Acute Vasoreactivity Testing and Outcomes in Pulmonary Arterial Hypertension: A Call for Increased Testing.

BACKGROUND: Pulmonary arterial hypertension (PAH) has a progressive, unremitting clinical course. Vasoreactivity testing (VdT) during right heart catheterisation (RHC) identifies a subgroup with excellent long-term response to calcium channel blockade (CCB). Reporting on these patients is limited. Established in 2011, the Pulmonary Hypertension Society of Australia and New Zealand (PHSANZ) registry offers the opportunity to assess the frequency of VdT during RHC, treatment and follow up of PAH patients. METHODS: Registry data from 3,972 PAH patients with index RHC revealed 1,194 VdT appropriate patients. Data was analysed in three groups: 1) VdT+CCB+: VdT positive, CCB treated; 2) VdT+CCB-: VdT positive, no CCB prescribed, 3) VdT-/noVdT: VdT negative, or VdT not tested. Data was reviewed for adherence to guidelines, clinical response (World Health Organization functional class [WHO FC], 6-minute-walk-distance [6MWD], RHC), and outcomes (survival or lung transplantation). RESULTS: Patients included had idiopathic (IPAH=1,087), heritable (HPAH=67) and drug or toxin-induced PAH (DPAH=40). A VdT was performed in 22% (268/1,194), with incomplete data in 26% (70/268); 28% (55/198) were VdT+. Analysis group allocation was: VdT+CCB+ (33/55), VdT+CCB- (22/55), VdT- (143)/noVdT (996). From patients with 1-year data VdT+CCB+ and VdT-/noVdT patients improved WHO FC, 6MWD and cardiac index (CI); VdT+CCB- data remained similar. Within the VdT+CCB+ group, 30% (10/33) were long-term CCB responders with a 100% 5-year survival; non-responders had a 61% survival at 5.4 years. Long-term responders were younger at diagnosis (40 yrs vs 54 yrs). CONCLUSION: Use of VdT testing and documentation is poor in this contemporary patient cohort. Nonetheless, survival in VdT+CCB+ patients from the PHSANZ registry is excellent, supporting guidelines promoting VdT testing. Strategies to promote the use of VdT are warranted.

VX-445-Tezacaftor-Ivacaftor in Patients with Cystic Fibrosis and One or Two Phe508del Alleles.

BACKGROUND: VX-445 is a next-generation cystic fibrosis transmembrane conductance regulator (CFTR) corrector designed to restore Phe508del CFTR protein function in patients with cystic fibrosis when administered with tezacaftor and ivacaftor (VX-445-tezacaftor-ivacaftor). METHODS: We evaluated the effects of VX-445-tezacaftor-ivacaftor on Phe508del CFTR protein processing, trafficking, and chloride transport in human bronchial epithelial cells. On the basis of in vitro activity, a randomized, placebo-controlled, double-blind, dose-ranging, phase 2 trial was conducted to evaluate oral VX-445-tezacaftor-ivacaftor in patients heterozygous for the Phe508del CFTR mutation and a minimal-function mutation (Phe508del-MF) and in patients homozygous for the Phe508del CFTR mutation (Phe508del-Phe508del) after tezacaftor-ivacaftor run-in. Primary end points were safety and absolute change in percentage of predicted forced expiratory volume in 1 second (FEV1) from baseline. RESULTS: In vitro, VX-445-tezacaftor-ivacaftor significantly improved Phe508del CFTR protein processing, trafficking, and chloride transport to a greater extent than any two of these agents in dual combination. In patients with cystic fibrosis, VX-445-tezacaftor-ivacaftor had an acceptable safety and side-effect profile. Most adverse events were mild or moderate. The treatment also resulted in an increased percentage of predicted FEV1 of up to 13.8 points in the Phe508del-MF group (P<0.001). In patients in the Phe508del-Phe508del group, who were already receiving tezacaftor-ivacaftor, the addition of VX-445 resulted in an 11.0-point increase in the percentage of predicted FEV1 (P<0.001). In both groups, there was a decrease in sweat chloride concentrations and improvement in the respiratory domain score on the Cystic Fibrosis Questionnaire-Revised. CONCLUSIONS: The use of VX-445-tezacaftor-ivacaftor to target Phe508del CFTR protein resulted in increased CFTR function in vitro and translated to improvements in patients with cystic fibrosis with one or two Phe508del alleles. This approach has the potential to treat the underlying cause of cystic fibrosis in approximately 90% of patients. (Funded by Vertex Pharmaceuticals; VX16-445-001 ClinicalTrials.gov number, NCT03227471 ; and EudraCT number, 2017-000797-11 .).

