Idiopathic Pulmonary Fibrosis for Cardiologists: Differential Diagnosis, Cardiovascular Comorbidities, and Patient Management

Identification of shared molecular mechanisms and diagnostic biomarkers between heart failure and idiopathic pulmonary fibrosis

Background

Heart failure (HF) and idiopathic pulmonary fibrosis (IPF) are global public health concerns. The relationship between HF and IPF is widely acknowledged. However, the interaction mechanisms between these two diseases remain unclear, and early diagnosis is particularly difficult. Through the integration of bioinformatics and machine learning, our work aims to investigate common gene features, putative molecular causes, and prospective diagnostic indicators of IPF and HF.

Methods

The Gene Expression Omnibus (GEO) database provided the RNA-seq datasets for HF and IPF. Utilizing a weighted gene co-expression network analysis (WGCNA), possible genes linked to HF and IPF were found. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) were then employed to analyze the genes that were shared by HF and IPF. Using the cytoHubba and iRegulon algorithms, a competitive endogenous RNA (ceRNA) network was built based on seven basic diagnostic indicators. Additionally, hub genes were identified using machine learning approaches. External datasets were used to validate the findings. Lastly, the association between the number of immune cells in tissues and the discovered genes was estimated using the CIBERSORT method.

Results

In total, 63 shared genes were identified between HF- and IPF-related modules using WGCNA. Extracellular matrix (ECM)/structure organization, ECM-receptor interactions, focal, and protein digestion and absorption, were shown to be the most enrichment categories in GO and KEGG enrichment analysis of common genes. Furthermore, a total of seven fundamental genes, including COL1A1, COL3A1, THBS2, CCND1, ASPN, FAP, and S100A12, were recognized as pivotal genes implicated in the shared pathophysiological pathways of HF and IPF, and TCF12 may be the most important regulatory transcription factor. Two characteristic molecules, CCND1 and NAP1L3, were selected as potential diagnostic markers for HF and IPF, respectively, using a support vector machine-recursive feature elimination (SVM-RFE) model. Furthermore, the development of diseases and diagnostic markers may be associated with immune cells at varying degrees.

Conclusions

This study demonstrated that ECM/structure organisation, ECM-receptor interaction, focal adhesion, and protein digestion and absorption, are common pathogeneses of IPF and HF. Additionally, CCND1 and NAP1L3 were identified as potential diagnostic biomarkers for both HF and IPF. The results of our study contribute to the comprehension of the co-pathogenesis of HF and IPF at the genetic level and offer potential biological indicators for the early detection of both conditions.

Coronary artery calcium score is a prognostic factor for mortality in idiopathic pulmonary fibrosis

BACKGROUND

Cardiovascular diseases are frequent in idiopathic pulmonary fibrosis (IPF) and impact on survival. We investigated the association of coronary artery calcium (CAC) score at IPF diagnosis and during mid-term follow-up, with adverse cardiovascular events and all-cause mortality.

METHODS

Consecutive patients with IPF were retrospectively analyzed. Demographic data, smoking history, comorbidities and pulmonary function tests (PFTs) were recorded. All patients had at least two chest high resolution computed tomography (HRCT) performed 2 years apart. The total CAC score and visual fibrotic score were calculated, and all clinically significant cardiovascular events and deaths were reported.

RESULTS

The population consisted of 79 patients (57 males, mean age: 74.4±7.6 years); 67% of patients had a history of smoking, 48% of hypertension, 37% of dyslipidemia and 22.8% of diabetes. The visual score was 21.28±7.99% at T0 and 26.54±9.34% at T1, respectively (T1-T0 5.26±6.13%, P<0.001). CAC score at T0 and at T1 was 537.93±839.94 and 759.98±1027.6, respectively (T1-T0 224.66±406.87, P<0.001). Mean follow-up time was 2.47±1.1 years. On multivariate analysis, male sex (HR=3.58, 95% CI: 1.14-11.2) and CAC score at T0 (HR=1.04, 95% CI: 1.01-1.07) correlated with mortality and cardiovascular events. CAC score at T0≥405 showed 82% sensitivity and 100% specificity for predicting mortality and adverse cardiovascular events.

