How rapid is rapid? Exemplary results of real-life rapid rule-out troponin timing in troponin-positive acute coronary syndromes without persistent ST-segment elevation in two contrasting German chest pain unit facilities.

aimTo analyse the timing of cardiac troponin (cTn) measurements in high-risk and cTn-positive acute coronary syndromes without persistent ST-segment elevation (NSTE-ACS) in two structurally different German chest pain units (CPUs), contrasting an urban university maximum care and a rural regional primary care facility.

methodsAll patients encoded as NSTEMI during the year 2013 were retrospectively enrolled in two centres: site (I)--centre of maximum care in an urban university setting and site (II)--centre of primary care in a rural regional care setting. Data acquisition included time intervals from admission to baseline cTn and first and second cTn control as well as type and timing of invasive management.

resultsThe median times (site I vs. site II) from admission to cTn result announcement were 26.5 vs. 33.0 min (p = 0.02) for baseline, 4 vs. 4 h (p = 0.43) for the first and 11.0 vs. 16.5 h (p = 0.03) for the second control. Timely announcement, as recommended by guidelines, was available in 86.9% at baseline, 59.4% for the first or 41.1% for the second cTn control. Rates and timing of invasive management were independent from the time point of positive cTn announcement (p = 0.51 and p = 0.68, respectively).

conclusionsGerman CPUs provide timely identification of cTn-positive patients in a narrow and guideline-adherent time frame using a rapid rule-out protocol. Especially, baseline and early cTn timing was comparable between the urban university maximum care and the rural regional primary care facility without relevant impact on guideline-conforming invasive management, underlining the high standard of care in those highly professional institutions.