The Association Between Lung Hyperinflation and Coronary Artery Disease in Smokers

Lung Hyperinflation as Treatable Trait in Chronic Obstructive Pulmonary Disease: A Narrative Review

Lung hyperinflation (LH) is a common clinical feature in patients with chronic obstructive pulmonary disease (COPD). It results from a combination of reduced elastic lung recoil as a consequence of irreversible destruction of lung parenchyma and expiratory airflow limitation. LH is an important determinant of morbidity and mortality in COPD, partially independent of the degree of airflow limitation. Therefore, reducing LH has become a major target in the treatment of COPD over the last decades. Advances were made in the diagnostics of LH and several effective interventions became available. Moreover, there is increasing evidence suggesting that LH is not only an isolated feature in COPD but rather part of a distinct clinical phenotype that may require a more integrated management. This narrative review focuses on the pathophysiology and adverse consequences of LH, the assessment of LH with lung function measurements and imaging techniques and highlights LH as a treatable trait in COPD. Finally, several suggestions regarding future studies in this field are made.

Prevalence and clinical implications of coronary artery calcium scoring on non-gated thoracic computed tomography: a systematic review and meta-analysis

OBJECTIVES

Coronary artery calcifications (CACs) indicate the presence of coronary artery disease. CAC can be found on thoracic computed tomography (CT) conducted for non-cardiac reasons. This systematic review and meta-analysis of non-gated thoracic CT aims to assess the clinical impact and prevalence of CAC.

METHODS

Online databases were searched for articles assessing prevalence, demographic characteristics, accuracy and prognosis of incidental CAC on non-gated thoracic CT. Meta-analysis was performed using a random effects model.

RESULTS

A total of 108 studies (113,406 patients) were included (38% female). Prevalence of CAC ranged from 2.7 to 100% (pooled prevalence 52%, 95% confidence interval [CI] 46-58%). Patients with CAC were older (pooled standardised mean difference 0.88, 95% CI 0.65-1.11, p < 0.001), and more likely to be male (pooled odds ratio [OR] 1.95, 95% CI 1.55-2.45, p < 0.001), with diabetes (pooled OR 2.63, 95% CI 1.95-3.54, p < 0.001), hypercholesterolaemia (pooled OR 2.28, 95% CI 1.33-3.93, p < 0.01) and hypertension (pooled OR 3.89, 95% CI 2.26-6.70, p < 0.001), but not higher body mass index or smoking. Non-gated CT assessment of CAC had excellent agreement with electrocardiogram-gated CT (pooled correlation coefficient 0.96, 95% CI 0.92-0.98, p < 0.001). In 51,582 patients, followed-up for 51.6 ± 27.4 months, patients with CAC had increased all cause mortality (pooled relative risk [RR] 2.13, 95% CI 1.57-2.90, p = 0.004) and major adverse cardiovascular events (pooled RR 2.91, 95% CI 2.26-3.93, p < 0.001). When CAC was present on CT, it was reported in between 18.6% and 93% of reports.

CONCLUSION

CAC is a common, but underreported, finding on non-gated CT with important prognostic implications.

CLINICAL RELEVANCE STATEMENT

Coronary artery calcium is an important prognostic indicator of cardiovascular disease. It can be assessed on non-gated thoracic CT and is a commonly underreported finding. This represents a significant population where there is a potential missed opportunity for lifestyle modification recommendations and preventative therapies. This study aims to highlight the importance of reporting incidental coronary artery calcium on non-gated thoracic CT.

KEY POINTS

• Coronary artery calcification is a common finding on non-gated thoracic CT and can be reliably identified compared to gated-CT. • Coronary artery calcification on thoracic CT is associated with an increased risk of all cause mortality and major adverse cardiovascsular events. • Coronary artery calcification is frequently not reported on non-gated thoracic CT.

Gender and race disparities in the prevalence of chronic kidney disease among individuals with hypertension in the United States, 2001-2016

Background

Chronic kidney disease (CKD) is a common complication among individuals with hypertension. We aimed to identify the prevalence of CKD and the sex and race disparities within the hypertensive population in the United States from 2001-2016.

Methods

A total of 16,148 participants with hypertension were included, representing 561,909,480 individuals from the U.S. population between 2001 and 2016, as documented in the National Health and Nutrition Examination Survey. The prevalence of albuminuria and CKD stage were assessed using survey-weighted general linear regression analysis. Heterogeneity in the CKD stage among the hypertensive population, stratified by sex and race, was identified through survey-weighted logistic regression analysis.

Results

Overall, the prevalence of albuminuria remained stable (p for trend = 0.3196), and changes in the CKD stage were minimal (p for trend > 0.05) from 2001-2016. In the analysis of CKD stage heterogeneity by sex and race, the prevalence of CKD was higher among women than men and higher among individuals of other races combined than non-Hispanic Whites, but the differences were not statistically significant.

Conclusion

The overall CKD stage within the hypertensive population plateaued between 2001 and 2016. Our findings highlight the importance of continuous monitoring and potential refinement of renoprotection strategies in individuals with hypertension to mitigate the persistent burden of CKD and address health disparities among different demographic groups.

