Percent emphysema, airflow obstruction, and impaired left ventricular filling

A Research Agenda to Improve Outcomes in Patients with Chronic Obstructive Pulmonary Disease and Cardiovascular Disease: An Official American Thoracic Society Research Statement

Background: Individuals with chronic obstructive pulmonary disease (COPD) are often at risk for or have comorbid cardiovascular disease and are likely to die of cardiovascular-related causes. Objectives: To prioritize a list of research topics related to the diagnosis and management of patients with COPD and comorbid cardiovascular diseases (heart failure, atherosclerotic vascular disease, and atrial fibrillation) by summarizing existing evidence and using consensus-based methods. Methods: A literature search was performed. References were reviewed by committee co-chairs. An international, multidisciplinary committee, including a patient advocate, met virtually to review evidence and identify research topics. A modified Delphi approach was used to prioritize topics in real time on the basis of their potential for advancing the field. Results: Gaps spanned the translational science spectrum from basic science to implementation: 1) disease mechanisms; 2) epidemiology; 3) subphenotyping; 4) diagnosis and management; 5) clinical trials; 6) care delivery; 7) medication access, adherence, and side effects; 8) risk factor mitigation; 9) cardiac and pulmonary rehabilitation; and 10) health equity. Seventeen experts participated, and quorum was achieved for all votes (>80%). Of 17 topics, ≥70% agreement was achieved for 12 topics after two rounds of voting. The range of summative Likert scores was -15 to 25. The highest priority was "Conduct pragmatic clinical trials with patient-centered outcomes that collect both pulmonary and cardiac data elements." Health equity was identified as an important topic that should be embedded within all research. Conclusions: We propose a prioritized research agenda with the purpose of stimulating high-impact research that will hopefully improve outcomes among people with COPD and cardiovascular disease.

The cold temperature associated with new-onset heart failure after incorporating dynamic status of multimorbidity: nationwide cohort, Taiwan 2012-2019

AIMS

Cold temperatures are known to affect heart failure (HF) hospitalizations, but the dynamic status of multi-morbidity of HF was rarely incorporated. We investigated the relationship between temperature and new-onset HF by risk strata.

METHODS AND RESULTS

This nationwide cohort study analysed daily data on ambient temperature, the dynamic status of risk factors (age, diabetes, chronic obstructive pulmonary disease, coronary artery disease, chronic kidney disease, hypertension, myocardial infarction, and atrial fibrillation), and new-onset HF among the Taiwan population from 2012 to 2019. Poisson regression, Austin's algorithm, and classification and regression tree (CART) were used to determine risk strata and obtain the predicted HF rate. 148 708 patients developed new-onset HF over 152.52 million person-years. Three risk strata for HF were identified: Stratum 1 was predominantly those without any comorbidity (89.9%); Stratum 2 was those aged 60-69 with 2-3 comorbidities or aged 70+ with 1-2 comorbidities (9.0%), and Stratum 3 was those aged 70+ and had four or more comorbidity (1.1%). The HF incidence rates for these three strata were 25.54, 555.27, and 2315.52 per 100 000 person-years, respectively. The R2 of the Poisson regression with the three risk strata and the daily minimum temperature on the ln HF incidence rates was 77.99%. The risk of HF increased as temperatures decreased, and the slopes were 1.032, 1.040, and 1.034 for Strata 1-3, respectively. The rate ratios of HF at the winter median temperature of 17°C vs. the summer median temperature of 29°C were 1.45, 1.58, and 1.49 for Strata 1-3, respectively. Cross-validation reveals a good fit and predicted HF rates by ambient temperature for the three strata were provided.

CONCLUSION

Cold temperatures are associated with an increased risk of new-onset HF. Stratum 2 (aged 60-69 with 2-3 comorbidities or aged 70+ with 1-2 comorbidities) are particularly susceptible to cold-related new-onset HF.

Lung function trajectories from school age to adulthood and their relationship with markers of cardiovascular disease risk

RATIONALE

Lung function in early adulthood is associated with subsequent adverse health outcomes.

OBJECTIVES

To ascertain whether stable and reproducible lung function trajectories can be derived in different populations and investigate their association with objective measures of cardiovascular structure and function.

METHODS

Using latent profile modelling, we studied three population-based birth cohorts with repeat spirometry data from childhood into early adulthood to identify trajectories of forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC). We used multinomial logistic regression models to investigate early-life predictors of the derived trajectories. We then ascertained the extent of the association between the derived FEV1/FVC trajectories and blood pressure and echocardiographic markers of increased cardiovascular risk and stroke in ~3200 participants at age 24 years in one of our cohorts.

RESULTS

We identified four FEV1/FVC trajectories with strikingly similar latent profiles across cohorts (pooled N=6377): above average (49.5%); average (38.3%); below average (10.6%); and persistently low (1.7%). Male sex, wheeze, asthma diagnosis/medication and allergic sensitisation were associated with trajectories with diminished lung function in all cohorts. We found evidence of an increase in cardiovascular risk markers ascertained by echocardiography (including left ventricular mass indexed to height and carotid intima-media thickness) with decreasing FEV1/FVC (with p values for the mean crude effects per-trajectory ranging from 0.10 to p<0.001). In this analysis, we considered trajectories as a pseudo-continuous variable; we confirmed the assumption of linearity in all the regression models.

CONCLUSIONS

Childhood lung function trajectories may serve as predictors in the development of not only future lung disease, but also the cardiovascular disease and multimorbidity in adulthood.

Vessel and Airway Characteristics in One-Year Computed Tomography-defined Rapid Emphysema Progression: SPIROMICS

Rationale: Rates of emphysema progression vary in chronic obstructive pulmonary disease (COPD), and the relationships with vascular and airway pathophysiology remain unclear. Objectives: We sought to determine if indices of peripheral (segmental and beyond) pulmonary arterial dilation measured on computed tomography (CT) are associated with a 1-year index of emphysema (EI; percentage of voxels <-950 Hounsfield units) progression. Methods: Five hundred ninety-nine former and never-smokers (Global Initiative for Chronic Obstructive Lung Disease stages 0-3) were evaluated from the SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study) cohort: rapid emphysema progressors (RPs; n = 188, 1-year ΔEI > 1%), nonprogressors (n = 301, 1-year ΔEI ± 0.5%), and never-smokers (n = 110). Segmental pulmonary arterial cross-sectional areas were standardized to associated airway luminal areas (segmental pulmonary artery-to-airway ratio [PAARseg]). Full-inspiratory CT scan-derived total (arteries and veins) pulmonary vascular volume (TPVV) was compared with small vessel volume (radius smaller than 0.75 mm). Ratios of airway to lung volume (an index of dysanapsis and COPD risk) were compared with ratios of TPVV to lung volume. Results: Compared with nonprogressors, RPs exhibited significantly larger PAARseg (0.73 ± 0.29 vs. 0.67 ± 0.23; P = 0.001), lower ratios of TPVV to lung volume (3.21 ± 0.42% vs. 3.48 ± 0.38%; P = 5.0 × 10-12), lower ratios of airway to lung volume (0.031 ± 0.003 vs. 0.034 ± 0.004; P = 6.1 × 10-13), and larger ratios of small vessel volume to TPVV (37.91 ± 4.26% vs. 35.53 ± 4.89%; P = 1.9 × 10-7). In adjusted analyses, an increment of 1 standard deviation in PAARseg was associated with a 98.4% higher rate of severe exacerbations (95% confidence interval, 29-206%; P = 0.002) and 79.3% higher odds of being in the RP group (95% confidence interval, 24-157%; P = 0.001). At 2-year follow-up, the CT-defined RP group demonstrated a significant decline in postbronchodilator percentage predicted forced expiratory volume in 1 second. Conclusions: Rapid one-year progression of emphysema was associated with indices indicative of higher peripheral pulmonary vascular resistance and a possible role played by pulmonary vascular-airway dysanapsis.

Electrocardiographic alterations in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality, and its incidence has grown within several years, quickly becoming the third leading cause of mortality. The disease is characterized by alveolar destruction, air-trapping, and chronic inflammation due to persistent exposure to a large spectrum of harmful particles. The diagnosis of COPD is made by demonstration of persistent and not fully reversible airflow limitation, and different phenotypes may be recognized based on pathophysiological, clinical, and radiological features. However, COPD is a systemic disease with effects involving several organs. For example, mechanical and functional alterations secondary to COPD involve heart function. Indeed, cardiovascular diseases are highly prevalent in patients affected by COPD and represent the primary cause of mortality in such patients. An electrocardiogram is a simple and cheap test that gives much information about the heart status of COPD patients. Consequently, variations from "normality" can be appreciated in these patients, with the most frequent abnormalities being P-wave, QRS axis, and ventricular repolarization abnormalities, in addition to conduction alterations and a vast number of arrhythmias. As a result, ECG should be routinely performed as a valuable tool to recognize alterations due to COPD (i.e., mechanical and functional) and possible associated heart diseases. This review aims to describe the typical ECG features in most COPD patients and to provide a systematic summary that can be used in clinical practice.

The association between declining lung function and stroke risk: insights from an observational study and Mendelian randomization

Background

Stroke, prevalent globally, particularly impacts low- and middle-income countries. Decreased lung function is one of the risk factors for stroke, and there is a lack of sufficient research on the association between the two, especially based on evidence from representative large samples. We aimed to explore the association between lung function and stroke incidence.

