Pulmonary function changes associated with cardiomegaly in chronic heart failure

Risks of dementia in a general Japanese older population with preserved ratio impaired spirometry: The Hisayama Study

BACKGROUND

Studies on the association between preserved ratio impaired spirometry (PRISm) and dementia are limited. Indeed, PRISm has often been overlooked or ignored as an index of lung function impairment. Therefore, we investigated the association of PRISm with the risk for the development of dementia in an older Japanese population.

METHODS

A total of 1202 community-dwelling, older Japanese participants aged ≥65 years without dementia were followed up for a median of 5.0 years. Participants were categorized by spirometry as follows: normal spirometry (FEV1/FVC ≥0.70 and FEV1 ≥80% predicted), PRISm (≥0.70 and <80%), airflow limitation (AFL) Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1 (<0.70 and ≥80%), and AFL GOLD 2 to 4 (<0.70 and <80%). Hazard ratios (HRs) and their 95% confidence intervals (CIs) were computed using a Cox proportional hazards model.

RESULTS

During the follow-up period, 122 participants developed dementia. The age- and sex-adjusted incidences of dementia in the participants with normal spirometry, PRISm, AFL GOLD 1, and AFL GOLD 2 to 4 were 20.5, 37.0, 18.4, and 28.6 per 1000 person-years, respectively. Participants with PRISm had a higher risk of dementia (HR 2.04 [95%CI, 1.19-3.49]) than those with normal spirometry after adjusting for confounders. Moreover, both reduced FEV1% predicted values and FVC% predicted values were associated with the risk for dementia.

CONCLUSION

PRISm was associated with an increased risk of dementia in a general older Japanese population.

The Effect of the Pyrethroid Pesticide Fenpropathrin on the Cardiac Performance of Zebrafish and the Potential Mechanism of Toxicity

Fenpropathrin, a pyrethroid insecticide, has been widely used for many years in agricultural fields. It works by disturbing the voltage-gated sodium channel, leading to paralysis and the death of the target animal. While past studies have focused on neurodegeneration following fenpropathrin poisoning in humans, relatively few pieces of research have examined its effect on other peripheral organs. This study successfully investigated the potential toxicity of fenpropathrin on the cardiovascular system using zebrafish as an animal model. Zebrafish larvae exposed to varying doses of fenpropathrin underwent an evaluation of cardiac physiology by measuring the heart rate, stroke volume, cardiac output, and shortening fraction. The blood flow velocity and the dorsal aorta diameter were also measured to assess the impact of fenpropathrin exposure on the vascular system. Furthermore, molecular docking was performed to evaluate the pesticide binding affinity to various proteins associated with the cardiovascular system, revealing the potential mechanism of the fenpropathrin cardiotoxic effect. The findings demonstrated a significant dose-dependent increase in the heart rate stroke volume, cardiac output, shortening fraction, and ejection fraction of zebrafish larvae after 24 h of acute treatment with fenpropathrin. Additionally, zebrafish treated at a concentration of 1 ppm exhibited significantly larger blood vessels in diameter and an increased blood flow velocity compared to the control group. According to molecular docking, fenpropathrin showed a high affinity for various voltage-gated sodium channels like scn1lab, cacna1sb, and clcn3. Finally, from the results, we found that fenpropathrin caused cardiomegaly, which may have been induced by the voltage-gated sodium channel disruption. This study highlights the significant disruption of fenpropathrin in the cardiovascular system and emphasizes the need for further research on the health implications of this pesticide.

Rightward imbalanced pulmonary perfusion predicts better exercise stroke volume in children after Fallot repair

BACKGROUND

Residual lesions following Fallot repair are primarily pulmonary regurgitation and right ventricular outflow tract obstruction. These lesions may impact exercise tolerance, particularly because of a poor increase in left ventricular stroke volume. Pulmonary perfusion imbalance is also common, but its effect on cardiac adaptation to exercise is not known.

AIM

To assess the association between pulmonary perfusion asymmetry and peak indexed exercise stroke volume (pSVi) in young patients.

METHODS

We retrospectively studied 82 consecutive patients with Fallot repair (mean age 15.2±3.8 years) who underwent echocardiography, four-dimensional flow magnetic resonance imaging and cardiopulmonary testing with pSVi measurement by thoracic bioimpedance. Normal pulmonary flow distribution was defined as right pulmonary artery perfusion between 43 and 61%.

RESULTS

Normal, rightward and leftward flow distributions were found in 52 (63%), 26 (32%) and four (5%) patients, respectively. Independent predictors of pSVi were right pulmonary artery perfusion (β=0.368, 95% confidence interval [CI] 0.188 to 0.548; P=0.0003), right ventricular ejection fraction (β=0.205, 95% CI 0.026 to 0.383; P=0.049), pulmonary regurgitation fraction (β=-0.283, 95% CI -0.495 to -0.072; P=0.006) and Fallot variant with pulmonary atresia (β=-0.213, 95% CI -0.416 to -0.009; P=0.041). The pSVi prediction was similar when the categorical variable right pulmonary artery perfusion>61% was used (β=0.210, 95% CI 0.006 to 0.415; P=0.044).

CONCLUSION

In addition to right ventricular ejection fraction, pulmonary regurgitation fraction and Fallot variant with pulmonary atresia, right pulmonary artery perfusion is a predictor of pSVi, in that rightward imbalanced pulmonary perfusion favours greater pSVi.

Risk Stratification in Transthyretin Cardiac Amyloidosis: The Added Value of Lung Spirometry

Transthyretin cardiac amyloidosis (ATTR-CA) is an increasingly recognized disease that often results in heart failure and death. Traditionally, biological staging systems are used to stratify disease severity. Reduced aerobic capacity has recently been described as useful in identifying higher risk of cardiovascular events and death. Assessment of lung volume via simple spirometry might also hold prognostic relevance. We aimed to assess the combined prognostic value of spirometry, cardiopulmonary exercise testing (CPET) and biomarker staging in ATTR-CA patients in a multi-parametric approach. We retrospectively reviewed patient records with pulmonary function and CPET testing. Patients were followed until study endpoint (MACE: composite of heart-failure-related hospitalization and all-cause death) or censure (1 April 2022). In total, 82 patients were enrolled. Median follow-up was 9 months with 31 (38%) MACE. Impaired peak VO₂ and forced vital capacity (FVC) were independent predictors of MACE-free survival, with peak VO₂ < 50% and FVC < 70% defining the highest risk group (HR 26, 95% CI: 5-142, mean survival: 15 months) compared to patients with the lowest risk (peak VO₂ ≥ 50% and FVC ≥ 70%). Combined peak VO₂, FVC and ATTR biomarker staging significantly improved MACE prediction by 35% compared to ATTR staging alone, with 67% patients reassigned a higher risk category (p < 0.01). In conclusion, combining functional and biological markers might synergistically improve risk stratification in ATTR-CA. Integrating simple, non-invasive and easily applicable CPET and spirometry in the routine management of ATTR-CA patients might prove useful for improved risk prediction, optimized monitoring and timely introduction of newer-generation therapies.

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.

Risks of Mortality and Airflow Limitation in Japanese with Preserved Ratio Impaired Spirometry

RATIONALE

Several Western studies have reported that participants with preserved ratio impaired spirometry (PRISm) have higher risks of airflow limitation (AFL) and death. However, evidence in East Asian populations is limited.

OBJECTIVES

To investigate the relation between PRISm and the risks of death and incident AFL in a Japanese population.

METHODS

A total of 3,032 community-dwelling Japanese participants aged ≥40 years were followed up for a median of 5.3 years by annual spirometry examinations. Participants were classified into lung function categories at baseline as follows: normal spirometry (forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) ≥0.70 and FEV1 ≥80% predicted), PRISm (≥0.70 and <80%), AFL Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1 (<0.70 and ≥80%), and AFL GOLD 2-4 (<0.70 and <80%). Hazard ratios (HRs) and their 95% confidence intervals (CIs) were computed using a Cox proportional hazard model.

MEASUREMENTS AND MAIN RESULTS

During the follow-up period, 131 participants died, 22 of whom died from cardiovascular disease, and 218 participants developed AFL. When examining the prognosis of each baseline pulmonary function category, participants with PRISm had higher risks of all-cause death (HR 2.20 [95%CI: 1.35 to 3.59]) and cardiovascular death (HR 4.07 [1.07 to 15.42]) than those with normal spirometry after adjusting for confounders. Moreover, the multivariable-adjusted risk of incident AFL was greater in participants with PRISm than in those with normal spirometry (HR 2.48 [1.83 to 3.36]).

