Suspected Non-ST-elevation acute coronary syndrome meeting rapid rule-out criteria: resource utilization, diagnostic yield, and clinical outcomes of hospital admission

Many patients with suspected non-ST-elevation (NSTE) acute coronary syndromes (ACS) are admitted, even those with initial high-sensitivity cardiac troponins (hs-cTn) values who meet rapid rule-out criteria for myocardial infarction (MI). We examined the clinical outcomes, resource utilization, and diagnostic yield of suspected NSTE-ACS patients, who presented with hs-cTnT values meeting these criteria but were nevertheless hospitalized.

Applying the 2020 European Society of Cardiology (ESC) rapid rule-out MI criteria, we identified consecutive patients with an initial value of hs-cTnT <5 ng/L or an initial value of ≥5 ng/L but <14 ng/L (99^th percentile) and a small increment in a subsequent test, who were nevertheless admitted. The majority (85.4%) of patients presented to the emergency department (ED) with suspected NSTE-ACS had an initial hs-cTnT <99^th percentile. We examined 3775 admitted patients out of 11 477 patients who were triaged and met MI rule-out criteria. Only 0.32% (12 patients) of admitted patients experienced index MI or overall death within 30 days. Resource utilization in terms of ED stay, hospital stay, noninvasive and invasive tests was substantial, yet revascularization was uncommon (2.5%). Multivariate adjustment for age, gender, and baseline cardiovascular risk factors demonstrates similar survival of admitted vs. discharged patients (P = 0.88). Initial hs-cTnT even below the 99^th percentile provided a prognostic stratification for long term mortality.

Our findings support a policy of ED discharge of suspected NSTE-ACS patients meeting rapid MI rule-out criteria and subsequent ambulatory evaluation, sparing resource-consuming admissions. In-hospital and ensuing prognosis were better with lower initial hs-cTnT values.