Impact of a rapid high-sensitivity troponin pathway on patient flow in an urban emergency department

Abstract

Study objective: To evaluate whether the introduction of a 1-hour high-sensitivity cardiac troponin-T (hs-TnT) pathway for patients who present to the emergency department (ED) with suspected acute coronary syndrome (ACS) improves ED patient flow without changing the rate of "missed" major adverse cardiac events (MACE), compared to use of conventional cardiac troponin with an associated 3-hour pathway.

Methods: This was a prospective, uncontrolled observational study conducted before and after implementation of a 1-hour hs-TnT pathway at a high-volume urban ED. Patients undergoing evaluation for ACS in the ED were enrolled during their initial visit and clinical outcomes were assessed at 30 and 90 days. Throughput markers were extracted from the electronic medical record and compared. The primary outcome was provider-to-disposition decision time.

Results: A total of 1892 patients were enrolled, 1071 patients while using conventional troponin and 821 after introduction of hs-TnT. With the new assay and pathway, median interval between troponin tests decreased from 4.7 hours (interquartile range [IQR] 3.9-5.7 hours) to 2.3 hours (IQR 1.5-3.4 hours) (P < 0.001). However, there was no difference in median provider-to-disposition decision time, which measured 4.7 hours (IQR 2.9-7.2) and 4.8 hours (IQR 3.1-7.1) (P = 0.428) respectively. Total 30-day MACE rate in discharged patients was low in both groups, occurring in only 4/472 (0.85%) encounters in the first cohort and 4/381 (1.0%) encounters in the second.

Conclusion: Introduction of a 1-hour hs-TnT ACS evaluation pathway reduced the troponin collection interval but did not reduce provider to disposition time. There was no difference in rate of 30-day MACE in patients discharged from the ED.

Keywords: acute coronary syndrome; high‐sensitivity cardiac troponin; length of stay; myocardial infarction; throughput; troponin.

FIGURE 1

Flow diagram of patient enrollment. * These were mostly encounters where troponin testing was ultimately not performed in the ED, either because of misplaced specimens or change in the planned clinical workup. Other reasons for exclusion were 4 patients with heart transplant or left‐ventricular assist device, 2 patients who did not speak English or Spanish, 1 patient with STEMI, and 1 patient who had psychiatric decompensation noted during the ED and was likely lacked capacity to consent.” Abbreviations: ED, emergency department; EHR, electronic health record; MACE, major adverse cardiac events; STEMI, ST‐segment–elevation myocardial infarction

FIGURE 2

Provider‐to‐decision time (PtDT) and serial troponin draw intervals before and after rapid algorithm and hs‐TnT implementation. Boxes A and B show histograms of PtDT and troponin interval time, respectively. The pink and teal bars represent the count of encounters in each bin for conventional and hs‐TnT cohorts, respectively; the shading is darker where the heights of the bars overlap. The dashed lines denote the medians. Note the axes are scaled differently between these 2 diagrams. Boxes C and D show the same data as box plots. The dark vertical line represents the median, and the limits of the box denote the interquartile range (IQR). The whiskers are set at 1.5*IQR above and below the 75th and 25th percentiles, respectively. Data beyond the end of the whiskers are plotted individually. The median PtDT was not significantly different between groups (P = 0.428); however, the median troponin draw interval did decrease significantly (P < 0.001).” Abbreviation: hs‐TnT, high‐sensitivity troponin T