PracticeUpdate: Cardiology - Winter 2018

EDITOR’S PICKS 6

Prospective Validation of the 0/1-h Algorithm for Early Diagnosis of Myocardial Infarction JACC: Journal of the American College of Cardiology

Take-home message • In this study, patients presenting to the emergency department with symptoms suggestive of NSTEMI were examined to validate the ESC 0/1-h algorithm. Among 4368 patients with available serial hs-cTnT measurements, the safety of rule-out, accuracy of rule-in, and overall efficacy were found to be high. Similar results were found among 3500 patients with serial hs-cTnI measurements. • These findings demonstrate the safety and efficacy of the ESC 0/1-h algorithm in patients with suspected NSTEMI.

" I recommend that the 0/1-h algorithm for patients

Abstract BACKGROUND The safety of the European Soci- ety of Cardiology (ESC) 0/1-h algorithm for rapid rule-out and rule-in of non-ST-segment elevation myocardial infarction (NSTEMI) using high-sensitivity cardiac troponin (hs-cTn) has been questioned. OBJECTIVES This study aimed to validate the diagnostic performance of the 0/1-h algorithm in a large multicenter study. METHODS The authors prospectively enrolled unselected patients in 6 countries presenting to the emergency department with symptoms sug- gestive of NSTEMI. Final diagnosis was centrally adjudicated by 2 independent cardiologists. Hs-cTnT and hs-cTnI blood concentrations were measured at presentation and after 1 h. Safety of rule-out was quantified by the negative predic- tive value (NPV) for NSTEMI, accuracy of rule-in by the positive predictive value (PPV), and over- all efficacy by the proportion of patients triaged towards rule-out or rule-in within 1 h. RESULTS Prevalence of NSTEMI was 17%. Among 4,368 patients with serial hs-cTnT measurements available, safety of rule-out (NPV 99.8%, 2,488 of 2,493), accuracy of rule-in (PPV 74.5%, 572 of 768), and overall efficacy were high by assign- ing three-fourths of patients either to rule-out (57%, 2,493 to 4,368) or rule-in (18%, 768 to 4,368). Similarly, among 3,500 patients with serial hs-cTnI measurements, safety of rule-out (NPV 99.7%, 1,528 of 1,533), accuracy of rule-in (PPV 62.3%, 498 of 800), and overall efficacy were high by assigning more than two-thirds of patients either to rule-out (44%, 1,533 of 3,500) or rule-in (23%, 800 of 3,500). Excellent safety was confirmed in multiple subgroup analyses including patients presenting early (≤3 h) after chest pain onset. CONCLUSIONS The ESC 0/1-h algorithm using hs-cTnT and hs-cTnI is very safe and effective in triaging patients with suspected NSTEMI. Prospective Validation of the 0/1-h Algorithm for Early Diagnosis of Myocardial Infarction. J Am Coll Cardiol 2018 Aug 07;72(6)620-632, R Twer- enbold, JT Neumann, NA Sörensen, et al. www.practiceupdate.com/c/71698 with low-risk chest pain be considered for use by institutions with laboratories well-practiced and expert with hs-cTn assays. "

COMMENT By Ezra Amsterdam MD T he utility of very early measurement of high-sensitivity cardiac troponin (hs-cTn) to reliably exclude (ACS) has been supported by multiple studies in thousands of patients. However, the safety of this approach, which comprises measurement of cTn at patient presenta- tion and 1 hour later (0/1-h), has been questioned. The aim of this prospective, multicenter validation investigation was assessment of the accuracy and safety of the 0/1-h algorithm for ruling out ACS in patients presenting with chest pain. The study cohort comprised >8100 patients, approximately half of whom were evalu- ated by high-sensitivity cardiac troponin T (hs-cTnT) and half by high-sensitivity car- diac troponin I (hs-cTnI). The safety of the 0/1-h rule-out algorithm was confirmed by a negative predictive value of 99.7% (1528 of 1533 patients), similar to the estimates observed in previous studies. It is notable that 30% of patients presented very early (≤3 hours after symptom onset); they comprise the largest cohort of early presenters ever tested for performance of the 0/1-h algorithm, and their outcomes matched those of the later presenters.

Results consistent with the overall cohort findings were demonstrated in multiple subgroup analyses, including sex, age, his- tory of CAD, and renal dysfunction. Patients who ruled out had very low all-cause mor- tality at 30 days and 1 year (0.1% and 0.8% for hs-cTnT, respectively; 0.1% and 1.0% for hs-cTnI, respectively). The 30-day mortality was ~ 24 to 29 times higher in patients tri- aged toward rule-in comparedwith patients triaged toward rule-out by the hs-cTn. Based on these results, I recommend that the 0/1-h algorithm for patients with low- risk chest pain be considered for use by institutions with laboratories well-prac- ticed and expert with hs-cTn assays. For the present in this country, I feel it is pru- dent to use a 0/3-h algorithm for low-risk patients presenting with chest pain.

Dr. Amsterdam is Distinguished Professor of Internal Medicine, and Associate Chief for Academic Affairs in the Division of Cardiovascular Medicine at University of California (Davis) Medical

Center in Sacramento, California.

PRACTICEUPDATE CARDIOLOGY