The use of troponin in general practice

General practitioners are able to measure cardiac troponin in order to help triage patients with symptoms suspicious of acute coronary syndrome. The aim of this study was to assess the utilisation of cardiac troponin testing in the community.

An audit of all cardiac troponin testing in an urban community from a single laboratory in 2010 was performed. Data regarding admissions and adverse events over a 6-month period was carried out in all patients.

Cardiac troponin was measured during 2662 patient events during 2010. There were 223 patients episodes (8.4%) in which greater than and equal to 1 troponin result was elevated, 184 (82.5%) were admitted to hospital, 101 (54.9%) were diagnosed as acute coronary syndrome. Of the 2439 with normal troponin results, 344 (14.1%) were admitted, 42 (12.2%) were diagnosed as acute coronary syndrome. Only 12.1% had serial troponin measurements. The 6-month rates of death were 8.5% versus 1.1%, myocardial infarction were 2.2% versus 1.2%, revascularisation were 1.8% versus 0.7%, heart failure were 3.1% versus 1.0% in those with elevated versus normal troponin respectively.

The use of troponin in the community appropriately triages patients regarding the need for admission. However, many patients had elevated troponin due to non-coronary causes. The indication for testing only in cases of suspected ACS and the use of serial cTn measurement in early presenters should be emphasised.