Six-minute-walk distance predicts waiting list survival in idiopathic pulmonary fibrosis

Prognostic factors and outcomes in Japanese lung transplant candidates with interstitial lung disease

OBJECTIVE

Young patients with advanced interstitial lung disease (ILD) are potential candidates for cadaveric lung transplantation. This study aimed to examine clinical features, outcomes, and prognostic factors in Japanese ILD patients awaiting lung transplantation.

METHODS

We investigated the clinical features and outcomes of 77 consecutive candidates with ILD who were referred to Kyoto University Hospital and subsequently actively listed for lung transplant in the Japan Organ Transplant Network between 2010 and 2014.

RESULTS

Of the 77 candidates, 33 had idiopathic pulmonary fibrosis (IPF) and 15 had unclassifiable ILD. During the observational period, 23 patients (30%) received lung transplantations and 49 patients (64%) died before transplantation. Of the 33 patients with IPF, 13 (39%) had a family history of ILD and 13 (39%) had an "inconsistent with usual interstitial pneumonia pattern" on high-resolution computed tomography (HRCT). The median survival time from registration was 16.7 months, and mortality was similar among patients with IPF, unclassifiable ILD, and other ILDs. Using a multivariate stepwise Cox proportional hazards model, 6-min walking distance was shown to be an independent prognostic factor in candidates with ILD (per 10 m, hazard ratio (HR): 0.97; 95% confidence interval (CI): 0.95-0.99, p<0.01), while lower body mass index (HR: 0.83; 95% CI: 0.72-0.95, p < 0.01) independently contributed to mortality in patients with IPF.

CONCLUSIONS

Japanese patients with ILD awaiting transplantation had very poor outcomes regardless of their specific diagnosis. A substantial percentage of IPF patients had an atypical HRCT pattern. 6-min walking distance in ILD patients and body mass index in IPF patients were independent predictors of mortality.

Daily physical activity affects exercise capacity in patients with idiopathic pulmonary fibrosis

[Purpose] The aim of this study was to determine which factors, including pulmonary, physical, and mental functions; dyspnea; and daily physical activity (PA) affect the 6-minute walk distance (6MWD) in IPF patients. [Subjects and Methods] The pulmonary, physical, and mental functions; dyspnea; PA; and 6MWD were assessed in 38 outpatients with IPF. PA was represented by the mean number of steps per day. [Results] The mean 6MWD was 443.8 m (SD, 98.5), and the mean number of steps per day showing PA was 5148.4 (SD, 3295.7). The 6MWD was correlated with age, base dyspnea index, vital capacity (VC), diffusion capacity of carbon monoxide, quadriceps force (QF), dyspnea during the 6-minute walk test, and PA. Stepwise multiple regression analysis revealed that VC (β=0.382), QF (β=0.272), and PA (β=0.574) were contributing factors of the 6MWD. [Conclusion] In patients with IPF, PA has a greater effect on the 6MWD than VC and QF. The evaluation of daily PA, in addition to physiological and muscle functions, is important in patients with IPF.

Comorbid Conditions in Idiopathic Pulmonary Fibrosis: Recognition and Management

Idiopathic pulmonary fibrosis (IPF), a fibrosing interstitial pneumonia of unknown etiology, primarily affects older adults and leads to a progressive decline in lung function and quality of life. With a median survival of 3-5 years, IPF is the most common and deadly of the idiopathic interstitial pneumonias. Despite the poor survivorship, there exists substantial variation in disease progression, making accurate prognostication difficult. Lung transplantation remains the sole curative intervention in IPF, but two anti-fibrotic therapies were recently shown to slow pulmonary function decline and are now approved for the treatment of IPF in many countries around the world. While the approval of these therapies represents an important first step in combatting of this devastating disease, a comprehensive approach to diagnosing and treating patients with IPF remains critically important. Included in this comprehensive assessment is the recognition and appropriate management of comorbid conditions. Though IPF is characterized by single organ involvement, many comorbid conditions occur within other organ systems. Common cardiovascular processes include coronary artery disease and pulmonary hypertension (PH), while gastroesophageal reflux and hiatal hernia are the most commonly encountered gastrointestinal disorders. Hematologic abnormalities appear to place patients with IPF at increased risk of venous thromboembolism, while diabetes mellitus (DM) and hypothyroidism are prevalent metabolic disorders. Several pulmonary comorbidities have also been linked to IPF, and include emphysema, lung cancer, and obstructive sleep apnea. While the treatment of some comorbid conditions, such as CAD, DM, and hypothyroidism is recommended irrespective of IPF, the benefit of treating others, such as gastroesophageal reflux and PH, remains unclear. In this review, we highlight common comorbid conditions encountered in IPF, discuss disease-specific diagnostic modalities, and review the current state of treatment data for several key comorbidities.

Predictors of Mortality Poorly Predict Common Measures of Disease Progression in Idiopathic Pulmonary Fibrosis

RATIONALE

Mortality prediction is well studied in idiopathic pulmonary fibrosis (IPF), but little is known about predictors of premortality disease progression. Identification of patients at risk for disease progression would be useful for clinical decision-making and designing clinical trials.

OBJECTIVES

To develop prediction models for disease progression in IPF.

METHODS

In a large clinical trial cohort of patients with IPF (n = 1,113), we comprehensively screened multivariate models of candidate baseline and past-change predictors for disease progression defined by 48-week worsening of FVC, dyspnea (University of California, San Diego Shortness of Breath Questionnaire [UCSD SOBQ]), 6-minute-walk distance (6MWD), and occurrence of respiratory hospitalization, or death. Progression outcomes were modeled as appropriate, by slope change using linear regression models and time to binary outcomes using Cox proportional hazards models.

MEASUREMENTS AND MAIN RESULTS

The overall cohort experienced considerable disease progression. Top-performing prediction models did not meaningfully predict most measures of disease progression. For example, prediction modeling explained less than or equal to 1% of the observed variation in 48-week slope change in FVC, UCSD SOBQ, and 6MWD. Models performed better for binary measures of time to disease progression but were still largely inaccurate (cross-validated C statistic ≤0.63 for ≥10% decline in FVC or death, ≤0.68 for ≥20-U increase in UCSD SOBQ or death, ≤0.70 for ≥100 m decline in 6MWD or death). Models for time to respiratory hospitalization or death (C statistic ≤0.77) or death alone (C statistic ≤0.81) demonstrated acceptable discriminative performance.

CONCLUSIONS

Clinical prediction models poorly predicted physiologic and functional disease progression in IPF. This is in contrast to respiratory hospitalization and mortality prediction.

Epigenetics, inflammation and metabolism in right heart failure associated with pulmonary hypertension

Right ventricular failure (RVF) is the most important prognostic factor for both morbidity and mortality in pulmonary arterial hypertension (PAH), but also occurs in numerous other common diseases and conditions, including left ventricle dysfunction. RVF remains understudied compared with left ventricular failure (LVF). However, right and left ventricles have many differences at the morphological level or the embryologic origin, and respond differently to pressure overload. Therefore, knowledge from the left ventricle cannot be extrapolated to the right ventricle. Few studies have focused on the right ventricle and have permitted to increase our knowledge on the right ventricular-specific mechanisms driving decompensation. Here we review basic principles such as mechanisms accounting for right ventricle hypertrophy, dysfunction, and transition toward failure, with a focus on epigenetics, inflammatory, and metabolic processes.