Chronic thromboembolic pulmonary hypertension in Australia and New Zealand: An analysis of the PHSANZ registry.

BACKGROUND AND OBJECTIVE: Chronic thromboembolic pulmonary hypertension (CTEPH) is a serious condition occurring in 2%-4% of patients after acute pulmonary embolism. Pulmonary endarterectomy (PEA) is a potential cure for technically operable disease. The epidemiology and long-term outcomes of CTEPH have not been previously described in Australia and New Zealand. METHODS: Data were extracted from the Pulmonary Hypertension Society of Australia and New Zealand (PHSANZ) registry for patients diagnosed with CTEPH between January 2004 and March 2020. Baseline characteristics, treatment strategies, outcome data and long-term survival are reported. RESULTS: A total of 386 patients were included with 146 (37.8%) undergoing PEA and 240 (62.2%) in the non-PEA group. PEA patients were younger (55 ± 16 vs. 62 ± 16 years, p < 0.001) with higher baseline 6-min walk distance (6MWD; 405 ± 122 vs. 323 ± 146 m, p = 0.021), whilst both groups had similar baseline pulmonary haemodynamics. Pulmonary hypertension-specific therapy was used in 54% of patients post-PEA and 88% in the non-PEA group. The 1-, 3- and 5-year survival rates were 93%, 87% and 84% for the PEA group compared to 86%, 73% and 62%, respectively, for the non-PEA group (p < 0.001). Multivariate survival analysis showed baseline 6MWD was an independent predictor of survival in both operated and medically managed patients. CONCLUSION: In this first multicentre report of CTEPH in Australia and New Zealand, long-term survival is comparable to that in other contemporary CTEPH registries. However, PEA was only performed in a minority of CTEPH patients (37.8%) and significantly less than overseas reports. Greater awareness of PEA and improved patient access to experienced CTEPH centres are important priorities.

Re-imagining cystic fibrosis care: next generation thinking.

Cystic fibrosis (CF) is a common multi-system genetically inherited condition, predominately found in individuals of Caucasian decent. Since the identification of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene in 1989, and the subsequent improvement in understanding of CF pathophysiology, significant increases in life-expectancy have followed. Initially this was related to improvements in the management and systems of care for treating the various affected organ systems. These cornerstone treatments are still essential for CF patients born today. However, over the last decade, the major advance has been in therapies that target the resultant genetic defect: the dysfunctional CFTR protein. Small molecule agents that target this dysfunctional protein via a variety of mechanisms have led to lung function improvements, reductions in pulmonary exacerbation rates and increases in weight and quality-of-life indices. As more patients receive these agents earlier and earlier in life, it is likely that general CF care will increasingly pivot around these specific therapies, although it is also likely that effects other than those identified in the initial trials will be discovered and need to be managed. Despite great excitement for modulator therapies, they are unlikely to be suitable or available for all; whether this is due to a lack of availability for specific CFTR mutations, drug-reactions or the health economic set-up in certain countries. Nevertheless, the CF community must be applauded for its ongoing focus on research and development for this life-limiting disease. With time, personalised individualised therapy would ideally be the mainstay of CF care.

Pulmonary arterial hypertension with below threshold pulmonary vascular resistance.

