Stroke in atrial fibrillation: inflammation as additional risk (retrospective study)
Authors: Grigoryan S , Hazarapetyan LG , Stepanyan AA , Andreasyan DM 
Published: May 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Atrial fibrillation (AF) is a highly prevalent problem that is becoming more common with population aging and has many complication. The most significant complication of AF is thromboembolism, particularly stroke, because AF produces a hypercoagulable state and provokes pro-fibrotic, pro-hypertrophic, and pro-inflammatory responses in a variety of tissues. Various inflammation markers such as interleukin-6 (IL-6) and high sensitivy C-reactive protein (hsCRP) have been linked with AF. Several prothrombotic factors have been found to be elevated in AF, which contributed to an increased risk for stroke.The tissue factor (TF) as a principal initiator of the coagulation cascade. The aim of this study is to investigate the relationship between inflammation markers and risk of dynamic cerebrovascular accident or stroke, including the impact of this interaction on the outcome in patients with AF
Methods. We observed 441 patients with nonvalvular AF during 5 years (2010-2016). Clinical examination of patients included a study of complaints (especially HF, dynamic cerebrovascular accident and stroke), physical, laboratory and instrumental examination, also additional biochemical blood tests , such as TF, hsCRP and IL-6. The blood tests were determined by ELISA on the analyzer "Stat Fax 303 Plus". Treatment regimens carried out in all patients included standard therapy, which is held in the hospital for the treatment of AF. Studies were conducted on the basis of simple randomized open-label protocols, using the universal statistical packages SPSS 13.0

Results
Obtained results have shown that among 441 patients with AF within 5 years, heart failure was detected in 257 patients, 116 had either a cerebral circulation disorder or a stroke. It was found that in patients undergoing dynamic cerebrovascular accident or stroke there was a significant increase in levels of inflammatory markers compared with other patients with AF. So, the significant differences between the levels of hsCRP are 6, 7± 1.8 vs. 3.2 ± 0.6 p = 0.002 and level of IL-6 is 4.2± 0.8 vs. 2.6± 1.1 p = 0.043 accordingly. We revealed also that in patients with dynamic cerebrovascular accident or stroke the level of TF is improved as compared the other patients with AF (1200± 50.vs 850 ± 31.9 p = 0.026). Moreover plasma levels of hsCRP were higher among AF patients at high risk of stroke (=3 or more) by CHA2DS2-VASc (p = 0.003). Besides the levels of hsCRP and IL-6 are markedly elevated in patients with dilated left atrium, poorly functioning left atrial appendage and ventricular dysfunction .The similar tendency of hsCRP, IL-6 and TF was also observed in patients with AF and heart failure.

Conclusion
we have demonstrated that inflammation markers such as hsCRP and IL-6, together with coagulation cascade markers, are additional prognostic criteria that contribute to the development of dynamic cerebral circulation disorders or stroke in patients with AF