Clinical characteristics of Japanese candidates for lung transplant for interstitial lung disease and risk factors for early death while on the waiting list

BACKGROUND

Lung transplants have produced very favorable outcomes for patients with interstitial lung disease (ILD) in Japan. However, because of the severe donor lung shortage, patients must wait approximately 2.5 years before they can undergo transplantation and many candidates die before allocation. We reveal the clinical characteristics of Japanese patients with ILD who are candidates for lung transplants and the risk factors for early death while on the waiting list.

METHODS

We retrospectively reviewed the clinical data of patients registered in the Japan Organ Transplant Network from Okayama University Hospital who are candidates for cadaveric lung transplants for ILD between 1999 and 2015.

RESULTS

Fifty-three patients with ILD were included (24 patients with idiopathic pulmonary fibrosis and 29 others). They had severe pulmonary dysfunction and low exercise tolerability. The median waiting time for transplantation was 462 days, and 22 patients died before allocation. Patients who died before 462 days without undergoing transplantation had more severe dyspnea, shorter 6-minute walk distance (6MWD), and lower performance status than those who waited ≥462 days.

CONCLUSIONS

Japanese candidates for cadaveric lung transplants for ILD have severe pulmonary dysfunction. Severe dyspnea, short 6MWD, and low performance status are risk factors for early death while on the waiting list.

A Cost-Effectiveness Analysis of Nintedanib in Idiopathic Pulmonary Fibrosis in the UK

BACKGROUND

International guidelines recommend nintedanib (OFEV^®) as an option for the treatment of idiopathic pulmonary fibrosis (IPF).

OBJECTIVE

The objective of this study was to assess the cost effectiveness of nintedanib versus pirfenidone, N-acetylcysteine and best supportive care (BSC) for the treatment of IPF from a UK payer's perspective.

METHODS

A Markov model was designed to capture the changes in the condition of adults with IPF. Efficacy outcomes included mortality, lung function decline and acute exacerbations. Treatment safety (serious adverse events) and tolerability (overall discontinuation) were also considered. The baseline risk of these events was derived from patient-level data from the placebo arms of nintedanib clinical trials (TOMORROW, INPULSIS-1, INPULSIS-2). A network meta-analysis (NMA) was conducted to estimate the relative effectiveness of the comparator treatments. Quality of life and healthcare resource use data from the clinical trials were also incorporated in the economic model.

RESULTS

Nintedanib showed statistically significant differences against placebo on acute exacerbation events avoided and lung function decline. In the cost-effectiveness analysis, the results were split between two treatments with relative low costs and modest effectiveness (BSC and N-acetylcysteine) and two that showed improved effectiveness (lung function) and higher costs (nintedanib and pirfenidone). All comparators were assumed to have similar projected survival and the difference in quality-adjusted life-years (QALYs) was driven by the acute exacerbations and lung function estimates. In the base-case deterministic pairwise comparison with pirfenidone, nintedanib was found to have fewer acute exacerbations and resulted in less costs and more QALYs gained.

CONCLUSIONS

Compared with BSC (placebo), nintedanib and pirfenidone were the only treatments to show statistical significance in the efficacy parameters. We found substantial uncertainty in the overall cost-effectiveness results between nintedanib and pirfenidone. N-Acetylcysteine was largely similar to BSC but with a worse survival profile. INPULSIS-1 and INPULSIS-2 ClinicalTrials.gov numbers, NCT01335464 and NCT01335477.

Fat-free mass index predicts survival in patients with idiopathic pulmonary fibrosis

BACKGROUND AND OBJECTIVE

Detailed body composition, such as fat-free mass, has not been examined in idiopathic pulmonary fibrosis (IPF). We investigated whether the fat-free mass index (FFMI), an index of lean body mass, predicted survival.

METHODS

Forty-four patients with IPF were enrolled in the study. Their body composition was assessed using direct segmental multi-frequency bioelectrical impedance analysis. The degree of correlation between variables of body composition and other variables such as forced vital capacity (FVC) and survival was examined.

RESULTS

There was a significant positive correlation between FFMI and FVC, diffusion capacity of the lung for carbon monoxide (DL_CO ) and 6-min walk distance, and a significant negative correlation with age. However, there was no significant correlation between FFMI and percentage predicted FVC or DL_CO , with the degree of correlation being similar to that observed for BMI. The mean observation period in the survival analysis was 837.5 ± 407.5 days. A univariate Cox proportional hazard model showed that several variables, but not BMI, were associated significantly with survival. FFMI (hazard ratio (HR): 0.64, 95% CI: 0.43-0.94, P = 0.02) and percentage predicted FVC (HR: 0.96, 95% CI: 0.93-0.99, P=0.008) were significant factors in a multivariate model.

CONCLUSION

We conclude that FFMI is a significant independent predictor of survival in patients with IPF.

Cardiopulmonary exercise factors predict survival in patients with advanced interstitial lung disease referred for lung transplantation

BACKGROUND

The purpose of this work was to determine if parameters assessed during Cardiopulmonary Exercise Testing (CPET) while using supplemental oxygen can independently predict one-year transplant-free survival in patients with Interstitial Lung Disease (ILD) referred for lung transplant evaluation.

METHODS

We performed a chart review of patients with ILD who completed CPET with 30% FiO₂ and gathered spirometry, pulmonary hemodynamic, six-minute walk, and CPET data. The primary end-point was death or lung transplantation within one-year of CPET.

RESULTS

The final data set included 192 patients. 79 patients died/underwent transplant, 113 survived transplant-free. Multivariable Cox regression revealed peak workload % predicted, nadir CPET SpO₂, and FVC% predicted as independent predictors of one-year transplant-free survival. Of the independent predictors of survival, receiver operating characteristics analysis revealed peak workload %predicted cutoff of 35% to be highly discriminatory, more so than nadir CPET SpO₂ or FVC % predicted in identifying patients at risk for one-year mortality or transplant (peak workload % predicted < 35% HR = 4.71, 95% CI = 2.64-8.38 and area under the curve (AUC) = 0.740, nadir CPET SpO₂ < 86% HR = 2.27, 95%CI = 1.41-3.68, AUC = 0.645, FVC %predicted <45% HR = 1.82, 95% CI = 1.15-2.87, AUC = 0.624).

CONCLUSION

Peak workload % predicted, nadir CPET SpO₂, and FVC% predicted in ILD patients referred for lung transplant evaluation are independently predictive of one-year mortality or need for transplant.

Effects of pulmonary rehabilitation in lung transplant candidates: a systematic review

OBJECTIVES

The aim of this systematic review of randomised controlled trials (RCTs), and quasi-experimental and retrospective studies is to investigate the effects of pulmonary rehabilitation (PR) in patients with advanced chronic disease on the waiting list for lung transplantation.

SETTING

PR performed for inpatient or outpatient lung transplant candidates.

INTERVENTION

PR programme including aerobic exercise training and/or resistance exercise training.

PRIMARY AND SECONDARY OUTCOMES

Quality of life and exercise capacity (primary outcomes). Survival rate after transplant surgery; pulmonary function; respiratory muscle strength; psychological aspects; upper and lower extremity muscle strength and adverse effects (secondary outcomes). Two review authors independently selected the studies, assessed study quality and extracted data. Studies in any language were included.