Pulmonary vascular resistance (PVR) >3 Wood units is a criterion of the haemodynamic definition of pulmonary arterial hypertension (PAH). However, this cut-off is conservative and arbitrarily defined. Data is lacking on the natural history, response to therapy and survival of patients diagnosed with precapillary pulmonary hypertension (PH) with mild or borderline elevation of PVR.In Australia, PAH therapy could be prescribed solely on mean pulmonary arterial pressure (PAP) and pulmonary arterial wedge pressure (PAWP) criteria. Using the Australian and New Zealand Pulmonary Hypertension Registry, we aimed to study a population diagnosed with PAH between January 2004 and December 2017 with the pre-defined haemodynamic characteristics of mean PAP ≥25 mmHg, PAWP ≤15 mmHg and PVR <3 Wood units.Eighty-two patients met the pre-defined haemodynamic inclusion criteria (mean age 63±11 years; 67 females). Underlying aetiologies included idiopathic disease (n=39), connective tissue disease (CTD; n=42) and HIV infection (n=1). At diagnosis, mean PAP was 27 mmHg (interquartile range (IQR) 25-30 mmHg), PAWP 13 mmHg (IQR 11-14 mmHg) and PVR 2.2 Wood units (IQR 1.9-2.7 Wood units). Baseline 6-min walk distance (6MWD) was 352 m (IQR 280-416 m) and 77% of subjects were in New York Heart Association (NYHA) functional class 3 or 4. All patients were commenced on initial monotherapy with an endothelin receptor antagonist (ERA; n=66) or phosphodiesterase type-5 inhibitor (PDE5i; n=16). At first re-evaluation, 6MWD increased by 46 m (IQR 7-96 m) and 35% of subjects demonstrated improvement in NYHA functional class. After a median follow-up of 65 months (IQR 32-101 months), 18 out of 82 subjects (22.0%) had died, with estimated 1-year and 5-year survival rates of 98% and 84%, respectively. Death attributed to PAH occurred in six out of these 18 patients (33.3%, 7% of total cohort).Patients with precapillary PH and "borderline" PVR falling outside the current definition have adverse outcomes. Such patients appear to respond to PAH therapy; however, this requires further study in randomised trials.

Diagnostic delay in pulmonary arterial hypertension: Insights from the Australian and New Zealand pulmonary hypertension registry.

BACKGROUND AND OBJECTIVE: Early diagnosis of PAH is clinically challenging. Patterns of diagnostic delay in Australian and New Zealand PAH populations have not been explored in large-scale studies. We aimed to evaluate the magnitude, risk factors and survival impact of diagnostic delay in Australian and New Zealand PAH patients. METHODS: A cohort study of PAH patients from the PHSANZ Registry diagnosed from 2004 to 2017 was performed. Diagnostic interval was the time from symptom onset to diagnostic right heart catheterization as recorded in the registry. Factors associated with diagnostic delay were analysed in a multivariate logistic regression model. Survival rates were compared across patients based on the time to diagnosis using Kaplan-Meier method and Cox regression. RESULTS: A total of 2044 patients were included in analysis. At diagnosis, median age was 58 years (IQR: 43-69), female-to-male ratio was 2.8:1 and majority of patients were in NYHA FC III-IV (82%). Median diagnostic interval was 1.2 years (IQR: 0.6-2.7). Age, CHD-PAH, obstructive sleep apnoea and peripheral vascular disease were independently associated with diagnostic interval of ≥1 year. No improvement in diagnostic interval was seen during the study period. Longer diagnostic interval was associated with decreased 5-year survival. CONCLUSION: PAH patients experience significant diagnostic interval, which has not improved despite increased community awareness. Age, cardiovascular and respiratory comorbidities are significantly associated with longer time to diagnosis. Mortality rates appear higher in patients who experience longer diagnostic interval.

Pharmacological Treatment of Pulmonary Arterial Hypertension in Australia: Current Trends and Challenges.

BACKGROUND: Combination drug therapy for pulmonary arterial hypertension (PAH) is the international standard of care for most patients, however in Australia there are barriers to drug access. This study evaluates current treatment of PAH patients in Australia and the consistency of therapy with international guidelines. METHODS: Cross-sectional analysis of patients with Group 1 PAH enrolled in the Pulmonary Hypertension Society of Australia and New Zealand Registry (PHSANZ) at 31 December 2017. Drug treatment was classified as monotherapy or combination therapy and adequacy of treatment was determined by risk status assessment using the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) 2.0 risk calculator. Predictors of monotherapy were assessed using a generalised linear model with Poisson distribution and logarithmic link function. RESULTS: 1,046 patients met the criteria for analysis. Treatment was classified as monotherapy in 536 (51%) and combination therapy in 510 (49%) cases. Based on REVEAL 2.0, 184 (34%) patients on monotherapy failed to meet low-risk criteria and should be considered inadequately treated. Independent predictors of monotherapy included age greater than 60 years (risk ratio [RR] 1.23, 95% confidence interval [CI] 1.09-1.38; p=0.001), prevalent enrolment in the registry (RR 1.21 [95%CI 1.08-1.36]; p=0.001) and comorbid systemic hypertension (RR 1.17 [95%CI 1.03-1.32]; p=0.014), while idiopathic/heritable/drug-induced PAH subtype (RR 0.85 [95%CI 0.76-0.96]; p=0.006), functional class IV (RR 0.50 [95%CI 0.29-0.86]; p=0.012), increased right ventricular systolic pressure (RR 0.99 [95%CI 0.99-1.00]; p<0.001) and increased pulmonary vascular resistance (RR 0.96 [95%CI 0.95-0.98]; p<0.001) were less likely to be associated with monotherapy. CONCLUSIONS: Most Australian PAH patients are treated with monotherapy and a significant proportion remain at risk of poor outcomes. This is below the standard of care recommended by international guidelines and at risk patients should be escalated to combination therapy.