CONCLUSIONS

IPF patients with a CAC score at diagnosis ≥405 have a poor prognosis over a mid-term follow-up. A higher CAC score is associated with mortality and cardiovascular events.

Comparison of clinical scoring to predict mortality risk in mild-to-moderate idiopathic pulmonary fibrosis

BACKGROUND

During the last decade, a number of clinical scores, such as Gender-Age-Physiology (GAP) Index, TORVAN Score and Charlson Comorbidity Index (CCI), have been separately used to measure comorbidity burden in idiopathic pulmonary fibrosis (IPF). However, no previous study compared the prognostic value of these scores to assess mortality risk stratification in IPF patients with mild-to-moderate disease.

METHODS

All consecutive patients with mild-to-moderate IPF who underwent high-resolution computed tomography, spirometry, transthoracic echocardiography and carotid ultrasonography at our Institution, between January 2016 and December 2018, were retrospectively analyzed. GAP Index, TORVAN Score and CCI were calculated in all patients. Primary endpoint was all-cause mortality, whereas secondary endpoint was the composite of all-cause mortality and rehospitalizations for all-causes, over medium-term follow-up.

RESULTS

Seventy IPF patients (70.2±7.4 yrs, 74.3% males) were examined. At baseline, GAP Index, TORVAN Score and CCI were 3.4±1.1, 14.7±4.1 and 5.3±2.4, respectively. A strong correlation between coronary artery calcification (CAC) and common carotid artery (CCA) intima-media thickness (IMT) (r=0.88), CCI and CAC (r=0.80), CCI and CCA-IMT (r=0.81), was demonstrated in the study group. Follow-up period was 3.5±1.2 years. During follow-up, 19 patients died and 32 rehospitalizations were detected. CCI (HR 2.39, 95% CI: 1.31-4.35) and heart rate (HR 1.10, 95% CI: 1.04-1.17) were independently associated with primary endpoint. CCI (HR 1.54, 95% CI: 1.15-2.06) predicted secondary endpoint, also. A CCI ≥6 was the optimal cut-off for predicting both outcomes.

CONCLUSIONS

Due to the increased atherosclerotic and comorbidity burden, IPF patients with CCI ≥6 at an early-stage disease have poor outcome over medium-term follow-up.

Prognostic role of CHA2DS2-VASc score for mortality risk assessment in non-advanced idiopathic pulmonary fibrosis: a preliminary observation

During the last decade, the CHA₂DS₂-VASc score has been used for stratifying the mortality risk in both atrial fibrillation (AF) and non-AF patients. However, no previous study considered this score as a prognostic indicator in non-AF patients with mild-to-moderate idiopathic pulmonary fibrosis (IPF). All consecutive non-AF patients with mild-to-moderate IPF, diagnosed between January 2016 and December 2018 at our Institution, entered this study. All patients underwent physical examination, blood tests, spirometry, high-resolution computed tomography and transthoracic echocardiography. CHA₂DS₂-VASc score, Gender-Age-Physiology (GAP) index and Charlson Comorbidity Index (CCI) were determined in all patients. Primary endpoint was all-cause mortality, while the secondary endpoint was the composite of all-cause mortality and rehospitalizations for all causes over mid-term follow-up. 103 consecutive IPF patients (70.7 ± 7.3 yrs, 79.6% males) were retrospectively analyzed. At the basal evaluation, CHA₂DS₂-VASc score, GAP index and CCI were 3.7 ± 1.6, 3.6 ± 1.2 and 5.5 ± 2.3, respectively. Mean follow-up was 3.5 ± 1.3 yrs. During the follow-up period, 29 patients died and 43 were re-hospitalized (44.2% due to cardiopulmonary causes). On multivariate Cox regression analysis, CHA₂DS₂-VASc score (HR 2.15, 95% CI 1.59-2.91) and left ventricular ejection fraction (LVEF) (HR 0.91, 95% CI 0.86-0.97) were independently associated with all-cause mortality in IPF patients. CHA₂DS₂-VASc score (HR 1.66, 95% CI 1.39-1.99) and LVEF (HR 0.94, 95% CI 0.90-0.98) also predicted the secondary endpoint in the same study group. CHA₂DS₂-VASc score > 4 was the optimal cut-off for predicting both outcomes. At mid-term follow-up, a CHA₂DS₂-VASc score > 4 predicts an increased risk of all-cause mortality and rehospitalizations for all causes in non-AF patients with mild-to-moderate IPF.