RESULTS

This was a systematic review and studies were searched on the Cochrane Library, MEDLINE, EMBASE, CINAHL and PEDro. Experimental and retrospective studies evaluating the effects of PR in candidates for lung transplantation (>18 years old) with any lung diseases were included. 2 RCTs, and two quasi-experimental and two retrospectives studies, involving 1305 participants were included in the review. 5 studies included an enhancement reported in quality of life using the Short Form 36 questionnaire and showed improvements in some domains. All studies included exercise capacity evaluated through 6 min walk test and in five of them, there were improvements in this outcome after PR. Owing to the different characteristics of the studies, it was not possible to perform a meta-analysis.

CONCLUSIONS

Studies included in this review showed that PR is an effective treatment option for patients on the waiting list for lung transplantation and can improve quality of life and exercise capacity in those patients. Although individual studies reported positive effects of PR, this review shows that there is a need for more studies of a high methodological quality addressing PR effects in lung transplant candidates.

TRIAL REGISTRATION NUMBER

PROSPERO CDR42015025110.

Treatment of idiopathic pulmonary fibrosis: a position paper from a Nordic expert group

Idiopathic pulmonary fibrosis (IPF) is a fatal progressive lung disease occurring in adults. In the last decade, the results of a number of clinical trials based on the updated disease classification have been published. The registration of pirfenidone and nintedanib, the first two pharmacological treatment options approved for IPF, marks a new chapter in the management of patients with this disease. Other nonpharmacological treatments such as lung transplantation, rehabilitation and palliation have also been shown to be beneficial for these patients. In this review, past and present management is discussed based on a comprehensive literature search. A treatment algorithm is presented based on available evidence and our overall clinical experience. In addition, unmet needs with regard to treatment are highlighted and discussed. We describe the development of various treatment options for IPF from the first consensus to recent guidelines based on evidence from large-scale, multinational, randomized clinical trials, which have led to registration of the first drugs for IPF.

The St. George's Respiratory Questionnaire as a prognostic factor in IPF

BACKGROUND

It is unclear whether health related quality of life (HRQL) may have a predictive value for mortality in idiopathic pulmonary fibrosis (IPF). We investigated the relationship between HRQL assessed using the St. George's Respiratory Questionnaire (SGRQ) and survival time in patients with IPF, and tried to determine a clinical meaningful cut off value to predict poorer survival rates.

METHODS

We retrospectively analyzed consecutive patients with IPF who underwent an initial evaluation from May 2007 to December 2012. The diagnosis of IPF was made according to the 2011 international consensus guidelines. We used Cox proportional hazard models to identify independent predictors for mortality rate in patients with IPF.

RESULTS

We examined 182 eligible cases, average age was 66 years old, and 86% were male. Mean levels of percent predicted FVC, DLco, six-minute-walk test distance, and the SGRQ total score were around 80%, 58%, 580 m, and 34 points. On multivariate analysis, the SGRQ total score (hazard ratio [HR], 1.012; 95% confidence interval [CI] 1.001-1.023; P = .029) and percent predicted FVC (HR, 0.957; 95% CI 0.944-0.971, P < .001) were independent predictors for mortality rate. Moreover, a score higher than 30 points in the SGRQ total score showed higher mortality rate (HR, 2.047; 95% CI, 1.329-3.153; P = .001).

CONCLUSIONS

The SGRQ total score was one of independent prognostic factors in patients with IPF. Total scores higher than 30 points were associated with higher mortality rates.

TRIAL REGISTRATION

This study was retrospective, observational study, so it is not applicable.

The utility of 6-minute walk distance in predicting waitlist mortality for lung transplant candidates

BACKGROUND

The lung allocation score (LAS) has led to improved organ allocation for transplant candidates. At present, the 6-minute walk distance (6MWD) is treated as a binary categorical variable of whether or not a candidate can walk more than 150 feet in 6 minutes. In this study, we tested the hypothesis that 6MWD is presently under-utilized with respect to discriminatory power, and that, as a continuous variable, could better prognosticate risk of waitlist mortality.

METHODS

A retrospective cohort analysis was performed using the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) transplant database. Candidates listed for isolated lung transplant between May 2005 and December 2011 were included. The population was stratified by 6MWD quartiles and unadjusted survival rates were estimated. Multivariable Cox proportional hazards modeling was used to assess the effect of 6MWD on risk of death. The Scientific Registry of Transplant Recipients (SRTR) Waitlist Risk Model was used to adjust for confounders. The optimal 6MWD for discriminative accuracy in predicting waitlist mortality was assessed by receiver-operating characteristic (ROC) curves.

RESULTS

Analysis was performed on 12,298 recipients. Recipients were segregated into quartiles by distance walked. Waitlist mortality decreased as 6MWD increased. In the multivariable model, significant variables included 6MWD, male gender, non-white ethnicity and restrictive lung diseases. ROC curves discriminated 6-month mortality was best at 655 feet.

CONCLUSIONS

The 6MWD is a significant predictor of waitlist mortality. A cut-off of 150 feet sub-optimally identifies candidates with increased risk of mortality. A cut-off between 550 and 655 feet is more optimal if 6MWD is to be treated as a dichotomous variable. Utilization of the LAS as a continuous variable could further enhance predictive capabilities.

Interstitial lung disease increases mortality in systemic sclerosis patients with pulmonary arterial hypertension without affecting hemodynamics and exercise capacity

Published data suggest that coexisting interstitial lung disease (ILD) has an impact on mortality in patients with systemic sclerosis (SSc) and pulmonary arterial hypertension (PAH), but there is scarce knowledge if this is reflected by hemodynamics, exercise capacity, autoantibody profile, or pulmonary function. In this partially retrospective study, 27 SSc-PAH patients were compared to 24 SSc-PAH patients with coexisting ILD respecting to survival, pulmonary function, hemodynamics, exercise capacity, and laboratory parameters. Survival was significantly worse in SSc-PAH-ILD patients than in SSc patients with isolated PAH (1, 5, and 10-year survival rates 86, 54, and 54% versus 96, 92, and 82%, p = 0.013). Compared to isolated SSc-PAH patients, patients with SSc-PAH-ILD revealed lower forced expiratory volume after 1 s (FEV1) values at the time of PAH diagnosis as well as 1 and 2 years later (p = 0.002) without significant decrease in the PAH course in both groups. At PAH diagnosis, diffusion capacity for carbon monoxide (DLCO) values were lower in the ILD-PAH group. Coexisting ILD was not associated with lower exercise capacity, different FEV1/forced vital capacity (FVC) ratio, higher WHO functional class, or reduced hemodynamics. Higher levels of antibodies against angiotensin and endothelin receptors predict mortality in all SSc-PAH patients but could not differentiate between PAH patients with and without ILD. Our study confirmed an impact of ILD on mortality in SSc-PAH patients. Pulmonary function parameters can be used to distinguish PAH from PAH-ILD. The higher mortality rate cannot be explained by differences in hemodynamics, exercise capacity, or autoantibody levels. Mechanisms of mortality remain to be studied.

The 6-Minute-Walk Distance Test as a Chronic Obstructive Pulmonary Disease Stratification Tool. Insights from the COPD Biomarker Qualification Consortium

RATIONALE

The 6-minute-walk distance (6MWD) test predicts mortality in chronic obstructive pulmonary disease (COPD). Whether variability in study type (observational vs. interventional) or region performed limits use of the test as a stratification tool or outcome measure for therapeutic trials is unclear.

OBJECTIVES

To analyze the original data from several large observational studies and from randomized clinical trials with bronchodilators to support the qualification of the 6MWD test as a drug development tool in COPD.

