The effects of pulmonary rehabilitation on endothelial function and arterial stiffness in patients with chronic obstructive pulmonary disease

Pulmonary rehabilitation and endothelial function in patients with chronic obstructive pulmonary disease: A prospective cohort study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with subclinical atherosclerosis and endothelial dysfunction, thereby leading to increased cardiovascular risk. In the present study, we evaluated the changes in endothelium-dependent flow-mediated dilation (FMD) in a cohort of severe COPD patients undergoing pulmonary rehabilitation.

METHODS

Consecutive COPD patients referred to our Pulmonary Rehabilitation Unit were screened for inclusion. All study procedures were performed at hospital admission and discharge.

RESULTS

Of 78 patients screened for eligibility, a total of 40 participants (67.5% males, median age 72.5 years) were included. After pulmonary rehabilitation, a significant improvement in functional parameters, exercise capacity, and measures of disability and quality of life were documented. FMD changed from 3.25% (IQR: 2.31-4.26) to 4.95% (IQR: 3.57-6.02), corresponding to a 52.3% increase of its median value (P < 0.001). Significantly lower changes in FMD were documented in COPD patients with hypercholesterolemia as compared to those without (+0.33% ± 1.61 vs. +1.62% ± 1.59, P = 0.037). Changes in FMD (ΔFMD) were positively associated with changes in forced expiratory volume in 1 s (FEV1), when expressed both as absolute values (ΔFEV1) (r = 0.503, P = 0.002) and as percentages of predicted values (ΔFEV1%) (r = 0.608; P < 0.001). In multiple linear regressions, after adjusting for major cardiovascular risk factors, ΔFEV1 (β=0.342; P = 0.049) and ΔFEV1% (β=0.480; P = 0.015) were both confirmed as independent predictors of ΔFMD.

CONCLUSIONS

Results of our study suggest that endothelial function may improve in COPD after pulmonary rehabilitation. The potential beneficial effect in terms of cardiovascular risk prevention should be evaluated in ad hoc designed studies.

Analysis of retinal blood vessel diameters in patients with COPD undergoing a pulmonary rehabilitation program

BACKGROUND

Regular exercise positively affects cardiovascular physiology, translating into the adequate capacity of microvascular blood vessels to dilate in response to acute bouts of exercise. However, this remains unstudied in patients with chronic obstructive pulmonary disease (COPD), who often suffer from cardiovascular comorbidity. Therefore, we studied acute changes in retinal blood vessel diameters in response to high-intensity exercise in patients with COPD. The effect of an exercise-based 8-week pulmonary rehabilitation (PR) program was evaluated. We consider changes in these retinal metrics as an indicator of microvascular reactivity.

METHODS

Demographics and clinical characteristics of 41 patients were collected at the start and end of the PR program. Patients performed a high-intensity exercise test on a cycle ergometer at the start and end of the PR program, during which we collected retinal images. Fundus images were taken immediately before and 0, 5, 10, 15, and 30 min after the ergometer test. Widths of retinal blood vessels, represented as Central Retinal Arteriolar and Venular Equivalents (CRAE and CRVE), were calculated.

RESULTS

Thirty patients with COPD completed the study protocol (57% males; mean age: 64 ± 7 years; mean FEV₁: 45 ± 17%pred). We did not observe a change in retinal vessel widths following the ergometer test at the start of the PR program. This null result remained at the end of the 8-week PR program. Our observations did not alter when considering responders and non-responders to PR.

CONCLUSION

Retinal blood vessel diameters of patients with COPD did not change following an exercise test on an ergometer. The exercise-based PR program of eight weeks did not counteract the blunted retinal microvascular response.