Methods

We collected data from 13,371 participants from the 2007-2012 U.S. national cross-sectional study and 11,192 participants from the Chinese national cohort study during the 2011-2018 follow-up period. Multivariate logistic regression and Cox proportional hazards regression were used to assess cross-sectional and longitudinal associations of peak expiratory flow with stroke risks. Additionally, we used publicly available GWAS data from a European population to conduct Mendelian randomization analysis, further exploring the potential causal relationship.

Results

The results of the cross-sectional study suggest that a decline in peak expiratory flow may be associated with an increased risk of stroke. The cohort study revealed that, compared to the first tertile group, the risk of stroke incidence in the second and third tertile groups of PEF decreased by 19% (hazard ratio (HR) = 0.810, 95%CI = 0.684-0.960) and 21.4% (HR = 0.786, 95%CI = 0.647-0.956), respectively. Mendelian randomization analysis clarified that higher PEF levels are significantly associated with a reduced risk of stroke (OR = 0.852, 95%CI = 0.727-0.997).

Conclusion

Decreased lung function is a risk factor for stroke. As a simple and accurate indicator of lung function, PEF can be used to monitor lung function in community populations and patients for primary stroke prevention.

Chronic Obstructive Pulmonary Disease in Heart Failure: Challenges in Diagnosis and Treatment for HFpEF and HFrEF

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) is common in heart failure (HF), and it has a significant impact on the prognosis and quality of life of patients. Additionally, COPD is independently associated with lower adherence to first-line HF therapies. In this review, we outline the challenges of identifying and managing HF with preserved (HFpEF) and reduced (HFrEF) ejection fraction with coexisting COPD.

RECENT FINDINGS

Spirometry is necessary for COPD diagnosis and prognosis but is underused in HF. Therefore, misdiagnosis is a concern. Also, disease-modifying drugs for HF and COPD are usually safe but underprescribed when HF and COPD coexist. Patients with HF-COPD are poorly enrolled in clinical trials. Guidelines recommend that HF treatment should be offered regardless of COPD presence, but modern registries show that undertreatment persists. Treatment gaps could be attenuated by ensuring an accurate and earlier COPD diagnosis in patients with HF, clarifying the concerns related to pharmacotherapy safety, and increasing the use of non-pharmacologic treatments. Acknowledging the uncertainties, this review aims to provide key clinical resources to support better physician-patient co-decision-making and improve collaboration between health professionals.

Traditional and Advanced Echocardiographic Evaluation in Chronic Obstructive Pulmonary Disease: The Forgotten Relation

Chronic obstructive pulmonary disease (COPD) is a significant preventable and treatable clinical disorder defined by a persistent, typically progressive airflow obstruction. This disease has a significant negative impact on mortality and morbidity worldwide. However, the complex interaction between the heart and lungs is usually underestimated, necessitating more attention to improve clinical outcomes and prognosis. Indeed, COPD significantly impacts ventricular function, right and left chamber architecture, tricuspid valve functionality, and pulmonary blood vessels. Accordingly, more emphasis should be paid to their diagnosis since cardiac alterations may occur very early before COPD progresses and generate pulmonary hypertension (PH). Echocardiography enables a quick, noninvasive, portable, and accurate assessment of such changes. Indeed, recent advancements in imaging technology have improved the characterization of the heart chambers and made it possible to investigate the association between a few cardiac function indexes and clinical and functional aspects of COPD. This review aims to describe the intricate relation between COPD and heart changes and provide basic and advanced echocardiographic methods to detect early right ventricular and left ventricular morphologic alterations and early systolic and diastolic dysfunction. In addition, it is crucial to comprehend the clinical and prognostic significance of functional tricuspid regurgitation in COPD and PH and the currently available transcatheter therapeutic approaches for its treatment. Moreover, it is also essential to assess noninvasively PH and pulmonary resistance in patients with COPD by applying new echocardiographic parameters. In conclusion, echocardiography should be used more frequently in assessing patients with COPD because it may aid in discovering previously unrecognized heart abnormalities and selecting the most appropriate treatment to improve the patient's symptoms, quality of life, and survival.

Characteristics of Postoperative Heart Failure in Older Hip Fractures Patients Combined with Coronary Heart Disease and Construction of a Prediction Model of Nomogram, a Retrospective Cohort Study

Introduction

Older patients combined with coronary heart disease (CHD) develop acute heart failure (AHF) after hip fracture surgery is common, and this study aimed to investigate the risk factors of postoperative AHF in older hip fracture patients and to construct a nomogram prediction model.

Methods

We retrospectively collected older hip fracture patients with CHD who underwent hip fracture surgery at the Third Hospital of Hebei Medical University from January 2017 to December 2021. We divided them into a training set and a validation set. We collected the demographic data, laboratory indicators and imaging examination results. We identified risk factors for postoperative AHF and used R language software to establish a nomogram prediction model, plot ROC curves, calibration curves and DCA decision curves.

Results

We retrospectively collected 1288 older hip fractures patients with CHD. After excluding 214 patients who did not meet the criteria, 1074 patients were included in our research and we divided them into the training set and the validation set. In the training set, a total of 346 (42.8%) patients developing postoperative AHF. Through univariate and multivariate logistic regression analysis, we identified the risk factors for postoperative AHF and constructed a nomogram prediction model. The AUC of the prediction model is 0.778. The correction curve shows that the model has good consistency. The decision curve analysis shows that the model has good clinical practicality.

Conclusion

There were 42.8% older patients combined with CHD develop postoperative AHF. Among them, fracture type, age, anemia at admission, combined with COPD, ASA ≥ 3, and preoperative waiting time >3 days are risk factors for postoperative AHF. We constructed a nomogram prediction model that can effectively predict the risk of postoperative AHF in older hip fracture patients combined with CHD.

Multidisciplinary Management of Patients With Chronic Obstructive Pulmonary Disease and Cardiovascular Disease

Chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD) frequently coexist, increasing the prevalence of both entities and impacting on symptoms and prognosis. CVD should be suspected in patients with COPD who have high/very high risk scores on validated scales, frequent exacerbations, precordial pain, disproportionate dyspnea, or palpitations. They should be referred to cardiology if they have palpitations of unknown cause or angina pain. COPD should be suspected in patients with CVD if they have recurrent bronchitis, cough and expectoration, or disproportionate dyspnea. They should be referred to a pulmonologist if they have rhonchi or wheezing, air trapping, emphysema, or signs of chronic bronchitis. Treatment of COPD in cardiovascular patients should include long-acting muscarinic receptor antagonists (LAMA) or long-acting beta-agonists (LABA) in low-risk or high-risk non-exacerbators, and LAMA/LABA/inhaled corticosteroids in exacerbators who are not controlled with bronchodilators. Cardioselective beta-blockers should be favored in patients with CVD, the long-term need for amiodarone should be assessed, and antiplatelet drugs should be maintained if indicated.

Haemodynamic compensations for exercise tissue oxygenation in early stages of COPD: an integrated cardiorespiratory assessment study

BACKGROUND

Cardiovascular comorbidities are increasingly being recognised in early stages of chronic obstructive pulmonary disease (COPD) yet complete cardiorespiratory functional assessments of individuals with mild COPD or presenting with COPD risk factors are lacking. This paper reports on the effectiveness of the cardiocirculatory-limb muscles oxygen delivery and utilisation axis in smokers exhibiting no, or mild to moderate degrees of airflow obstruction using standardised cardiopulmonary exercise testing (CPET).

METHODS

Post-bronchodilator spirometry was used to classify participants as 'ever smokers without' (n=88), with 'mild' (n=63) or 'mild-moderate' COPD (n=56). All underwent CPET with continuous concurrent monitoring of oxygen uptake (V'O2) and of bioimpedance cardiac output (Qc) enabling computation of arteriovenous differences (a-vO2). Mean values of Qc and a-vO2 were mapped across set ranges of V'O2 and Qc isolines to allow for meaningful group comparisons, at same metabolic and circulatory requirements.

RESULTS

Peak exercise capacity was significantly reduced in the 'mild-moderate COPD' as compared with the two other groups who showed similar pulmonary function and exercise capacity. Self-reported cardiovascular and skeletal muscle comorbidities were not different between groups, yet disease impact and exercise intolerance scores were three times higher in the 'mild-moderate COPD' compared with the other groups. Mapping of exercise Qc and a-vO2 also showed a leftward shift of values in this group, indicative of a deficit in peripheral O2 extraction even for submaximal exercise demands. Concurrent with lung hyperinflation, a distinctive blunting of exercise stroke volume expansion was also observed in this group.

CONCLUSION

Contrary to the traditional view that cardiovascular complications were the hallmark of advanced disease, this study of early COPD spectrum showed a reduced exercise O2 delivery and utilisation in individuals meeting spirometry criteria for stage II COPD. These findings reinforce the preventive clinical management approach to preserve peripheral muscle circulatory and oxidative capacities.

Association of systemic anticholinergic medication use and accelerated decrease in lung function in older adults

Older adults are frequently exposed to medicines with systemic anticholinergic properties, which are linked to increased risk of negative health outcomes. The association between systemic anticholinergics and lung function has not been reported. The aim of this study was to investigate if exposure to systemic anticholinergics influences lung function in older adults. Participants of the southernmost centres of the Swedish National study on Aging and Care (SNAC) were followed from 2001 to 2021. In total, 2936 subjects (2253 from Good Aging in Skåne and 683 from SNAC-B) were included. An extensive medical examination including spirometry assessments was performed during the study visits. The systemic anticholinergic burden was described using the anticholinergic cognitive burden scale. The effect of new use of systemic anticholinergics on the annual change in forced expiratory volume (FEV1s) was estimated using mixed models. During follow-up, 802 (27.3%) participants were exposed to at least one systemic anticholinergic medicine. On average, the FEV1s of participants without systemic anticholinergic exposure decreased 37.2 ml/year (95% CI [33.8; 40.6]) while participants with low and high exposure lose 47.2 ml/year (95% CI [42.4; 52.0]) and 43.7 ml/year (95% CI [25.4; 62.0]). A novel association between new use of medicines with systemic anticholinergic properties and accelerated decrease in lung function in older adults was found. The accelerated decrease is comparable to that observed in smokers. Studies are needed to further explore this potential side effect of systemic anticholinergics.