METHODS

Original data from 14,497 patients with COPD from six observational (n = 9,641) and five interventional (n = 4,856) studies larger than 100 patients and longer than 6 months in duration were included. The geographical, anthropometrics, FEV1, dyspnea, comorbidities, and health status scores were measured. Associations between 6MWD and mortality, hospitalizations, and exacerbations adjusted by study type, age, and sex were evaluated. Thresholds for outcome prediction were calculated using receiver operating curves. The change in 6MWD after inhaled bronchodilator treatment and surgical lung volume reduction were analyzed to evaluate the responsiveness of the test as an outcome measure.

MEASUREMENTS AND MAIN RESULTS

The 6MWD was significantly lower in nonsurvivors, those hospitalized, or who exacerbated compared with those without events at 6, 12, and greater than 12 months. At these time points, the 6MWD receiver operating characteristic curve-area under the curve to predict mortality was 0.71, 0.70, and 0.68 and for hospitalizations was 0.61, 0.60, and 0.59, respectively. After treatment, the 6MWD was not different between placebo and bronchodilators but increased after surgical lung volume reduction compared with medical therapy. Variation across study types (observational or therapeutic) or regions did not confound the ability of 6MWD to predict outcome.

CONCLUSIONS

The 6MWD test can be used to stratify patients with COPD for clinical trials and interventions aimed at modifying exacerbations, hospitalizations, or death.

Physical rehabilitation for lung transplant candidates and recipients: An evidence-informed clinical approach

Physical rehabilitation of lung transplant candidates and recipients plays an important in optimizing physical function prior to transplant and facilitating recovery of function post-transplant. As medical and surgical interventions in lung transplantation have evolved over time, there has been a demographic shift of individuals undergoing lung transplantation including older individuals, those with multiple co-morbidites, and candidates with respiratory failure requiring bridging to transplantation. These changes have an impact on the rehabilitation needs of lung transplant candidates and recipients. This review provides a practical approach to rehabilitation based on research and clinical practice at our transplant centre. It focuses on functional assessment and exercise prescription during an uncomplicated and complicated clinical course in the pre-transplant, early and late post-transplant periods. The target audience includes clinicians involved in pre- and post-transplant patient care and rehabilitation researchers.

Can a Six-Minute Walk Distance Predict Right Ventricular Dysfunction in Patients with Diffuse Parenchymal Lung Disease and Pulmonary Hypertension?

OBJECTIVES

Pulmonary hypertension (PH) is commonly observed in patients with diffuse parenchymal lung disease (DPLD). The purpose of this study was to explore the influence of the 6-minute walk test (6MWT) as a simple, non-invasive tool to assess right ventricular (RV) function in patients with DPLD and to identify the need for an echocardiogram (ECHO) to screen for PH.

METHODS

We retrospectively reviewed 48 patients with PH secondary to DPLD, who were evaluated in the PH clinic at the Mayo Clinic in Jacksonville, Florida, from January 1999 to December 2014.

RESULTS

Fifty-two percent of patients had RV dysfunction. They had a significantly greater right heart pressure by ECHO and mean pulmonary arterial pressure (MPAP) from right heart catheterization (RHC) than those with normal RV function. A reduced 6-minute walk distance (6MWD) did not predict RV dysfunction (OR 0.995; 95% CI 0.980-1.001, p = 0.138). In addition, worsening restrictive physiology, heart rate at one-minute recovery and desaturation were not different between patients with and without RV dysfunction. However, there were inverse correlations between 6MWD and MPAP from RHC (r = -0.41, 
p = 0.010), 6MWD and RV systolic pressure (r = -0.51, p < 0.001), and 6MWD and MPAP measured by ECHO (r = -0.46, p =0.013). We also found no significant correlation between 6MWD and pulmonary function test parameters.

CONCLUSIONS

Our single-center cohort of patients with PH secondary to DPLD, PH was found to have an impact on 6MWD. In contrast to our expectations, 6MWD was not useful to predict RV dysfunction. Interestingly, a severe reduction in the 6MWD was related to PH and not to pulmonary function; therefore, it may be used to justify an ECHO to identify patients with a worse prognosis.

Physical Activity and Exertional Desaturation Are Associated with Mortality in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease that manifests in hypoxemia, inactivity, and poor prognosis. This study aimed to assess the prognostic role of physical activity (PA) and exertional desaturation (ED) with mortality in IPF. At baseline, 34 IPF patients (68 (50–81) years) were interviewed using the International Physical Activity Questionnaire (IPAQ), and SpO₂ was assessed pre to post 6-min walking test (∆SpO₂). Patients were prospectively followed up for 40 months. Receiver operating characteristics curve analysis determined cut-off points associated with mortality, and Cox proportional hazard ratio (HR) were conducted. Thresholds for increased mortality risk in IPF patients were determined as IPAQ ≤ 417 metabolic equivalent task (METS)-min/week, p = 0.004 (HR; 9.7, CI 95% (1.3–71.9), p = 0.027), and ∆SpO₂ ≥ 10%, p = 0.002, (HR; 23.3, CI 95% (1.5–365), p = 0.025). This study demonstrated a significant association of PA and ED with mortality in IPF patients. The findings emphasize the clinical importance of PA and ED assessments to aid in IPF risk stratification, prognosis prediction, and in providing early appropriate treatments, such as pulmonary rehabilitation, PA consultation, oxygen supplementation, and lung transplantation referral. These results underscore that even low levels of PA corresponding to 100–105 min/week were associated with a reduced mortality risk and better survival in IPF.

Frailty in Pulmonary and Critical Care Medicine

Conceptualized first in the field of geriatrics, frailty is a syndrome characterized by a generalized vulnerability to stressors resulting from an accumulation of physiologic deficits across multiple interrelated systems. This accumulation of deficits results in poorer functional status and disability. Frailty is a "state of risk" for subsequent disproportionate declines in health status following new exposure to a physiologic stressor. Two predominant models have emerged to operationalize the measurement of frailty. The phenotype model defines frailty as a distinct clinical syndrome that includes conceptual domains such as strength, activity, wasting, and mobility. The cumulative deficit model defines frailty by enumerating the number of age-related things wrong with a person. The biological pathways driving frailty include chronic systemic inflammation, sarcopenia, and neuroendocrine dysregulation, among others. In adults with chronic lung disease, frailty is independently associated with more frequent exacerbations of lung disease, all-cause hospitalization, declines in functional status, and all-cause mortality. In addition, frail adults who become critically ill are more likely develop chronic critical illness or severe disability and have higher in-hospital and long-term mortality rates. The evaluation of frailty appears to provide important prognostic information above and beyond routinely collected measures in adults with chronic lung disease and the critically ill. The study of frailty in these populations, however, requires multipronged efforts aimed at refining clinical assessments, understanding the mechanisms, and developing therapeutic interventions.

Exercise training in idiopathic pulmonary fibrosis: is it of benefit?

Key points

Educational aims

Exercise is a well-documented safe and effective intervention for prevention and rehabilitation of chronic diseases. Idiopathic pulmonary fibrosis (IPF) is a chronic deadly lung disease associated with severe signs and symptoms, exercise intolerance, diminished quality of life and poor prognosis. In the short term, supervised exercise training programmes have demonstrated clinical benefits in improving exercise capacity, dyspnoea and quality of life in patients with IPF. The underlying mechanisms of chronic adaption to a regular exercise regimen in IPF have yet to be well described and require further investigation. The available data underscore the importance of implementing training principles to target the pathophysiological impairments of IPF in order to optimise training adaption and enhance the outcomes. The current exercise training data in IPF provide sufficient evidence of clinical benefit for consideration to be given to recommending exercise-based pulmonary rehabilitation as standard of care for IPF.

