Cardiovascular benefits from standard pulmonary rehabilitation are related to baseline exercise tolerance levels in chronic obstructive pulmonary disease

Examining changes in vascular function, arterial stiffness and systemic inflammation during hospitalization and recovery from an acute exacerbation of chronic obstructive pulmonary disease

An acute exacerbation of COPD (AECOPD) is associated with increased risk of cardiovascular (CV) events. The elevated risk during an AECOPD may be related to changes in vascular function, arterial stiffness, and systemic inflammation; the time course of these measures and their corresponding recovery are poorly understood. Further, physical activity is reduced during an AECOPD, and physical activity may influence the cardiovascular responses to an AECOPD. The purpose of the study was to examine the acute impact of an AECOPD requiring hospitalization on vascular function, arterial stiffness, and systemic inflammation and examine whether physical activity modulates these variables during recovery. Patients hospitalized for an AECOPD were prospectively recruited and compared to control patients with stable COPD. Vascular function, arterial stiffness, and systemic inflammation (CRP, IL-6) were measured at hospital admission, hospital discharge and within 14 days of discharge. Physical activity was electronically tracked daily while in hospital and for 7 days following discharge using a Fitbit. One hundred and twenty-one patients with an AECOPD requiring hospitalization and 33 control patients with stable COPD were enrolled in the study. Vascular function was significantly lower, and systemic inflammation higher at hospital admission in patients with an AECOPD compared to stable COPD. Significant improvements in vascular function and inflammation were observed within 14 days of hospital discharge; however, vascular function remained lower than stable COPD. Physical activity was low at admission and increased following discharge; however, physical activity was unrelated to measures of vascular function or inflammation at any time point. An AECOPD requiring hospitalization is associated with impaired vascular function that persists during recovery. These findings provide a mechanistic link to help explain the enduring increase in CV risk and mortality following a severe AECOPD event.Clinical trial registration: ClinicalTrials.gov #NCT01949727; Registered: 09/20/2013.

Pulmonary rehabilitation outcomes in individuals with chronic obstructive pulmonary disease: a systematic review

BACKGROUND

The magnitude of response to pulmonary rehabilitation (PR) is influenced by the selection of outcomes and measures.

OBJECTIVES

This systematic review aimed to review all outcomes and measures used in clinical trials of PR for individuals with chronic obstructive pulmonary disease (COPD).

METHODS

The review involved a search of Scopus, Web of Knowledge, Cochrane Library, EBSCO, Science Direct and PubMed databases for studies of stable individuals with COPD undergoing PR. Frequency of reporting for each domain, outcome and measure was synthesized by using Microsoft Excel.

RESULTS

We included 267 studies (43153 individuals with COPD). A broad range of domains (n=22), outcomes (n=163) and measures (n=217) were reported. Several measures were used for the same outcome. The most reported outcomes were exercise capacity (n=218) assessed with the 6-min walk test (n=140), health-related quality of life (n=204) assessed with the Saint George's respiratory questionnaire (n=99), and symptoms (n=158) assessed with the modified Medical Research Council dyspnea scale (n=56). The least reported outcomes were comorbidities, adverse events and knowledge.

CONCLUSIONS

This systematic review reinforces the need for a core outcome set for PR in individuals with COPD because of high heterogeneity in reported outcomes and measures. Future studies should assess the importance of each outcome for PR involving different stakeholders.

PROSPERO ID

CRD42017079935.

Pulmonary rehabilitation, physical activity and aortic stiffness in COPD

Background

Patients with chronic obstructive pulmonary disease (COPD) have elevated cardiovascular risk, and cardiovascular disease is a major cause of death in COPD. The current literature indicates that changes in cardiovascular risk during pulmonary rehabilitation (assessed using aortic stiffness) are heterogeneous suggesting that there may be sub-groups of patients who do and do not benefit.

Objectives

To investigate the characteristics of COPD patients who do and do not experience aortic stiffness reduction during pulmonary rehabilitation, examine how changes relate to physical activity and exercise capacity, and assess whether changes in aortic stiffness are maintained at 6 weeks following rehabilitation.

Methods

We prospectively measured arterial stiffness (aortic pulse-wave velocity), exercise capacity (Incremental Shuttle Walk Test) and physical activity (daily step count) in 92 COPD patients who started a six week pulmonary rehabilitation programme, 54 of whom completed rehabilitation, and 29 of whom were re-assessed six weeks later.

