A comparative 30-day outcome analysis of inpatient evaluation vs outpatient testing in patients presenting with chest pain in the high-sensitivity troponin era. A propensity score matched case-control retrospective study

Background: The best disposition of chest pain patients who rule out for myocardial infarction (MI) but have non-low clinical risk scores in the high-sensitivity troponin era is not well studied. Hypothesis: In carefully selected patients who rule out for MI, and have a high-sensitivity troponin T ≤ 50 ng/L with an absolute increase less than 5 ng/L on repeat measurements, early emergency room (ER) discharge might be equivalent to inpatient evaluation in regards to 30-day incidence of adverse cardiac events (ACEs) regardless of the clinical risk score. Methods: A total of 12 847 chest pain patients presenting to our health system ERs from January 2017 to September 2019 were retrospectively investigated. A propensity score matching algorithm was used to account for baseline differences between admitted and discharged cohorts. We then estimated and compared the incidence of 30-day and 1-year composite ACEs (MI, urgent revascularization, or cardiovascular death) between both groups. A multivariate Cox regression model was used to evaluate the effect of admission on outcomes. Results: A total of 2060 patients were matched in 1:1 fashion. The primary endpoint of 30-day composite ACEs occurred in 0.6% and 0.4% of the admission and the discharged cohorts, respectively (P =.76). One-year composite ACEs was also similar between both groups (4% vs 3.7%, P =.75). In a multivariate Cox regression model, the effect of inpatient evaluation was neutral (hazard ratio 1.1, confidence interval 0.62-1.9, P =.75). Conclusions: Inpatient evaluation was not associated with better outcomes in our selected group of patients. Larger-scale randomized trials are needed to confirm our findings.