Incremental prognostic value of arterial elastance in mild-to-moderate idiopathic pulmonary fibrosis

Previous reports suggested that poor pulmonary function was associated with increased arterial elastance (Ea) in patients with chronic obstructive pulmonary disease and systemic sclerosis. The mechanisms connecting pulmonary function and Ea have not yet been accurately studied in patients with idiopathic pulmonary fibrosis (IPF). The present study was designed to assess Ea in IPF patients without chronic severe pulmonary hypertension and to determine its prognostic role over a medium-term follow-up. This retrospective study included 60 consecutive patients with mild-to-moderate IPF (73.8 ± 6.6 years, 75% males) and 60 controls matched by age, sex and cardiovascular risk factors. All patients underwent physical examination, spirometry, blood tests, modified Haller index (MHI, chest transverse diameter over the distance between sternum and spine) assessment, conventional transthoracic echocardiography implemented with speckle tracking analysis of left atrial positive global strain (LA-GSA+ ) and finally carotid Doppler ultrasonography, at basal evaluation. The effective arterial elastance index (EaI) was calculated as the ratio of end-systolic pressure to stroke volume index. During follow-up period, we evaluated the composite endpoint of (1) pulmonary or cardiovascular hospitalizations; (2) all-cause mortality. At baseline, EaI was significantly higher in IPF patients than controls (4.1 ± 1.3 vs 3.5 ± 1.0 mmHg/ml/m2, p = 0.01). EaI was strongly correlated to the following variables: C-reactive protein (CRP) (r = 0.86), forced vital capacity (FVC) (r =  - 0.91), E/e' ratio (r = 0.91), LA-GSA+  (r =  - 0.92), common carotid artery-cross sectional area (CCA-CSA) (r = 0.89) and MHI (r = 0.86), in IPF patients. Mean follow-up time was 2.4 ± 1.3 years. During follow-up, 12 patients died and 17 were hospitalized due to major adverse clinical events. At univariate Cox analysis, CRP (HR 1.51, 95% CI 1.25-1.82), FVC (HR 0.88, 95% CI 0.85-0.91), LA-GSA+  (HR 0.85, 95% CI 0.77-0.94), CCA-CSA (HR 1.12, 95% CI 1.03-1.22) and EaI (HR 2.43, 95% CI 1.75-3.37) were significantly associated with outcome. At multivariate Cox analysis, only EaI (HR 1.60, 95% CI 1.03-2.50) retained statistical significance. An EaI ≥ 4 mmHg/ml/m2 showed 100% sensitivity and 99.4% specificity for predicting outcome (AUC = 0.98). In patients with mild-to-moderate IPF, an EaI ≥ 4 mmHg/ml/m2 is a negative prognostic factor over a medium-term follow-up.

Influence of chest wall conformation on spirometry parameters and outcome in mild-to-moderate idiopathic pulmonary fibrosis