CONCLUSIONS

PRISm was associated with higher risks of all-cause and cardiovascular death and a greater risk of the development of AFL in a Japanese community.

Association of 71 cardiovascular disease-related plasma proteins with pulmonary function in the community

RATIONALE

It has been speculated that shared mechanisms underlie respiratory and cardiovascular diseases (CVD) including systemic inflammation or mutual risk factors. In this context, we sought to examine the associations of CVD-related plasma proteins with lung function as measured by spirometry in a large community-based cohort of adults.

METHODS

The study included 5777 Framingham Heart Study participants who had spirometry and measurement of 71 CVD-related plasma proteins. The association of plasma proteins with lung function was assessed cross-sectionally and longitudinally using models accounting for familial correlations. Linear mixed models were used for the following measurements: FEV1%predicted, FVC%predicted, and FEV1/FVC ratio with secondary analyses examining obstructive and restrictive physiology at baseline and their new onset during follow up.

MEASUREMENTS AND MAIN RESULTS

Among the 71 CVD-related plasma proteins, 13 proteins were associated in cross-sectional analyses with FEV1%predicted, 17 proteins were associated with FVC%predicted, and 1 protein was associated with FEV1/FVC. The proteins with the greatest inverse relations to FEV1%predicted and FVC%predicted included leptin, adrenomedullin, and plasminogen activator inhibitor-1; in contrast there were three proteins with positive relations to FEV1%predicted and FVC%predicted including insulin growth factor binding protein 2, tetranectin, and soluble receptor for advanced glycation end products. In longitudinal analyses, three proteins were associated with longitudinal change in FEV1 (ΔFEV1) and four with ΔFVC; no proteins were associated with ΔFEV1/FVC.

CONCLUSION

Our findings highlight CVD-related plasma proteins that are associated with lung function including markers of inflammation, adiposity, and fibrosis, representing proteins that may contribute both to respiratory and CVD risk.

Prognostic Role of Pulmonary Function in Patients With Heart Failure With Reduced Ejection Fraction

Background

Both ventilatory abnormalities and pulmonary hypertension (PH) are frequently observed in patients with heart failure with reduced ejection fraction. We aim to investigate the association between ventilatory abnormalities and PH in heart failure with reduced ejection fraction, as well as their prognostic impacts.

Methods and Results

A total of 440 ambulatory patients (age, 66.2±15.8 years; 77% men) with left ventricular ejection fraction ≤40% who underwent comprehensive echocardiography and spirometry were enrolled. Total lung capacity, forced vital capacity, and forced expiratory volume in the first second were obtained. Pulmonary arterial systolic pressure was estimated. PH was defined as a pulmonary arterial systolic pressure of >50 mm Hg. The primary end point was all‐cause mortality at 5 years. Patients with PH had significantly reduced total lung capacity, forced vital capacity, and forced expiratory volume in the first second. During a median follow‐up of 25.9 months, there were 111 deaths. After accounting for age, sex, body mass index, renal function, smoking, left ventricular ejection fraction, and functional capacity, total lung capacity (hazard ratio [HR] per 1 SD, 0.66; 95% CI per 1 SD, 0.46–0.96), forced vital capacity (HR per 1 SD, 0.64; 95% CI per 1 SD, 0.48–0.84), and forced expiratory volume in the first second (HR per 1 SD, 0.72; 95% CI per 1 SD, 0.53–0.98) were all significantly correlated with mortality in patients without PH. Kaplan‐Meier curve demonstrated impaired pulmonary function, defined as forced expiratory volume in the first second ≤58% of predicted or forced vital capacity ≤65% of predicted, was associated with higher mortality in patients without PH (HR, 2.85; 95% CI, 1.66–4.89), but not in patients with PH (HR, 1.05; 95% CI, 0.61–1.82).

Conclusions

Ventilatory abnormality was more prevalent in patients with heart failure with reduced ejection fraction with PH than those without. However, such ventilatory defects were related to long‐term survival only in patients without PH, regardless of their functional status.

The clinical associations with cardiomegaly in patients undergoing evaluation for pulmonary hypertension

Background

Chest radiographs can identify important abnormalities in patients undergoing diagnostic evaluation for cardiovascular diseases. Cardiomegaly often reflects cardiac chamber dilation, or cardiac muscle hypertrophy, or both conditions. The clinical implications of cardiomegaly depend on the underlying clinical disorder. Does cardiomegaly have any clinical, laboratory, echocardiographic, and right heart catheterization associations in patients undergoing evaluation for pulmonary hypertension?

Methods

Patients referred to a pulmonary vascular disease clinic for possible pulmonary hypertension underwent a comprehensive evaluation that included right heart catheterization. These patients also had chest radiographs, laboratory studies, and echocardiograms. The patients were divided into two groups based on the presence or absence of cardiomegaly.

Results

This study included 102 patients (63.7% female) with a mean age of 62.3 ± 15.0 years. Patients with cardiomegaly (n = 64) had elevated BNP, BUN, and creatinine levels. They had elevated right atrial pressures, right ventricular pressures, and pulmonary artery pressures and reduced cardiac indices and reduced mixed venous oxygen saturations. There were no differences in echocardiographic parameters between the two groups.

Conclusions

This study demonstrates that the presence of cardiomegaly on chest radiographs has important clinical implications, including increased BNP levels and increased right heart pressures, in patients undergoing evaluation for pulmonary hypertension. Consequently, the presence of cardiomegaly supports the need for additional evaluation, including right heart catheterization, and provides useful information for primary care physicians and specialists.

Determinants of minute ventilation-carbon dioxide production relationship in Chagas cardiomyopathy

INTRODUCTION:

The minute ventilation-carbon dioxide production relationship (VE/VCO₂ slope) is among the main prognostic factors of Chagas cardiomyopathy whose determinants remain unknown.

METHODS:

Seventy-eight patients with Chagas cardiomyopathy were evaluated using clinical assessment, cardiopulmonary exercise test, echocardiography, and International Physical Activity Questionnaire.

RESULTS:

Age, functional class, International Physical Activity Questionnaire score, and dilated cardiomyopathy with systolic dysfunction were independent determinants of VE/VCO₂ slope, and these variables explained 63% of its variance.

CONCLUSIONS:

The VE/VCO₂ slope was related to age, functional class, physical activity level, and dilated cardiomyopathy with systolic dysfunction in patients with Chagas cardiomyopathy.

Pulmonary Function Testing Pre-heart Transplant Predicts Posttransplant Survival

Supplemental Digital Content is available in the text.

Although pulmonary function testing (PFT) is typically performed for heart transplant evaluation, the prognostic utility of PFTs after transplantation is unknown. We evaluated whether PFT parameters were correlated with outcomes following heart transplantation.

Prevalence and Prognostic Significance of Pulmonary Function Test Abnormalities in Hospitalized Patients With Acute Decompensated Heart Failure With Preserved and Reduced Ejection Fraction

BACKGROUND

This study evaluated the prevalence and prognostic impact of lung function abnormalities in patients with acute decompensated heart failure (ADHF) with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF).Methods and Results:Of the 1,012 consecutive patients who were admitted to Nara Medical University with ADHF between 2011 and 2018, 657 routinely underwent spirometry (pulmonary function test [PFT]) before discharge. Lung function was classified as normal or abnormal (restrictive, obstructive, or mixed). Abnormal PFTs were seen in 63.0% of patients with ADHF (36.7%, 13.1%, and 13.2% for restrictive, obstructive, and mixed, respectively). The prevalence of abnormal PFT increased with age (P<0.001). Overall, abnormal PFT was an independent predictor of the composite endpoint of cardiovascular mortality or hospitalization for HF (adjusted hazard ratio [HR] 1.402; 95% confidence interval [CI] 1.039-1.914; P=0.027). Abnormal PFT (adjusted HR 2.294; 95% CI 1.368-4.064; P=0.001), as well as the restrictive (HR 2.299; 95% CI 1.322-4.175; P=0.003) and mixed (HR 2.784; 95% CI 1.399-5.581; P=0.004) patterns, were predictive of the composite endpoint in HFpEF, but not in HFrEF.

CONCLUSIONS

Abnormal PFT was prevalent and associated with poor outcomes in ADHF. Spirometry may be a useful tool in patients with ADHF, especially in those with HFpEF, to identify those at higher risk of a poorer outcome.