Cardiovascular disease and risk in COPD: a state of the art review

INTRODUCTION

Chronic Obstructive Pulmonary Disease (COPD) and cardiovascular diseases (CVD) commonly co-exist. Outcomes of people living with both conditions are poor in terms of symptom burden, receiving evidence-based treatment and mortality. Increased understanding of the underlying mechanisms may help to identify treatments to relieve this disease burden. This narrative review covers the overlap of COPD and CVD with a focus on clinical presentation, mechanisms, and interventions. Literature up to December 2023 are cited.

AREAS COVERED

1. What is COPD 2. The co-existence of COPD and cardiovascular disease 3. Mechanisms of cardiovascular disease in COPD. 4. Populations with COPD are at risk of CVD 5. Complexity in the co-diagnosis of COPD in those with cardiovascular disease. 6. Therapy for COPD and implications for cardiovascular events and risk. 7. Cardiovascular risk and exacerbations of COPD. 8. Pro-active identification and management of CV risk in COPD.

EXPERT OPINION

The prospective identification of co-morbid COPD in CVD patients and of CVD and CV risk in people with COPD is crucial for optimizing clinical outcomes. This includes the identification of novel treatment targets and the design of clinical trials specifically designed to reduce the cardiovascular burden and mortality associated with COPD. Databases searched: Pubmed, 2006-2023.

Pulmonary function and atherosclerosis in the general population: causal associations and clinical implications

Reduced lung function is associated with cardiovascular mortality, but the relationships with atherosclerosis are unclear. The population-based Swedish CArdioPulmonary BioImage study measured lung function, emphysema, coronary CT angiography, coronary calcium, carotid plaques and ankle-brachial index in 29,593 men and women aged 50-64 years. The results were confirmed using 2-sample Mendelian randomization. Lower lung function and emphysema were associated with more atherosclerosis, but these relationships were attenuated after adjustment for cardiovascular risk factors. Lung function was not associated with coronary atherosclerosis in 14,524 never-smokers. No potentially causal effect of lung function on atherosclerosis, or vice versa, was found in the 2-sample Mendelian randomization analysis. Here we show that reduced lung function and atherosclerosis are correlated in the population, but probably not causally related. Assessing lung function in addition to conventional cardiovascular risk factors to gauge risk of subclinical atherosclerosis is probably not meaningful, but low lung function found by chance should alert for atherosclerosis.

Visual Ordinal Coronary Artery Calcium Score from Non-Gated Chest CT Predicts Mortality After Severe Chronic Obstructive Pulmonary Disease Exacerbation

Purpose

Chronic obstructive pulmonary disease (COPD) patients often undergo chest CT for various indications. Coronary artery calcium (CAC) can be quantified visually on ungated chest CT using an ordinal score that has been shown to correlate well with traditional Agatston CAC scoring. The prognostic role of CAC was studied mainly in stable COPD patients. We aim to study the association between ordinal CAC and mortality amongst patients admitted for acute exacerbation of COPD (AECOPD).

Patients and Methods

Retrospective study of AECOPD cases with no previous coronary revascularization admitted between 1st January 2016 to 30th June 2017 with a chest CT performed during admission or within 365 days prior. Ordinal CAC scoring (scale of 0-12) was performed by an experienced CT cardiologist blinded to patient data and outcomes. Patient demographics and future clinical events were retrieved from electronic medical records.

Results

There were 93 patients included (87.1% male, mean age 75 years) with the majority (59.1%) in GOLD Stage III. There were 21 (22.6%) patients with no CAC as well as 39 (41.9%) and 33 (35.5%) with ordinal CAC of 1-3 and 4-12, respectively. There were no significant differences in Charlson Comorbidity Index (CCI) and the proportion of patients with traditional cardiovascular risk factors (namely hypertension, dyslipidaemia, diabetes and smoking status) between the ordinal CAC score groups. Over a median follow-up period of 2.9 (1.1-3.9) years, there were 51 (54.8%) deaths. An ordinal CAC score of 4-12 was the only significant predictor of mortality after multivariate Cox-regression analysis adjustment for age, gender, body mass index, prior exacerbations, FEV1, cardiovascular risk factors and CCI [HR 3.944, (95% confidence interval 1.647-9.433, p = 0.002)].

Conclusion

Ordinal CAC measured from a current or recent ungated chest CT is an independent predictor of all-cause mortality in admitted AECOPD patients with no previous coronary revascularization.

Predicting left/right lung volumes, thoracic cavity volume, and heart volume from subject demographics to improve lung transplant

Purpose

Lung transplantation is the standard treatment for end-stage lung diseases. A crucial factor affecting its success is size matching between the donor's lungs and the recipient's thorax. Computed tomography (CT) scans can accurately determine recipient's lung size, but donor's lung size is often unknown due to the absence of medical images. We aim to predict donor's right/left/total lung volume, thoracic cavity, and heart volume from only subject demographics to improve the accuracy of size matching.

