COPD and cardiovascular disease: the missing link?
Cardiovascular disease is the most prevalent and significant comorbidity for people living with COPD. Hypotheses regarding mechanistic links between the two conditions have been emerging in recent years, yet we still have much left to learn.
Unfortunately for those living with chronic obstructive pulmonary disease (COPD), comorbidities are pervasive and can be associated with worse outcomes than the condition alone. Of these comorbidities, cardiovascular disease (CVD) is known to be the most common and significant, with several studies demonstrating an increased risk of cardiovascular-related mortality in patients with COPD.1,2 So how do the two conditions interlink? Numerous mechanisms have been proposed over the years, including extracellular matrix destruction, abnormal cell repair, oxidative stress, and increased airway inflammation; all of which are linked to the recurrent damage caused by cigarette smoke. Vascular remodeling is also thought to have a direct impact on cardiac function, while airflow obstruction is an independent predictor of atherosclerosis. But in recent years, a new hypothesis has emerged.2
A common factor
Elastin degradation is a critical process in the pathogenesis of emphysema, whereby cigarette smoke induced lung inflammation triggers destruction of elastin in alveolar walls by proteases. Researchers have previously demonstrated that arterial stiffness (a key biomarker of cardiovascular risk) in COPD is associated with elastin degradation in the skin. Is elastin degradation therefore a mechanistic link between COPD and CVD risk? Over the past few years this hypothesis has become increasingly accepted in the field. Researchers such as Rabinovich et al. have worked to demonstrate that in patients with COPD, excess elastin degradation relates to cardiovascular comorbidities, atherosclerosis, systemic inflammation and mortality. With no successful interventions to replace elastin loss currently available, and multiple other mechanisms likely to be involved, these results highlight an urgent need to gain a deeper understanding of COPD and CVD pathophysiology.2,3
But what are the ramifications of comorbid CVD for COPD clinical practice? In contrast to mechanistic research findings, fewer advances have been made from a clinical practice perspective over the past decade. Concomitant CVD in those with COPD is linked to a host of negative outcomes, including an increased number of hospitalizations, a greater risk for all-cause and CVD mortality, and a reduced quality of life.4 Treatment of comorbid CVD unavoidably complicates the management of COPD, and this is exacerbated by the lack of clinical guidelines focused on this population. Current regulations state that CVD should be treated in those with COPD as it would be if they did not have the lung disease, leaving physicians in the dark about how to manage the comorbidity.5 If we directly juxtapose COPD with conditions such as kidney disease, diabetes and inflammatory arthritis, which have specific sets of guidelines regarding the screening and treatment of CVD, it’s evident that this highlights a clear unmet need. In addition, underdiagnosis and undertreatment of CVD in COPD remains ubiquitous. Without guideline recommendations physicians may not routinely assess cardiovascular health in those with COPD and may be uncertain of when and how to screen for comorbid CVD.4
A clear unmet need
For those living with COPD and concomitant CVD, there is an opportunity for earlier intervention and primary prevention, either with routine screening implemented in primary care settings, or collaboration with specialist clinics. Alongside this, the development of more detailed evidence-based comorbidity guidelines is critical to provide physicians with the relevant recommendations to help ensure these patients receive a better quality of care.4 Explore more about COPD in our article, COPD and autoimmunity.
- Rabe KF et al. Eur Respir Rev 2018; 27: 180057.
- Bafadhel M and Russell REK. Eur Respir J 2016; 47: 1307–1309.
- Rabinovich RA et al. Eur Respir J 2016; 47: 1365–1373.
- Morgan AD et al. Ther Adv Respir Dis 2018; 12: 1753465817750524.
- GOLD. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. 2019 report. Available at: https://goldcopd.org/wp-content/uploads/2018/11/GOLD-2019-v1.7-FINAL-14Nov2018-WMS.pdf. Accessed: December 2019
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