Enhancing oxygenation of patients with coronavirus disease 2019: Effects on immunity and other health-related conditions

Coronavirus disease 2019 (COVID-19) distresses the pulmonary system causing acute respiratory distress syndrome, which might lead to death. There is no cure for COVID-19 infection. COVID-19 is a self-limited infection, and the methods that can enhance immunity are strongly required. Enhancing oxygenation is one safe and effective intervention to enhance immunity and pulmonary functions. This review deliberates the probable influences of enhancing oxygenation on immunity and other health-connected conditions in patients with COVID-19. An extensive search was conducted through Web of Science, Scopus, Medline databases, and EBSCO for the influence of enhancing oxygenation on immunity, pulmonary functions, psycho-immune hormones, and COVID-19 risk factors. This search included clinical trials and literature and systematic reviews. This search revealed that enhancing oxygenation has a strong effect on improving immunity and pulmonary functions and psycho-immune hormones. Also, enhancing oxygenation has a self-protective role counter to COVID-19 risk factors. Lastly, this search revealed the recommended safe and effective exercise protocol to enhance oxygenation in patients with COVID-19. Enhancing oxygenation should be involved in managing patients with COVID-19 because of its significant effects on immunity, pulmonary functions, and COVID-19 risk factors. A mild to moderate cycling or walking with 60%-80% Vo2max for 20-60 min performed 2-3 times per week could be a safe and effective aerobic exercise program in patients with COVID-19 to enhance their immunity and pulmonary functions.

Misdiagnosis of Heart Failure: A Systematic Review of the Literature

BACKGROUND

Heart failure (HF) is a chronic disease associated with a significant burden to patients, families, and health services. The diagnosis of HF can be easily missed owing to similar symptoms with other conditions especially respiratory diseases.

METHODS AND RESULTS

We conducted a systematic review to determine the rates of HF and cardiomyopathy misdiagnosis and explored the potential causes. The included studies were narratively synthesized. Ten studies were identified including a total of 223,859 patients. There was a lack of definition of HF misdiagnosis in the studies and inconsistent diagnostic criteria were used. The rates of HF misdiagnosis ranged from 16.1% in hospital setting to 68.5% when general practitioner referred patients to specialist setting. The most common cause for misdiagnosis was chronic obstructive pulmonary disease (COPD). One study using a COPD cohort showed that HF was unrecognized in 20.5% of patients and 8.1% had misdiagnosis of HF as COPD. Another study suggests that anemia and chronic kidney disease are associated with an increase in the odds of unrecognized left ventricular systolic dysfunction. Other comorbidities such as obesity, old age, atrial fibrillation, and ischemic heart disease are prevalent in patients with a misdiagnosis of HF.

CONCLUSIONS

The misdiagnosis of HF is an unfortunate part of everyday clinical practice that occurs with a variable rate depending on the population studied. HF is frequently misdiagnosed as COPD. More research is needed to better understand the missed opportunities to correctly diagnose HF so that harm to patients can be avoided and effective treatments can be implemented.

Exercise Intolerance in Heart Failure: Central Role for the Pulmonary System

We propose that abnormalities of the pulmonary system contribute significantly to the exertional dyspnea and exercise intolerance observed in patients with chronic heart failure. Interventions designed to address the deleterious pulmonary manifestations of heart failure may, therefore, yield promising improvements in exercise tolerance in this population.

The role of pulmonary function in patients with heart failure and preserved ejection fraction: Looking beyond chronic obstructive pulmonary disease

Background

The prognostic value of chronic obstructive pulmonary disease (COPD) as a comorbidity in heart failure has been well documented. However, the role of pulmonary function indices in patients with heart failure and preserved ejection fraction (HFpEF) remains to be elucidated.

Methods

Subjects with HFpEF received pulmonary function tests and echocardiogram. Total lung capacity (TLC), residual volume (RV), forced expiratory flow rate between 25% and 75% of vital capacity (FEF25-75), forced expiratory volume in the 1^st second (FEV1), forced vital capacity (FVC), and vital capacity (VC) were measured. Echocardiographic indices, including pulmonary artery systolic pressure (PASP), the ratio of early ventricular filling flow velocity to the septal mitral annulus tissue velocity (E/e’), and left ventricular mass (LVM), were recorded. National Death Registry was linked for the identification of mortality.

Results

A total of 1194 patients (72.4±13.2 years, 59% men) were enrolled. PASP, E/e’ and LVM were associated with either obstructive (RV/TLC, FEV1 and FEF25-75) or restrictive (VC and TLC) ventilatory indices. During a mean follow-up of 23.0±12.8 months, 182 patients died. Subjects with COPD had a lower survival rate than those without COPD. While VC, FVC, RV/TLC, and FEV1 were all independently associated with all-cause mortality in patients without COPD, only FEF25-75 was predictive of outcomes in those with COPD.

Conclusions

The abnormalities of pulmonary function were related to the cardiac hemodynamics in patients with HFpEF. In addition, these ventilatory indices were independently associated with long-term mortality, especially in those without COPD.

Role of increasing the aerobic capacity on improving the function of immune and respiratory systems in patients with coronavirus (COVID-19): A review

BACKGROUND AND AIMS

COVID-19 is a public world crisis, however, it is a self-limited infection. In COVID-19, the strength of immune and respiratory systems is a critical element. Thus, this review was conducted to demonstrate the short and long term effects of increasing the aerobic capacity on increasing the function and strength of immune and respiratory systems, particularly those essential for overcoming COVID-19 infections and associated disorders.

METHODS

This review was carried out by searching in Web of Science, Scopus, EBSCO, Medline databases. The search was conducted over clinical trials and literature and systematic reviews on the effects of increasing the aerobic capacity on the function and strength of specific immune and respiratory elements essential for overcoming COVID-19 infections.

RESULTS

This review found that increasing the aerobic capacity could produce short-term safe improvements in the function of immune and respiratory systems, particularly those specific for COVID-19 infections. This could be mainly produced through three mechanisms. Firstly, it could improve immunity by increasing the level and function of immune cells and immunoglobulins, regulating CRP levels, and decreasing anxiety and depression. Secondly, it could improve respiratory system functions by acting as an antibiotic, antioxidant, and antimycotic, restoring normal lung tissue elasticity and strength. Lastly, it could act as a protective barrier to decrease COVID-19 risk factors, which helps to decrease the incidence and progression of COVID-19.

CONCLUSION

This review summarizes that increasing the aerobic capacity is recommended because it has potential of improving immune and respiratory functions which would help counter COVID-19.

Low DLCO predicts all-cause hospital admissions in patients with reduced left ventricular ejection fraction or diastolic dysfunction

The diffusing capacity of the lung for carbon monoxide (D_LCO) can be decreased in many disease states, including COPD and interstitial lung disease [1, 2]. Low D_LCO can also be seen in those with clinically relevant congestive heart failure (CHF) due to its deleterious consequences on lung volumes, perfusion and gas exchange efficiency [3, 4]. Pulmonary function testing results are frequently available in patients with CHF. D_LCO measurements have previously been shown to impact exercise capacity in CHF patients with either reduced or preserved left ventricular ejection fraction (LVEF) [5–7]. Impaired D_LCO has also been suggested as a potential predictor of negative clinical outcomes in CHF [8]. We, therefore, aimed to determine if patients with reduced LVEF or isolated diastolic dysfunction on echocardiography and a low D_LCO are at a higher risk of hospital admissions than their counterparts with a preserved D_LCO. Confirmation of this hypothesis would support the need for closer monitoring of CHF patients who also present with a reduced D_LCO.

