Endothelial dysfunction and coronary artery disease in patients with COPD

<bold>Introduction:</bold> Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of atherosclerosis and major adverse cardiovascular events. Impairments in vascular function could contribute to this. We aimed to determine if endothelial function related to the presence and severity of radiologically detected coronary artery disease (CAD) in COPD. <bold>Methods:</bold> Patients with COPD underwent assessment of endothelial function (reactive hyperaemia index: RHI) using finger plethysmography peripheral arterial tonometry (EndoPAT; Itamar Medical). CT coronary angiogram (CTCA) was undertaken to quantify the presence of CAD, obstructive CAD (≥50% stenosis of any vessel), multivessel disease (>1 major vessel involved), number of diseased coronary segments (segment involvement score: SIS) and burden of calcified plaque (coronary artery calcium score: CACS). <bold>Results:</bold> Of 32 patients included (mean age 73.1±6.7, 65.6% male), obstructive CAD was present in 10 (31.3%), non-obstructive CAD in 16 (50%) and no CAD in 6 (18.8%). In univariate analysis, the natural log of RHI (LnRHI) was inversely associated with CACS (R= -0.39, p=0.03), SIS (R= -0.37, p=0.04) and was reduced in multivessel disease (0.58 vs. 0.71, p=0.03). There was a trend for reduced LnRHI in those with obstructive CAD (0.57 vs. 0.71, p=0.07). In multivariate analysis correcting for age and sex, CACS remained borderline significant (p=0.052), but other parameters did not. <bold>Conclusion:</bold> Peripheral endothelial dysfunction correlates to the burden and severity of underlying CAD and may hold prognostic value in COPD. Future studies should focus on endothelial-mediated pathways and how they contribute to atheroma development in this patient group.