An overview of data on exercise for IPF patients, highlighting the importance of exercise training in IPF managementhttp://ow.ly/4mWCCd

Ambrisentan response in connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) - A subgroup analysis of the ARIES-E clinical trial

OBJECTIVE

Pulmonary arterial hypertension (PAH) is a condition which may lead to right ventricular failure and early mortality and is an important complication in patients with connective tissue disease (CTD). Previously, the endothelin A selective receptor antagonist, ambrisentan, demonstrated efficacy and safety in treating patients with PAH due to WHO Group I etiologies. These analyses describe the 3-year efficacy and safety of ambrisentan in patients specifically with CTD associated PAH (CTD-PAH).

METHODS

Patients with CTD-PAH participating in the ARIES-1 and -2 clinical trials and their long-term extension were evaluated. Efficacy evaluations including 6-min walk distance (6MWD), clinical worsening, and survival were collected at routine study visits. Additional analyses of 6MWD categorical (30 m) breakpoints were conducted to determine any relationship between 6MWD and a prognostic threshold for survival.

RESULTS

124 patients with CTD-PAH were evaluated. 62.6%, 57.3%, and 58.2% of CTD-PAH patients treated with ambrisentan exhibited increases in 6MWD at 1-, 2-, and 3- years respectively. At 3 years, 64% of patients were free from clinical worsening and 76% of patients were still alive (Kaplan-Meier estimates). Identified factors holding prognostic relevance for survival include: baseline functional class, CTD-PAH subgroup, patient sex, improvement in 6MWD ≥30 m over the first 12 weeks of treatment, the most recent 6MWD, and a 6MWD absolute threshold of 222 m.

CONCLUSION

These first analyses of the 3-year treatment of CTD-PAH patients with ambrisentan revealed fewer clinical worsening events and improved survival compared to historical controls. Key exercise parameters were also identified which appear important in guiding treatment.

Pulmonary Hemodynamics and Six-Minute Walk Test Outcomes in Patients with Interstitial Lung Disease

Background. Six-minute walk test (6MWT) has 3 measurement outcomes, which are walk distance, desaturation, and symptom. The aim of this study was to examine whether routinely measured right-heart catheter (RHC) data correlate with 6MWT outcomes in patients with interstitial lung disease (ILD). Methods. Between June 2010 and December 2012, consecutive patients with ILD who underwent evaluation, including pulmonary function test, hemodynamic studies with right-heart catheter, and 6MWT as routine general practice, were recruited. Correlates of 3 outcomes of 6MWT were examined to reveal significant predictors. Results. Forty-six patients consisting of 20 with idiopathic pulmonary fibrosis, 14 with collagen vascular disease associated ILD, and 12 with other idiopathic interstitial pneumonia were recruited (mean % predicted FVC: 76.7 ± 17.1%). Several physiological variables, including mean pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR), were correlated with each 6MWT outcome. Stepwise multivariate regression analyses showed that % predicted FVC and % predicted DLco were independent predictors of walk distance (r² = 0.35, p = 0.0002). For SpO₂ at the end of 6MWT, % predicted DLco and PVR were selected as independent predictors (r² = 0.46, p < 0.0001). For dyspnea at the end of 6MWT, % predicted DLco was only one predictor (r² = 0.18, p = 0.005). Conclusion. Mean PAP had little impact on 6MWT outcomes in ILD patients who were nonselectively recruited, although PVR was one of predictors of desaturation.

Determinants of 6-minute walk distance in patients with idiopathic pulmonary fibrosis undergoing lung transplant evaluation

Little is known about the physiologic determinants of 6-minute walk distance in idiopathic pulmonary fibrosis. We investigated the demographic, pulmonary function, echocardiographic, and hemodynamic determinants of 6-minute walk distance in patients with idiopathic pulmonary fibrosis evaluated for lung transplantation. We performed a cross-sectional analysis of 130 patients with idiopathic pulmonary fibrosis who completed a lung transplantation evaluation at the Hospital of the University of Pennsylvania between 2005 and 2010. Multivariable linear regression analysis was used to generate an explanatory model for 6-minute walk distance. After adjustment for age, sex, race, height, and weight, the presence of right ventricular dilation was associated with a decrease of 50.9 m (95% confidence interval [CI], 8.4-93.3) in 6-minute walk distance ([Formula: see text]). For each 200-mL reduction in forced vital capacity, the walk distance decreased by 15.0 m (95% CI, 9.0-21.1; [Formula: see text]). For every increase of 1 Wood unit in pulmonary vascular resistance, the walk distance decreased by 17.3 m (95% CI, 5.1-29.5; [Formula: see text]). Six-minute walk distance in idiopathic pulmonary fibrosis depends in part on circulatory impairment and the degree of restrictive lung disease. Future trials that target right ventricular morphology, pulmonary vascular resistance, and forced vital capacity may potentially improve exercise capacity in patients with idiopathic pulmonary fibrosis.

Comparisons of Prognosis between Surgically and Clinically Diagnosed Idiopathic Pulmonary Fibrosis Using Gap Model: A Korean National Cohort Study

Although a multidisciplinary approach has become an important criterion for an idiopathic pulmonary fibrosis (IPF) diagnosis, lung biopsies remain crucial. However, the prognosis of patients with surgically diagnosed IPF (sIPF) is uncertain. We aimed to investigate the prognosis of patients with clinically diagnosed IPF (cIPF) and sIPF. In this retrospective observational study, the Korean Interstitial Lung Disease Study Group conducted a national survey to evaluate the clinical, physiological, radiological, and survival characteristics of patients with IPF from January 1, 2003 to December 31, 2007. Patients were recruited from 54 universities and teaching hospitals across the Republic of Korea. IPF diagnoses were established according to the 2002 American Thoracic Society (ATS)/European Respiratory Society criteria (ERS) guideline. A total of 1685 patients with IPF (1027 cIPF and 658 sIPF) were enrolled. Patients with sIPF were significantly younger, predominantly female, and nonsmokers (all P < 0.001). sIPF group had significantly better initial pulmonary function. The proportion of computed tomography-based honeycomb findings of patients with cIPF was higher than in those with sIPF (P < 0.001). A Kaplan-Meier analysis showed that the sIPF group had a better prognosis (P = 0.001). A survival analysis showed that age, pulmonary function parameters, pulmonary oxygen tension, honeycombing change, and combined lung cancer had a significant influence on patient prognosis. However, there was no significant difference in prognosis between the cIPF and sIPF groups after adjusting for GAP (gender, age, physiology) stage. The patients with sIPF had better clinical features than those with cIPF. However, after adjusting for GAP stage, the sIPF group showed similar prognoses as the cIPF group. This study showed that after adjusting for GAP stage, the prognosis of patients with IPF is the same regardless of the diagnostic method used.

The utility of preoperative six-minute-walk distance in lung transplantation

RATIONALE

The use of 6-minute-walk distance (6MWD) as an indicator of exercise capacity to predict postoperative survival in lung transplantation has not previously been well studied.

OBJECTIVES

To evaluate the association between 6MWD and postoperative survival following lung transplantation.

