A review of the peri-operative risk stratification assessment tools used for the prediction of cardiovascular complications in non-cardiac surgery

The development of atherosclerosis is a complex process that involves several inflammatory mechanisms. The evolution of a fatty streak to a mature occlusive atheromatous plaque occurs over several decades. However, during acute plaque rupture, to a varying degree, these same inflammatory systems are involved. Evidence exists that suggests a relationship between the activated inflammatory pathways; in the setting of lower respiratory tract or urinary tract infections and cardiac events such as unstable angina or myocardial infarctions. Peripheral vascular disease patients demonstrate atheromatous disease throughout their arterial tree, with coronary artery involvement in a significant proportion of individuals. The stress that a surgical intervention creates may be the catalyst for an acute coronary syndrome through the activation of these inflammatory pathways. Individual responses to the surgical insult are unpredictable and the extent to which the inflammatory mechanisms are stimulated is variable. The measurements of inflammatory biomarkers, such as C-reactive protein, have been associated with adverse short- and long-term mortality in patients who experience an acute coronary syndrome. This review article looks at the previous assessment tools that have been developed over time to try and predict the peri-operative risk of patients undergoing non-cardiac surgery, based on traditional patient parameters. We also explore the use of bio-markers in addition to these characteristics and how future work is being developed to look at the potential use of these to improve individual risk profiles.