A low D_LCO should be valued as a predictor of all-cause hospital admissions in patients with reduced LVEF or isolated diastolic dysfunction. The severity of the impairment seen on D_LCO testing also appears to affect the risk of hospitalisation.https://bit.ly/3e4r8bH

Mechanical cardiopulmonary interactions during exercise in health and disease

The heart and lungs are anatomically coupled through the pulmonary circulation and coexist within the sealed thoracic cavity, making the function of these systems highly interdependent. Understanding of the complex mechanical interactions between cardiac and pulmonary systems has evolved over the last century to appreciate that changes in respiratory mechanics significantly impact pulmonary hemodynamics and ventricular filling and ejection. Furthermore, given that the left and right heart share a common septum and are surrounded by the nondistensible pericardium, direct ventricular interaction is an important mediator of both diastolic and systolic performance. Although it is generally considered that cardiopulmonary interaction in healthy individuals at rest minimally affects hemodynamics, the significance during exercise is less clear. Adverse heart-lung interaction in respiratory disease is of growing interest as it may contribute to the pathogenesis of comorbid cardiovascular dysfunction and exercise intolerance in these patients. Similarly, heart failure represents a pathological uncoupling of the cardiovascular and pulmonary systems, whereby cardiac function may be impaired by the normal ventilatory response to exercise. Despite significant research contributions to this complex area, the mechanisms of cardiopulmonary interaction in the intact human and the clinical consequences of adverse interactions in common respiratory and cardiovascular diseases, particularly during exercise, remain incompletely understood. The purpose of this review is to present the key physiological principles of cardiopulmonary interaction as they pertain to resting and exercising hemodynamics in healthy humans and the clinical implications of adverse cardiopulmonary interaction during exercise in chronic obstructive pulmonary disease (COPD), pulmonary hypertension, and heart failure.

Clinical and Physiologic Implications of Negative Cardiopulmonary Interactions in Coexisting Chronic Obstructive Pulmonary Disease-Heart Failure

Chronic obstructive pulmonary disease (COPD) and heart failure with reduced ejection fraction (HF) frequently coexist in the elderly. Expiratory flow limitation and lung hyperinflation due to COPD may adversely affect central hemodynamics in HF. Low lung compliance, increased alveolar-capillary membrane thickness, and abnormalities in pulmonary perfusion because of HF further deteriorates lung function in COPD. We discuss how those negative cardiopulmonary interactions create challenges in clinical interpretation of pulmonary function and cardiopulmonary exercise tests in coexisting COPD-HF. In the light of physiologic concepts, we also discuss the influence of COPD or HF on the current medical treatment of each disease.

Trajectory and mortality of preserved ratio impaired spirometry: the Rotterdam Study

Preserved ratio impaired spirometry (PRISm) is a heterogeneous condition but its course and disease progression remain to be elucidated. We aimed to examine its prevalence, trajectories and prognosis in the general population.In the Rotterdam Study (population-based prospective cohort) we examined prevalence, trajectories and prognosis of subjects with normal spirometry (controls; forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ≥0.7, FEV₁  ≥80%), PRISm (FEV₁/FVC ≥0.7, FEV₁ <80%) and chronic obstructive pulmonary disease (COPD) (FEV₁/FVC <0.7) at two study visits. Hazard ratios with 95% confidence intervals for mortality (until December 30, 2018) were adjusted for age, sex, body mass index, current smoking and pack-years.Of 5487 subjects (age 69.1±8.9 years; 7.1% PRISm), 1603 were re-examined after 4.5 years. Of the re-examined PRISm subjects, 15.7% transitioned to normal spirometry and 49.4% to COPD. Median lung function decline was highest in subjects with incident PRISm (FEV₁ -92.8 mL·year^-1, interquartile range (IQR) -131.9- -65.8 mL·year^-1; FVC -93.3 mL·year^-1, IQR -159.8- -49.1 mL·year^-1), but similar in persistent PRISm (FEV₁ -30.2 mL·year^-1, IQR -67.9- -7.5 mL·year^-1; FVC -20.1 mL·year^-1, IQR -47.7-21.7 mL·year^-1) and persistent controls (FEV₁ -39.6 mL·year^-1, IQR -64.3--12.7 mL·year^-1; FVC -20.0 mL·year^-1, IQR -55.4-18.8 mL·year^-1). Of 5459 subjects with informed consent for follow-up, 692 (12.7%) died during 9.3 years (maximum) follow-up: 10.3% of controls, 18.7% of PRISm subjects and 20.8% of COPD subjects. Relative to controls, subjects with PRISm and COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2-4 had increased all-cause mortality (PRISm: HR 1.6, 95% CI 1.2-2.0; COPD GOLD 2-4: HR 1.7, 95% CI 1.4-2.1) and cardiovascular mortality (PRISm: HR 2.8, 95% CI 1.5-5.1; COPD 2-4: HR 2.1, 95% CI 1.2-3.6). Mortality within <1 year was highest in PRISm, with patients often having cardiovascular comorbidities (heart failure or coronary heart disease; 70.0%).PRISm is associated with increased mortality and this population encompasses at least three distinct subsets: one that develops COPD during follow-up, a second with high cardiovascular burden and early mortality, and a third with persistent PRISm and normal age-related lung function decline.

The interactions between respiratory and cardiovascular systems in systolic heart failure

Heart failure (HF) is a complex and multifaceted disease. The disease affects multiple organ systems, including the respiratory system. This review provides three unique examples illustrating how the cardiovascular and respiratory systems interrelate because of the pathology of HF. Specifically, these examples outline the impact of HF pathophysiology on 1) respiratory mechanics and the mechanical "cost" of breathing; 2) mechanical interactions of the heart and lungs; and on 3) abnormalities of pulmonary gas exchange during exercise, and how this may be applied to treatment. The goal of this review is to, therefore, raise the awareness that HF, though primarily a disease of the heart, is accompanied by marked pathology of the respiratory system.

Association between pulmonary function and left ventricular volume and function in duchenne muscular dystrophy

INTRODUCTION

Duchenne muscular dystrophy (DMD) is characterized by absence of the subsarcolemmal protein dystrophin, present in skeletal muscles and cardiomyocytes. We hypothesized that progressive respiratory and left ventricular (LV) insufficiencies in DMD could be parallel and interrelated phenomena.

METHODS

We conducted a retrospective chart review of 27 patients with DMD. Our primary objective was to compare the rates of decline between pulmonary function test (PFT) measures (forced expiratory volume in the first second, forced vital capacity, peak expiratory flow rate, maximal inspiratory/expiratory pressure) and echocardiographic estimates of LV end-diastolic volume and LV ejection fraction.

RESULTS

The rates of decline/year of PFTs and LV estimates were not significantly different. Pulmonary function test measures of ventilatory efficiency and strength had strong intercorrelations. Pulmonary function tests and LV estimates had weak but statistically significant correlations.

DISCUSSION

A comparable rate of decline in PFTs and LV indices in DMD provides evidence for concurrently progressive deterioration in respiratory and LV functions. Muscle Nerve, 2019.

Exercise Ventilatory Efficiency in Older and Younger Heart Failure Patients With Preserved Ejection Fraction

BACKGROUND

Patients with heart failure with preserved ejection fraction (HFpEF) exhibit pulmonary abnormalities, but the studies to date have reported wide variability in the ventilatory equivalent for carbon dioxide (V̇_E/V̇CO₂) slope. It is possible that aging may contribute to that variability. We sought to compare ventilatory efficiency and its components in older and younger HFpEF patients during exercise.

METHODS AND RESULTS

Eighteen older (O; 80 ± 4 y) and 19 younger (Y; 59 ± 7 y) HFpEF patients performed cardiopulmonary exercise testing to volitional fatigue. Measurements of arterial blood gases were used to derive V_D/V_T, dead space ventilation, and alveolar ventilation. V̇_E/V̇CO₂ slope was greater in older compared with younger HFpEF patients (O 36 ± 7vs Y 31 ± 7; P = .04). At peak exercise, older HFpEF exhibited greater V_D/V_T compared with younger HFpEF (O 0.37 ± 0.10vs Y 0.28 ± 0.10; P < .01), whereas PaCO₂ was not different between groups (P = .58). V̇_E and alveolar ventilation were similar (P > .23), but dead space ventilation was greater in older compared with younger HFpEF at peak exercise (P = .04).

CONCLUSIONS

Older HFpEF patients exhibit greater ventilatory inefficiency resulting from elevated physiologic dead space during peak exercise compared with younger HFpEF patients. These results suggest that aging can worsen the pathophysiologic mechanisms underlying ventilatory efficiency during exercise in HFpEF.

Lung diffusion capacity in advanced heart failure: relation to central haemodynamics and outcome

Aims

Patients with heart failure (HF) are known to have a reduced pulmonary diffusion capacity for carbon monoxide (D_LCO), but little is known about how lung function relates to central haemodynamics. The aim of this study was to investigate the association between haemodynamic variables and pulmonary diffusion capacity adjusted for alveolar volume in congestive HF patients and to analyse how predicted D_LCO/V_A affects mortality in relation to the haemodynamic status.