Extrinsic causes of restrictive lung syndrome in idiopathic pulmonary fibrosis (IPF) patients have been poorly investigated. We aimed to investigate the influence of the anterior chest wall deformity, noninvasively assessed by modified Haller index (MHI), on spirometry parameters and outcome in a consecutive population of patients with mild-to-moderate IPF. Sixty consecutive IPF patients (73.8 ± 6.6 years, 45 males) were included in this retrospective study. All patients underwent physical examination, spirometry, blood tests, conventional transthoracic echocardiography and MHI assessment (chest transverse diameter over the distance between sternum and spine) at basal evaluation. During follow-up, we evaluated the composite endpoint of (1) pulmonary or cardiovascular hospitalizations and (2) all-cause mortality. IPF patients with concave-shaped chest wall (MHI > 2.5) (36.7% of total) and those with normal chest shape (MHI ≤ 2.5) (63.3%) were separately analyzed. In comparison to IPF patients with MHI ≤ 2.5, those with MHI > 2.5: were less likely to be men and smokers; had a more severe restrictive pattern; had significantly smaller cardiac chamber dimensions and significantly higher systolic pulmonary artery pressure (51.9 ± 15.1 vs 42.4 ± 14.3 mmHg, p = 0.02). Mean follow-up time was 2.5 ± 1.4 years. During follow-up, 13 deaths and 16 pulmonary or cardiovascular hospitalizations were detected. At multivariate Cox regression analysis, concave-shaped chest wall (MHI > 2.5) (HR 4.55, 95% CI 1.02-20.4), increased C-reactive protein (HR 1.68, 95% CI 1.08-2.61) and absence of beta-blocker therapy (HR 0.13, 95% CI 0.01-0.26) were independently associated to the investigated outcome. MHI assessment and implementation may help the clinician to identify, among IPF patients, those with poorer prognosis over a medium-term follow-up.

Association between C-reactive protein and carotid plaque in mild-to-moderate idiopathic pulmonary fibrosis

An association between C-reactive protein (CRP) levels and carotid plaque has never been investigated in idiopathic pulmonary fibrosis (IPF). The aim of this study was to evaluate the extent of carotid atherosclerosis in mild-to-moderate IPF and to assess its relationship to serum CRP. This observational retrospective case-control study included 60 consecutive IPF patients (73.8 ± 6.6 years, 45 males) and 60 matched controls, examined between Sep 2017 and Jan 2019. All patients underwent CRP assessment and a carotid Doppler ultrasonography. CRP levels were significantly higher in IPF patients than controls (0.2 ± 0.09 mg/dl vs 0.09 ± 0.04 mg/dl, p < 0.0001). A total of 46 plaques were detected, with higher prevalence in IPF patients than controls (38 vs 8, p < 0.0001). On univariate logistic regression the main variables independently associated with carotid plaque were: age (HR 1.09, 95% CI 1.03-1.16, p = 0.006), hypertension duration (HR 1.05, 95% CI 1.01-1.09, p = 0.01), diabetes duration (HR 1.09, 95% CI 1.01-1.18, p = 0.03), LDL-cholesterol (HR 1.07, 95% CI 1.04-1.10, p < 0.0001) and finally CRP levels (HR 1.73, 95% CI 0.59-5.00, p < 0.0001). Multivariate logistic regression analysis revealed that LDL-cholesterol (HR 1.05, 95% CI 1.01-1.08, p = 0.009) and CRP levels (HR 1.43, 95% CI 0.39-5.19, p < 0.0001) retained statistical significance. Common carotid artery-intima media thickness was significantly correlated with CRP levels in IPF patients (r = 0.86). SerumCRP might represent both an early marker and a potential therapeutic target for carotid atherosclerosis in mild-to-moderate IPF.

[Research and Application of Stem Cell-Based Therapy in Idiopathic Pulmonary Fibrosis: A Review]

Idiopathic pulmonary fibrosis (IPF) is a type of pulmonary disease that progresses acutely or slowly into irreversible pulmonary diseases, resulting in the end severe damages to patients' lung functions, as well as deaths. At present, the pathogenesis of pulmonary fibrosis is still not clear and there is no effective therapeutic measure available to control the progression of the disease. Research findings indicate that stem cells, being the origin of all cells of organisms, participate in the development of individuals at various stages and play an important role in repairing pulmonary tissue damage. Stem cells are attracting growing attention in the field of regenerative medicine, providing new ideas for treating IPF with transplanted stem cells. Herein, in order to better explore the potential applications of stem cell transplantation in treating IPF, we attempt to summarize preliminary studies of stem cell-mediated pulmonary remodeling after IPF, as well as cutting-edge clinical trials in stem cell-based IPF therapy.