Prevalence of Cardiovascular Disease and Rate of Major Adverse Cardiovascular Events in Severe Alpha-1 Antitrypsin Deficiency COPD

Aim

Alpha-1 antitrypsin deficiency is an autosomal co-dominant condition that predisposes individuals to early-onset emphysema. As with COPD, AATD-COPD is associated with pulmonary exacerbations, which impacts on overall mortality and quality of life. Though there is evidence that COPD is associated with a higher prevalence of cardiovascular disease and major adverse cardiovascular events (MACE), it is unclear if this is true for patients with AATD-COPD.

Methods

Prevalence of cardiovascular disease was determined in two separate severe AATD cohorts: AlphaNet, USA and the Birmingham AATD registry, UK. All patients had preexisting lung disease. Cardiovascular disease was defined as presence of any of the following: heart failure, ischaemic heart disease, atrial fibrillation, stroke, and myocardial infarction. A Cox proportional hazards model was used to assess the impact of prior cardiovascular disease and frequent exacerbator phenotype on risk of future MACE.

Results

Out of 3493 patients with severe AATD, 14.7% had prior cardiovascular disease, including stroke (2.3%), myocardial infarction (2.2%), and heart failure (2.5%). Frequent exacerbators were more likely to have preexisting cardiovascular disease compared with those with one or no exacerbations in the preceding year (63% vs 44.8%, p = 0.001). There was increased risk of future MACE in frequent exacerbators (HR 1.85, 95% CI 1.24 to 2.75), former and current smokers (HR 1.80, 95% CI 1.07 to 3.02, p = 0.026, and HR 4.04, 95% CI 1.44 to 11.32, p = 0.008, respectively), and those with prior cardiovascular disease (HR 3.81, 95% CI 2.60 to 5.58, p < 0.001).

Conclusion

In severe AATD-COPD, MACE are associated with an increased exacerbation frequency, previous cardiovascular disease, and a history of smoking.

GLI-12 Reference Values versus Fixed 0.7 Ratio for the Detection of Airflow Obstruction in the Presence of Lung Hyperinflation

Introduction

Airflow obstruction (AO) is evidenced by reduced forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) with the threshold for diagnosis often being set at <0.7. However, currently the ATS/ERS standards for interpretation of lung function tests recommend the lower limit of normal (LLN), calculated by reference equations of the Global Lung Initiative from 2012 (GLI-12), as a threshold for AO diagnosis. The present study aims to investigate phenotypes, with focus on hyperinflation, which influence AO prevalence defined by FEV1/FVC < LLN when compared to the fixed 0.7 threshold.

Methods

Data from 3,875 lung function tests (56.4% men, aged 18-95) including 3,824 body plethysmography recordings performed from July 2021 to June 2022 were analysed. The difference between both classifiers was quantified, before and after stratification by sex, age, and hyperinflation.

Results

AO diagnosis was significantly less frequent with the LLN threshold (18.2%) compared to the fixed threshold (28.0%) (p < 0.001) with discordance rate of 10.5%. In the presence of mild or moderate hyperinflation, there was substantial agreement (Cohen's kappa: 0.616, 0.718) between the classifiers compared to near perfect agreement in the presence of severe hyperinflation (Cohen's kappa: 0.896). In addition, subgroup analysis after stratification for sex, age, and hyperinflation showed significant differences between both classifiers.

Conclusion

The importance of using the LLN threshold instead of the fixed 0.7 threshold for the diagnosis of AO is highlighted. When using the fixed threshold AO, misdiagnosis was more common in the presence of mild to moderate hyperinflation.

Associating the Severity of Emphysema with Coronary Flow Reserve and Left Atrial Conduit Function for the Emphysema Patients with Known or Suspected Coronary Artery Disease

PURPOSE

Pulmonary emphysema may associate with ischemic heart disease through systemic microvascular abnormality as a common pathway. Stress cardiovascular MR (CMR) allows for the assessment of global coronary flow reserve (CFR). The purpose of this study was to evaluate the association between the emphysema severity and the multiple MRI parameters in the emphysema patients with known or suspected coronary artery disease (CAD).

METHODS

A total of 210 patients with known or suspected CAD who underwent both 3.0T CMR including cine CMR, stress and rest perfusion CMR, stress and rest phase-contrast (PC) cine CMR of coronary sinus, and late gadolinium enhancement (LGE) CMR, and lung CT within 6 months were studied. Global CFR, volumes and functions of both ventricles and atria, and presence or absence of myocardial ischemia and infarction were evaluated. Emphysema severity was visually determined on lung CT by Goddard method.

RESULT

Seventy nine (71.0 ± 7.9 years, 75 male) of 210 patients with known or suspected CAD had emphysema on lung CT. Goddard score was significantly correlated with CFR (r = -0.246, P = 0.029), left ventricular end-diastolic volume index (LV EDVI) (r = -0.230, P = 0.041), right ventricular systolic volume index (RV SVI) (r = -0.280, P = 0.012), left atrial (LA) total emptying volume index (r = -0.269, P = 0.017), LA passive emptying volume index (r = -0.309, P = 0.006), LA systolic strain (Es) (r = -0.244, P = 0.030), and LA conduit strain (Ee) (r = -0.285, P = 0.011) in the patients with emphysema. Multiple linear regression analysis revealed LA conduit function was independently associated with emphysema severity as determined by Goddard method (beta = -0.361, P = 0.006).

CONCLUSION

LA conduit function independently associates with emphysema severity in the emphysema patients with known or suspected CAD after adjusting age, sex, smoking, and the CMR indexes including CFR. These findings suggest that impairment of LA function predominantly occurs prior to the reduction of the CFR in the emphysema patients with known or suspected CAD.

By deflating the lungs pulmonologists help the cardiologists. A literature review

In this review, we present the effects of lung hyperinflation on the cardiovascular system (CVS) and the beneficial outcomes of different deflation treatment modalities. We discuss the effects of long-acting bronchodilator drugs, medical and surgical lung volume reduction on the performance of the CVS. Although there is a small number of studies investigating lung deflation and the CVS, the short-term improvement in heart function was clearly demonstrated. However, more studies, with longer duration, are needed to verify these significant beneficial effects of deflation of the lungs on the CVS. Dynamic hyperinflation during exercise could be a research model to investigate further the effects of lung hyperinflation and/or deflation on the CVS.

Association Between Pulmonary Vascular Volume and Cardiac Structure and Function in Patients With Atrial Fibrillation

Pulmonary vascular abnormalities, quantified from computed tomography scans, have frequently been observed in patients with pulmonary diseases. However, little is known about pulmonary vascular changes in patients with cardiac disease. Thus, we aimed to examine the cardiopulmonary relation in patients with atrial fibrillation (AF) by comparing pulmonary vascular volume (PVV) to echocardiographic measures and AF severity. A total of 742 patients (median age 63 years, 70% men) who underwent ablation for AF were included. Preprocedural cardiac computed tomography was used to measure the total and small-vessel PVV, along with the pulmonary artery to aorta ratio and the degree of emphysema. The association between PVV and echocardiographic parameters was evaluated using a multivariable linear regression analysis. Lower total and small-vessel PVV were associated with more impaired measures of cardiac structure and function, including but not limited to left ventricular ejection fraction and peak atrial longitudinal strain. Patients with reduced total and small-vessel PVV had higher odds of having persistent AF than paroxysmal AF in the unadjusted logistic regression analyses. However, after clinical and echocardiographic adjustments, only reduced small-vessel PVV remained independently associated with persistent AF (odds ratio 1.90, 95% confidence interval 1.26 to 2.87, p = 0.002). In conclusion, pulmonary vascular remodeling is associated with persistent AF and with more impaired measures of cardiac structure and function, providing further insights into heart-lung interactions in this patient group.

Assessing the relationship between cardiovascular and small airway disease and acute events in COPD: The ARCADIA study protocol

The initial alterations of chronic obstructive pulmonary disease (COPD) involve the small airways. Small airway disease (SAD) is related to lung hyperinflation and air trapping. Several lung function tests may detect the presence of SAD, namely forced mid-expiratory flows, residual volume (RV), RV/total lung capacity (TLC) ratio, functional residual capacity, airway resistances obtained with body-plethysmography and oscillometry, and the single-breath nitrogen washout test. Additionally, high-resolution computed tomography can detect SAD. In addition to SAD, COPD is related to cardiovascular disease (CVD) such as heart failure, peripheral vascular disease, and ischemic heart disease. No studies have assessed the relationship between CVD, COPD, and SAD. Therefore, the main objective of the Assessing the Relationship between Cardiovascular and small Airway Disease and Acute events in COPD (ARCADIA) study is to assess the risk of CVD in COPD patients according to SAD in a real-life setting. The correlation between CVD, mortality, and acute exacerbation of COPD (AECOPD) is also evaluated. ARCADIA is a 52-week prospective, multicentre, pilot, observational, cohort study conducted in ≥22 pulmonary centres in Italy and that enrols ≥500 COPD patients, regardless of disease severity (protocol registration: ISRCTN49392136). SAD is evaluated at baseline, after that CVD, mortality, and AECOPD are recorded at 6 and 12 months. Bayesian inference is used to quantify the risk and correlation of the investigated outcomes in COPD patients according to SAD. The ARCADIA study provides relevant findings in the daily clinical management of COPD patients.