Methods and results

We retrospectively studied right heart catheterization (RHC) and lung function data on 262 HF patients (mean age 51 ± 13 years) with a left ventricular ejection fraction < 45% referred non‐urgently for evaluation for heart transplantation (HTX) or left ventricular assist device (LVAD). Univariate and multivariate linear regression models were constructed to examine the associations between predicted values of D_LCO/V_A, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁), and haemodynamic parameters [pulmonary capillary wedge pressure (PCWP), central venous pressure, cardiac index, mean pulmonary artery pressure, and mean arterial pressure] as well as other factors known to affect lung function in HF. FEV₁ was reduced to <80% of predicted value in 55% of the population, and D_LCO/V_A was reduced in 63% of the population. D_LCO/V_A correlated positively with pulmonary capillary wedge pressure in both univariate and multivariate analyses for all included patients (P < 0.001 and P = 0.045, respectively) and a restricted population of patients with the shortest time between RHC and lung function testing (P = 0.005, P = 0.015). D_LCO/V_A predicted mortality in multivariate models [hazard ratio 1.5 (1.1–2.1)] but not the combined endpoint of death, LVAD implantation, or HTX. There was no significant correlation between haemodynamics and predicted FVC or FEV₁.

Conclusions

Pulmonary diffusion capacity correlates positively with left ventricular fillings pressures, and reduced values predict increased mortality in patients with HF. This might be driven by increased lung capillary volume in patients with pulmonary congestion.

Association of Medication Intensity and Stages of Airflow Limitation With the Risk of Hospitalization or Death in Patients With Heart Failure and Chronic Obstructive Pulmonary Disease

IMPORTANCE

In heart failure (HF), chronic obstructive pulmonary disease (COPD) increases the risk of poor outcomes, but the effect of COPD severity is unknown. This information is important for early intervention tailored to the highest-risk groups.

OBJECTIVES

To determine the associations between COPD medication intensity or stage of airflow limitation and the risk of hospitalization or death in patients with HF.

DESIGN, SETTING, AND PARTICIPANTS

This UK population-based, nested case-control study with risk-set sampling used the Clinical Practice Research Datalink linked to Hospital Episode Statistics between January 1, 2002, to January 1, 2014. Participants included patients aged 40 years and older with a new diagnosis of HF in their family practice clinical record. Data analysis was conducted from 2017 to 2018.

EXPOSURES

In patients with HF, those with COPD were compared with those without it. International COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD]) guidelines were used to stratify patients with COPD by 7 medication intensity levels and 4 airflow limitation severity stages using automatically recorded prescriptions and routinely requested forced expiratory volume in 1 second (FEV1) data.

MAIN OUTCOMES AND MEASURES

First all-cause admission or all-cause death.

RESULTS

There were 50 114 patients with new HF (median age, 79 years [interquartile range, 71-85 years]; 46% women) during the study period. In patients with HF, COPD (18 478 [13.8%]) was significantly associated with increased mortality (adjusted odds ratio [AOR], 1.31; 95% CI, 1.26-1.36) and hospitalization (AOR, 1.33; 95% CI, 1.26-1.39). The 3 most severe medication intensity levels showed significantly increasing mortality associations from full inhaler therapy (AOR, 1.17; 95% CI, 1.06-1.29) to oral corticosteroids (AOR, 1.69; 95% CI, 1.57-1.81) to oxygen therapy (AOR, 2.82; 95% CI, 2.42-3.28). The respective estimates for hospitalization were AORs of 1.17 (95% CI, 1.03-1.33), 1.75 (95% CI, 1.59-1.92), and 2.84 (95% CI, 1.22-3.63). Availability of spirometry data was limited but showed that increasing airflow limitation was associated with increased risk of mortality, with the following AORs: FEV1 80% or more, 1.63 (95% CI, 1.42-1.87); FEV1 50% to 79%, 1.69 (95% CI, 1.56-1.83); FEV1 30% to 49%, 2.21 (95% CI, 2.01-2.42); FEV1 less than 30%, 2.93 (95% CI, 2.49-3.43). The strength of associations between FEV1 and hospitalization risk were similar among stages ranging from FEV1 80% or more (AOR, 1.48; 95% CI, 1.31-1.68) to FEV1 less than 30% (AOR, 1.73; 95% CI, 1.40-2.12).

CONCLUSIONS AND RELEVANCE

In the UK HF community setting, increasing COPD severity was associated with increasing risk of mortality and hospitalization. Prescribed COPD medication intensity and airflow limitation provide the basis for targeting high-risk groups.

Ventilatory constraints influence physiological dead space in heart failure

NEW FINDINGS

What is the central question of this study? The goal of this study was to investigate the effect of alterations in tidal volume and alveolar volume on the elevated physiological dead space and the contribution of ventilatory constraints thereof in heart failure patients during submaximal exercise. What is the main finding and its importance? We found that physiological dead space was elevated in heart failure via reduced tidal volume and alveolar volume. Furthermore, the degree of ventilatory constraints was associated with physiological dead space and alveolar volume.

ABSTRACT

Patients who have heart failure with reduced ejection fraction (HFrEF) exhibit impaired ventilatory efficiency [i.e. greater ventilatory equivalent for carbon dioxide ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mi>E</mml:mi></mml:msub> <mml:mo>/</mml:mo> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:mi>C</mml:mi> <mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> ) slope] and elevated physiological dead space (V_D /V_T ). However, the impact of breathing strategy on V_D /V_T during submaximal exercise in HFrEF is unclear. The HFrEF (n = 9) and control (CTL, n = 9) participants performed constant-load cycling exercise at similar ventilation ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mi>E</mml:mi></mml:msub> </mml:math> ). Inspiratory capacity, operating lung volumes and arterial blood gases were measured during submaximal exercise. Arterial blood gases were used to derive V_D /V_T , alveolar volume, dead space volume, alveolar ventilation and dead space ventilation. During submaximal exercise, HFrEF patients had greater <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mi>E</mml:mi></mml:msub> <mml:mo>/</mml:mo> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mrow><mml:mi>C</mml:mi> <mml:msub><mml:mi>O</mml:mi> <mml:mn>2</mml:mn></mml:msub> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> slope and V_D /V_T than CTL subjects (P = 0.01). At similar <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub><mml:mover><mml:mi>V</mml:mi> <mml:mo>̇</mml:mo></mml:mover> <mml:mi>E</mml:mi></mml:msub> </mml:math> , HFrEF patients had smaller tidal volumes and alveolar volumes (HFrEF 1.11 ± 0.33 litres versus CTL 1.66 ± 0.37 litres; both P ≤ 0.01), whereas dead space volume was not different (P = 0.47). The augmented breathing frequency in HFrEF patients resulted in greater dead space ventilation compared with CTL subjects (HFrEF 15 ± 4 l min^-1 versus CTL 10 ± 5 l min^-1 ; P = 0.048). The HFrEF patients exhibited greater increases in expiratory reserve volume and lower inspiratory capacity (as a percentage of predicted) than CTL subjects (both P < 0.05), which were significantly related to V_D /V_T and alveolar volume in HFrEF patients (all P < 0.03). In HFrEF, the reduced tidal volume and alveolar volume elevate physiological dead space during submaximal exercise, which is worsened in those with the greatest ventilatory constraints. These findings highlight the negative consequences of ventilatory constraints on physiological dead space during submaximal exercise in HFrEF.

Current challenges in managing comorbid heart failure and COPD

INTRODUCTION

Heart failure (HF) with reduced ejection fraction and chronic obstructive pulmonary disease (COPD) frequently coexist, particularly in the elderly. Given their rising prevalence and the contemporary trend to longer life expectancy, overlapping HF-COPD will become a major cause of morbidity and mortality in the next decade. Areas covered: Drawing on current clinical and physiological constructs, the consequences of negative cardiopulmonary interactions on the interpretation of pulmonary function and cardiopulmonary exercise tests in HF-COPD are discussed. Although those interactions may create challenges for the diagnosis and assessment of disease stability, they provide a valuable conceptual framework to rationalize HF-COPD treatment. The impact of COPD or HF on the pharmacological treatment of HF or COPD, respectively, is then comprehensively discussed. Authors finalize by outlining how the non-pharmacological treatment (i.e. rehabilitation and exercise reconditioning) can be tailored to the specific needs of patients with HF-COPD. Expert commentary: Randomized clinical trials testing the efficacy and safety of new medications for HF or COPD should include a sizeable fraction of patients with these coexistent pathologies. Multidisciplinary clinics involving cardiologists and respirologists trained in both diseases (with access to unified cardiorespiratory rehabilitation programs) are paramount to decrease the humanitarian and social burden of HF-COPD.