METHODS

Adult, first time, lung-only transplantations per the United Network for Organ Sharing database from May 2005 to December 2011 were analyzed. Kaplan-Meier methods and Cox proportional hazards modeling were used to determine the association between preoperative 6MWD and post-transplant survival after adjusting for potential confounders. A receiver operating characteristic curve was used to determine the 6MWD value that provided maximal separation in 1-year mortality. A subanalysis was performed to assess the association between 6MWD and post-transplant survival by disease category.

MEASUREMENTS AND MAIN RESULTS

A total of 9,526 patients were included for analysis. The median 6MWD was 787 ft (25th-75th percentiles = 450-1,082 ft). Increasing 6MWD was associated with significantly lower overall hazard of death (P < 0.001). Continuous increase in walk distance through 1,200-1,400 ft conferred an incremental survival advantage. Although 6MWD strongly correlated with survival, the impact of a single dichotomous value to predict outcomes was limited. All disease categories demonstrated significantly longer survival with increasing 6MWD (P ≤ 0.009) except pulmonary vascular disease (P = 0.74); however, the low volume in this category (n = 312; 3.3%) may limit the ability to detect an association.

CONCLUSIONS

6MWD is significantly associated with post-transplant survival and is best incorporated into transplant evaluations on a continuous basis given limited ability of a single, dichotomous value to predict outcomes.

Expanding the lung donor pool: advancements and emerging pathways

PURPOSE OF REVIEW

The number of patients listed for lung transplantation largely exceeds the number of available transplantable organs because of a shortage of organ donors and a low utilization rate of lungs from those donors who are available. In recent years, novel strategies have been developed to increase the donor lung pool: improved donor management, the use of lungs from donations after cardiac death (DCD), the use of lobar lung living-donors (LLLD) and the use of ex-vivo lung perfusion (EVLP) to assess and repair injured donor lungs.

RECENT FINDINGS

An adapted donor management strategy could expand the donor pool up to 20%. DCD lung transplant is an increasing part of the donor pool expansion. Outcomes after controlled DCD seem to be similar to donation after brain death. LLLD transplantation has excellent results for small and critically ill patients. EVLP treatment allows for a significant increase in the rate of suitable lungs and represents an optimal platform for lung reconditioning and specific lung therapies.

SUMMARY

A significant increase in the number of available lungs for transplantation is expected in the future because of the wider use of lungs from controlled or uncontrolled DCD and LLLD lungs, and with organ-specific EVLP treatment strategies.

Ex vivo lung perfusion

Lung transplantation is an established life-saving therapy for patients with end-stage lung disease. Unfortunately, greater success in lung transplantation is hindered by a shortage of lung donors and the relatively poor early-, mid-, and long-term outcomes associated with severe primary graft dysfunction. Ex vivo lung perfusion has emerged as a modern preservation technique that allows for a more accurate lung assessment and improvement in lung quality. This review outlines the: (i) rationale behind the method; (ii) techniques and protocols; (iii) Toronto ex vivo lung perfusion method; (iv) devices available; and (v) clinical experience worldwide. We also highlight the potential of ex vivo lung perfusion in leading a new era of lung preservation.

IPF clinical trial design and endpoints

Purpose of review

There remains a dire need for therapies that impact the clinical course of patients with idiopathic pulmonary fibrosis (IPF). Indeed, there is a surge of interest in IPF therapeutics, with many candidate agents in various stages of development. Optimal design and implementation of the appropriate prospective clinical trials are essential to demonstrate clinical efficacy of promising drugs for the treatment of IPF. A key element in the success of such clinical trials is the choice of the best endpoint(s) to match the design of the study.

Recent findings

Although the results of many IPF clinical trials have been disappointing, these trials have provided valuable insights into the epidemiology and natural history of the disease and have sparked debate into the best clinical trial designs and endpoints.

Summary

This review will discuss the various clinical trial endpoints that have been used or proposed with a focus on their potential utility, as well as possible pitfalls that investigators should consider in the design of such studies.

Video abstract

http://links.lww.com/COPM/A13

Exercise training in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic devastating interstitial lung disease associated with exercise intolerance, dyspnea, hypoxemia, diminished quality of life and poor prognosis. A growing body of evidence with respect to short-term effects of exercise training has demonstrated clinical benefits in IPF patients. A recent systematic review showed significant improvements in 6-min walking distance, peak aerobic capacity, reduced dyspnea and improved quality of life. However, aspects of training programs, maintenance and predictors of improvement and the impact on prognosis need to be further explored. The aim of this paper was to comprehensively review the existing scientific literature regarding exercise training in patients with IPF and identify important gaps that should be studied in the future.

Lung transplantation in IIP: A review

The idiopathic interstitial pneumonias (IIP) encompass a large and diverse subtype of interstitial lung disease (ILD) with idiopathic pulmonary fibrosis (IPF) and non-specific interstitial pneumonia (NSIP) being the most common types. Although pharmacologic treatments are available for most types of IIP, many patients progress to advanced lung disease and require lung transplantation. Close monitoring with serial functional and radiographic tests for disease progression coupled with early referral for lung transplantation are of great importance in the management of patients with IIP. Both single and bilateral lung transplantation are acceptable procedures for IIP. Procedure selection is a complex decision influenced by multiple factors related to patient, donor and transplant centre. While single lung transplant may reduce waitlist time and mortality, the long-term outcomes after bilateral lung transplantation may be slightly superior. There are numerous complications following lung transplantation including primary graft dysfunction, chronic lung allograft dysfunction (CLAD), infections, gastroesophageal reflux disease (GERD) and airway disease that limit post-transplant longevity. The median survival after lung transplantation is 4.7 years in patients with ILD, which is less than in patients with other underlying lung diseases. Although long-term survival is limited, this intervention still conveys a survival benefit and improved quality of life in suitable IIP patients with advanced lung disease and chronic hypoxemic respiratory failure.

Self-Report Daily Life Activity as a Prognostic Marker of Idiopathic Pulmonary Fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive disease, leading to substantial physical impairment. The distance walked in 6 min (6MWD) is a measure of exercise tolerance and is of prognostic relevance in IPF. While 6MWD is a punctual measurement which may not be representative, self-reported daily life activity may represent the patients' functional capacity more globally even in less severe affected patients.

OBJECTIVES

We evaluated and characterized a simple classification system based on the patients' self-reported daily activity and analyzed if this would add significantly to the prognostic information of the 6MWD alone in IPF patients.

METHODS

Daily life activity was assessed in IPF (n = 156) patients with standardized questions and categorized in activity classes (AC I-IV), comprising the less severe impaired in AC I and II. The 6MWD was also assessed.

RESULTS

ACs were related to the lung functional impairment and inversely correlated to the 6MWD. Thirty-two patients were in AC I/II, 98 in AC III and 26 patients in AC IV. Thirty-seven (23.7%) patients died during a median follow-up of 14.9 months, comprising 1 patient in AC I/II. In addition, a 6MWD <470 m predicted mortality. Combining AC I/II and a 6MWD >470 m identified a subgroup of patients with favorable outcome.

CONCLUSIONS

AC is a novel scoring system which can easily be obtained and correlates with lung functional and physical impairments as well as mortality. Moreover, AC adds prognostic information to the 6MWD.

Predictors of mortality in rheumatoid arthritis-associated interstitial lung disease

Interstitial lung disease (ILD) is a common pulmonary manifestation of rheumatoid arthritis. There is lack of clarity around predictors of mortality and disease behaviour over time in these patients.