Survival of Idiopathic Pulmonary Arterial Hypertension Patients in the Modern Era in Australia and New Zealand.

BACKGROUND: Epidemiology and treatment strategies continue to evolve in pulmonary arterial hypertension (PAH). We sought to define the characteristics and survival of patients with idiopathic, heritable and drug-induced PAH in the current management era. METHODS: Consecutive cases of idiopathic, heritable and drug-induced PAH were prospectively enrolled into an Australian and New Zealand Registry. RESULTS: Between January 2012 and December 2016, a total of 220 incident cases were enrolled (mean age 57.2±18.7years, female 69.5%) and followed for a median duration of 26 months (IQR17-39). Co-morbidities were common such as obesity (34.1%), systemic hypertension (30.5%), coronary artery disease (16.4%) and diabetes mellitus (19.5%). Initial combination therapy was used in 54 patients (dual, n=50; triple, n=4). Estimated survival rates at 1-year, 2-years and 3-years were 95.6% (CI 92.8-98.5%), 87.3% (CI 82.5-92.4%) and 77.0% (CI 70.3-84.3%), respectively. Multivariate analysis showed that male sex and lower 6-minute distance at diagnosis independently predicted worse survival, whereas obesity was associated with improved survival. Co-morbidities other than obesity did not impact survival. Initial dual oral combination therapy was associated with a trend towards better survival compared with initial oral monotherapy (adjusted HR=0.27, CI 0.06-1.18, p=0.082) CONCLUSIONS: The epidemiology and survival of patients with idiopathic PAH in Australia and New Zealand are similar to contemporary registries reported in Europe and North America. Male sex and poorer exercise capacity are predictive of mortality whereas obesity appears to exert a protective effect. Despite current therapies, PAH remains a life-threatening disease associated with significant early mortality.

Improvement in exercise duration, lung function and well-being in G551D-cystic fibrosis patients: a double-blind, placebo-controlled, randomized, cross-over study with ivacaftor treatment.

G551D, a mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, results in impaired chloride channel function in cystic fibrosis (CF) with multiple end-organ manifestations. The effect of ivacaftor, a CFTR-potentiator, on exercise capacity in CF is unknown. Twenty G551D-CF patients were recruited to a single-centre, double-blind, placebo-controlled, 28-day crossover study of ivacaftor. Variables measured included percentage change from baseline (%Δ) of VO2max (maximal oxygen consumption, primary outcome) during cardiopulmonary exercise testing (CPET), relevant other CPET physiological variables, lung function, body mass index (BMI), sweat chloride and disease-specific health related quality of life (QOL) measures (CFQ-R and Alfred Wellness (AWEscore)). %ΔVO2max was unchanged compared with placebo as was %Δminute ventilation. However, %Δexercise time (mean 7.3, CI 0.5-14,1, P=0.0222) significantly increased as did %ΔFEV1 (11.7%, range 5.3-18.1, P<0·005) and %ΔBMI (1.2%, range 0.1-2.3, P=0·0393) whereas sweat chloride decreased (mean -43.4; range -55.5-18.1 mmol·l-1, P<0·005). Total and activity based domains in both CFQ-R and AWEscore also increased. A positive treatment effect on spirometry, BMI (increased), SCT (decreased) and total and activity based CF-specific QOL measures was expected. However, the lack of discernible improvement in VO2max and VE despite other positive changes including spirometric lung function and exercise time with a 28-day ivacaftor intervention suggests that ventilatory parameters are not the sole driver of change in exercise capacity in this study cohort. Investigation over a more prolonged period may delineate the potential interdependencies of the observed discordances over time. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov-NCT01937325.