Approach

A cohort of 4610 subjects with chest CT scans and basic demographics (i.e., age, gender, race, smoking status, smoking history, weight, and height) was used in this study. The right and left lungs, thoracic cavity, and heart depicted on chest CT scans were automatically segmented using U-Net, and their volumes were computed. Eight machine learning models [i.e., random forest, multivariate linear regression, support vector machine, extreme gradient boosting (XGBoost), multilayer perceptron (MLP), decision tree, k -nearest neighbors, and Bayesian regression) were developed and used to predict the volume measures from subject demographics. The 10-fold cross-validation method was used to evaluate the performances of the prediction models. R -squared (R 2 ), mean absolute error (MAE), and mean absolute percentage error (MAPE) were used as performance metrics.

Results

The MLP model demonstrated the best performance for predicting the thoracic cavity volume (R 2 : 0.628, MAE: 0.736 L, MAPE: 10.9%), right lung volume (R 2 : 0.501, MAE: 0.383 L, MAPE: 13.9%), and left lung volume (R 2 : 0.507, MAE: 0.365 L, MAPE: 15.2%), and the XGBoost model demonstrated the best performance for predicting the total lung volume (R 2 : 0.514, MAE: 0.728 L, MAPE: 14.0%) and heart volume (R 2 : 0.430, MAE: 0.075 L, MAPE: 13.9%).

Conclusions

Our results demonstrate the feasibility of predicting lung, heart, and thoracic cavity volumes from subject demographics with superior performance compared with available studies in predicting lung volumes.

Chronic obstructive pulmonary disease and the risk for myocardial infarction by type in people with HIV

OBJECTIVES

The relationship between chronic obstructive pulmonary disease (COPD) and cardiovascular disease in people with HIV (PWH) is incompletely understood. We determined whether COPD is associated with risk of myocardial infarction (MI) among PWH, and if this differs for type 1 (T1MI) and type 2 (T2MI).

DESIGN

We utilized data from five sites in the Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort, a multisite observational study.

METHODS

Our primary outcome was an adjudicated MI, classified as T1MI or T2MI. We defined COPD based on a validated algorithm requiring COPD diagnosis codes and at least 90-day continuous supply of inhalers. We conducted time-to-event analyses to first MI and used multivariable Cox proportional hazards models to measure associations between COPD and MI.

RESULTS

Among 12 046 PWH, 945 had COPD. Overall, 309 PWH had an MI: 58% had T1MI ( N  = 178) and 42% T2MI ( N  = 131). In adjusted models, COPD was associated with a significantly increased risk of all MI [adjusted hazard ratio (aHR) 2.68 (95% confidence interval (CI) 1.99-3.60)] even after including self-reported smoking [aHR 2.40 (95% CI 1.76-3.26)]. COPD was also associated with significantly increased risk of T1MI and T2MI individually, and with sepsis and non-sepsis causes of T2MI. Associations were generally minimally changed adjusting for substance use.

CONCLUSION

COPD is associated with a substantially increased risk for MI, including both T1MI and T2MI, among PWH. Given the association with both T1MI and T2MI, diverse mechanistic pathways are involved. Future strategies to decrease risk of T1MI and T2MI in PWH who have COPD are needed.

A Model to Predict Residual Volume from Forced Spirometry Measurements in Chronic Obstructive Pulmonary Disease

Background

Lung hyperinflation with elevated residual volume (RV) is associated with poor prognosis in adults with chronic obstructive pulmonary disease (COPD) and is a critical criterion for lung volume reduction selection. Here, we proposed that patterns within spirometric measures could represent the degree of hyperinflation.

Methods

Fractional polynomial multivariate regression was used to develop a prediction model based on age, biological sex, forced expiratory volume in 1 second (FEV₁), and forced vital capacity (FVC) to estimate plethysmography measured RV in patients in the Pittsburgh Specialized Center for Clinically Oriented Research (SCCOR) cohort (n=450). Receiver operating characteristic area under the curve (ROC-AUC) and optimal cut-points from the model were identified. The model was validated in a separate cohort (n=793).

Results

The best fit model: RV %est=[FVC %predicted] x 3.46-[FEV₁/FVC] x 179.80- [FVC % (sqrt)] x 79.53-[age] x 0.98- [sex] x 10.88 + 737.06, where [sex], m=1. R² of observed versus %predicted RV was 0.71. The optimal cut-point to predict an RV % >175% was 161. At this cut-point, ROC-AUC was 0.95, with a sensitivity 0.95, specificity 0.86, positive predictive value (PPV) of 97%, negative predictive value (NPV) of 76%, positive likelihood ratio (LR) of 6.6, and negative LR of 0.06. In a validation cohort of COPD patients (n=793), the model performed similarly, with a sensitivity of 0.82, specificity of 0.83, PPV of 85%, NPV of 79%, positive LR of 4.7, and negative LR of 0.21.

Conclusion

In patients with COPD, a model using only spirometry, age, and biological sex can estimate elevated RV. This tool could facilitate the identification of candidates for lung volume reduction procedures and can be integrated into existing epidemiologic databases to investigate the clinical impact of hyperinflation.