Representativeness in randomised clinical trials supporting acute coronary syndrome guidelines

Aims Clinical practice guidelines (CPGs) are published to guide the management of acute coronary syndrome (ACS). We aimed to critically appraise the representativeness and standard of care of randomised clinical trials (RCTs) supporting CPGs for ACS. Methods and results American and European CPGs for ST- and non-ST-elevation ACS were screened to extract all references (n = 2128) and recommendations (n = 600). Among the 407 primary publications of RCTs (19.1%), there were 52.6 and 73.2% recruiting patients in North America and Europe, respectively, whereas other regions were largely under-represented (e.g. 25.3% RCTs recruited in Asia). There was 68.6% RCTs enrolling patient with ACS, whereas the remaining 31.4% did not enrol any patient with ACS. There was under-representation of some important subgroups, including elderly, female (29.9%), and non-white patients (<20%). The incidence and type of reperfusion reported in these RCTs were not reflective of current clinical practice (the percentage of patients who underwent percutaneous coronary intervention (PCI) among all RCTs was 42.7%; whereas for ST-Elevation Myocardial Infarction patients, the number of participants who underwent fibrinolysis was 3.3-fold higher than those who underwent primary PCI). All-cause mortality in these RCTs was 11.9% in RCTs with a follow-up <= 1 year. Conclusion Randomised clinical trials supporting CPGs for ACS are not fully representative of the diversity of the ACS population and their current standard of care. While some of these issues with representativeness may be explained by how evidence has been accrued over time, efforts should be made by trialists to ensure that the evidence supporting CPGs is representative of the wider ACS population.