Impact of Left Heart Disease Risk Factors on Outcomes in Pulmonary Arterial Hypertension Therapy.

BACKGROUND: Current guidelines recommend initial monotherapy for pulmonary arterial hypertension (PAH) with cardiopulmonary comorbidities, despite limited available evidence to guide management. RESEARCH QUESTION: Do left heart disease (LHD) risk factors have an impact on treatment response and influence applicability of risk assessment in a real-world cohort of patients with PAH? STUDY DESIGN AND METHODS: The Ambrisentan and Tadalafil in Patients with Pulmonary Arterial Hypertension (AMBITION) trial criteria was used to define the phenotype of patients with PAH with risk factors for LHD. Treatment strategy, functional outcome, long-term survival, and risk discrimination were compared with a reference PAH cohort using the Pulmonary Hypertension Society of Australia and New Zealand Registry. RESULTS: A total of 487 incident patients with PAH diagnosed between 2011 and 2020 were included. Of these, 103 (21.1%) fulfilled the definition of PAH with LHD risk factors, with 384 (78.9%) remaining as the reference group. Patients in the PAH with LHD risk factors group were older (66 ± 13 vs 58 ± 19 years; P < .001), had lower pulmonary vascular resistance (393 ± 266 vs 708 ± 391 dyn.s/cm5; P = .031), and had worse 6-min walk distance (286 ± 130 vs 327 ± 136 m; P = .005) at diagnosis. The PAH with LHD risk factors group was less likely to receive initial combination therapy (27% vs 44%; P = .02). Changes in 6-min walk distance at 12 months were similar in both groups (43 ± 77 m in the PAH with LHD risk factors group and 50 ± 90 m in the reference group; P = .50), including when stratified by initial treatment strategy (PAH with LHD risk factors group vs reference PAH group: monotherapy: 40 ± 81 vs 38 ± 95 m, P = .87; combination therapy: 53 ± 78 vs 64 ± 106 m, P = .511). Functional class improvements were also similar in both groups. REVEAL Registry 2.0 risk score effectively discriminated risk in both populations (C statistic = 0.756 for the PAH with LHD risk factors group and C statistic = 0.750 for the reference PAH group). There was no difference in survival between the two groups (log-rank test, P = .29). INTERPRETATION: In a real-world cohort, patients with PAH with LHD risk factors were less likely to be exposed to initial combination therapy. Nevertheless, selected patients with PAH with LHD risk factors who were treated with initial combination therapy derived similar functional response compared with the reference group. Further studies are needed to phenotype patients with PAH with cardiopulmonary comorbidities who may benefit from initial combination therapy.

Relationship between trough plasma and epithelial lining fluid concentrations of voriconazole in lung transplant recipients.

Trough (predose) voriconazole concentrations in plasma and pulmonary epithelial lining fluid (ELF) of lung transplant recipients receiving oral voriconazole preemptive treatment were determined. The mean (± standard deviation [SD]) ELF/plasma ratio was 12.5 ± 6.3. A strong positive linear relationship was noted between trough plasma and ELF voriconazole concentrations (r(2) = 0.87), suggesting the feasibility of using trough plasma voriconazole concentration as a surrogate to estimate the corresponding concentration in ELF of lung transplant recipients.

A case of extreme carboxyhaemoglominemia due to vaping.

Acute carbon monoxide (CO) poisoning is known to cause neurological, metabolic and cardiorespiratory sequalae. However, data on chronic CO exposure are scant, particularly in the context of vaping, which recent literature suggests may be a greater source of CO than tobacco cigarette smoking. During a series of admissions at the time of vaping, our patient repeatedly presented with significant CO poisoning and developed pulmonary arterial hypertension with resultant high-output right heart failure. On each occasion, our patient's levels of carboxyhaemoglobin were both higher and took longer to resolve than 12 smokers who underwent arterial blood gas testing at two time points. Our observation may reveal an association between vaping, chronic carboxyhaemoglobinemia and the development of cardiorespiratory disease. Thus, further studies into the safety of vaping and chronic CO exposure are urged.

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) and massive hemoptysis: The rationale for bronchial artery embolization.