Vascular endothelial damage in COPD: current functional assessment methods and future perspectives

Introduction: Cardiovascular disease is a major cause of death in chronic obstructive pulmonary disease (COPD), but the relationship between these two entities is not fully understood; smoking, inflammation, arterial stiffness and endothelial dysfunction are significant determinants. Endothelial dysfunction is not only associated with cardiovascular disease, but also with COPD severity.Areas covered: Several functional methods have been developed to evaluate endothelial function in healthy and diseased individuals; from the invasive angiography of epicardial coronary arteries and Venous-Occlusion-Plethysmography, to more modern, noninvasive approaches such as Flow-Mediated-Dilatation, Peripheral-Arterial-Tonometry and Near-Infrared-Spectroscopy, all these methods have boosted clinical research in this field. In this context, this narrative review, which included articles published in PubMed and Scopus up to 25-November-2020, summarizes available functional methods for endothelial damage assessment in COPD and discusses existing evidence on their associations with comorbidities and outcomes in this population.Expert opinion: Accumulated evidence suggests that endothelial dysfunction occurs in early stages of CΟPD and worsens with pulmonary obstruction severity and during acute exacerbations. Novel methods evaluating endothelial function offer a detailed, real-time assessment of different parameters related to vascular function and should be increasingly used to shed more light on the role of endothelial damage on cardiovascular and COPD progression.

The Cost-Effectiveness of Pulmonary Rehabilitation for COPD in Different Settings: A Systematic Review

BACKGROUND

Chronic obstructive pulmonary disease (COPD) has high morbidity and mortality rates. COPD impairs body functioning, reduces quality of life, and creates a great economic burden for society. Pulmonary rehabilitation (PR) has become an important nonpharmacological treatment for COPD. This paper systematically reviews economic evaluations of PR in COPD patients in different settings.

OBJECTIVES

We aimed to understand the cost-effectiveness of PR in different settings for COPD to provide economic evidence for decision-makers.

METHODS

We searched eight databases from their inception to 23 November 2019. The results were presented in terms of an incremental cost-effectiveness ratio (ICER), and the decision uncertainty was expressed by cost-effectiveness acceptability curves (CEACs). We used the Consensus on Health Economic Criteria to assess study quality.

RESULTS

This review included ten studies that matched the selection criteria. Five studies compared PR with usual care in primary healthcare or outpatient departments. Two studies compared community-based PR with hospital PR or usual care. In the other studies, PR was mainly carried out at home. Compared with usual care, PR was cost-effective in primary healthcare institutions or outpatient departments. According to CEACs, community-based PR had a 50% probability of cost-effectiveness at £30,000/quality-adjusted life year (QALY) compared with hospital PR in the UK. Based on the ICER, community-based PR was "moderately" cost-effective, with a ratio of €32,425/QALY compared with usual care in the Netherlands. Home-based PR was dominant compared with usual care, and tele-rehabilitation was dominant compared with traditional home PR.

CONCLUSIONS

PR conducted in different settings can potentially be cost-effective, as measured using QALY or the Chronic Respiratory Questionnaire (CRQ).

The CT pulmonary vascular parameters and disease severity in COPD patients on acute exacerbation: a correlation analysis

Background

It is necessary to analyze the CT pulmonary vascular parameters and disease severity in chronic obstructive pulmonary disease (COPD) patients to provide evidence support for the management of COPD.

Methods

COPD patients on acute exacerbation admitted to our hospital from COPD patients from January 2019 to March 2020 was selected. The characteristics and ratio of the cross-sectional area (CSA) of small pulmonary vessels to the total area of the lung field, and the ratio of pulmonary artery and aorta (PA/A) cross-sectional diameter in patients with COPD were analyzed.

Results

A total of 128 COPD patients were included. There were significant differences in the duration of COPD, smoking history, the PaO₂, PaCO₂, pH, and FEV1, FVC and FEV1/FVC among COPD patients with different severity (all p < 0.05). The duration of COPD, smoking, PaO₂, PaCO₂, CSA and PA/A were correlated with the COPD severity (all p < 0.05). Both CSA, PA/A were correlated with post BD FEV1 (all p < 0.05). The cutoff value of CSA and PA/A for the diagnosis of severe COPD was 0.61 and 0.87 respectively, and the AUC of CSA and PA/A for the diagnosis of severe COPD was 0.724 and 0.782 respectively.

Conclusions

Patients with CSA ≤ 0.61 and PA/A ≥ 0.87 may have higher risks for severe COPD, and more studies are needed in the future to further elucidate the management of COPD.