We identified rheumatoid arthritis-related interstitial lung disease (RA-ILD) patients evaluated at National Jewish Health (Denver, CO, USA) from 1995 to 2013 whose baseline high-resolution computed tomography (HRCT) scans showed either a nonspecific interstitial pneumonia (NSIP) or a “definite” or “possible” usual interstitial pneumonia (UIP) pattern. We used univariate, multivariate and longitudinal analytical methods to identify clinical predictors of mortality and to model disease behaviour over time.

The cohort included 137 subjects; 108 had UIP on HRCT (RA-UIP) and 29 had NSIP on HRCT (RA-NSIP). Those with RA-UIP had a shorter survival time than those with RA-NSIP (log rank p=0.02). In a model controlling for age, sex, smoking and HRCT pattern, a lower baseline % predicted forced vital capacity (FVC % pred) (HR 1.46; p<0.0001) and a 10% decline in FVC % pred from baseline to any time during follow up (HR 2.57; p<0.0001) were independently associated with an increased risk of death.

Data from this study suggest that in RA-ILD, disease progression and survival differ between subgroups defined by HRCT pattern; however, when controlling for potentially influential variables, pulmonary physiology, but not HRCT pattern, independently predicts mortality.

CC-chemokine ligand 2 inhibition in idiopathic pulmonary fibrosis: a phase 2 trial of carlumab

The objective of this study was to determine the safety and efficacy of carlumab in the treatment of idiopathic pulmonary fibrosis (IPF).A phase 2, randomised, double-blind placebo-controlled dose-ranging study was conducted in patients with IPF (n=126). Patients were randomised to carlumab (1 mg·kg(-1), 5 mg·kg(-1), or 15 mg·kg(-1)) or placebo every 4 weeks. The primary endpoint was the rate of percentage change in forced vital capacity (FVC). Secondary endpoints were time to disease progression, absolute change in FVC, relative change in diffusing capacity of the lung for carbon monoxide (DLCO), and St George's Respiratory Questionnaire (SGRQ) total score.Due to a pre-planned, unfavourable interim benefit-risk analysis, dosing was suspended. The rate of percentage change in FVC showed no treatment effect (placebo -0.582%, 1 mg·kg(-1) -0.533%, 5 mg·kg(-1) -0.799% and 15 mg·kg(-1) -0.470%; p=0.261). All active treatment groups showed a greater decline in FVC (1 mg·kg(-1) -290 mL, 5 mg·kg(-1) -370 mL and 15 mg·kg(-1) -320 mL) compared with placebo (-130 mL). No effect on disease progression, DLCO, infection rates or mortality was observed. SGRQ scores showed a nonsignificant trend toward worsening with active treatment. Unexpectedly, free CC-chemokine ligand 2 levels were elevated above baseline at both 24 and 52 weeks. A higher proportion of patients with one or more serious adverse events was observed in the 5 mg·kg(-1) group (53.1%) compared with 1 mg·kg(-1) (15.2%), 15 mg·kg(-1) (21.9%) and placebo (46.4%), although no unexpected serious adverse events were noted.Although dosing was stopped prematurely, it is unlikely that carlumab provides benefit to IPF patients.

Pulmonary Hypertension in Sarcoidosis

Pulmonary hypertension is a complication of sarcoidosis leading to dyspnea and associated with increased morbidity and mortality. Sarcoidosis-associated pulmonary hypertension (SAPH) can be due to several factors, including vascular involvement by the granulomatous inflammation, compression of the pulmonary arteries by adenopathy, fibrotic changes within the lung, and left ventricular diastolic dysfunction. Several case series have suggested that some patients with SAPH benefit from specific therapy for pulmonary hypertension. A randomized, placebo-controlled trial found 16 weeks' bosentan therapy to be associated with significant improvement in pulmonary artery pressure. Future studies may better define who would respond to treatment of pulmonary hypertension.

Comorbidities in idiopathic pulmonary fibrosis patients: a systematic literature review

Idiopathic pulmonary fibrosis (IPF) is associated with a fatal prognosis and manifests in patients over 60 years old who may have comorbidities. The prevalence and impact of comorbidities on the clinical course of IPF is unclear.

This systematic literature review examined the prevalence of comorbidities and mortality associated with comorbidities in IPF patients. Relevant observational studies published in English from January 1990 to January 2015 identifiedviaMEDLINE and EMBASE were included; bibliographies of articles were also searched.

Among the 126 studies included, prevalence of pulmonary hypertension (PH) was 3–86%, 6–91% for obstructive sleep apnoea, 3–48% for lung cancer and 6–67% for chronic obstructive pulmonary disease (COPD). Nonrespiratory comorbidities included ischaemic heart disease (IHD) (3–68%) and gastro-oesophageal reflux (GER) (0–94%). Mortality was highest among patients with IPF and lung cancer. Most studies assessed relatively small samples of patients with IPF.

PH, COPD, lung cancer, GER and IHD are significant comorbidities; differences in IPF severity, case definitions and patient characteristics limited the comparability of findings. The identification and prompt treatment of comorbidities may have a clinically significant impact on overall outcome that is meaningful for patients with IPF.

Management of Rheumatoid Arthritis Patients with Interstitial Lung Disease: Safety of Biological Antirheumatic Drugs and Assessment of Pulmonary Fibrosis

Interstitial lung disease (ILD) is one of the major causes of morbidity and mortality of patients with rheumatoid arthritis (RA). Accompanying the increased number of reports on the development or exacerbation of ILD in RA patients following therapy with biological disease-modifying antirheumatic drugs (DMARDs), RA-associated ILD (RA-ILD) has aroused renewed interest. Although such cases have been reported mainly in association with the use of tumor necrosis factor inhibitors, the use of other biological DMARDs has also become a matter of concern. Nevertheless, it is difficult to establish a causative relationship between the use of biological DMARDs and either the development or exacerbation of ILD. Such pulmonary complications may occur in the natural course of RA regardless of the use of biological DMARDs. Since rheumatologists currently aim to achieve remission in RA patients, the administration of biological DMARDs is increasing, even for those with RA-ILD. However, there are no reliable, evidence-based guidelines for deciding whether biological DMARDs can be safely introduced and continued in RA-ILD patients. A standardized staging system for pulmonary conditions of RA-ILD patients is needed when making therapeutic decisions at baseline and monitoring during biological DMARD therapy. Based on the available information regarding the safety of biological DMARDs and the predictive factors for a worse prognosis, this review discusses candidate parameters for risk evaluation of ILD in RA patients who are scheduled to receive biological antirheumatic therapy.

What Is the Optimal Transplant for Older Patients With Idiopathic Pulmonary Fibrosis?

BACKGROUND

There is controversy regarding the optimal type of lung transplant--single orthotopic lung transplantation (SOLT) versus bilateral orthotopic lung transplantation (BOLT)--for patients with idiopathic pulmonary fibrosis. We performed this study to determine which type of transplant is more appropriate for older patients with this condition.

METHODS

We conducted a review of the United Network for Organ Sharing database from 2005 to 2013 for patients aged 65 years or more with idiopathic pulmonary fibrosis. A 1:1 nearest-neighbor propensity match was utilized to determine differences in survival by transplant procedure type (SOLT versus BOLT). Logistic regression modeling taking into account interaction terms between prespecified variables and the type of transplant was utilized to determine variables that altered the survival outcomes associated with SOLT versus BOLT.