INTRODUCTION: In many patients with Chronic Thromboembolic Pulmonary Hypertension (CTEPH), bronchial artery hypertrophy is observed. Patients with bronchial dilatation have been shown to be at increased risk of hemoptysis introducing the risk of airway obstruction. In this study from an academic tertiary referral center, we aimed to assess the incidence of massive hemoptysis in our CTEPH patients, the success of bronchial artery embolization (BAE), recurrence, and hemoptysis-related mortality. METHODS: Retrospective cohort study of all adults with CTEPH who underwent BAE for massive hemoptysis between 1 January 2015 and 30 July 2021. Primary endpoints were hemoptysis relapse and hemoptysis-related mortality. RESULTS: There were 367 patients who were being treated and managed with a diagnosis of CTEPH at our institution. There were 24 bronchial artery embolization procedures performed for all causes. A total of 3 patients during this time met inclusion criteria with acute massive hemoptysis and CTEPH. All patients were taking therapeutic-dose anticoagulation. Technical success after BAE was 100%. No hemoptysis recurrence was demonstrated at 17, 24, and 40-months follow-up respectively. No patient died from hemoptysis. However, 1 patient died 24 months after the embolization procedure due to a non-hemoptysis cause. CONCLUSION: This study highlights the low but important incidence of massive hemoptysis in patients with CTEPH. Unlike other causes of hemoptysis, this unique cohort requires balancing anticoagulation and hemorrhage control. Given the high degree of success, BAE is a viable option, allowing continuation or early re-establishment of anticoagulation.

Feasibility of the A-STEP for the assessment of exercise capacity in people with cystic fibrosis.

OBJECTIVES: To evaluate feasibility of the Alfred Step Test Exercise Protocol (A-STEP) for the assessment of exercise capacity in adults and children with cystic fibrosis (CF); in adults to test whether demographics and/or lung function correlated with exercise capacity. METHODS: Adults and children with stable CF from two centres completed the A-STEP (a recently developed incremental maximal-effort step test). Feasibility was evaluated by: usefulness for exercise capacity assessment (measures of exercise capacity were: level reached, exercise-induced desaturation, and achievement of at least one maximal effort criteria); safety; operational factors; time to complete; floor and/or ceiling effects. We used multiple linear regression to test whether demographics and/or lung function correlated with exercise capacity. RESULTS: A total of 49 participants: 38 adults (18 male), percent predicted (pp) forced expiration in one second (FEV1 ) 29-109, aged 22-48 years and 11 children (6 male), ppFEV1 68-107, aged 10-15 years were included. Levels reached (mean (SD) [range]) were 10.2 (2.4) [6-15] (adults), 10.1 (2.5) [7-14] (children); desaturation (change between baseline and peak-exercise SpO2 ): was 8.4 (3.8 [0-15]% (adults), 2.0 (2.0) [0-7]% (children). A total of 8 (21%) adults and no children desaturated <90% SpO2 . At least one criterion for maximal effort was reached by 33 (84%) adults and 10 (91%) children. There were no adverse events. The A-STEP was straightforward to use and carried out by one operator. A total of 26 (68.4%) adults and 7 (63.6%) children completed the test within the recommended 8-12 min. All participants completed a minimum of 6 levels, and completed the test before the final 16th level. In adults, ppFEV1 and ppFVC correlated with the level reached (r = 0.55; p = <0.001 and r = 0.66, p = <0.0001) and desaturation (r = 0.55, p = <0.001 and r = 0.45, p = <0.005). CONCLUSION: In adults and children with stable CF, the A-STEP was feasible, safe, and operationally easy to use for the assessment of exercise capacity, without floor or ceiling effects. In adults, lung function correlated with exercise capacity.

VO2max as an exercise tolerance endpoint in people with cystic fibrosis: Lessons from a lumacaftor/ivacaftor trial.

