Systemic vascular dysfunction is associated with emphysema burden in mild COPD

作者：Zelt Joel T; Jones Joshua H; Hirai Daniel M; King Trevor J; Berton Danilo C; Pyke Kyra E; O'Donnell Denis E; Neder J Alberto^*

来源：Respiratory Medicine, 2018, 136: 29-36.

DOI：10.1016/j.rmed.2018.01.007

• Emphysema
• Computed tomography
• Gas exchange
• Blood flow
• Vascular function

Background: Cardiovascular diseases play a major role in morbidity and mortality in the earlier stages of COPD. We hypothesized that systemic vascular dysfunction would be present even in patients who are currently considered at "low-risk" for negative cardiovascular outcomes, i.e., those with largely preserved FEV1, few exacerbations and only mild burden of respiratory symptoms ( GOLD spirometric grade 1, clinical group A).
Methods: 16 patients ( FEV1=86 +/- 13%) and 16 age- and gender-matched controls underwent measurements of: a) central arterial stiffness by pulse wave velocity, b) brachial flow-mediated dilation and c) forearm muscle oxygenation by near-infrared spectroscopy. Computed tomography quantified emphysema (% of low attenuation areas ( LAA)) and airway disease.
Results: Patients and controls were well matched for key clinical variables including co-morbidities burden. Thirteen patients presented with more than 5% LAA: emphysema extension was negatively related to transfer factor for carbon monoxide ( TLCO) ( r=-0.63; p=.01). Compared to controls, patients had higher central arterial stiffness, lower normalized ( to shear stress) flow-mediated dilation, delayed time to peak flow-mediated dilation and poorer muscle oxygenation ( p<.05). TLCO and emphysema, but not airway disease, were significantly related to each of these functional abnormalities ( r values ranging from 0.51 to 0.66; p<.05).
Conclusion: Systemic vascular dysfunction is present in the earlier stages of COPD, particularly in patients with greater emphysema burden and low TLCO. Regardless FEV1, patients showing those structural and functional abnormalities might be at higher risk of negative events thereby deserving closer follow-up for early detection of cardiovascular disease.

• 出版日期2018-3