To explore the predictive value of single high-sensitivity cardiac troponin I (hs-cTnI) concentration of 30-day cardiovascular adverse events in patients with suspected acute coronary syndrome (ACS).

This is a multicenter, prospective and observational clinical study. Patients with suspected ACS who were admitted into the emergency department of Fuwai Hospital, the First Affiliated Hospital of Sun Yat-sen University and Nanjing First Hospital from January 2017 to September 2020 were enrolled. hs-cTnI result at the time of visit was obtained from patients with suspected ACS. Patients were followed up for 30 days and patients were divided into no events group and events group according to the presence or absence of 30-day cardiovascular adverse events (acute myocardial infarction (including index), unplanned revascularization and cardiovascular death). The predictive value of single Hs-cTnI at different concentration thresholds on the adverse event was evaluated in terms of sensitivity, negative predictive value (NPV) and 95% confidence interval (CI). The best threshold was defined as: missed diagnosis rate <2% and NPV >99%. Patients were sub-grouped according to the confounders of hs-cTnI (sex, age, chest pain duration, estimated glomerular filtration rate), and Chi-square test was used to compare sensitivity and NPV among various subgroups.

A total of 1 461 patients were included. Among them, 387 patients (26.5%) had 30-day adverse cardiovascular events and 1 074 patients (73.5%) had no adverse cardiovascular events. Mean age was (62±12) years old and 905 were males (61.9%). When the concentration of hs-cTnI was less than 2 ng/L (limit of detection), the missed diagnosis rate of 30-day cardiovascular adverse events was 0.8% (3/387), the sensitivity was 99.2% (95%CI 97.6%-99.8%), and NPV was 98.7% (95%CI 96.0%-99.7%). When hs-cTnI concentration was less than 6 ng/L, the missed diagnosis rate was 1.8%, the sensitivity was 98.2% (95%CI 96.1%-99.2%), and NPV was 99.0% (95%CI 97.9%-99.6%). Subgroup analysis showed that the sensitivity and NPV of single hs-cTnI concentration <6 ng/L for 30-day cardiovascular adverse events were lower in patients with chest pain less than 3 h than those with chest pain time>3 hours (P<0.05).

Single hs-cTnI concentration less than 6 ng/L can predict the risk of 30-day cardiovascular adverse events in suspected ACS patients, but continuous monitoring is recommended for patients with chest pain onset≤3 hours.

High sensitivity troponin; Acute coronary syndrome; Cardiovascular adverse events