BACKGROUND: The impact of lumacaftor/ivacaftor on exercise tolerance in people with cystic fibrosis (CF) has not been thoroughly studied. METHODS: We conducted a multisite Phase 4 trial comparing the impact of lumacaftor/ivacaftor on exercise tolerance with that of placebo in participants ≥ 12 years of age with CF homozygous for F508del-CFTR. The primary endpoint was relative change from baseline in maximum oxygen consumption (VO2max) during cardiopulmonary exercise testing (CPET) at Week 24. The key secondary endpoint was relative change from baseline in exercise duration during CPET at Week 24. Other secondary endpoints included changes in other indices of exercise tolerance and changes in CF assessments; safety and tolerability were assessed as an endpoint. RESULTS: Seventy participants were randomized to receive lumacaftor/ivacaftor (n = 34) or placebo (n = 36). The least-squares mean difference for lumacaftor/ivacaftor versus placebo in relative change in VO2max from baseline at Week 24 was -3.2% (95% CI: -9.2, 2.9; P=0.3021); the least-squares mean difference in relative change from baseline in exercise duration at Week 24 was -3.2% (95% CI: -8.0, 1.6). Safety results were consistent with the known lumacaftor/ivacaftor safety profile. CONCLUSIONS: Definitive conclusions regarding the impact of lumacaftor/ivacaftor on exercise tolerance cannot be drawn from these results; however, multicenter studies using CPETs can be reliably performed with multiple time points and conventional methods, provided that calibration can be achieved. Future studies of exercise tolerance may benefit from lessons learned from this study. NCT02875366.

Development of the A-STEP: A new incremental maximal exercise capacity step test in cystic fibrosis.

BACKGROUND: Exercise testing is important in people with cystic fibrosis (pwCF). The aim was to develop an incremental maximal step test to assess exercise capacity across the range of pwCF, without floor or ceiling effects, within restrictions of space, and infection prevention. METHODS: The step test was developed in adults with stable CF. Subjects assisted in selecting: step height, start rate, increments, stage and test duration parameters. Equipment to externally pace and time the test and measure exercise parameters were selected. Reasons for stopping, criteria for achieving a maximal test, and key outcome measures were determined. Documentation to record and standardize the test and instructions to set up the metronome and timer App were developed. Infection control practices were considered. RESULTS: Eight subjects were recruited to develop the Alfred Step Test Exercise Protocol (A-STEP) on a 20 cm portable step. The A-STEP package included a pretest information sheet, clinical assessment and instructions, recording worksheet, and the metronome/timer instructions. The test started at 18 steps/min. Each level increased by two steps/min to a maximum of 48 steps (Level 16). Results were presented as mean (SD) [range] for: age 30.63 (5.89) [21-39] years; FEV1 58.13 (18.33) [32-89]%; levels: 10.31 (3.29) [6-15.5]. The A-STEP required space of 2 m2 and complied with current infection control guidelines. CONCLUSIONS: The A-STEP is a new incremental maximal step test to assess exercise capacity in pwCF, without floor or ceiling effects. It addresses the issues of space restrictions and the need for strict infection prevention in the clinical setting.

Lumacaftor/ivacaftor-associated health stabilisation in adults with severe cystic fibrosis.

INTRODUCTION: Lumacaftor/ivacaftor (LUM/IVA) has been shown to improve clinical outcomes in cystic fibrosis (CF) patients homozygous for Phe508del with forced expiratory volume in 1 s (FEV1) % pred >40%. We assessed the clinical utility of LUM/IVA in all eligible adult CF patients with FEV1 % pred <40% treated for at least 1 year under a single-centre managed access programme. METHODS: Following clinical optimisation, eligible patients (n=40) with FEV1 % pred <40% were commenced on LUM/IVA and monitored for tolerance and clinical outcomes, including health service utilisation, pulmonary function, weight and body composition. 24 patients reached 1 year of treatment by the time of evaluation. Six patients discontinued due to adverse events (five for increased airways reactivity) and three underwent lung transplantation. RESULTS: In comparison with the year prior to LUM/IVA commencement, significant reductions (median per year) were observed in the treatment year in the number of pulmonary exacerbations requiring hospitalisation (from 3 to 1.5; p=0.0002), hospitalisation days (from 27 to 17; p=0.0002) and intravenous antibiotic (IVAB) usage days (from 45 to 27; p=0.0007). Mean±sd change in FEV1 % pred was -2.10±1.18% per year in the year prior, with the decline reversed in the year following (+1.45±1.13% per year; p=0.035), although there was significant heterogeneity in individual responses. Mean±sd weight gain at 1 year was 2.5±4.1 kg (p=0.0007), comprising mainly fat mass (mean 2.2 kg). The proportion of patients severely underweight (body mass index <18.5 kg·m-2) decreased from 33% at baseline to 13% at 1 year (p=0.003). CONCLUSION: This real-world evaluation study demonstrated benefits over several clinical domains (infective exacerbations requiring hospitalisation, IVABs, pulmonary function decline and nutritional parameters) in CF patients with severe lung disease.