Jörres R, Behr J, Welte T. The Diagnosis and Treatment of COPD and Its Comorbidities

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is the third most common cause of death around the world. The affected patients suffer not only from impaired lung function, but also from a wide variety of comorbidities. Their cardiac comorbidities, in particular, lead to increased mortality.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, including guidelines from Germany and abroad.

RESULTS

The usual diagnostic criteria for COPD are a post-bronchodilator FEV1/FVC quotient below the fixed threshold of 0.7, or, preferably, below the lower limit of normal (LLN) according to the GLI reference values for the avoidance of over- and underdiagnosis. The overall prognosis is markedly affected by comorbidities of the lung itself and those that involve other organs; in particular, many persons with COPD die of heart disease. The potential presence of heart disease must be borne in mind in the evaluation of patients with COPD, as lung disease can impair the detection of heart disease.

CONCLUSION

As patients with COPD are often multimorbid, the early diagnosis and adequate treatment not only of their lung disease, but also of their extrapulmonary comorbidities are very important. Well-established diagnostic instruments and well-tested treatments are available and are described in detail in the guidelines concerning the comorbidities. Preliminary observations suggest that more attention should be paid to the potential positive effects of treating comorbidities on the lung disease itself, and vice versa.

MUC5B, telomere length and longitudinal quantitative interstitial lung changes: the MESA Lung Study

BACKGROUND

The MUC5B promoter variant (rs35705950) and telomere length are linked to pulmonary fibrosis and CT-based qualitative assessments of interstitial abnormalities, but their associations with longitudinal quantitative changes of the lung interstitium among community-dwelling adults are unknown.

METHODS

We used data from participants in the Multi-Ethnic Study of Atherosclerosis with high-attenuation areas (HAAs, Examinations 1-6 (2000-2018)) and MUC5B genotype (n=4552) and telomere length (n=4488) assessments. HAA was defined as the per cent of imaged lung with attenuation of -600 to -250 Hounsfield units. We used linear mixed-effects models to examine associations of MUC5B risk allele (T) and telomere length with longitudinal changes in HAAs. Joint models were used to examine associations of longitudinal changes in HAAs with death and interstitial lung disease (ILD).

RESULTS

The MUC5B risk allele (T) was associated with an absolute change in HAAs of 2.60% (95% CI 0.36% to 4.86%) per 10 years overall. This association was stronger among those with a telomere length below an age-adjusted percentile of 5% (p value for interaction=0.008). A 1% increase in HAAs per year was associated with 7% increase in mortality risk (rate ratio (RR)=1.07, 95% CI 1.02 to 1.12) for overall death and 34% increase in ILD (RR=1.34, 95% CI 1.20 to 1.50). Longer baseline telomere length was cross-sectionally associated with less HAAs from baseline scans, but not with longitudinal changes in HAAs.

CONCLUSIONS

Longitudinal increases in HAAs were associated with the MUC5B risk allele and a higher risk of death and ILD.

Obstructive Sleep Apnea and Longitudinal Changes in Interstitial Lung Imaging and Lung Function: The MESA Study

Rationale: Obstructive sleep apnea (OSA) has been hypothesized to be a risk factor in interstitial lung disease (ILD) and is associated with radiological markers that may represent the earlier stages of ILD. Prior studies have been limited by their cross-sectional design and potential confounding by body habitus. Objectives: To test the hypothesis that OSA severity is associated with more high-attenuation areas (HAAs) on computed tomography and worse lung function over time among older community-dwelling adults. Methods: We used data from participants in the MESA (Multi-Ethnic Study of Atherosclerosis) who had apnea-hypopnea index (AHI) measured from polysomnography (2010-2013), high attenuation areas (HAAs, -600 to -250 Hounsfield units, n = 784), assessments from exams 5 (2010-2012) and 6 (2016-2018) full-lung computed tomography scans, and spirometry assessments (n = 677). Linear mixed-effects models with random intercept were used to examine associations of OSA severity (i.e., AHI and hypoxic burden) with changes in HAAs, total lung volumes, and forced vital capacity (FVC) between exams 5 and 6. Potential confounders were adjusted for in the model, including age, sex, smoking history, height, and weight. Results: Among those with a higher AHI there were more men and a higher body mass index. Participants with AHI ⩾ 15 events/h and in the highest hypoxic burden quartile each had increases in HAAs of 11.30% (95% confidence interval [CI], 3.74-19.35%) and 9.85% (95% CI, 1.40-19.01%) per 10 years, respectively. There was a more rapid decline in total lung volumes imaged and FVC among those with AHI ⩾ 15 events/h of 220.2 ml (95% CI, 47.8-392.5 ml) and 3.63% (95% CI, 0.43-6.83%) per 10 years, respectively. Conclusions: A greater burden of hypoxia related to obstructive events during sleep was associated with increased lung densities over time and a more rapid decline in lung volumes regardless of body habitus. Our findings suggest OSA may be a contributing factor in the early stages of ILD.

Impaired pulmonary function and associated factors in the elderly with tuberculosis on admission: a preliminary report

BACKGROUND

Pulmonary tuberculosis (TB) can impair pulmonary function (PF), especially in the elderly. The risk factors associated with the severity of PF impairment in the elderly with pulmonary TB remain unclear. Hence, this retrospective study aimed to address this issue to help improve the management of TB in the elderly population.

METHODS

From January 2019 to February 2022, the elderly who were admitted to our hospital for pulmonary TB and underwent PF testing were included in this analysis. The forced expiratory volume in one second percent of predicted (FEV1% predicted) and clinical characteristics were collected and analyzed retrospectively. The extent of impaired PF was then categorized based on the FEV1% predicted and classified as grade 1-5. Logistic regression analysis was used to analyze the risk factors for impaired PF.

RESULTS

A total of 249 patients who met the enrollment criteria were included in this analysis. According to the results of FEV1% predicted, all patients were classified as grade 1 (n = 37), grade 2 (n = 46), grade 3 (n = 55), grade 4 (n = 56), or grade 5 (n = 55). Statistical analysis showed that albumin (adjusted odds ratio (aOR) = 0.928, P = 0.013), body mass index (BMI) < 18.5 kg/m² (aOR = 4.968, P = 0.046), lesion number ≥ 3 (aOR = 4.229, P < 0.001), male (aOR = 2.252, P = 0.009), respiratory disease (aOR = 1.669, P = 0.046), and cardiovascular disease (aOR = 2.489, P = 0.027) were related to the impairment of PF.

CONCLUSIONS

PF impairment is common in the elderly with pulmonary TB. The male sex, BMI < 18.5 kg/m², lesion number ≥ 3, hypoproteinemia, and respiratory and cardiovascular comorbidities were identified as risk factors for significant PF impairment. Our findings highlight the risk factors associated with PF impairment, which may be helpful to improve the current management of pulmonary TB in the elderly to save their lung function.

Sex-specific and age-specific incidence of ischaemic heart disease, atrial fibrillation and heart failure in community patients with chronic obstructive pulmonary disease

OBJECTIVE

To estimate the incidence of ischaemic heart disease, atrial fibrillation and heart failure in community patients with or without chronic obstructive pulmonary disease (COPD).

METHODS

For this population-based study, we used primary care data of the Julius General Practitioners' Network. Eligible participants were aged 40-80 years old and contributed data between January 2014 and February 2019. Participants were divided into groups according to COPD status and were followed up for new ischaemic heart disease, atrial fibrillation and/or heart failure. Age-specific and sex-specific incidence and incidence rate ratios were calculated for patients with and without COPD.

RESULTS

Mean follow-up was 3.9 years, 6223 patients were included in the COPD group, and 137 028 individuals in the background group without COPD. Incidence rates of all three heart diseases increased with age and were higher in males, independent of presence of COPD. Incidence rate ratios for patients with COPD, adjusted for age and sex, were 1.69 (95% CI 1.49 to 1.92) for ischaemic heart disease, 1.56 (95% CI 1.38 to 1.77) for atrial fibrillation and 2.96 (95% CI 2.58 to 3.40) for heart failure.

CONCLUSION

The incidence of all major cardiovascular diseases is higher in patients with COPD, with the highest incidence rate ratio observed for heart failure.

Heart Failure With Preserved Ejection Fraction as an Exercise Deficiency Syndrome: JACC Focus Seminar 2/4

Across differing spectrums of cardiac function and cardiac pathologies, there are strong associations between measures of cardiorespiratory fitness and burden of symptoms, quality of life, and prognosis. In this part 2 of a 4-part series, we contend that there is a strong association among physical activity, cardiorespiratory fitness, and cardiac function. We argue that a chronic lack of exercise is a major risk factor for heart failure with preserved ejection fraction in some patients. In support of this hypothesis, increasing physical activity is associated with greater cardiac mass, greater stroke volumes, greater cardiac output and peak oxygen consumption, and fewer clinical events. Conversely, physical inactivity results in cardiac atrophy, reduced output, reduced chamber size, and decreased ability to augment cardiac performance with exercise. Moreover, physical inactivity is a strong predictor of heart failure risk and death. In sum, exercise deficiency should be considered part of the broad heart failure with preserved ejection fraction phenotype.