HFpEF without elevated right ventricular systolic pressure is a favorable prognostic indicator in patients with IPF requiring hospitalization for heart failure

Background

Some patients with idiopathic pulmonary fibrosis (IPF) must be hospitalized because of heart failure (HF), including HF with preserved ejection fraction (HFpEF) and HF with reduced EF (HFrEF). The association between IPF and HF has not been clarified. We retrospectively investigated the clinical features and outcomes of patients with IPF who required nonelective hospitalization because of HF.

Methods

We examined data from IPF patients who required nonelective hospitalization for HF at the Kindai University Hospital from January 2008 to December 2018. We divided the patients into 3 groups: those with HFpEF without elevated right ventricular systolic pressure (RVSP), those with HFpEF and elevated RVSP, and those with HFrEF. The recurrence rates of HF after discharge and the 30- and 90-day mortality rates of the patients were evaluated.

Results

During the study period, 37 patients with IPF required hospitalization because of HF. Among the 34 patients included in the study, 17 (50.0%) were diagnosed with HFpEF without elevated RVSP, 11 (32.3%) with HFpEF and elevated RVSP, and 6 (17.6%) with HFrEF. Patients with HFrEF had significantly higher values for B-type natriuretic peptide (BNP) and left ventricular (LV) end-systolic and end-diastolic diameters than patients with the 2 types of HFpEF (BNP: P = 0.01 and P = 0.0004, LV end-systolic diameter: P <0.0001 and P <0.0001, and LV end-diastolic diameter: P = 0.01 and P = 0.0004, respectively). Notably, the difference between the LVEFs of the patients with 2 types of HFpEF was not significant. The patients with HFpEF without elevated RVSP had the lowest 30- and 90-day mortality rates (0%, P = 0.02 and 11.7%, P = 0.11, respectively).

Conclusions

Among patients with IPF, HFpEF without elevated RVSP was the most common type of HF that required hospitalization. Patients with HFpEF without elevated RVSP survived longer than the patients with the other 2 types of HF.

Dynamics in diagnoses and pharmacotherapy before and after diagnosing idiopathic pulmonary fibrosis

Background

Idiopathic pulmonary fibrosis (IPF) is a well-characterised interstitial lung disease. Typically, IPF diagnosis is delayed due to nonspecific symptoms, but can also be delayed due to treatment attempts on false indication or due to treatment targeting common comorbidities. This observational study aimed to assess the dynamics in the medication and diagnosis patterns in the period before and after an IPF diagnosis.

Methods

We identified all Danish patients with IPF between 2002 and 2017. We evaluated new and ongoing drug treatments and incident diagnoses 36 months before and 12 months after an IPF diagnosis by use of Danish nationwide registries. To aid interpretation, 10 random controls were recruited for each case.

Results

A total of 650 IPF patients were identified (median age 73 years (interquartile range 65–78), 70.3% males). Prior to the IPF diagnosis, the most prevalent diagnoses were dyspnoea and non-IPF interstitial lung diseases. For drug use, IPF patients had higher initiation rates for antibiotics, oral corticosteroids and mucolytics. In terms of drug volume, IPF patients used more respiratory drugs, antibiotics, immunosuppressants, corticosteroids, proton pump inhibitors, benzodiazepines and opium alkaloids within the 6 months preceding their IPF diagnosis, compared to the controls. Overall drug use decreased after an IPF diagnosis, mainly due to a reduced glucocorticoid and cardiovascular drug use.

Conclusion

Among IPF patients, an increased drug use was observed for diagnoses with symptoms overlapping those of IPF, particularly this was observed during the last 6 months before an IPF diagnosis. This emphasises the need for an increased IPF awareness.