When the Heart Is Not to Blame: Managing Lung Disease in Adult Congenital Heart Disease

It is well-recognized now that adult survivors with congenital heart disease (CHD) are at risk for non-cardiac co-morbidities and complications that can impact symptoms and clinical outcomes. Lung disease, in particular, is common in this population, but likely an under-recognized and undertreated cause for long-term morbidity. Abnormal lung function contributes to exercise intolerance and is associated with a higher risk for mortality in this population. The exact mechanisms that contribute to abnormal measurements of lung function are not entirely known, and are likely multifactorial and variable depending on the underlying CHD. Nevertheless, lung disease is a potentially modifiable risk factor in this patient population, the management of which may result in improved clinical outcomes. This review summarizes our current understanding of the prevalence, impact and management of lung disease in adults with CHD.

Assessment of Thoracic Blood Volume by Computerized Tomography in Patients With Heart Failure and Periodic Breathing

BACKGROUND

Periodic breathing (PB) is often observed in patients with HF at rest, with sleep and during exercise. However, mechanisms underlying abnormal ventilatory control are not entirely established.

METHODS

Eleven subjects with HF (10 males, age = 69 ± 12 y) and 12 age-matched control subjects (8 males, age = 65 ± 9 y) participated in the study. PB was defined as a peak in the 0.003-0.04 Hz frequency range of the flow signal during 6 minutes of awake resting breathing. Thoracic blood volumes (V_t, thorax; V_h, heart; V_p, pulmonary), mean transit times (MTTs), and extravascular lung water (EVLW) were quantified using computerized tomography.

RESULTS

PB was observed in 7 subjects with HF and was associated with worse functional status. The HF PB-present group had thoracic blood volumes nearly double those of control and HF PB-absent subjects (volumes reported as mL/m² body surface area, P values vs control: control = 813 ± 246, HF PB-absent = 822 ± 161 P = .981, HF PB-present = 1579 ± 548 P = .002). PB was associated with longer pulmonary MTT (control = 6.7 ± 1.2 s, HF PB-absent = 6.0 ± 0.8 s, HF PB-present = 8.4 ± 1.6 s; P = .033, HF PB-present vs HF PB-absent). EVLW was not elevated in the PB group.

CONCLUSIONS

Subjects with HF and PB at rest have greater centralization of blood volume.

Influence of Thoracic Fluid Compartments on Pulmonary Congestion in Chronic Heart Failure

INTRODUCTION

Pulmonary congestion is a common finding of heart failure (HF), but it remains unclear how pulmonary and heart blood volumes (V_p and V_h, respectively) and extravascular lung water (EVLW) change in stable HF and affect lung function.

METHODS

Fourteen patients with HF (age 68 ± 11 y, LVEF 33 ± 8%) and 12 control subjects (age 65 ± 9 y) were recruited. A pulmonary function test, thoracic computerized tomographic (CT) scan, and contrast perfusion scan were performed. From the thoracic scan, a histogram of CT attenuation of lung tissue was generated and skew, kurtosis, and full-width half-max (FWHM) calculated as surrogates of EVLW. Blood volumes were calculated from the transit time of the contrast through the great vessels of the heart.

RESULTS

Patients with HF had greater V_p and V_h (V_p 0.55 ± 0.21 L vs 0.41 ± 0.13 L; V_h 0.53 ± 0.33 L vs 0.40 ± 0.15 L) and EVLW (skew 3.2 ± 0.5 vs 3.7 ± 0.7; kurtosis 19.4 ± 6.6 vs 25.9 ± 9.4; FWHM 73 ± 13 HU vs 59 ± 9 HU). Spirometric measures were decreased in HF (percentage of predicted: forced vital capacity 86 ± 17% vs 104 ± 9%; forced expiratory volume in 1 second 83 ± 20% vs 105 ± 11%; maximal mid-expiratory flow 82 ± 42% vs 115 ± 43%). V_p was associated with decreased expiratory flows, and EVLW was associated with decreased lung volumes.

CONCLUSIONS

Congestion in stable patients with HF includes expanded V_p and V_h and increased EVLW associated with reductions in lung volumes and expiratory flows.

Influence of heart failure on resting lung volumes in patients with COPD

Objective:

To evaluate the influence of chronic heart failure (CHF) on resting lung volumes in patients with COPD, i.e., inspiratory fraction-inspiratory capacity (IC)/TLC-and relative inspiratory reserve-[1 − (end-inspiratory lung volume/TLC)].

Methods:

This was a prospective study involving 56 patients with COPD-24 (23 males/1 female) with COPD+CHF and 32 (28 males/4 females) with COPD only-who, after careful clinical stabilization, underwent spirometry (with forced and slow maneuvers) and whole-body plethysmography.

Results:

Although FEV₁, as well as the FEV₁/FVC and FEV₁/slow vital capacity ratios, were higher in the COPD+CHF group than in the COPD group, all major "static" volumes-RV, functional residual capacity (FRC), and TLC-were lower in the former group (p < 0.05). There was a greater reduction in FRC than in RV, resulting in the expiratory reserve volume being lower in the COPD+CHF group than in the COPD group. There were relatively proportional reductions in FRC and TLC in the two groups; therefore, IC was also comparable. Consequently, the inspiratory fraction was higher in the COPD+CHF group than in the COPD group (0.42 ± 0.10 vs. 0.36 ± 0.10; p < 0.05). Although the tidal volume/IC ratio was higher in the COPD+CHF group, the relative inspiratory reserve was remarkably similar between the two groups (0.35 ± 0.09 vs. 0.44 ± 0.14; p < 0.05).

Conclusions:

Despite the restrictive effects of CHF, patients with COPD+CHF have relatively higher inspiratory limits (a greater inspiratory fraction). However, those patients use only a part of those limits, probably in order to avoid critical reductions in inspiratory reserve and increases in elastic recoil.

Impact of chronic systolic heart failure on lung structure-function relationships in large airways

Heart failure (HF) is often associated with pulmonary congestion, reduced lung function, abnormal gas exchange, and dyspnea. We tested whether pulmonary congestion is associated with expanded vascular beds or an actual increase in extravascular lung water (EVLW) and how airway caliber is affected in stable HF. Subsequently we assessed the influence of an inhaled short acting beta agonist (SABA). Thirty‐one HF (7F; age, 62 ± 11 years; ht. 175 ± 9 cm; wt. 91 ± 17 kg; LVEF, 28 ± 15%) and 29 controls (11F; age; 56 ± 11 years; ht. 174 ± 8 cm; wt. 77 ± 14 kg) completed the study. Subjects performed PFTs and a chest computed tomography (CT) scan before and after SABA. CT measures of attenuation, skew, and kurtosis were obtained from areas of lung tissue to assess EVLW. Airway luminal areas and wall thicknesses were also measured. CT tissue density suggested increased EVLW in HF without differences in the ratio of airway wall thickness to luminal area or luminal area to TLC (skew: 2.85 ± 1.08 vs. 2.11 ± 0.79, P < 0.01; Kurtosis: 15.5 ± 9.5 vs. 9.3 ± 5.5 P < 0.01; control vs. HF). PFTs were decreased in HF at baseline (% predicted FVC:101 ± 15% vs. 83 ± 18%, P < 0.01;FEV1:103 ± 15% vs. 82 ± 19%, P < 0.01;FEF25–75: 118 ± 36% vs. 86 ± 36%, P < 0.01; control vs. HF). Airway luminal areas, but not CT measures, were correlated with PFTs at baseline. The SABA cleared EVLW and decreased airway wall thickness but did not change luminal area. Patients with HF had evidence of increased EVLW, but not an expanded bronchial circulation. Airway caliber was maintained relative to controls, despite reductions in lung volume and flow rates. SABA improved lung function, primarily by reducing EVLW.

Vicious circle between progressive right ventricular dilatation and pulmonary regurgitation in patients after tetralogy of Fallot repair? Right heart enlargement promotes flow reversal in the left pulmonary artery

BACKGROUND

The left pulmonary artery (LPA) contributes more than the right (RPA) to total pulmonary regurgitation (PR) in patients after tetralogy of Fallot (TOF) repair, but the mechanism of this difference is not well understood. This study aimed to analyze the interplay between heart and lung size, mediastinal geometry, and differential PR.

