One-hour rule-in and rule-out of acute myocardial infarction using high-sensitivity cardiac troponin I.
Am J Med. 2015 Mar 31;
Authors: Rubini Gimenez M, Twerenbold R, Jaeger C, Schindler C, Puelacher C, Wildi K, Reichlin T, Haaf P, Merk S, Honegger U, Wagener M, Druey S, Schumacher C, Krivoshei L, Hillinger P, Herrmann T, Campodarve I, Rentsch K, Bassetti S, Osswald S, Mueller C
Abstract
OBJECTIVE: We aimed to prospectively derive and validate a novel 1h-algorithm using high-sensitivity cardiac troponin I (hs-cTnI) for early rule-out and rule-in of acute myocardial infarction.
METHODS: We performed a prospective multicenter diagnostic study enrolling 1811 patients with suspected acute myocardial infarction. The final diagnosis was centrally adjudicated by two independent cardiologists using all available information including coronary angiography, echocardiography, follow-up data, and serial measurements of hs-cTnT (but not hs-cTnI). The hs-cTnI 1h-algorithm incorporating measurements performed at baseline and absolute changes within 1 hour, was derived in a randomly selected sample of 906 patients (derivation cohort), and then validated in the remaining 905 patients (validation cohort).
RESULTS: acute myocardial infarction was the final diagnosis in 18% of patients. After applying the hs-cTnI 1h-algorithm developed in the derivation cohort to the validation cohort, 50.5% of patients could be classified as "rule-out", 19% as "rule-in", 30.5% as "observe ". In the validation cohort the negative predictive value (NPV) for acute myocardial infarction in the "rule-out" zone was 99.6% (95%CI, 98.4-99.9%), and the positive predictive value (PPV) for acute myocardial infarction in the "rule-in" zone was 75.6% (95%CI, 68.5-81.8%), respectively. NPV of the 1h-algorithm was higher compared to the classical dichotomous interpretation of hs-cTnI and to the standard-of-care combining hs-cTnI with the ECG (both p<0.001). PPV also was higher compared to the standard-of-care (p<0.001).
CONCLUSION: Using a simple algorithm incorporating baseline hs-cTnI values and the absolute change within the first hour allows safe rule-out as well as accurate rule-in of acute myocardial infarction in 70% of patients presenting with suspected acute myocardial infarction. Clinical Trial Registration-URL:http://www.clinicaltrials.govUnique identifier:NCT00470587.
PMID: 25840034 [PubMed - as supplied by publisher]