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BARCELONA -- A 1-hour rule-out algorithm for suspected non-ST segment elevation myocardial infarction (NSTEMI) was as safe as a 3-hour algorithm, according to a study validating European guidelines but with implications for the newly-approved assay in the U.S. as well.
The high-sensitivity cardiac troponin T (hs-cTnT) had a negative predictive value of 99.8% and sensitivity of 99.3% in rule-out and 74.7% positive predictive value and specificity of 94.5% for rule-in, reported Raphael Twerenbold, MD, of Cardiovascular Research Institute Basel, Switzerland, at the (ESC) meeting.
Again using the algorithm set out by ESC guidelines, for high-sensitivity cardiac troponin I (hs-cTnI, Architect, not available in the U.S.) the negative predictive value was 99.6% and sensitivity 98.8% for rule-out. Its rule-in positive predictive value was 64.2% and specificity 90.4%.
Twerenbold concluded that the algorithm for testing at presentation and 1 hour was "very safe" and pointed also to their "largest-ever subgroup analysis in early presenters confirmed very high safety."
Co-investigator Christian Mueller, MD, PhD, of the same institute, added in a press release from the ESC: "These findings are of immediate and critical clinical relevance as many institutions worldwide are considering switching to the implementation of an accelerated, high-sensitivity cardiac troponin-based diagnostic protocol such as the 0/1-hour algorithm recommended by the ESC."
In January, the FDA cleared the first in a new generation of cardiac troponin T blood tests for rapid diagnosis of acute MI, Roche's Elecsys TnT Gen 5 STAT test, which has a turn-around time of 9 minutes.
Such TnT blood tests have been used in Europe and other regions for 7 years, but the company is not allowed to call it a "high-sensitivity" troponin T test. It has been advised by the FDA to use the term "next generation" instead, although it is the same test referred to as a high-sensitivity TnT assay in published studies and outside the U.S., she said.
The study included pooled patient-level data from the APACE and BACC prospective studies with 4,350 unselected patients presenting with symptoms suggestive of MI to emergency departments at four centers in six European countries. Patients with STEMI were excluded, and final diagnosis was centrally adjudicated.
Disclosures
The APACE study was supported by the Swiss National Science Foundation, the Swiss Heart Foundation, the KTI, the European Union, the Stiftung für kardiovaskuläre Forschung Basel; Abbott, Beckman Coulter, Biomerieux, Brahms, Roche, Siemens, and Singulex.
The BACC study was supported by the German Center of Cardiovascular Research and Abbott Diagnostics. The investigated high-sensitivity cardiac troponin T and I assays were donated by Roche and Abbott, who had no role in the design of the study, the analysis of the data, the preparation of the manuscript, or the decision to submit the manuscript for publication.
Twerenbold disclosed support from the Swiss National Science Foundation and relevant relationships with Roche Diagnostics, Abbott Diagnostics, Siemens, and Brahms.
Primary Source
European Society of Cardiology
Twerenbold R, et al "Validation of the European Society of Cardiology 0/1-Hour algorithm for rule-out and rule-in of acute myocardial infarction" ESC 2017.