Journal Article

Patient selection for high sensitivity cardiac troponin testing and diagnosis of myocardial infarction: prospective cohort study

Adamson, Philip D, D’Souza, Michelle S, Sexter, Anne, Apple, Fred S, Mills, Nicholas L, Noaman, Ala, Newby, David E, Smith, Stephen W, Sandoval, Yader, Griffiths, Megan, Denvir, Martin A, Gray, Alasdair J, Vaswani, Amar, Shah, Anoop S V, McAllister, David A, Gibbins, Mathew, Chapman, Andrew R, Anand, Atul, Strachan, Fiona E

2017

Overview

AbstractObjectiveTo evaluate how selection of patients for high sensitivity cardiac troponin testing affects the diagnosis of myocardial infarction across different healthcare settings.DesignProspective study of three independent consecutive patient populations presenting to emergency departments.SettingSecondary and tertiary care hospitals in the United Kingdom and United States.ParticipantsHigh sensitivity cardiac troponin I concentrations were measured in 8500 consecutive patients presenting to emergency departments: unselected patients in the UK (n=1054) and two selected populations of patients in whom troponin testing was requested by the attending clinician in the UK (n=5815) and the US (n=1631). The final diagnosis of type 1 or type 2 myocardial infarction or myocardial injury was independently adjudicated.Main outcome measuresPositive predictive value of an elevated cardiac troponin concentration for a diagnosis of type 1 myocardial infarction.ResultsCardiac troponin concentrations were elevated in 13.7% (144/1054) of unselected patients, with a prevalence of 1.6% (17/1054) for type 1 myocardial infarction and a positive predictive value of 11.8% (95% confidence interval 7.0% to 18.2%). In selected patients, in whom troponin testing was guided by the attending clinician, the prevalence and positive predictive value were 14.5% (843/5815) and 59.7% (57.0% to 62.2%) in the UK and 4.2% (68/1631) and 16.4% (13.0% to 20.3%) in the US. Across both selected patient populations, the positive predictive value was highest in patients with chest pain, with ischaemia on the electrocardiogram, and with a history of ischaemic heart disease.ConclusionsWhen high sensitivity cardiac troponin testing is performed widely or without previous clinical assessment, elevated troponin concentrations are common and predominantly reflect myocardial injury rather than myocardial infarction. These observations highlight how selection of patients for cardiac troponin testing varies across healthcare settings and markedly influences the positive predictive value for a diagnosis of myocardial infarction.

• Publisher: British Medical Journal Publishing Group,BMJ Publishing Group LTD,BMJ Publishing Group Ltd
• Subject: Acute coronary syndromes / Calcium-binding protein / Cardiology / Cohort analysis / Coronary artery disease / Diagnosis / EKG / Electrocardiography / Embolisms / Emergency Service, Hospital / Female / Gangrene / Health risk assessment / Heart attacks / Heart diseases / Heart failure / Humans / Ischemia / Laboratories / Male / Medical diagnosis / Middle Aged / Myocardial infarction / Myocardial Infarction - blood / Myocardial Infarction - epidemiology / Pain / Patient Selection / Patients / Predictive Value of Tests / Prevalence / Prospective Studies / Sensitivity and Specificity / Task forces / Troponin / Troponin I / Troponin I - blood / United Kingdom - epidemiology / United States - epidemiology