Factors affecting length of hospital stay in chronic obstructive pulmonary disease patients in a tertiary hospital of Nepal: A retrospective cross-sectional study

Background

Despite the increasing burden of chronic obstructive pulmonary disease in Nepal, studies analyzing the factors associated with inpatient length of hospital stay are lacking.

Methods

This is a retrospective, cross-sectional hospital-based study conducted between July 2020 and July 2021 on patients admitted to the inpatient ward of Pulmonary and Critical Care Medicine of Tribhuvan University Teaching Hospital with a primary diagnosis of acute exacerbation of chronic obstructive pulmonary disease. The sample size of our study was 90. Clinical and demographic factors, blood investigation parameters, and treatment received were analyzed via univariate and multivariate analysis to find the factors associated with length of stay.

Results

The mean age of chronic obstructive pulmonary disease patients was 68.84 ± 10.22 years, with 42.2% of males and 43.3% of current smokers. The length of hospital stay ranged from 2 to 25 days, with an average stay of 6.69 ± 4.02 days. Factors associated with length of stay are the number of comorbidities (p = 0.007), blood eosinophils at admission (p = 0.022), and use of mechanical ventilatory support (p < 0.001).

Conclusions

Proper management of comorbidities and eosinophilic exacerbations as well as careful use of mechanical ventilatory support are required to further reduce the duration of hospital stay in chronic obstructive pulmonary disease patients.

Association of Pulmonary Function With Late-Life Cardiac Function and Heart Failure Risk: The ARIC Study

Background Pulmonary and cardiac functions decline with age, but the associations of pulmonary dysfunction with cardiac function and heart failure (HF) risk in late life is not known. We aimed to determine the associations of percent predicted forced vital capacity (ppFVC) and the ratio of forced expired volume in 1 second (FEV₁) to forced vital capacity (FVC; FEV₁/FVC) with cardiac function and incident HF with preserved or reduced ejection fraction in late life. Methods and Results Among 3854 HF-free participants in the ARIC (Atherosclerosis Risk in Communities) cohort study who underwent echocardiography and spirometry at the fifth study visit (2011-2013), associations of FEV₁/FVC and ppFVC with echocardiographic measures, cardiac biomarkers, and risk of HF, HF with preserved ejection fraction, and HF with reduced ejection fraction were assessed. Multivariable linear and Cox regression models adjusted for demographics, body mass index, coronary disease, atrial fibrillation, hypertension, and diabetes. Mean age was 75±5 years, 40% were men, 19% were Black, and 61% were ever smokers. Mean FEV₁/FVC was 72±8%, and ppFVC was 98±17%. In adjusted analyses, lower FEV₁/FVC and ppFVC were associated with higher NT-proBNP (N-terminal pro-B-type natriuretic peptide; both P<0.001) and pulmonary artery pressure (P<0.004). Lower ppFVC was also associated with higher left ventricular mass, left ventricular filling pressure, and high-sensitivity C-reactive protein (all P<0.01). Lower FEV₁/FVC was associated with a trend toward higher risk of incident HF with preserved ejection fraction (hazard ratio [HR] per 10-point decrease, 1.31; 95% CI, 0.98-1.74; P=0.07) and HF with reduced ejection fraction (HR per 10-point decrease, 1.24; 95% CI, 0.91-1.70; P=0.18), but these associations did not reach statistical significance. Lower ppFVC was associated with incident HF with preserved ejection fraction (HR per 10-unit decrease, 1.21; 95% CI, 1.04-1.41; P=0.013) but not with HF with reduced ejection fraction (HR per 10-unit decrease, 0.90; 95% CI, 0.76-1.07; P=0.24). Conclusions Subclinical reductions in FEV₁/FVC and ppFVC differentially associate with cardiac function and HF risk in late life.

Lung function impairment and risk of incident heart failure: the NHLBI Pooled Cohorts Study

AIMS

The aim is to evaluate associations of lung function impairment with risk of incident heart failure (HF).

METHODS AND RESULTS

Data were pooled across eight US population-based cohorts that enrolled participants from 1987 to 2004. Participants with self-reported baseline cardiovascular disease were excluded. Spirometry was used to define obstructive [forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) <0.70] or restrictive (FEV1/FVC ≥0.70, FVC <80%) lung physiology. The incident HF was defined as hospitalization or death caused by HF. In a sub-set, HF events were sub-classified as HF with reduced ejection fraction (HFrEF; EF <50%) or preserved EF (HFpEF; EF ≥50%). The Fine-Gray proportional sub-distribution hazards models were adjusted for sociodemographic factors, smoking, and cardiovascular risk factors. In models of incident HF sub-types, HFrEF, HFpEF, and non-HF mortality were treated as competing risks. Among 31 677 adults, there were 3344 incident HF events over a median follow-up of 21.0 years. Of 2066 classifiable HF events, 1030 were classified as HFrEF and 1036 as HFpEF. Obstructive [adjusted hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.07-1.27] and restrictive physiology (adjusted HR 1.43, 95% CI 1.27-1.62) were associated with incident HF. Obstructive and restrictive ventilatory defects were associated with HFpEF but not HFrEF. The magnitude of the association between restrictive physiology and HFpEF was similar to associations with hypertension, diabetes, and smoking.

CONCLUSION

Lung function impairment was associated with increased risk of incident HF, and particularly incident HFpEF, independent of and to a similar extent as major known cardiovascular risk factors.

Chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity, mortality, and health-care use worldwide. COPD is caused by exposure to inhaled noxious particles, notably tobacco smoke and pollutants. However, the broad range of factors that increase the risk of development and progression of COPD throughout the life course are increasingly being recognised. Innovations in omics and imaging techniques have provided greater insight into disease pathobiology, which might result in advances in COPD prevention, diagnosis, and treatment. Although few novel treatments have been approved for COPD in the past 5 years, advances have been made in targeting existing therapies to specific subpopulations using new biomarker-based strategies. Additionally, COVID-19 has undeniably affected individuals with COPD, who are not only at higher risk for severe disease manifestations than healthy individuals but also negatively affected by interruptions in health-care delivery and social isolation. This Seminar reviews COPD with an emphasis on recent advances in epidemiology, pathophysiology, imaging, diagnosis, and treatment.

Allergic asthma aggravates angiotensin Ⅱ-induced cardiac remodeling in mice

Cardiovascular disease remains the leading cause of death globally, and heart failure (HF) represents its terminal stage. Asthma, one of the most common chronic diseases, has been reported to be associated with an increased risk of cardiovascular disease. However, the link between asthma and HF has rarely been studied, and the possible mechanisms by which asthma affects HF are unclear. This study aimed to explore the influence of asthma on HF and the possible mechanisms. We analyzed data from the National Health and Nutrition Examination Survey and found a higher prevalence of HF among asthmatic individuals, and identified an independent association between HF and asthma. Subsequently, we produced mice with concurrent ovalbumin (OVA) sensitization-induced allergic asthma and angiotensin Ⅱ infusion-induced cardiac remodeling to explore the effect of asthma on cardiac remodeling in vivo. The results showed that OVA-induced asthma impaired heart function and aggravated cardiac remodeling in mice. We also found that OVA sensitization increased the expression levels of immunoglobulin E (IgE) in serum and IgE receptor (FcεR1) in the heart, and enhanced the activation of downstream signaling molecules of IgE-FcεR1 in the heart. Importantly, blockage of IgE-FcεR1 using FcεR1-deficient mice or an anti-IgE antibody prevented asthma-induced decline of cardiac function, and alleviated cardiac remodeling. These findings demonstrate the adverse effects of allergic asthma on the heart, and suggest the potential application of anti-IgE therapy in the treatment of asthma complicated with heart conditions.

Computational lung modelling in respiratory medicine

Computational modelling of the lungs is an active field of study that integrates computational advances with lung biophysics, biomechanics, physiology and medical imaging to promote individualized diagnosis, prognosis and therapy evaluation in lung diseases. The complex and hierarchical architecture of the lung offers a rich, but also challenging, research area demanding a cross-scale understanding of lung mechanics and advanced computational tools to effectively model lung biomechanics in both health and disease. Various approaches have been proposed to study different aspects of respiration, ranging from compartmental to discrete micromechanical and continuum representations of the lungs. This article reviews several developments in computational lung modelling and how they are integrated with preclinical and clinical data. We begin with a description of lung anatomy and how different tissue components across multiple length scales affect lung mechanics at the organ level. We then review common physiological and imaging data acquisition methods used to inform modelling efforts. Building on these reviews, we next present a selection of model-based paradigms that integrate data acquisitions with modelling to understand, simulate and predict lung dynamics in health and disease. Finally, we highlight possible future directions where computational modelling can improve our understanding of the structure-function relationship in the lung.

Reduction of Lung Hyperinflation Improves Cardiac Preload, Contractility, and Output in Emphysema: A Prospective Cardiac Magnetic Resonance Study in Patients Who Received Endobronchial Valves

RATIONALE

Pulmonary hyperinflation in patients with Chronic Obstructive Pulmonary Disease (COPD) has been related to smaller cardiac chamber sizes and impaired cardiac function. Nowadays, bronchoscopic lung volume reduction (BLVR) with endobronchial valves is a treatment option to reduce pulmonary hyperinflation in patients with severe emphysema.

OBJECTIVES

We hypothesized that reduction of hyperinflation would improve cardiac preload in this patient group. In addition, we investigated whether the treatment would result in elevated pulmonary artery pressures due to pulmonary vascular bed reduction.

