Academy of Diagnostics & Laboratory Medicine - Scientific Short

Is Cardiac Troponin Testing Over-Utilized in Patient Care to Rule In and Rule Out Acute Myocardial Infarction?

Olaia Rodriguez Fraga

Cardiovascular disease is the leading cause of death in industrialized countries. Early diagnosis is critical to initiating appropriate therapy. The role of cardiac troponin  (cTn) in the evaluation, diagnosis and prognosis of patients with suspected acute coronary syndrome (ACS), including myocardial infarction (MI), is well established in response to the need for early identification of MI according to the 2012 Third Universal Definition of Myocardial Infraction guidelines. Evaluating patients suspected with MI may generate inappropriate and excessive cardiac troponin (cTn) orders; challenging resource utilization outside of appropriate clinical context. Our objective was to determine clinician utilization of cTnI testing in their assessment of 100 consecutive patients at moderate risk of ACS / MI in a cardiac-renal monitored telemetry unit staffed by attending and resident physicians.  We evaluated the number and timing of cTn orders, along with the clinical history, symptoms at presentation and final diagnosis of these patients. Clinicians were not limited to any number of order sets. Thirty-six were diagnosed with MI (36%); 9 type 1 MI (25%) and 27 type 2 MI (75%). In the MI group (no PCI), 222 cTnI values were measured, and 107 (48%) were determined to be excessive (measured after the diagnosis of MI was determined (adjudicated based on the Third Universal Definition of Myocardial Infraction). There were 52 additional cTnIs beyond the initial 0, 3, 6, 9 h order set (an order set is defined by 4 serial, timed cTnI measurements; as single orders are not available to providers), with an average of 7.2 cTnI values per MI patient. 23% were from unnecessary second or third serial order set. In the no-MI group, 378 cTnIs were measured, with 150 cTnIs (39%) determined to be excessive (measured after the diagnosis of MI was excluded.  There were 63 additional cTnI orders beyond the initial one, with an average of 6.0 cTnI values per no-MI patient. 18% were from unnecessary second or third order sets. We conclude that clinicians over utilized cTnI testing in both patients with and without the diagnosis of MI. Decreasing the number of unnecessary cTnI tests after a diagnosis would not compromise patient care and result in financial saving. Laboratorians should take the lead in educating their clinical colleagues on the use of cTn monitoring based on clinical practice guidelines to reach agreement about appropriate cTn orders and interpretation criteria without reducing the quality of patient care.

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Academy of Diagnostics & Laboratory Medicine Designation

Fellows of the Academy use the designation of FADLM. This designation is equivalent to FACB and FAACC, the previous designations used by fellows of the National Academy of Clinical Biochemistry and AACC Academy. Those groups were rebranded as Academy of Diagnostics & Laboratory Medicine in 2023.