0.573 (95% confidence interval [CI] 0.361-0.908; p = 0.0178); intermediate, 0.423 (95% CI 0.274-0.655; p = 0.0001); and high, 0.711 (9% CI 0.520-0.972; p = 0.0326). Odds ratios for risk improvement were 2.0 (95% CI 1.50-2.65), 1.8 (95% CI 1.38-2.43), and 2.0 (95% CI 1.43-2.72) for selexipag versus placebo at 16, 26, and 52 weeks, respectively (all p < 0.001). REVEAL Lite 2 risk improvement at week 16 explained 19.1% of the treatment effect in all patients and 47.0% in patients with REVEAL Lite 2 baseline risk score of ≥7. CONCLUSIONS: REVEAL Lite 2 can monitor PAH M/M risk and facilitate treatment optimization. Baseline REVEAL Lite 2 risk score was prognostic of M/M risk in patients with PAH and mediates treatment effect up to 47% for those at higher risk. Lower M/M risk with selexipag versus placebo occurred irrespective of baseline risk category (ClinicalTrials.gov identifier: NCT01106014).

Safety and efficacy of riociguat in patients with pulmonary arterial hypertension and cardiometabolic comorbidities: Data from interventional clinical trials.

BACKGROUND: There is limited evidence to support treatment recommendations in patients with pulmonary arterial hypertension (PAH) and comorbidities. To investigate the impact of riociguat treatment in this patient population, we analyzed pooled data from randomized controlled trials of riociguat. METHODS: This post hoc analysis included data from the PATENT-1, PATENT-2, PATENT PLUS, and REPLACE studies. Safety, efficacy (6-minute walk distance [6MWD], World Health Organization functional class [WHO-FC], and N-terminal probrain natriuretic peptide [NT-proBNP]), and COMPERA 2.0 risk status were assessed in patients with 0, 1 to 2, or 3 to 4 cardiometabolic comorbidities (obesity, systemic hypertension, diabetes mellitus, coronary artery disease) in the main phase of the studies. Safety was also assessed in the long-term extensions. RESULTS: The analysis included 686 patients (riociguat, n = 440; placebo, n = 132; phosphodiesterase type 5 inhibitors [PDE5i], n = 114), of whom 55%, 39%, and 6% had 0, 1 to 2, and 3 to 4 comorbidities, respectively. In the main phase, rates and severity of adverse events (AEs) were similar in riociguat-treated patients across comorbidity subgroups. After 2 years, discontinuations of riociguat due to AEs were also similar across subgroups. Compared with placebo and PDE5i, riociguat improved 6MWD and NT-proBNP across comorbidity groups and improved WHO-FC and COMPERA 2.0 risk status in patients with 0 or 1 to 2 comorbidities. CONCLUSIONS: Riociguat had an acceptable safety profile in PAH patients with cardiometabolic comorbidities. Efficacy and risk assessment results suggest that riociguat can be beneficial for patients with PAH, irrespective of the presence of comorbidities.

MK-5475, an inhaled soluble guanylate cyclase stimulator, for treatment of pulmonary arterial hypertension: the INSIGNIA-PAH study.

BACKGROUND: MK-5475 is an investigational inhaled soluble guanylate cyclase stimulator hypothesised to avoid most side-effects of systemic vasodilation. METHODS: The phase 2 INSIGNIA-PAH (NCT04732221) trial randomised adults with pulmonary arterial hypertension (PAH) on stable background therapy 1:1:1:1 to once-daily dosing with placebo, MK-5475 32 µg, 100 µg or 380 µg via dry powder inhalation for 12 weeks. OBJECTIVES: The objectives were to evaluate pulmonary vascular resistance (PVR; primary), 6-min walk distance (6MWD; secondary), additional selected haemodynamic parameters, and safety and tolerability in participants with PAH. RESULTS: 168 participants were randomised to placebo (n=41), MK-5475 32 µg (n=42), 100 µg (n=44), and 380 µg (n=41). Median age was 51 years. Most participants were female (73.8%), diagnosed with idiopathic PAH (63.7%), receiving concomitant phosphodiesterase type 5 inhibitors (PDE5i; 93.5%), and treated with double or triple combination therapy (85.1%). At week 12, the placebo-corrected changes in PVR by least-squares means were -9.2% (95% CI -21.3%, 2.9%; p=0.068) with 32 µg, -22.0% (95% CI -33.7%, -10.3%; p<0.001) with 100 µg, and -19.9% (95% CI -33.4%, -6.4%; p=0.002) with 380 µg MK-5475. No treatment differences versus placebo were observed in 6MWD. Treatment-related adverse events and serious adverse events were similar across treatment groups. Three participants died: two on placebo and one on MK-5475 100 µg. One participant had symptomatic hypotension and one had haemoptysis (both on MK-5475 100 µg). CONCLUSIONS: In participants with PAH on stable background therapy, including PDE5i, inhaled MK-5475 reduced PVR and was well tolerated, without evidence of systemic side-effects such as hypotension, suggesting a pulmonary selective pharmacodynamic effect.