METHODS

We included patients with emphysema and severe hyperinflation (defined by a baseline residual volume >175% of predicted) who were eligible for BLVR with endobronchial valves. Cardiac magnetic resonance imaging was obtained one day prior to treatment and at eight week follow-up. Primary endpoint was cardiac preload, as measured by the right ventricle end-diastolic volume index (RVEDVI). As secondary endpoints, we measured indexed end-diastolic and end-systolic volumes of the right ventricle, left atrium, and left ventricle, pulmonary artery pressures, cardiac output, ejection fraction, and strain.

MEASUREMENTS AND MAIN RESULTS

Twenty-four patients were included. At eight week follow-up, RVEDVI was significantly improved (+7.9 ml/m2, SD 10.0, p=0.001). In addition to increased stroke volumes, we found significantly higher ejection fractions and strain measurements. Although cardiac output was significantly increased (+0.9L/min, SD 1.5, p=0.007), there were no changes in pulmonary artery pressures.

CONCLUSIONS

We found that reduction of hyperinflation using BLVR with endobronchial valves significantly improved cardiac preload, myocardial contractility, and cardiac output, without changes in pulmonary artery pressures. Clinical trial registered with ClinicalTrials.gov (NCT03474471).

An Up-to-Date Article Regarding Particularities of Drug Treatment in Patients with Chronic Heart Failure

Since the prevalence of heart failure (HF) increases with age, HF is now one of the most common reasons for the hospitalization of elderly people. Although the treatment strategies and overall outcomes of HF patients have improved over time, hospitalization and mortality rates remain elevated, especially in developed countries where populations are aging. Therefore, this paper is intended to be a valuable multidisciplinary source of information for both doctors (cardiologists and general physicians) and pharmacists in order to decrease the morbidity and mortality of heart failure patients. We address several aspects regarding pharmacological treatment (including new approaches in HF treatment strategies [sacubitril/valsartan combination and sodium glucose co-transporter-2 inhibitors]), as well as the particularities of patients (age-induced changes and sex differences) and treatment (pharmacokinetic and pharmacodynamic changes in drugs; cardiorenal syndrome). The article also highlights several drugs and food supplements that may worsen the prognosis of HF patients and discusses some potential drug-drug interactions, their consequences and recommendations for health care providers, as well as the risks of adverse drug reactions and treatment discontinuation, as an interdisciplinary approach to treatment is essential for HF patients.

Origins of and lessons from quantitative functional X-ray computed tomography of the lung

Functional CT of the lung has emerged from quantitative CT (qCT). Structural details extracted at multiple lung volumes offer indices of function. Additionally, single volumetric images, if acquired at standardized lung volumes and body posture, can be used to model function by employing such engineering techniques as computational fluid dynamics. With the emergence of multispectral CT imaging including dual energy from energy integrating CT scanners and multienergy binning using the newly released photon counting CT technology, function is tagged via use of contrast agents. Lung disease phenotypes have previously been lumped together by the limitations of spirometry and plethysmography. QCT and its functional embodiment have been imbedded into studies seeking to characterize chronic obstructive pulmonary disease, severe asthma, interstitial lung disease and more. Reductions in radiation dose by an order of magnitude or more have been achieved. At the same time, we have seen significant increases in spatial and density resolution along with methodologic validations of extracted metrics. Together, these have allowed attention to turn towards more mild forms of disease and younger populations. In early applications, clinical CT offered anatomic details of the lung. Functional CT offers regional measures of lung mechanics, the assessment of functional small airways disease, as well as regional ventilation-perfusion matching (V/Q) and more. This paper will focus on the use of quantitative/functional CT for the non-invasive exploration of dynamic three-dimensional functioning of the breathing lung and beating heart within the unique negative pressure intrathoracic environment of the closed chest.

Associations of sleep duration and sleep-wake rhythm with lung parenchymal abnormalities on computed tomography: The MESA study

Impairment of the circadian rhythm promotes lung inflammation and fibrosis in pre-clinical models. We aimed to examine whether short and/or long sleep duration and other markers of sleep-wake patterns are associated with a greater burden of lung parenchymal abnormalities on computed tomography among adults. We cross-sectionally examined associations of sleep duration captured by actigraphy with interstitial lung abnormalities (n = 1111) and high attenuation areas (n = 1416) on computed tomography scan in the Multi-Ethnic Study of Atherosclerosis at Exam 5 (2010-2013). We adjusted for potential confounders in logistic and linear regression models for interstitial lung abnormalities and high attenuation area, respectively. High attenuation area models were also adjusted for study site, lung volume imaged, radiation dose and stratified by body mass index. Secondary exposures were self-reported sleep duration, sleep fragmentation index, sleep midpoint and chronotype. The mean age of those with longer sleep duration (≥ 8 hr) was 70 years and the prevalence of interstitial lung abnormalities was 14%. Increasing actigraphy-based sleep duration among participants with ≥ 8 hr of sleep was associated with a higher adjusted odds of interstitial lung abnormalities (odds ratio of 2.66 per 1-hr increment, 95% confidence interval 1.42-4.99). Longer sleep duration and higher sleep fragmentation index were associated with greater high attenuation area on computed tomography among participants with a body mass index < 25 kg m-2 (p-value for interaction < 0.02). Self-reported sleep duration, later sleep midpoint and evening chronotype were not associated with outcomes. Actigraphy-based longer sleep duration and sleep fragmentation were associated with a greater burden of lung abnormalities on computed tomography scan.

Associations of Monocyte Count and Other Immune Cell Types with Interstitial Lung Abnormalities

Rationale: Higher blood monocyte counts are associated with worse survival in adults with clinically diagnosed pulmonary fibrosis. Their association with the development and progression of interstitial lung abnormalities (ILA) in humans is unknown. Objectives: We evaluated the associations of blood monocyte count, and other immune cell types, with ILA, high-attenuation areas, and FVC in four independent cohorts. Methods: We included participants with measured monocyte counts and computed tomographic (CT) imaging enrolled in MESA (Multi-Ethnic Study of Atherosclerosis, n = 484), AGES-Reykjavik (Age/Gene Environment Susceptibility Study, n = 3,547), COPDGene (Genetic Epidemiology of COPD, n = 2,719), and the ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points, n = 646). Measurements and Main Results: After adjustment for covariates, a 1-SD increment in blood monocyte count was associated with ILA in MESA (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.0-1.8), AGES-Reykjavik (OR, 1.2; 95% CI, 1.1-1.3), COPDGene (OR, 1.3; 95% CI, 1.2-1.4), and ECLIPSE (OR, 1.2; 95% CI, 1.0-1.4). A higher monocyte count was associated with ILA progression over 5 years in AGES-Reykjavik (OR, 1.2; 95% CI, 1.0-1.3). Compared with participants without ILA, there was a higher percentage of activated monocytes among those with ILA in MESA. Higher monocyte count was associated with greater high-attenuation areas in MESA and lower FVC in MESA and COPDGene. Associations of other immune cell types were less consistent. Conclusions: Higher blood monocyte counts were associated with the presence and progression of interstitial lung abnormalities and lower FVC.

Empagliflozin in patients with type 2 diabetes mellitus and chronic obstructive pulmonary disease

AIMS

Type 2 diabetes mellitus (T2DM) and chronic obstructive pulmonary disease (COPD) often co-exist, yielding increased risk of cardiovascular (CV) complications including heart failure (HF). We assessed risk of cardiorenal outcomes, mortality and safety in patients with versus without COPD in the EMPA-REG OUTCOME trial.

METHODS

Patients (n = 7,020) with T2DM and CV disease (CVD) were treated with empagliflozin (10 mg or 25 mg) or placebo. Cox regression was used to assess COPD subgroup (placebo only) associations with, and treatment effects of empagliflozin versus placebo on first hospitalization for HF (HHF), CV death, all-cause mortality, incident/worsening nephropathy, and all-cause hospitalization.

RESULTS

At baseline, patients with COPD (n = 707) had more HF and used insulin more frequently than those without COPD. During follow-up in the placebo group, those with baseline COPD had increased risk of HHF (HR 2.15 [95% CI 1.32, 3.49]), HHF/CV death (1.60 [1.10, 2.33]), incident/worsening nephropathy (1.68 [1.26, 2.24]), all-cause hospitalization (1.44 [1.19, 1.74]) and all-cause death (1.60 [1.09, 2.35]) compared to those without COPD. Empagliflozin consistently reduced all clinical outcomes, irrespective of COPD status (interaction p-values 0.14 to 0.96), with a confirmed safety profile.

CONCLUSIONS

In patients with T2DM and CVD, COPD increased the risk of mortality and cardiorenal outcomes, including HF. Empagliflozin consistently reduced these outcomes versus placebo regardless of COPD, suggesting that empagliflozin's benefits in patients with T2DM and CVD are not mitigated by the presence of COPD.

Impaired Ventilatory Efficiency, Dyspnea and Exercise Intolerance in Chronic Obstructive Pulmonary Disease: Results from the CanCOLD Study

RATIONALE

Impaired exercise ventilatory efficiency (high ventilatory requirements for CO2 [V̇E/V̇CO2]) provides an indication of pulmonary gas exchange abnormalities in chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To determine: 1) the association between high V̇E/V̇CO2 and clinical outcomes (dyspnea and exercise capacity) and its relationship to lung function and structural radiographic abnormalities; and 2) its prevalence in a large population-based cohort.

