Impact of treatment algorithms on the prescribing of antithrombotic therapy in patients with suspected acute coronary syndrome – a prospective audit

Chest pain presentations are common although most patients do not have an acute coronary syndrome (ACS). We hypothesized that our local therapeutic guideline was leading to many low risk patients being inappropriately treated with potent anti-thrombotic therapy for ACS.We conducted a prospective analysis of patients presenting with suspected ACS to the Western Infirmary Glasgow over a 2 month period between 6/10/13-3/11/13 and 5/4/14-2/5/14. We collated data on demographics, investigation, initial management and final diagnosis. Patients taking warfarin were excluded. We calculated sensitivity, specificity and receiver operating characteristic (ROC) curves for our local guideline, the SIGN guideline and a new guideline proposal.We studied 202 patients of whom 112 (55%) were male with mean (SD) age 60 (15) years. Full anti-thrombotic therapy for ACS was recommended in 91 patients (45%) according to the NHS GGC guideline, 37 (18%) by the SIGN guideline and 30 (15%) by our new guideline proposal. The final diagnosis was ACS in 39 patients (19%). The current NHS GGC guideline had a sensitivity of 80%, specificity 63% and AUROC 0.71 (95% CI 0.63, 0.80). The respective values were 62%, 92% and 0.77 (95% CI 0.67, 0.86) for the SIGN guideline and 54%, 94% and 0.74 (95% CI 0.64, 0.84) for our new proposed guideline.Only one-fifth of patients who present with chest pain or suspected ACS have ACS as their final diagnosis. Our new guideline proposal is highly specific and would minimize unnecessary administration of potent anti-thrombotic therapy to low risk patients.