Among IPF patients, an increased drug use was observed for diagnoses with symptoms overlapping those of IPF. Particularly this was observed during the last 6 months before an IPF diagnosis. This emphasises the need for an increased IPF awareness.https://bit.ly/3bAzveS

Using forced vital capacity (FVC) in the clinic to monitor patients with idiopathic pulmonary fibrosis (IPF): pros and cons

INTRODUCTION

Forced vital capacity (FVC) decline is predictive of mortality in patients with idiopathic pulmonary fibrosis (IPF) and has been used as a clinical trial endpoint to define disease progression. How to interpret FVC findings in an individual patient with IPF in the real-world setting amid uncertainty about the measurement accuracy and variability has not been well established.

AREAS COVERED

This review highlights the challenges and limitations of using FVC in the clinic to monitor disease progression in patients with IPF. Spirometry is noninvasive, relatively simple, and inexpensive. FVC measurements provide evidence for trends over time in patients with IPF. When using FVC in the clinic, several important challenges and limitations, including visit-to-visit variability, dependence on patient effort, inconsistent quality control, limitations on accuracy, and the influence of comorbidities and pretest factors, must be considered. Recent studies suggest the potential for home spirometry devices to facilitate more frequent collection of data and perhaps demonstrate more accurate trends.

EXPERT OPINION

Measuring FVC decline in the clinic has an important role in monitoring disease progression in patients with IPF, but additional measures of disease progression should be considered along with FVC to facilitate decision-making about disease management.

Cardiovascular implications of idiopathic pulmonary fibrosis: A way forward together?

Cardiovascular disease has an increased prevalence among patients with idiopathic pulmonary fibrosis (IPF). Cardiovascular disease and IPF share similar symptoms with overlapping demographics and risk factors for disease development. Common cellular mediators leading to disease development and progression have been identified in both the cardiovascular and pulmonary organ systems. In this context, discovery of new therapeutic targets and medical therapies could be mutually beneficial across cardiopulmonary diseases. Here we present (1) a clinical review of IPF for the cardiovascular clinician and (2) common cellular mechanisms responsible for fibrosis in the heart and lungs and (3) highlight future research considerations and the potential role of novel therapeutic agents which may be mutually beneficial in cardiac and pulmonary fibrosis.

Early left atrial dysfunction in idiopathic pulmonary fibrosis patients without chronic right heart failure

No data are actually available regarding the left atrial (LA) functional assessment by two-dimensional speckle tracking echocardiography (2D-STE) in early-stage idiopathic pulmonary fibrosis (IPF). The primary end-point of our study was to assess whether global LA peak strain (GLAPS), measured by 2D-STE analysis, may detect early alterations in LA function in IPF patients without right heart failure (RHF). Between September 2017 and January 2019, 50 consecutive IPF patients (73.8 ± 6.8 years, 36 males) without chronic RHF and 30 controls matched by age, sex and cardiovascular risk factors, were enrolled in an observational retrospective case-control study. All patients underwent a complete echocardiographic study implemented with 2D-STE analysis. GLAPS, left ventricular (LV) global longitudinal strain (GLS), right atrial (RA) reservoir strain (GSA+) and right ventricular (RV)-GLS were obtained in each patient. LVFP were significantly increased in IPF patients in comparison to controls (average E/e' ratio 14.4 ± 3.0 vs 9.6 ± 1.5, p < 0.0001), while LV-GLS was slightly reduced in IPF patients compared to controls (19.4 ± 3.6% vs 21.0 ± 2.2%, p = 0.03).Moreover, GLAPS was significantly impaired in IPF patients in comparison to controls (18.4 ± 3.7% vs 28.4 ± 5.6%, p < 0.0001).Finally, the two groups of patients did not show any statistically significant difference in both RA-GSA + (23.9 ± 3.7% vs 24.5 ± 4.0%, p = 0.49) and RV-GLS (- 22.6 ± 3.3% vs - 23.5 ± 3.0%, p = 0.22). Notably, LV-GLS was strongly inversely correlated both with RV/LV basal diameter ratio and TRV in IPF patients (r = - 0.87 and - 0.82, respectively) but not in controls (r = - 0.29 and - 0.27, respectively). This finding highlights a likely process of ventricular interdependence in non-advanced IPF, with consequent LV diastolic dysfunction and secondary impairment in LV-GLS and GLAPS. Early LA reservoir dysfunction in IPF patients may be secondary to LV diastolic dysfunction induced by ventricular interdependence and may develop before RV diastolic and systolic dysfunction.

