Patented biomarker for cardiac injury. 

Patented biomarker for cardiac injury. 

AMI (Acute Myocardial Infarction)

ECG combined with cardiac biomarkers is the most common method to triage and diagnose patients suspected of having Acute Myocardial Infarction (AMI).

Fewer patients have the diagnostic ECG changes of ST elevation or depression that allow triage at presentation[6,7]. 
68% of all patients eventually diagnosed with an acute coronary syndrome present with a non-ST elevation myocardial infarction[8].
130 million attendances to emergency departments (EDs) in the United States each year (2018) [13].
7 million (6%) are acute chest pain patients.
10% of these patients have a final diagnosis of AMI[1–5].

Guidelines published by the ESC [ref], mandate the use of cardiac biomarkers for the diagnosis of AMI.

Troponin is currently the most commonly used cardiac biomarker for triaging chest pain patients

Cardiac Troponins T & I have emerged as the gold standard necrosis biomarker for patients presenting with chest pain and are incorporated into the universal definition of Acute Myocardial Infarction (AMI)[10]. A slow-release profile means that Troponins reach peak concentrations many hours after symptom onset[10]. The development of high-sensitivity Troponin assays has facilitated the routine detection of ever-smaller concentrations – to allow an earlier triage of patients with chest pain.

Troponin limitations

Troponin concentrations close to the Limit of Detection (LoD) are used as a tool for early rule-out of myocardial infarction[11]. This is at odds with specificity, as chronic or subacute Troponin elevation is common – we frequently detect Troponin values above the LoD in patients with chronic obstructive pulmonary disease (COPD), renal dysfunction and – particularly common – congestive cardiac failure[12]. This has prompted the European Society of Cardiology (ESC) to publish guidance incorporating a 3-tiered risk system for patients presenting with chest pain and no diagnostic ECG changes (bearing in mind this is only validated with the onset of chest pain >3 hours ago).
In some institutions, over 50% of patients have a Troponin value that falls into the intermediate-risk category – an observational ‘grey zone’ with no clear guidance attached. And even the best rule-out and rule-in algorithms rely on repeat measurements 1-3 hours following initial blood draws to optimise sensitivity and specificity, further prolonging hospital stays and psychological burden on patients.
There is a medical need to faster Rule-out more patients with suspected AMI using the first blood sample.

References 

[1]: S Goodacre, E Cross, J Arnold, et al. The health care burden of acute chest pain. Heart 91(2), 229–230 (2005). DOI: 10.1136/hrt.2003.027599

[2]: N F Murphy, K MacIntyre, S Capewell, et al. Hospital discharge rates for suspected acute coronary syndromes between 1990 and 2000: population-based analysis. BMJ 328(7453), 1413–1414 (2004) DOI: 10.1136/bmj.38111.650741.F7

[3]: Blatchford O, Capewell S, Murray S, Blatchford M. Emergency medical admissions in Glasgow: general practices vary despite adjustment for age, sex and deprivation. Br. J. Gen. Pract. 49(444), 551–554 (1999). PMCID: PMC1313475

[4]: Harris T, McDonald K. Is the case-mix of patients who self-present to ED similar to general practice and other acute-care facilities? Emerg. Med. J. 31(12), 970–974 (2014). DOI: 10.1136/emermed-2013-202845

[5]: Healthcare Quality Improvement Partnership. MINAP Analyses 2012. https://data.gov.uk/dataset/a517d8f2-cccd-4f8a-870e-4433bfc1d732/minap-analyses-2012

[6]: Jennings SM, Bennett K, Lonergan M, Shelley E. Trends in hospitalisation for acute myocardial infarction in Ireland, 1997–2008. Heart 98(17), 1285–1289 (2012).DOI: 10.1136/heartjnl-2012-301822

[7]: Rogers WJ, Frederick PD, Stoehr E, et al. Trends in presenting characteristics and hospital mortality among patients with ST elevation and non-ST elevation myocardial infarction in the National Registry of Myocardial Infarction from 1990 to 2006. Am. Heart J. 156(6), 1026–1034 (2008). DOI: 10.1016/j.ahj.2008.07.030

[8]: McManus DD, Gore J, Yarzebski J, Spencer F, et al. Recent trends in the incidence, treatment and outcomes of patients with STEMI and NSTEMI. Am. J. Med. 124(1), 40–47 (2011). DOI: 10.1016/j.amjmed.2010.07.023

[9]: Marjot J, Kaier TE, Henderson K, Hunter L, Marber MS, Perera D. A single centre prospective cohort study addressing the effect of a rule-in/rule-out troponin algorithm on routine clinical practice. European Heart Journal: Acute Cardiovascular Care (2017). https://doi.org/10.1177/2048872617746850

[10]: H A Katus, A Remppis, F J Neumann, T Scheffold, et al. Diagnostic efficiency of troponin T measurements in acute myocardial infarction, Circulation 1991 Mar; 83(3):902-12. DOI: 10.1161/01.cir.83.3.902

[11]: Marco Roffi, Carlo Patrono, Jean-Philippe Collet, Christian Mueller, et al. 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: Task Force for the Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-Segment Elevation of the European Society of Cardiology (ESC). Eur Heart J. 2016 Jan 14;37(3):267-315. DOI: 10.1093/eurheartj/ehv320

[12]: Anupam Basuray, Benjamin French, Bonnie Ky, et al. Heart failure with recovered ejection fraction: clinical description, biomarkers, and outcomes. Circulation. 2014 Jun 10;129(23):2380-7. DOI: 10.1161/CIRCULATIONAHA.113.006855

[13]: CDC (2020) https://www.cdc.gov/nchs/fastats/emergency-department.htm