METHODS

Forty-eight Cardiovascular Magnetic Resonance (CMR) studies in patients after TOF repair were analyzed. In addition to the routine blood flow and ventricular volume quantification cardiac angle between the thoracic anterior-posterior line and the interventricular septum, right and left lung areas as well as right and left hemithorax areas were measured on an axial image. Statistical analysis was performed to compare flow parameters between RPA and LPA and to assess correlation among right ventricular volume, pulmonary blood flow parameters and lung area.

RESULTS

There was no difference between LPA and RPA diameters. The LPA showed significantly less total forward flow (2.49 ± 0.87 L/min/m(2) vs 2.86 ± 0.89 L/min/m(2); p = 0.02), smaller net forward flow (1.40 ± 0.51 vs 1.89 ± 0.60 mL/min/m(2); p = <0.001), and greater regurgitant fraction (RF) (34 ± 10 % vs 43 ± 12 %; p = 0.001) than the RPA. There was no difference in regurgitant flow volume between RPA and LPA (p = 0.29). Indexed right ventricular end-diastolic volume (RVEDVi) correlated with LPA RF (R = 0.48, p < 0.001), but not with RPA RF (p = 0.09). Larger RVEDVi correlated with a more leftward cardiac axis (R = 0.46, p < 0.001) and with smaller left lung area (R = -0.58, p < 0.001). LPA RF, but not RPA RF, correlated inversely with left lung area (R = -0.34, p = 0.02). The follow-up CMRs in 20 patients showed a correlation of the rate of RV enlargement with the rates of LPA RF worsening (R = 0.50, p = 0.03), and of increasing left lung compression (R = -0.55, p = 0.012).

CONCLUSION

An enlarged and levorotated heart is associated with left lung compression and impaired flow into the left lung.

Inter-tissue coexpression network analysis reveals DPP4 as an important gene in heart to blood communication

BACKGROUND

Inter-tissue molecular interactions are critical to the function and behavior of biological systems in multicellular organisms, but systematic studies of interactions between tissues are lacking. Also, existing studies of inter-tissue interactions are based on direct gene expression correlations, which can't distinguish correlations due to common genetic architectures versus biochemical or molecular signal exchange between tissues.

METHODS

We developed a novel strategy to study inter-tissue interaction by removing effects of genetic regulation of gene expression (genetic decorrelation). We applied our method to the comprehensive atlas of gene expression across nine human tissues in the Genotype-Tissue Expression (GTEx) project to generate novel genetically decorrelated inter-tissue networks. From this we derived modules of genes important in inter-tissue interactions that are likely driven by biological signal exchange instead of their common genetic basis. Importantly we highlighted communication between tissues and elucidated gene activities in one tissue inducing gene expression changes in others.

RESULTS

We reveal global unidirectional inter-tissue coordination of specific biological pathways such as protein synthesis. Using our data, we highlighted a clinically relevant example whereby heart expression of DPP4 was coordinated with a gene expression signature characteristic for whole blood proliferation, potentially impacting peripheral stem cell mobilization. We also showed that expression of the poorly characterized FOCAD in heart correlated with protein biosynthetic processes in the lung.

CONCLUSIONS

In summary, this is the first resource of human multi-tissue networks enabling the investigation of molecular inter-tissue interactions. With the networks in hand, we may systematically design combination therapies that simultaneously target multiple tissues or pinpoint potential side effects of a drug in other tissues.

Lung function in pulmonary hypertension

Breathlessness is a common symptom in pulmonary hypertension (PH) and an important cause of morbidity. Though this has been attributed to the well described pulmonary vascular abnormalities and subsequent cardiac remodelling, changes in the airways of these patients have also been reported and may contribute to symptoms. Our understanding of these airway abnormalities is poor with conflicting findings in many studies. The present review evaluates these studies for the major PH groups. In addition we describe the role of cardiopulmonary exercise testing in the assessment of pulmonary arterial hypertension (PAH) by evaluating cardiopulmonary interaction during exercise. As yet, the reasons for the abnormalities in lung function are unclear, but potential causes and the possible role of inflammation are discussed. Future research is required to provide a better understanding of this to help improve the management of these patients.

Changes in lung volumes and gas trapping in patients with large hiatal hernia

BACKGROUND AND AIMS

Studies assessing hiatal hernia (HH)-related effects on lung volumes derived by body plethysmography are limited. We aimed to evaluate the effect of hernia size on lung volumes (including assessment by body plethysmography) and the relationship to functional capacity, as well as the impact of corrective surgery.

METHODS

Seventy-three patients (70 ± 10 years; 54 female) with large HH [mean ± standard deviation, intra-thoracic stomach (ITS) (%): 63 ± 20%; type III in 65/73] had respiratory function data (spirometry, 73/73; body plethysmography, 64/73; diffusing capacity, 71/73) and underwent HH surgery. Respiratory function was analysed in relation to hernia size (groups I, II and III: ≤50, 50%-75% and ≥75% ITS, respectively) and functional capacity. Post-operative changes were quantified in a subgroup.

RESULTS

Total lung capacity (TLC) and vital capacity (VC) correlated inversely with hernia size (TLC: 97 ± 11%, 96 ± 13%, 88 ± 10% predicted in groups I, II and III, respectively, P = 0.01; VC: 110 ± 17%, 111 ± 14%, 98 ± 14% predicted, P = 0.02); however, mean values were normal and only 14% had abnormal lung volumes. Surgery increased TLC (93 ± 11% vs 97 ± 10% predicted) and VC (105 ± 15% vs 116 ± 18%), and decreased residual volume/total lung capacity (RV/TLC) ratio (39 ± 7% vs 37 ± 6%) (P < 0.01 for all). Respiratory changes were modest relative to the marked functional class improvement. Among parameters that improved following HH surgery, decreased TLC and forced expiratory volume in 1 s and increased RV/TLC ratio correlated with poorer functional class pre-operatively.

CONCLUSIONS

Increasing HH size correlates with reduced TLC and VC. Surgery improves lung volumes and gas trapping; however, the changes are mild and within the normal range.

Pulmonary function differences in patients with chronic right heart failure secondary to pulmonary arterial hypertension and chronic left heart failure

BACKGROUND

Pulmonary abnormalities are found in both chronic heart failure (CHF) and pulmonary arterial hypertension (PAH). The differences of pulmonary function in chronic left heart failure and chronic right heart failure are not fully understood.

MATERIAL AND METHODS

We evaluated 120 patients with stable CHF (60 with chronic left heart failure and 60 with chronic right heart failure). All patients had pulmonary function testing, including pulmonary function testing at rest and incremental cardiopulmonary exercise testing (CPX).

RESULTS

Patients with right heart failure had a significantly lower end-tidal partial pressure of CO2 (PetCO2), higher end-tidal partial pressure of O2 (PetO2) and minute ventilation/CO2 production (VE/VCO2) at rest. Patients with right heart failure had a lower peak PetCO2, and a higher peak dead space volume/tidal volume (VD/VT) ratio, peak PetO2, peak VE/VCO2, and VE/VCO2 slope during exercise. Patients with right heart failure had more changes in ∆PetCO2 and ∆VE/VCO2, from rest to exercise.

CONCLUSIONS

Patients with right heart failure had worse pulmonary function at rest and exercise, which was due to severe ventilation/perfusion (V/Q) mismatching, severe ventilation inefficiency, and gas exchange abnormality.

Prognostic value of alveolar volume in systolic heart failure: a prospective observational study

Background

Ventilatory impairment is known to occur in patients with heart failure (HF). Alveolar volume (V_A) is measured by the dilution of an inert gas during a single breath-hold maneuver. Such measurement is sensitive to ventilatory disturbances. We conducted a prospective, observational study to establish the prognostic value of V_A in systolic HF.

Methods

We studied 260 consecutive patients who were hospitalized for systolic HF. All patients were evaluated under stable clinical conditions, before hospital discharge. Lung function studies included spirometry and determination of the lung diffusing capacity for carbon monoxide (DL_CO) by the single-breath method. We also measured the cardiothoracic ratio on frontal chest radiographs, and the circulating levels of N-terminal pro-hormone of B-type natriuretic peptide (NT-proBNP). The hazard ratio (HR) of death was estimated with Cox regression, and the percentiles of survival time with Laplace regression. For survival analysis, V_A was categorized as < 80% (n = 135), or ≥ 80% of the predicted value (n = 125).