[Protective role of myelocytic nitric oxide synthases in pulmonary hypertension due to lung diseases and/or hypoxia]

Nitric oxide (NO), formed from NO synthases (NOSs), plays a pathogenetic role in pulmonary hypertension (PH). However, the role of NO/NOSs in bone marrow (BM) cells in PH remains to be clarified. We addressed this point in clinical and basic studies. We demonstrated that, in 36 consecutive patients with idiopathic pulmonary fibrosis, pulmonary artery systolic pressure is inversely correlated with NOx levels in the bronchoalveolar lavage fluid, suggesting reduced pulmonary NO production in group III PH. We then revealed that transplantation of BM cells from mice lacking all NOSs aggravates hypoxia-induced PH in wild-type (WT) mice, and transplantation of BM cells from the WT mice ameliorates hypoxia-induced PH in the NOSs^-/- mice, indicating a protective role of myelocytic NOSs in the pathogenesis of PH. Immune and inflammatory mechanisms appeared to be involved in the aggravation of hypoxia-induced PH caused by transplantation of BM cells from the NOSs^-/- mice. Our findings provide novel insights into the cellular and molecular basis of group III PH.

Comorbidities in idiopathic pulmonary fibrosis: an underestimated issue

Idiopathic pulmonary fibrosis (IPF) is a progressive and fibrosing lung disease with a poor prognosis. Between 60% and 70% of IPF patients die of IPF; the remaining causes of death may be due to comorbidities occurring in this ageing population. Interest in the role played by comorbidities in IPF has increased in the past few years. The optimal clinical management of IPF is multifaceted and not only involves antifibrotic treatment, but also vaccinations, oxygen supplementation, evaluation of nutritional status as well as psychological support and patient education. Symptom management, pulmonary rehabilitation, palliative care and treatment of comorbidities represent further areas of clinical intervention. This review analyses the major comorbidities observed in IPF, focusing on those that have the greatest impact on mortality and quality of life (QoL). The identification and treatment of comorbidities may help to improve patients' health-related QoL (i.e. sleep apnoea and depression), while some comorbidities (i.e. lung cancer, cardiovascular diseases and pulmonary hypertension) influence survival. It has been outlined that gathering comorbidities data improves the prediction of survival beyond the clinical and physiological parameters of IPF.

Efficacy of pirfenidone for the treatment of pulmonary fibrosis: An updated systematic review protocol of randomized controlled trial

BACKGROUND

This study will systematically assess the efficacy and safety of pirfenidone for the treatment of patients with pulmonary fibrosis (PF).

METHODS

We will search potential records from following literature sources from their inceptions to the present without language, and publication status limitations: Cochrane Library, EMBASE, PUBMED, the Cumulative Index to Nursing and Allied Health Literature, the Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. In addition, we also search grey literature sources, such as dissertations, conference proceedings, as well as the reference lists of included studies. All randomized controlled trials related to the pirfenidone for treating PF will be included. All the process of study selection, data extraction, and methodological evaluation will be carried out by 2 authors independently. The primary outcome comprises of all-cause-mortality, and lung function status, as measured by forced vital capacity. The secondary outcomes consist of 6-minute walk distance, progression-free survival, dyspnea, acute exacerbation, quality of life, and adverse events. Whenever possible, all results data will be pooled and meta-analysis will be performed.

RESULTS

This study will systematically assess the efficacy and safety of pirfenidone for the treatment of patients with PF.

CONCLUSION

The findings of the present study will summarize most recent evidence of pirfenidone for PF.

ETHICS AND DISSEMINATION

No individual data will be analyzed in this study, thus, no research ethics approval is required in this study. The findings of this study are expected to be disseminated in a peer-reviewed journal or conference presentations.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019126958.