Cardiac Troponin-I, A Biomarker for Predicting COVID-Induced Myocardial Damage Prognosis

To analyse the utility of cardiac Troponin-I as a prognostic marker in COVID-19-induced myocardial injury.

A descriptive study. Place and Duration of the Study: COVID Intensive Therapeutic Unit (ITC) and Pathology Department, Combined Military Hospital (CMH), Malir, Karachi, from September 2021 to February 2022.

Patients with chest pain, who tested positive for COVID-19 by real-time PCR, were inducted. Blood samples were screened for inflammatory and cardiac biomarkers. The levels of cardiac Troponin I (cTn-I) were categorised as normal (99th percentile = ≤0.01 ng/ml), raised (5 times the 99th percentile = >0.01 ng/ml), and markedly raised (>10 times the 99th percentile = >10 ng/ml) based on serial monitoring over a duration of 6-8 hours.

Out of a total of 104 patients, the mean age was 48 ± 15.94 years; 78 (75%) were males and 26 (25%) were females. The mean levels of cardiac Troponin I (cTn-I) were 1.91 ng/ml, C-reactive protein (CRP) was 85 mg/l, Interleukin-6 (IL-6) was 43.3 ng/ml, Procalcitonin (PCT) was 1.40 ng/ml, Creatinine Kinase (CK) was 203 U/l, CK MB was 31 U/l, and Ferritin was 471 ng/ml. Forty-four (42.4%) had normal cTn-I levels, 38 (36.5%) had raised levels, and 22 (21.1%) had markedly raised levels. A persistent rising pattern of cTn-I with a maximum rise up to 30 ng/ml was observed in 16 patients (15.3%) labelled as myocarditis, while only 8 (7.6%) showed a rise-fall pattern. Cardiac Tn-I and CRP were significantly higher in patients with myocarditis (p <0.01). Six out of 104 patients (5.7%) died due to COVID- induced myocardial injury all having raised cTn-I.

Cardiac Troponin-I is an effective biomarker for measuring myocardial injury in COVID-19 patients and can be an independent predictor to assess for severity of cardiac injury than other inflammatory markers in COVID-19.

COVID-19, Cardiac Troponin I, Inflammatory markers, Myocardial injury, Prognosis.