Critical roles of inflammation in atherosclerosis

There is accumulating evidence that vascular inflammation plays critical roles in pathophysiology of atherosclerosis. It is widely accepted that both innate and adaptive immune responses are important for initiation and progression of atherosclerosis, which mainly consist of monocytes, macrophages, neutrophils, T lymphocytes, and B lymphocytes. Moreover, inflammatory biomarkers such as high-sensitivity C-reactive protein and interleukin-6 are known to predict future cardiovascular events, as well as conventional low-density or high-density lipoprotein cholesterol. Thus, current understanding of the inflammatory mechanisms of atherosclerosis have led us to explore novel therapeutic approaches that reducing vascular inflammation itself could lower the rates of critical cardiovascular events. To address the inflammatory hypothesis of atherosclerosis, results of the Canakinumab Anti-inflammatory Thrombosis Outcomes Study (CANTOS) trial have been recently reported that anti-inflammatory therapy using canakinumab, a monoclonal antibody targeting interleukin-1β, significantly reduced recurrent cardiovascular events for secondary prevention of myocardial infarction at high inflammatory risk. In this review, we will first outline the mechanisms of atherosclerosis, especially focusing on their inflammatory aspects. Then we will introduce several critical inflammatory biomarkers that contribute to risk stratification of clinical cardiovascular events. Lastly, we will discuss potentiality and future perspectives of reducing inflammation as a novel therapeutic target for atherosclerotic cardiovascular diseases.