METHODS

Participants were recruited randomly from the population and underwent clinical evaluation, pulmonary function, cardiopulmonary exercise testing and chest computed tomography (CT). Impaired exercise ventilatory efficiency was defined by a nadir V̇E/V̇CO2 above the upper limit of normal (V̇E/V̇CO2>ULN), using population-based normative values.

MEASUREMENTS AND MAIN RESULTS

Participants included 445 never-smokers, 381 ever-smokers without airflow obstruction, 224 with GOLD 1 COPD, and 200 with GOLD 2-4 COPD. Participants with V̇E/V̇CO2>ULN were more likely to have activity-related dyspnea (Medical Research Council dyspnea scale≥2, odds ratio=1.77[1.31-2.39]) and abnormally low peak oxygen uptake (V̇O2peak<LLN, odds ratio=4.58[3.06-6.86]). The carbon monoxide transfer coefficient (KCO) had a stronger correlation with nadir V̇E/V̇CO2 (r=-0.38, p<0.001) than other relevant lung function and CT metrics. The prevalence of V̇E/V̇CO2>ULN was 24% in COPD (similar in GOLD 1 and 2-4), which was greater than in never-smokers (13%) and ever-smokers (12%).

CONCLUSIONS

V̇E/V̇CO2>ULN was associated with greater dyspnea and low VO2peak and was present in 24% of all participants with COPD, regardless of GOLD stage. The results show the importance of recognizing impaired exercise ventilatory efficiency as a potential contributor to dyspnea and exercise limitation, even in mild COPD.

Dynamic Quantitative Magnetic Resonance Imaging Assessment of Areas of the Lung During Free-Breathing of Patients with Chronic Obstructive Pulmonary Disease

RATIONALE AND OBJECTIVES

Changes in the geometry of the chest wall due to lung hyperinflation occur in COPD. However, the quantitative assessment of impaired lung motions and its association with the clinical characteristics of COPD patients are unclear. This study aimed to investigate the respiratory kinetics of COPD patients by dynamic MRI.

MATERIALS AND METHODS

This study enrolled 22 COPD patients and 10 normal participants who underwent dynamic MRI and pulmonary function testing (PFT). Changes in the areas of the lung and mediastinum during respiration were compared between the COPD patients and the normal controls. Relationships between MRI, CT parameters, and clinical measures that included PFT results also were evaluated.

RESULTS

Asynchronous movements and decreased diaphragmatic motion were found in COPD patients. COPD patients had a larger ratio of MRI-measured lung areas at expiration to inspiration, a smaller magnitude of the peak area change ratio, and a smaller mediastinal-thoracic area ratio than the normal participants. The lung area ratio was associated with FEV₁/FVC, predicted RV%, and CT lung volume/predicted total lung capacity (pTLC). The lung area ratio of the right lower and left lower lungs was significantly correlated with emphysema of each lower lobe. The expiratory mediastinal-thoracic area ratio was associated with FEV₁% predicted and RV/TLC.

CONCLUSION

Changes in the lung areas of COPD patients as shown on MRI reflected the severity of airflow limitation, hyperinflation, and the extent of emphysema. Dynamic MRI provides essential information about respiratory kinetics in COPD.

Characterization of the COPD alveolar niche using single-cell RNA sequencing

Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide, however our understanding of cell specific mechanisms underlying COPD pathobiology remains incomplete. Here, we analyze single-cell RNA sequencing profiles of explanted lung tissue from subjects with advanced COPD or control lungs, and we validate findings using single-cell RNA sequencing of lungs from mice exposed to 10 months of cigarette smoke, RNA sequencing of isolated human alveolar epithelial cells, functional in vitro models, and in situ hybridization and immunostaining of human lung tissue samples. We identify a subpopulation of alveolar epithelial type II cells with transcriptional evidence for aberrant cellular metabolism and reduced cellular stress tolerance in COPD. Using transcriptomic network analyses, we predict capillary endothelial cells are inflamed in COPD, particularly through increased CXCL-motif chemokine signaling. Finally, we detect a high-metallothionein expressing macrophage subpopulation enriched in advanced COPD. Collectively, these findings highlight cell-specific mechanisms involved in the pathobiology of advanced COPD.

Impaired Spontaneous Baroreceptor Reflex Sensitivity in Patients With COPD Compared to Healthy Controls: The Role of Lung Hyperinflation

Background and Objectives: Patients with chronic obstructive pulmonary disease (COPD) are at increased risk for cardiovascular disease. This study aimed to investigate the relationship between pulmonary hyperinflation and baroreceptor reflex sensitivity (BRS), a surrogate for cardiovascular risk. Methods: 33 patients with COPD, free from clinical cardiovascular disease, and 12 healthy controls were studied. Participants underwent pulmonary function and non-invasive hemodynamic measurements. BRS was evaluated using the sequence method during resting conditions and mental arithmetic stress testing. Results: Patients with COPD had evidence of airflow obstruction [forced expiratory volume in 1 s predicted (FEV₁%) 26.5 (23.3-29.1) vs. 91.5 (82.8-100.8); P < 0.001; geometric means (GM) with 95% confidence interval (CI)] and lung hyperinflation [residual volume/total lung capacity (RV/TLC) 67.7 (64.3-71.3) vs. 41.0 (38.8-44.3); P < 0.001; GM with 95% CI] compared to controls. Spontaneous mean BRS (BRSmean) was significantly lower in COPD, both during rest [5.6 (4.2-6.9) vs. 12.0 (9.1-17.6); P = 0.003; GM with 95% CI] and stress testing [4.4 (3.7-5.3) vs. 9.6 (7.7-12.2); P < 0.001; GM with 95% CI]. Stroke volume (SV) was significantly lower in the patient group [-21.0 ml (-29.4 to -12.6); P < 0.001; difference of the means with 95% CI]. RV/TLC was found to be a predictor of BRS and SV (P < 0.05 for both), independent of resting heart rate. Conclusion: We herewith provide evidence of impaired BRS in patients with COPD. Hyperinflation may influence BRS through alteration of mechanosensitive vagal nerve activity.

Comparison of cerebral blood flow in subjects with and without chronic obstructive pulmonary disease from the population-based Rotterdam Study

OBJECTIVES

Patients with chronic obstructive pulmonary disease (COPD) are at increased risk of cerebrovascular disease, which might be associated with decreases in cerebral blood flow. Since studies examining cerebral blood flow in COPD remain scarce and are limited by sample size, we aimed to study cerebral blood flow in participants with and without COPD.

DESIGN

Observational cohort study.

SETTING

Population-based Rotterdam Study.

PARTICIPANTS

4177 participants (age 68.0±8.5 years; 53% females) with and without COPD.

PREDICTOR VARIABLE

Spirometry and pulmonary diffusing capacity.

OUTCOME MEASURES

Cerebral blood flow by two-dimensional phase-contrast cerebral MRI.

RESULTS

Compared with subjects with normal spirometry (forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ≥0.7 and FEV₁ ≥80%), multivariable adjusted cerebral blood flow (mL/min) was preserved in subjects with COPD Global initiative for Chronic Obstructive Lung Disease (GOLD1) (FEV₁/FVC <0.7 and FEV₁ ≥80%), but significantly lower in subjects with COPD GOLD2-3 (FEV₁/FVC <0.7 and FEV₁ <80%), even after adjustment for cardiovascular comorbidities. In sex-stratified analyses, this difference in cerebral blood flow was statistically significant in women but not in men. Cerebral blood flow was lowest in subjects with FEV₁, FVC and diffusion lung capacity for carbon monoxide % predicted values in the lowest quintile, even after adjustment for cardiovascular comorbidities and cardiac function.

CONCLUSION

We observed a lowered cerebral blood flow in subjects with COPD GOLD2-3.

Automatic pulmonary vessel segmentation on noncontrast chest CT: deep learning algorithm developed using spatiotemporally matched virtual noncontrast images and low-keV contrast-enhanced vessel maps

OBJECTIVES

To develop a deep learning-based pulmonary vessel segmentation algorithm (DLVS) from noncontrast chest CT and to investigate its clinical implications in assessing vascular remodeling of chronic obstructive lung disease (COPD) patients.

METHODS

For development, 104 pulmonary CT angiography scans (49,054 slices) using a dual-source CT were collected, and spatiotemporally matched virtual noncontrast and 50-keV images were generated. Vessel maps were extracted from the 50-keV images. The 3-dimensional U-Net-based DLVS was trained to segment pulmonary vessels (with a vessel map as the output) from virtual noncontrast images (as the input). For external validation, vendor-independent noncontrast CT images (n = 14) and the VESSEL 12 challenge open dataset (n = 3) were used. For each case, 200 points were selected including 20 intra-lesional points, and the probability value for each point was extracted. For clinical validation, we included 281 COPD patients with low-dose noncontrast CTs. The DLVS-calculated volume of vessels with a cross-sectional area < 5 mm2 (PVV5) and the PVV5 divided by total vessel volume (%PVV5) were measured.

RESULTS

DLVS correctly segmented 99.1% of the intravascular points (1,387/1,400) and 93.1% of the extravascular points (1,309/1,400). The areas-under-the receiver-operating characteristic curve (AUROCs) were 0.977 and 0.969 for the two external validation datasets. For the COPD patients, both PPV5 and %PPV5 successfully differentiated severe patients whose FEV1 < 50 (AUROCs; 0.715 and 0.804) and were significantly correlated with the emphysema index (Ps < .05).

CONCLUSIONS

DLVS successfully segmented pulmonary vessels on noncontrast chest CT by utilizing spatiotemporally matched 50-keV images from a dual-source CT scanner and showed promising clinical applicability in COPD.