RESULTS

Of 1,564 patients who met study criteria, 521 (33.3%) received BOLT. After propensity matching 498 BOLT recipients to 498 SOLT recipients, BOLT was associated with a significantly improved 5-year survival (48.7% versus 35.2%, p < 0.01). However, the mortality hazard associated with BOLT varied from a nonsignificant reduction in survival within 3 months after transplant (hazard ratio 1.24, 95% confidence interval: 0.80 to 1.93) to a significant survival benefit for patients who survived beyond 1 year (hazard ratio 0.64, 95% confidence interval: 0.47 to 0.86). Functional status was also found to be a significant predictor of the survival benefit associated with BOLT.

CONCLUSIONS

Bilateral orthotopic lung transplantation is associated with significantly improved survival over SOLT for older patients with idiopathic pulmonary fibrosis, driven by a late survival benefit from bilateral transplantation. However, patients with a reduced preoperative functional status do not appear to derive a similar benefit from bilateral transplantation.

Molecular classification of idiopathic pulmonary fibrosis: personalized medicine, genetics and biomarkers

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive fibrotic lung disease associated with high morbidity and poor survival. Characterized by substantial disease heterogeneity, the diagnostic considerations, clinical course and treatment response in individual patients can be variable. In the past decade, with the advent of high-throughput proteomic and genomic technologies, our understanding of the pathogenesis of IPF has greatly improved and has led to the recognition of novel treatment targets and numerous putative biomarkers. Molecular biomarkers with mechanistic plausibility are highly desired in IPF, where they have the potential to accelerate drug development, facilitate early detection in susceptible individuals, improve prognostic accuracy and inform treatment recommendations. Although the search for candidate biomarkers remains in its infancy, attractive targets such as MUC5B and MPP7 have already been validated in large cohorts and have demonstrated their potential to improve clinical predictors beyond that of routine clinical practices. The discovery and implementation of future biomarkers will face many challenges, but with strong collaborative efforts among scientists, clinicians and the industry the ultimate goal of personalized medicine may be realized.

Predicting 6-minute walking distance in recipients of lung transplantation: longitudinal study of 108 patients

BACKGROUND

Exercise capacity, muscle function, and physical activity levels remain reduced in recipients of lung transplantation. Factors associated with this deficiency in functional exercise capacity have not been studied longitudinally.

OBJECTIVE

The study aims were to analyze the longitudinal change in 6-minute walking distance and to identify factors contributing to this change.

DESIGN

This was a longitudinal historical cohort study.

METHODS

Data from patients who received a lung transplantation between March 2003 and March 2013 were analyzed for the change in 6-minute walking distance and contributing factors at screening, discharge, and 6 and 12 months after transplantation. Linear mixed-model and logistic regression analyses were performed with data on characteristics of patients, diagnosis, waiting list time, length of hospital stay, rejection, lung function, and peripheral muscle strength.

RESULTS

Data from 108 recipients were included. Factors predicting 6-minute walking distance were measurement moment, diagnosis, sex, quadriceps muscle and grip strength, forced expiratory volume in 1 second (percentage of predicted), and length of hospital stay. After transplantation, 6-minute walking distance increased considerably. This initial increase was not continued between 6 and 12 months. At 12 months after lung transplantation, 58.3% of recipients did not reach the cutoff point of 82% of the predicted 6-minute walking distance. Logistic regression demonstrated that discharge values for forced expiratory volume in 1 second and quadriceps or grip strength were predictive for reaching this criterion.

LIMITATIONS

Study limitations included lack of knowledge on the course of disease during the waiting list period, type and frequency of physical therapy after transplantation, and number of missing data points.

CONCLUSIONS

Peripheral muscle strength predicted 6-minute walking distance; this finding suggests that quadriceps strength training should be included in physical training to increase functional exercise capacity. Attention should be paid to further increasing 6-minute walking distance between 6 and 12 months after transplantation.

Validation of test performance characteristics and minimal clinically important difference of the 6-minute walk test in patients with idiopathic pulmonary fibrosis

BACKGROUND

The 6-minute walk test distance (6MWD) has been shown to be a valid and responsive outcome measure in patients with idiopathic pulmonary fibrosis (IPF). The analyses were based, however, on a single phase 3 trial and require validation in an independent cohort.

OBJECTIVE

To confirm the performance characteristics and estimates of minimal clinically important difference (MCID) of 6MWD in an independent cohort of patients with IPF.

METHODS

Patients randomized to placebo in the phase 3 CAPACITY trials who had a baseline 6MWD measurement were included in these analyses. The 6MWD and other functional parameters (lung function, dyspnea, and health-related quality of life) were measured at baseline and 24-week intervals. Validity and responsiveness were examined using Spearman correlation coefficients. The MCID was estimated using distribution- and anchor-based methods.

RESULTS

The analysis comprised 338 patients. Baseline 6MWD was significantly correlated with lung function measures, patient-reported outcomes, and quality-of-life measures (validity). Compared with baseline 6MWD, change in 6MWD (responsiveness) showed stronger correlations with change in lung function parameters and quality-of-life measures. Dyspnea measured by the University of California San Diego Shortness of Breath Questionnaire showed the strongest correlations with 6MWD (baseline: coefficient -0.35; 48-week change: coefficient -0.37; both p < 0.001). The distribution-based analyses of MCID using standard error of measurement yielded an MCID of 37 m, and distribution-based analyses by effect size resulted in 29.2 m. The MCID by anchor-based analysis using criterion referencing (health events of hospitalization or death) was 21.7 m.

CONCLUSIONS

The 6MWD is a valid and responsive clinical endpoint, which provides objective and clinically meaningful information regarding functional status and near-term prognosis. These results confirm previous findings in an independent cohort of patients with IPF.

Association between occupational dust exposure and prognosis of idiopathic pulmonary fibrosis: a Korean national survey

BACKGROUND

Previous studies have investigated the relationship between occupational and environmental agents and idiopathic pulmonary fibrosis (IPF). However, there have been few studies regarding the prognosis of patients with IPF according to patient occupation.

METHODS

We investigated whether occupational dust exposure was associated with clinically decreased lung function and poor prognosis. The Korean Interstitial Lung Disease Research Group conducted a national survey to evaluate the clinical, physiologic, radiologic, and survival characteristics of patients with IPF. A total of 1,311 patients with IPF were stratified into five groups according to their occupation: (1) unemployed or homemakers (n = 628); (2) farmers, fishers, or ranchers (n = 230); (3) sales or service personnel (n = 131); (4) clerical or professional personnel (n = 151); and (5) specific dust-exposed workers (n = 171).

RESULTS

The mean age of subjects at diagnosis, was 67.5 ± 9.7 years. Current smokers were 336 patients, 435 were exsmokers, and 456 were never smokers. Dust-exposed workers showed early onset of IPF (61.3 ± 8.6 years; P < .001) and a longer duration of symptoms at diagnosis (17.0 ± 28.2 months; P = .004). Aging (P = .001; hazard ratio [HR], 1.034; 95% CI, 1.014-1.054), FVC % predicted at diagnosis (P = .004; HR, 0.984; 95% CI, 0.974-0.995), and dust-exposure occupation (P = .033; HR, 1.813; 95% CI, 1.049-3.133) were associated with mortality.

CONCLUSIONS

These findings indicate that occupational dust may be an aggravating factor associated with a poor prognosis in IPF.