Coronary artery disease (CAD) affects over 20 million people worldwide and is the leading cause of morbidity and mortality1. In CAD, atherosclerosis narrows the coronary arteries leading to myocardial ischemia thence decreased systolic and diastolic cardiac function. Furthermore, previous studies highlight an association between CAD and atrial fibrillation (AF)2. The pathogenic mechanisms are complex, though elevations of inflammatory markers such as cytokines play a key role. However, clinical studies examining this are limited3. In this preliminary study, we measured plasma levels of cytokines in a CAD patient cohort then correlated those levels to indices of systolic and diastolic cardiac function.
The study was conducted in accordance with local and IRAS ethical approval (IRAS ID: 247341). Preoperative serum samples were collected from patients scheduled for routine coronary revascularisation surgery. Serum interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-1ß (IL-1ß) and tumour necrosis factor alpha (TNF-a) concentrations were measured using high-sensitivity ELISA kits (Abcam, UK & Invitrogen, USA). Statistical significance was taken when p < 0.05 and calculated using Pearson R correlation.
Average IL-6, IL-1ß, IL-10 and TNF-a concentrations were 15.20 ± 1.36, 1.46 ± 0.26, 4.21 ± 0.59 and 2.70 ± 0.61 pg/mL, respectively. We found no significant correlations between the levels of these cytokines and the indices of systolic function measured (EF, LVOT, TASPE, PASP). When cytokine levels were correlated to indices of diastolic function, IL-1ß and IL-10 correlated with peak E-wave velocity (IL-1ß: p = 0.02, r2 = 0.21, n = 27. IL-10: p = 0.04, r2 = 0.08, n = 53). No correlations between cytokine levels and end diastolic volume were observed.
These preliminary data indicate that levels of IL-1ß and IL-10 correlate to certain indices of cardiac diastolic function so may be of use as a prognostic marker in CAD patients. Further experiments will increase study power and seek to identify other key correlates including risk of arrythmia such as AF.