KEY POINTS

• We developed a deep learning pulmonary vessel segmentation algorithm using virtual noncontrast images and 50-keV enhanced images produced by a dual-source CT scanner. • Our algorithm successfully segmented vessels on diseased lungs. • Our algorithm showed promising results in assessing the loss of small vessel density in COPD patients.

Associations of D-Dimer with Computed Tomographic Lung Abnormalities, Serum Biomarkers of Lung Injury, and Forced Vital Capacity: MESA Lung Study

Rationale: The coagulation cascade may play a role in the pathogenesis of interstitial lung disease through increased production of thrombin and fibrin deposition. Whether circulating coagulation cascade factors are linked to lung inflammation and scarring among community-dwelling adults is unknown. Objectives: To test the hypothesis that higher baseline D-dimer concentrations are associated with markers of early lung injury and scarring. Methods: Using the MESA (Multi-Ethnic Study of Atherosclerosis) cohort (n = 6,814), we examined associations of baseline D-dimer concentrations with high attenuation areas from examination 1 (2000-2002; n = 6,184) and interstitial lung abnormalities from examination 5 computed tomographic (CT) scans (2010-2012; n = 2,227), and serum MMP-7 (matrix metalloproteinase-7) and SP-A (surfactant protein-A) from examination 1 (n = 1,098). We examined longitudinal change in forced vital capacity (FVC) from examinations 3-6 (2004-2018, n = 3,562). We used linear logistic regression and linear mixed models to examine associations and adjust for potential confounders. Results: The mean (standard deviation) age of the cohort was 62 (10) years, and the D-dimer concentration was 0.35 (0.69) ug/ml. For every 10% increase in D-dimer concentration, there was an increase in high attenuation area percentage of 0.27 (95% confidence interval (CI), 0.08-0.47) after adjustment for covariates. Associations were stronger among those older than 65 years (P values for interaction < 0.001). A 10% increase in D-dimer concentration was associated with an odds ratio of 1.05 for interstitial lung abnormalities (95% CI, 0.99-1.11). Higher D-dimer concentrations were associated with higher serum MMP-7 and a faster decline in FVC. D-dimer was not associated with SP-A. Conclusions: Higher D-dimer concentrations were associated with a greater burden of lung parenchymal abnormalities detected on CT scan, MMP-7, and FVC decline among community-dwelling adults.

FEV1 Predicts Cardiac Status and Outcome in Chronic Heart Failure

BACKGROUND

COPD is an established predictor of clinical outcome in patients with chronic heart failure (HF). However, little evidence is available about the predictive value of FEV₁ in chronic HF.

RESEARCH QUESTION

Is pulmonary function related to the progression of chronic HF?

STUDY DESIGN AND METHODS

The MyoVasc study (ClinicalTrials.gov Identifier: NCT04064450) is a prospective cohort study of HF. Information on pulmonary and cardiac functional and structural status was obtained by body plethysmography and echocardiography. The primary study end point was worsening of HF.

RESULTS

Overall 2,998 participants (age range, 35-84 years) with available FEV₁ data were eligible for analysis. Linear multivariate regression analysis revealed an independent relationship of FEV₁ (per -1 SD) with deteriorated systolic and diastolic left ventricle (LV) function as well as LV hypertrophy under adjustment of age, sex, height, cardiovascular risk factors (CVRFs), and clinical profile (LV ejection fraction: β-estimate, -1.63% [95% CI, -2.00% to -1.26%]; E/E' ratio: β-estimate, 0.82 [95% CI, 0.64-0.99]; and LV mass/height^2.7: β-estimate, 1.58 [95% CI, 1.07-2.10]; P < .001 for all). During a median time to follow-up of 2.6 years (interquartile range, 1.1-4.1 years), worsening of HF occurred in 235 individuals. In Cox regression model adjusted for age, sex, height, CVRF, and clinical profile, pulmonary function (FEV₁ per -1 SD) was an independent predictor of worsening of HF (hazard ratio [HR], 1.44 [95% CI, 1.27-1.63]; P < .001). Additional adjustment for obstructive airway pattern and C-reactive protein mitigated, but did not substantially alter, the results underlining the robustness of the observed effect (HR_FEV1, 1.39 [95% CI, 1.20-1.61]; P < .001). The predictive value of FEV₁ was consistent across subgroups, including individuals without obstruction (HR, 1.55 [95% CI, 1.34-1.77]; P < .001) and nonsmokers (HR, 1.72 [95% CI, 1.39-1.96]; P < .001).

INTERPRETATION

FEV₁ represents a strong candidate to improve future risk stratification and prevention strategies in individuals with chronic, stable HF.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT04064450; URL: www.clinicaltrials.gov.

Subclinical cardiac impairment relates to traditional pulmonary function test parameters and lung volume as derived from whole-body MRI in a population-based cohort study

To evaluate the relationship of cardiac function, including time-volume-curves, with lung volumes derived from pulmonary function tests (PFT) and MRI in subjects without cardiovascular diseases. 216 subjects underwent whole-body MRI and spirometry as part of the KORA-FF4 cohort study. Lung volumes derived semi-automatically using an in-house algorithm. Forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and residual volume were measured. Cardiac parameters derived from Cine-SSFP-sequence using cvi42, while left ventricle (LV) time-volume-curves were evaluated using pyHeart. Linear regression analyses assessed the relationships of cardiac parameters with PFT and MRI-based lung volumes. Mean age was 56.3 ± 9.2 years (57% males). LV and right ventricular (RV) end-diastolic-, end-systolic-, stroke volume, LV peak ejection- and early/late diastolic filling rate were associated with FEV1, FVC, and residual volume (excluding late diastolic filling rate with FEV1, LV end-systolic/stroke volume and RV end-diastolic/end-systolic volumes with residual volume). In contrast, LV end-diastolic volume (ß = - 0.14, p = 0.01), early diastolic filling rate (ß = - 0.11, p = 0.04), and LV/RV stroke volume (ß = - 0.14, p = 0.01; ß = - 0.11, p = 0.01) were inversely associated with MRI-based lung volume. Subclinical cardiac impairment was associated with reduced FEV1, FVC, and residual volume. Cardiac parameters decreased with increasing MRI-based lung volume contrasting the results of PFT.

Effect of Dynamic Hyperinflation on Cardiac Response to Exercise of Patients With Chronic Obstructive Pulmonary Disease

INTRODUCTION

Although the major limitation to exercise performance in patients with COPD is dynamic hyperinflation (DH), little is known about its relation with cardiac response to exercise. Our objectives were to compare the exercise response of stroke volume (SV) and cardiac output (CO) between COPD patients with or without DH and control subjects, and to assess the main determinants.

METHODS

Fifty-seven stable COPD patients without cardiac comorbidity and 25 healthy subjects were recruited. Clinical evaluation, baseline function tests, computed tomography and echocardiography were conducted in all subjects. Patients performed consecutive incremental exercise tests with measurement of operating lung volumes and non-invasive measurement of SV, CO and oxygen uptake (VO₂) by an inert gas rebreathing method. Biomarkers of systemic inflammation and oxidative stress, tissue damage/repair, cardiac involvement and airway inflammation were measured.

RESULTS

COPD patients showed a lower SV/VO₂ slope than control subjects, while CO response was compensated by a higher heart rate increase. COPD patients with DH experienced a reduction of SV/VO₂ and CO/VO₂ compared to those without DH. In COPD patients, the end-expiratory lung volume (EELV) increase was related to SV/VO₂ and CO/VO₂ slopes, and it was the only independent predictor of cardiac response to exercise. However, in the regression models without EELV, plasma IL-1β and high-sensitivity cardiac troponin T were also retained as independent predictors of SV/VO₂ slope.

CONCLUSION

Dynamic hyperinflation decreases the cardiac response to exercise of COPD patients. This effect is related to systemic inflammation and myocardial stress but not with left ventricle diastolic dysfunction.

Genetic evidence for a causative effect of airflow obstruction on left ventricular filling: a Mendelian randomisation study

Background

Observational studies on the general population have suggested that airflow obstruction associates with left ventricular (LV) filling. To limit the influence of environmental risk factors/exposures, we used a Mendelian randomisation (MR) approach based on common genetic variations and tested whether a causative relation between airflow obstruction and LV filling can be detected.

Methods

We used summary statistics from large genome-wide association studies (GWAS) on the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) measured by spirometry and the LV end-diastolic volume (LVEDV) as assessed by cardiac magnetic resonance imaging. The primary MR was based on an inverse variance weighted regression. Various complementary MR methods and subsets of the instrument variables were used to assess the plausibility of the findings.

Results

We obtained consistent evidence in our primary MR analysis and subsequent sensitivity analyses that reducing airflow obstruction leads to increased inflow to the LV (odds ratio [OR] from inverse variance weighted regression 1.05, 95% confidence interval [CI] 1.01–1.09, P = 0.0172). Sensitivity analyses indicated a certain extent of negative horizontal pleiotropy and the estimate from biased-corrected MR-Egger was adjusted upward (OR 1.2, 95% CI 1.09–1.31, P < 0.001). Prioritisation of single genetic variants revealed rs995758, rs2070600 and rs7733410 as major contributors to the MR result.

Conclusion

Our findings indicate a causal relationship between airflow obstruction and LV filling in the general population providing genetic context to observational associations. The results suggest that targeting (even subclinical) airflow obstruction can lead to direct cardiac improvements, demonstrated by an increase in LVEDV. Functional annotation of single genetic variants contributing most to the causal effect estimate could help to prioritise biological underpinnings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01795-9.