Risk stratification and treatment goals in pulmonary arterial hypertension.

Risk stratification has gained an increasing role in predicting outcomes and guiding the treatment of patients with pulmonary arterial hypertension (PAH). The most predictive prognostic factors are three noninvasive parameters (World Health Organization functional class, 6-min walk distance and natriuretic peptides) that are included in all currently validated risk stratification tools. However, suffering from limitations mainly related to reduced specificity of PAH severity, these variables may not always be adequate in isolation for guiding individualised treatment decisions. Moreover, with effective combination treatment regimens and emerging PAH therapies, markers associated with pulmonary vascular remodelling are expected to become of increasing relevance in guiding the treatment of patients with PAH. While reaching a low mortality risk, assessed with a validated risk tool, remains an important treatment goal, preliminary data suggest that invasive haemodynamics and cardiac imaging may add incremental value in guiding treatment decisions.

A scalable and cGMP-compatible autologous organotypic cell therapy for Dystrophic Epidermolysis Bullosa.

We present Dystrophic Epidermolysis Bullosa Cell Therapy (DEBCT), a scalable platform producing autologous organotypic iPS cell-derived induced skin composite (iSC) grafts for definitive treatment. Clinical-grade manufacturing integrates CRISPR-mediated genetic correction with reprogramming into one step, accelerating derivation of COL7A1-edited iPS cells from patients. Differentiation into epidermal, dermal and melanocyte progenitors is followed by CD49f-enrichment, minimizing maturation heterogeneity. Mouse xenografting of iSCs from four patients with different mutations demonstrates disease modifying activity at 1 month. Next-generation sequencing, biodistribution and tumorigenicity assays establish a favorable safety profile at 1-9 months. Single cell transcriptomics reveals that iSCs are composed of the major skin cell lineages and include prominent holoclone stem cell-like signatures of keratinocytes, and the recently described Gibbin-dependent signature of fibroblasts. The latter correlates with enhanced graftability of iSCs. In conclusion, DEBCT overcomes manufacturing and safety roadblocks and establishes a reproducible, safe, and cGMP-compatible therapeutic approach to heal lesions of DEB patients.

Initial combination therapy with macitentan and tadalafil in patients with pulmonary arterial hypertension, with and without cardiac comorbidities.

AIMS: According to current guidelines, initial monotherapy should be considered for pulmonary arterial hypertension (PAH) patients with cardiopulmonary comorbidities. This analysis of combined data from the TRITON and REPAIR clinical trials, assesses efficacy and safety of initial double combination therapy in patients without vs. with 1-2 cardiac comorbidities. METHODS AND RESULTS: Data were combined for patients from TRITON (NCT02558231) and REPAIR (NCT02310672) on initial macitentan and tadalafil double combination therapy (overall set, n = 148) and two subgroups defined as patients without cardiac comorbidities (n = 62) and those with 1-2 cardiac comorbidities (n = 78). Patients with ≥3 comorbidities were excluded from these studies. For the overall set, the median (Q1-Q3) duration of combined macitentan and tadalafil exposure was 513.0 (364.0-778.0) days, and was similar between subgroups. Change from baseline to Week 26 for pulmonary vascular resistance was -55% and -50% for patients without and with 1-2 cardiac comorbidities, respectively; marked improvements in other hemodynamic and functional parameters were also observed, although functional parameters improved to a lesser extent in patients with comorbidities. At Week 26, the majority of patients had improved PAH risk status, according to the non-invasive four-strata and REVEAL Lite 2.0 methods. The safety profile of initial macitentan plus tadalafil combination therapy was consistent with the known profiles of the two drugs, and similar between the subgroups. CONCLUSIONS: Initial double combination therapy with macitentan plus tadalafil is efficacious in patients with PAH with 1-2 cardiac comorbidities and those without, with similar safety and tolerability profiles between the two groups.

Phenotypes in pulmonary hypertension.

