Background Rapid assessment of patients with suspected acute coronary syndrome (ACS) allows the right patients to receive the right treatment at the right time. Discrimination of risk permits clinical triage into pathways of immediate inpatient or deferred outpatient care. It is known that a significant proportion of the ACS patients sent home following an “MI screen”, based on a negative 12-h troponin level, are misdiagnosed as having non-cardiac chest pain when in fact they are at high risk of cardiac events. It has been shown that the novel biomarker H-FABP can detect myocardial ischaemia even in the absence of myocyte necrosis. We hypothesise that a multi biomarker blood test incorporating troponin I, CK-MB and H-FABP, taken on admission, can accurately discriminate those patients with a non-cardiac cause of chest pain who are at low risk of cardiac morbidity or mortality.
Methods We studied 519 patients with suspected ACS admitted to a single UK Teaching Hospital. A risk scoring model was constructed based on tertile values for Randox Cardiac-Array measurement of troponin I, H-FABP and CK-MB. These were measured on a blood sample taken at the time of hospital admission. The lowest two lower tertiles were each given a score of 1 and the top tertile a score of 3. The scores were then combined by summation resulting in an overall score of between 3 and 9. Outcome measures up to 12 months were: (i) death from all causes; (ii) repeat acute coronary syndrome (ACS) (iii); readmission for heart failure; (iv) readmission for cerebrovascular event (CVA); (v) coronary revascularisation.
Results The distribution of Cardio-Array scores was: 3 (n=164; 31.6%); 5 (n=134; 25.8%); 7 (n=110; 21.2%); 9 (n=111; 21.4%). The cumulative incidence of events according to the Cardiac-Array score is shown in Abstract 6 table 1.
Conclusion Patients presenting with possible ACS who have a Cardiac-Array biomarker score of 3 or 5, as measured on their admission blood sample, have a very low rate of cardiovascular events. This tool could be used to safely triage patients towards early discharge and outpatient care, based upon available resources. A score of 7 or 9 would merit admission to hospital, and consideration of early cardiac catheterisation.