SEQC Spanish Society of Laboratory Medicine

Figure 1. An electrocardiogram assesses the electrical activity of the heart

- Recently, great advances have been made in the diagnostic tools available for the diagnosis of ACS.

- The use of high-sensitivity cardiac troponin allows the diagnosis of non-ST-segment elevation myocardial infarction to be ruled out quickly and safely.

- Troponin has been a useful marker for risk stratification of the COVID-19 patient.

- Various studies have shown the association between SARS-CoV-2 and the appearance of cardiovascular events once the acute phase of the disease has passed.

- The availability of markers such as troponin or natriuretic peptides can be very useful in the evaluation of patients with chest pain or dyspnea, which appear in a high percentage of patients with persistent COVID

Cardiovascular disease causes about 40% of deaths in Europe, most of it due to ischemic heart disease, a disease that is caused by an insufficient supply of blood to the myocardium due to the obstruction of the coronary arteries, generally due to atherosclerosis in the coronary arteries. Patients may have chronic (stable) or acute (unstable) disease. Acute coronary syndrome (ACS) encompasses the three most common acute clinical presentations: ST-segment elevation acute myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction (NSTEMI), and unstable angina.

The Spanish Society of Laboratory Medicine (SEQC^ML), on June 14, presented the course "The laboratory in the management of Acute Coronary Syndrome" in order to address the importance of applying standardized criteria for the interpretation of troponin values, a cardiac biomarker, in clinical practice, as well as its value in assessing chest pain or dyspnea, very common in patients with persistent COVID.

Recently, great advances have been made in the diagnostic tools available for the diagnosis of ACS. Firstly, due to the development of biomarkers, among them the determination of cardiac troponin with highly sensitive methods, noted by Doctor ​​Aitor Alquézar Arbé, specialist in internal medicine of the Emergency Department of the Santa Creu i Sant Pau Hospital in Barcelona. But also, he added, it is necessary to highlight the great progress of recent years in diagnostic imaging techniques. In particular, coronary angiography by computerized tomography and cardiac magnetic resonance imaging. "In addition, at treatment level, new antiplatelet drugs have been created and vascular endoprostheses (stents) have been improved."

Regarding troponin, according to Dr. Alquézar, it should be taken into account that it is cardiospecific, but it does not indicate the cause that produces the myocardial injury. Thus, during the SEQC^ML course, the different recommended diagnostic algorithms were reviewed, as well as their advantages and disadvantages.

According to the expert, “the use of high-sensitivity cardiac troponin not only enables an earlier and more accurate diagnosis of acute myocardial infarction without ST-segment elevation on the ECG (rule-in), but also allows it to be ruled out (rule -out) quickly and safely”. Dr. Alquézar stressed that the diagnosis of myocardial injury should be based on the determination of cardiac troponin with highly sensitive methods.

He also added that "in order to make an early and accurate diagnosis, the clinical laboratory must have the appropriate immunoassays and be able to give the results quickly."

Troponin and COVID-19

The disease caused by SARS-CoV-2 or COVID-19 infection was initially considered a respiratory pathology. However, it was soon confirmed that it was a pathology with multi-organ involvement. Thus, as explained by Dr. Luis García de Guadiana Romualdo, member of the SEQC^ML Commission on Biological Magnitudes related to Medical Emergencies, SARS-CoV-2 can interact with the cardiovascular system in multiple ways. One of them is the development of myocardial damage, "which can be reflected by an increase in the blood concentration of markers such as troponin."

In his presentation, "What does troponin contribute to patients with COVID-19?", Dr. García de Guadiana Romualdo addressed the role of troponin in risk stratification of COVID-19 patients during the acute phase of the disease. This role was evaluated in the BIOCOVID multicenter study, sponsored by the SEQC^ML and in which 32 Spanish hospitals participated, and which has recently been recognized by the European Society for Clinical Investigation (ESCI).

In addition, during the course the challenge that Laboratory Medicine faces as a specialty involved in the management of the post-COVID condition was highlighted.

Recent studies have shown the association between said infection and the appearance of cardiovascular events once the acute phase of the disease has passed. As Dr. García de Guadiana pointed out, “the availability of markers such as troponin or natriuretic peptides can be very useful in the evaluation of patients with chest pain or dyspnea, which appear in a high percentage of patients with persistent COVID, as included in the Clinical Guide for Patient Care "LONG COVID" in whose elaboration the SEQC^ML has participated. In this sense, Dr. Garcia de Guadiana pointed out the need for more studies to assess the usefulness of cardiac markers in the diagnosis and prediction of post-COVID cardiovascular disorders.