Impact of more conservative European Society of Cardiology Guidelines on the management of patients with acute chest pain.

OBJECTIVE Early diagnosis or rule-out of acute coronary syndrome (ACS) is a key competence of emergency medicine. Changes of the NSTE-ACS guidelines of the European Society of Cardiology (ESC) in 2015 and 2020 both warranted a henceforth more conservative approach regarding high-sensitivity troponin t (hsTnt) testing. We aimed to assess the impact of more conservative guidelines on the frequency of early rule-out and prolonged observation with repeated hsTnt testing at a high-volume tertiary care emergency department. PATIENTS AND METHODS We conducted a pre- and post-changeover analysis 3 months before and 3 months after transition from less (hsTnt cut-off 30ng/l, 3-hour rule-out) to more conservative (hsTnt cut-off 14ng/l, 1-hour rule-out) guidelines in 2015, comparing proportions of patients requiring repeated testing. RESULTS We included 5,442 cases of symptoms suspicious of acute cardiac origin (3,451 before, 1,991 after, 2,370 (44%) female, age 55 (SD 19) years). The proportion of patients fulfilling early-rule out criteria decreased from 68% (2,348 patients) before to 60% (1,195 patients) with the 2015 guidelines (p<0.01). Those requiring repeated testing significantly (p<0.01) increased from 22% (743 patients) to 25% (494 patients). Positive results in repeated testing significantly (p=0.02) decreased from 43% (320 patients) to 37% (181 patients). Invasive diagnostics were performed in 91 patients (2.6%) before and in 75 patients (3.8%) after (p=0.02) the guideline revision. CONCLUSION The implementation of the more conservative 2015 ESC guidelines led to a minor rise in prolonged observations due to an increase in negative repeated testing and to an increase in invasive procedures.