Results

Whilst on average there was no influence of pulmonary rehabilitation on aortic stiffness (pre- vs. post pulse-wave velocity 11.3 vs. 11.1 m/s p = 0.34), 56% patients responded with a significant reduction in aortic stiffness. Change in aortic stiffness (absolute and/or percentage) during rehabilitation was associated with both increased physical activity (rho = − 0.30, p = 0.042) and change in exercise capacity (rho = − 0.32, p = 0.02), but in multivariable analysis most closely with physical activity. 92% of the responders who attended maintained this response six weeks later.

Conclusion

Elevated aortic stiffness in COPD is potentially modifiable in a subgroup of patients during pulmonary rehabilitation and is associated with increased physical activity.

Trial registration

ClinicalTrials.gov Identifier: NCT03003208. Registered 26/12/ 2016.

Acute effects of salbutamol on systemic vascular function in people with asthma

BACKGROUND

Asthmatics are at increased cardiovascular disease risk, which has been linked to beta2(β₂)-agonist use. Inhalation of β₂-agonists increases sympathetic nerve activity (SNA) in healthy individuals, however the systemic impact of salbutamol in asthmatics using β₂-agonists regularly is unknown.

OBJECTIVES

This study compared the systemic vascular responses to a clinical dose of salbutamol (Phase I) and following an acute increase in SNA (Phase II) in asthmatics and controls.

METHODS

Fourteen controls and 14 asthmatics were recruited for Phase I. On separate days, flow-mediated dilation (FMD) and peripheral arterial stiffness (pPWV) were evaluated at baseline and following either 400 μg inhaled salbutamol or a placebo inhaler. For Phase II, heart rate, blood pressure, vascular conductance, pPWV, and central (c)PWV were evaluated in response to a large increase in SNA brought on by cold-water hand immersion (i.e. cold-pressor test) or body-temperature water hand immersion (i.e. control) in 10 controls and 10 asthmatics.

RESULTS

Following salbutamol, asthmatics demonstrated reduced FMD (-3.0%, p < 0.05) and increased pPWV (+0.7 m/s, p < 0.05); however, salbutamol had no effect in controls. The cold-pressor test resulted in similar increases in blood pressure, vascular flow rates and conductance, pPWV, and cPWV in both asthmatics and controls, suggesting similar neurovascular transduction in asthmatics and controls.

CONCLUSION

Inhaled Salbutamol leads to increased arterial stiffness and reduced FMD in asthmatics. As asthmatics and controls had similar vascular responses to an increase in SNA, these findings suggest asthmatics have heightened sympathetic responses to β₂-agonists which may contribute to the increased cardiovascular risk in asthma.

Improvements in functional and cognitive status following short-term pulmonary rehabilitation in COPD lung transplant recipients: a pilot study

BACKGROUND

Pulmonary rehabilitation (PR) following lung transplantation (LTx) is considered part of the optimal treatment in chronic obstructive pulmonary disease (COPD) for favourable post-operative outcomes. We investigated the effects of a PR intervention in the post-transplant phase with regard to lung function, exercise responses and cognitive function in COPD LTx recipients.

METHODS

24 COPD LTx recipients (mean±sd forced expiratory volume in 1 s 75±22% predicted) were assigned to a comprehensive 3-week inpatient PR programme. Changes from PR admission to discharge in lung function variables, 6-min walk test-derived outcomes and cognitive function were assessed and examined for several factors. The magnitude of changes was interpreted by effect size (ES).

RESULTS

In response to the PR intervention, LTx recipients had improved lung function with regard to diffusing capacity of the lung for carbon monoxide (+4.3%; p=0.012) and static hyperinflation (residual volume/total lung capacity -2.3%; p=0.017), increased exercise capacity (6-min walk test +86 m; p<0.001), and had small to large improvements (ES range 0.23-1.00; all p≤0.34) in 50% of the administered cognitive tests. Learning skills and memory ability presented the greatest benefits (ES composite scores 0.62 and 0.31, respectively), which remained similar after stratification by single or bilateral LTx and sex.

CONCLUSIONS

PR is an effective treatment for LTx recipients in the post-transplant phase, improving lung function, exercise responses, and domains of cognitive function of learning, memory and psychomotor speed. PR may facilitate the course of post-operative treatment and should be recommended in LTx.