The clinical classification of pulmonary hypertension (PH) has guided diagnosis and treatment of patients with PH for several decades. Discoveries relating to underlying mechanisms, pathobiology and responses to treatments for PH have informed the evolution in this clinical classification to describe the heterogeneity in PH phenotypes. In more recent years, advances in imaging, computational science and multi-omic approaches have yielded new insights into potential phenotypes and sub-phenotypes within the existing clinical classification. Identification of novel phenotypes in pulmonary arterial hypertension (PAH) with unique molecular profiles, for example, could lead to new precision therapies. Recent phenotyping studies have also identified groups of patients with PAH that more closely resemble patients with left heart disease (group 2 PH) and lung disease (group 3 PH), which has important prognostic and therapeutic implications. Within group 2 and group 3 PH, novel phenotypes have emerged that reflect a persistent and severe pulmonary vasculopathy that is associated with worse prognosis but still distinct from PAH. In group 4 PH (chronic thromboembolic pulmonary disease) and sarcoidosis (group 5 PH), the current approach to patient phenotyping integrates clinical, haemodynamic and imaging characteristics to guide treatment but applications of multi-omic approaches to sub-phenotyping in these areas are sparse. The next iterations of the PH clinical classification are likely to reflect several emerging PH phenotypes and improve the next generation of prognostication tools and clinical trial design, and improve treatment selection in clinical practice.

Tadalafil for Treatment of Combined Postcapillary and Precapillary Pulmonary Hypertension in Patients With Heart Failure and Preserved Ejection Fraction: A Randomized Controlled Phase 3 Study.

BACKGROUND: We assessed the efficacy and safety of tadalafil, a phosphodiesterase type 5 inhibitor, in patients with heart failure with preserved ejection fraction and combined postcapillary and precapillary pulmonary hypertension. METHODS: In the double-blind PASSION study (Phosphodiesterase-5 Inhibition in Patients With Heart Failure With Preserved Ejection Fraction and Combined Post- and Pre-Capillary Pulmonary Hypertension), patients with heart failure with preserved ejection fraction and combined postcapillary and precapillary pulmonary hypertension were randomized 1:1 to receive tadalafil at a target dose of 40 mg or placebo. The primary end point was the time to the first composite event of adjudicated heart failure hospitalization or all-cause death. Secondary end points included all-cause mortality and improvements in New York Heart Association functional class or ≥10% improvement in 6-minute walking distance from baseline. RESULTS: Initially targeting 372 patients, the study was terminated early because of disruption in study medication supply. At that point, 125 patients had been randomized (placebo: 63; tadalafil: 62,). Combined primary end-point events occurred in 20 patients (32%) assigned to placebo and 17 patients (27%) assigned to tadalafil (hazard ratio, 1.02 [95% CI, 0.52-2.01]; P=0.95). There was a possible signal of higher all-cause mortality in the tadalafil group (hazard ratio, 5.10 [95% CI, 1.10-23.69]; P=0.04). No significant between-group differences were observed in other secondary end points. Serious adverse events occurred in 29 participants (48%) in the tadalafil group and 35 (56%) in the placebo group. CONCLUSIONS: The PASSION trial, terminated prematurely due to study medication supply disruption, does not support tadalafil use in patients with heart failure with preserved ejection fraction and combined postcapillary and precapillary pulmonary hypertension, with potential safety concerns and no observed benefits in primary and secondary end points. REGISTRATION: URL: https://www.clinicaltrialsregister.eu/; Unique identifier: 2017-003688-37. URL: https://drks.de; Unique identifier: DRKS -DRKS00014595.

Application of REVEAL Lite 2 and COMPERA 2.0 risk scores to patients with pulmonary arterial hypertension switching to riociguat in the REPLACE study.

In Riociguat rEplacing PDE5i therapy evaLuated Against Continued PDE5i thErapy (REPLACE) (NCT02891850), improvements in risk status were observed in patients with pulmonary arterial hypertension (PAH) at intermediate risk switching to riociguat versus continuing phosphodiesterase-5 inhibitors (PDE5i). This post hoc study applied the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) Lite 2 and Comparative Prospective Registry of Newly Initiated Therapies for Pulmonary (COMPERA) 2.0 risk-assessment tools to REPLACE to investigate the impact of baseline risk status on clinical improvement. The proportions of riociguat- and PDE5i-treated patients achieving the primary end-point at REVEAL Lite 2 low, intermediate, and high baseline risk reflected the overall population. Proportions of riociguat-treated patients achieving the primary end-point were comparable between the COMPERA 2.0 intermediate-low risk (39%) and intermediate-high risk (43%) groups. Our findings show that patients in REPLACE achieved clinical improvement by switching from PDE5i to riociguat across all COMPERA 2.0 and most REVEAL Lite 2 baseline risk strata.

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.