Material and Methods
We analyzed the major studies on cardiac biomarkers about troponins NT-pro-BNP and CK-MB, and we have evaluated their evolution during hospitalization. The biomarkers evaluated were troponins, NT-pro-BNP and CK-MB. We divided the work for each of them in a sub-chapter and a summary table with all the studies analyzed.
Troponin T (TnT) Previous influenza infection epidemics have been associated with myocardial infarction, myocarditis and exacerbated heart failure[5]. These comorbid conditions contribute to significant mortality. Previous coronavirus were associated with arrhythmias, cardiomegaly, cardiac arrest, sub-clinical diastolic impairment and acute-onset heart failure[6], [7] .
The possible role of TnT in the prognosis of COVID-19 patients has been reported in numerous clinical studies (Table 1).
In China all patients reporting elevated TnT values, have developed a myocardial injury. Among these, the mortality rate at one month was more than 50% in those who had elevated TnT[8], [9] and it was also shown that high levels of this biomarker were a negative prognostic factor, predicting sometimes even death of patients[10], [11]. Therefore, increased blood levels of TnT were correlated with increased severity of infection from COVID 19 and its higher mortality rate[12].
Studies conducted in Italy have shown that the presence of elevated troponin levels was an independent variable associated with in-hospital mortality and an increased risk of cardiovascular complications, especially in patients with a previous history of heart disease.
Importantly, a correlation with heart failure, renal failure, pulmonary embolism and major bleeding was observed. In fact, half of COVID-19 patients with elevated troponins, with a history of cardiovascular disease and / or the presence of heart damage, have died[13], [14]. Therefore, to better stratify the prognosis of these patients, it becomes important to evaluate TnT at hospitalization and during hospitalization, up to discharge[13]–[15].
In the United States it has also been demonstrated the correlation between the changes of ECG with an increased risk of death, especially in the presence of atrial fibrillation, atrial flutter, or both[16], [17].