Results

Follow-up had a median duration of 2.7 years (interquartile range, 1.1 to 4.2 years). The crude mortality rate was 27% in the whole sample, 36% in patients with V_A < 80%, and 16% in those with V_A ≥ 80%. The HR of death was 2.3-fold higher in patients with V_A < 80% than in those with V_A ≥80% (p = 0.002). After adjusting for age, New York Heart Association class III-IV, cardiothoracic ratio >0.5, NT-proBNP, persistent atrial fibrillation, DL_CO, COPD comorbidity, use of beta-blockers and angiotensin converting enzyme inhibitors, the HR decreased to 1.9 but remained statistically significant (p = 0.039). Two percent of the patients with V_A < 80% died about 0.9 years earlier than those with V_A ≥ 80% (p = 0.033). The difference in survival time at the 20th percentile was 0.8 years.

Conclusions

V_A is a significant, independent predictor of reduced survival in patients with systolic HF.

Prognostic value of resting pulmonary function in heart failure

BACKGROUND

The heart and lungs are intimately linked anatomically and physiologically, and, as a result, heart failure (HF) patients often develop changes in pulmonary function. This study examined the prognostic value of resting pulmonary function (PF) in HF.

METHODS AND RESULTS

In all, 134 HF patients (enrolled from January 1, 1999 Through December 31, 2005; ejection fraction (EF) = 29% ± 11%; mean age = 55 ± 12 years; 65% male) were followed for 67 ± 34 months with death/transplant confirmed via the Social Security Index and Mayo Clinic registry. PF included forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), diffusing capacity of the lungs for carbon monoxide (DLCO), and alveolar volume (VA). Patients were divided in tertiles according to PF with survival analysis via log-rank Mantel-Cox test with chi-square analysis. Groups for FVC included (1) >96%, (2) 96% to 81%, and (3) <81% predicted (chi-square = 18.9, P < 0.001). Bonferroni correction for multiple comparisons (BC) suggested differences between groups 1 and 3 (P < 0.001) and 2 and 3 (P = 0.008). Groups for FEV1 included (1) >94%, (2) 94% to 77%, and (3) <77% predicted (chi-square = 17.3, P <0.001). BC suggested differences between groups 1 and 3 (P <0.001). Groups for DLCO included (1) >90%, (2) 90% to 75%, and (3) <75% predicted (chi-square = 11.9, P = 0.003). BC suggested differences between groups 1 and 3 (P < 0.001). Groups for VA included (1) >97%, (2) 97% to 87%, and (3) <87% predicted (Chi-square = 8.5, P = 0.01). BC suggested differences between groups 1 and 2 (P = 0.014) and 1 and 3 (P = 0.003).

CONCLUSIONS

In a well-defined cohort of HF patients, resting measures of PF are predictive of all-cause mortality.

Lungs in heart failure

Lung function abnormalities both at rest and during exercise are frequently observed in patients with chronic heart failure, also in the absence of respiratory disease. Alterations of respiratory mechanics and of gas exchange capacity are strictly related to heart failure. Severe heart failure patients often show a restrictive respiratory pattern, secondary to heart enlargement and increased lung fluids, and impairment of alveolar-capillary gas diffusion, mainly due to an increased resistance to molecular diffusion across the alveolar capillary membrane. Reduced gas diffusion contributes to exercise intolerance and to a worse prognosis. Cardiopulmonary exercise test is considered the “gold standard” when studying the cardiovascular, pulmonary, and metabolic adaptations to exercise in cardiac patients. During exercise, hyperventilation and consequent reduction of ventilation efficiency are often observed in heart failure patients, resulting in an increased slope of ventilation/carbon dioxide (VE/VCO₂) relationship. Ventilatory efficiency is as strong prognostic and an important stratification marker. This paper describes the pulmonary abnormalities at rest and during exercise in the patients with heart failure, highlighting the principal diagnostic tools for evaluation of lungs function, the possible pharmacological interventions, and the parameters that could be useful in prognostic assessment of heart failure patients.

The resistive and elastic work of breathing during exercise in patients with chronic heart failure

Patients with heart failure (HF) display numerous derangements in ventilatory function, which together serve to increase the work of breathing (W(b)) during exercise. However, the extent to which the resistive and elastic properties of the respiratory system contribute to the higher W(b) in these patients is unknown. We quantified the resistive and elastic W(b) in patients with stable HF (n = 9; New York Heart Association functional class I-II) and healthy control subjects (n = 9) at standardised levels of minute ventilation (V'(E)) during graded exercise. Dynamic lung compliance was systematically lower for a given level of V'(E) in HF patients than controls (p<0.05). HF patients displayed slightly higher levels of inspiratory elastic W(b) with greater amounts of ventilatory constraint and resistive W(b) than control subjects during exercise (p<0.05). Our data indicates that the higher W(b) in HF patients is primarily due to a greater resistive, rather than elastic, load to breathing. The greater resistive W(b) in these patients probably reflects an increased hysteresivity of the airways and lung tissues. The marginally higher inspiratory elastic W(b) observed in HF patients appears related to a combined decrease in the compliances of the lungs and chest wall. The clinical and physiological implications of our findings are discussed.

Frequency and significance of unrecognized chronic obstructive pulmonary disease in elderly patients with stable heart failure

BACKGROUND AND AIMS

Due to prolonged life-spans and modern therapeutic approaches, there has been an increase in the number of patients aged ≥ 65 years with chronic heart failure (CHF). The duration and quality of life in elderly patients with CHF also depend on accompanying diseases. Although frequency of chronic obstructive pulmonary disease (COPD) in patients with CHF is about 30%, it is hard to find similar data in the elderly population. COPD is defined as a spirometrically assessed ratio of a post-dilatory forced expiratory volume in the first second, divided by forced vital capacity (FEV1/FVC) <70%. The aims of our study were to assess the prevalence of previously undiagnosed COPD in outpatients (≥ 65 yrs) with stable CHF and to determine the effect of the combination of COPD and CHF on patients' functional capacity as measured by a 6-minute walking test.

METHODS AND RESULTS

Of the 174 study patients, 126 (72.4%) were men. In 48 patients (27.6%) we found previously unrecognized COPD. They were significantly older (75.6 ± 5.8 vs 73 ± 4.5 years, p<0.01) and more frequently had abdominal obesity and a greater waist circumference (98.8 ± 10.2 vs 94.9 ± 9.1 cm, p<0.05). Patients with COPD had significantly shorter 6-min walking distance (275.5 ± 112.9 vs 291.3 ± 96.7 m, p<0.05). Only patient's age had a positive prognostic association with unrecognized COPD (OR=1.16; 95% CI 1.01- 1.34, p<0.01). Patients with COPD showed a significant correlation between actual/predicted FEV1 and the 6-min walking distance (r=0.39, p<0.01).

CONCLUSIONS

We found a high prevalence of unrecognized COPD in elderly patients with CHF and central obesity. Chronic obstructive pulmonary disease influenced functional capacity in CHF patients, as determined by the 6-minute walking test. Closer co-operation between pulmonologists and cardiologists is necessary to optimize management of this large proportion of CHF patients.

A classe da NYHA tem relação com a condição funcional e qualidade de vida na insuficiência cardíaca

A insuficiência cardíaca (IC) é uma síndrome que se apresenta com crescente prevalência, podendo limitar o indivíduo quanto à capacidade físico-funcional, condição pulmonar e qualidade de vida. Este estudo tem como objetivo verificar as limitações pulmonares e físicas, bem como a qualidade de vida dos pacientes e compará-las com as classes funcionais da New York Heart Association (NYHA). Estudo transversal, com amostra de 66 pacientes (45 homens). Foram aplicados uma ficha de avaliação padronizada e o questionário de qualidade de vida Short Form-36 (SF-36). Foram realizados espirometria, manovacuometria e o teste da caminhada de seis minutos (TC6M). Os pacientes (classe I: 24 indivíduos, classe II: 27 e classe III: 15) possuíam uma média de idade de 57,95±10,96 anos e representaram uma amostra com características antropométricas homogêneas. Para a condição pulmonar, observou-se diferença estatística quanto a Capacidade Vital Forçada (CVF), Pico de Fluxo Expiratório e Pressão Expiratória Máxima (Pemáx). Na distância do TC6M houve diferença entre classe I e III e entre II e III (classe I: 439,27±58,85 m, classe II: 370,96±74,41 m e classe III: 268,96±83,88 m), com p<0,001. Para o SF-36, houve decréscimo da qualidade de vida conforme o agravo das classes funcionais. Pacientes com IC apresentam diminuição da condição pulmonar, capacidade físico-funcional e qualidade de vida relacionada ao aumento da classe funcional da NYHA.