Cardiac Troponin T-Based Assessment of Myocardial Dysfunction in Critically Ill Children Admitted to a Pediatric Intensive Care Unit: A Prospective Observational Study

Abstract

Background: Myocardial injury in critically ill children is often clinically silent at admission but may become important when shock, hypoxia, sepsis, respiratory failure, or multiorgan dysfunction increases myocardial oxygen demand while reducing effective oxygen delivery.

Aim: To assess myocardial status in critically ill children admitted to a pediatric intensive care unit using cardiac troponin T, bedside echocardiography, electrocardiography, and chest radiography, and to examine its association with selected clinical outcomes.

Materials and Methods: This hospital-based prospective observational study was conducted in the Pediatric Intensive Care Unit, Institute of Social Pediatrics, Government Stanley Medical College and Hospital, Chennai, from 1 April 2017 to 30 September 2017. Children aged 1 month to 12 years admitted to PICU without pre-existing congenital or acquired cardiac disease were included. Cardiac troponin T was measured at admission by electrochemiluminescence immunoassay; values >0.1 ng/mL were considered positive. Bedside two-dimensional/M-mode echocardiography, 12-lead ECG, and chest X-ray were recorded. Associations were tested using chi-square/Fisher exact tests and independent-samples t-test, with p<0.05 considered statistically significant.

Results: Among 112 children, 33 (29.5%) were troponin T positive. Troponin positivity was not significantly associated with sex (p=0.428) or age group (p=0.422). System-wise distribution among 87 children with a predominant major-system diagnosis showed significant variation in troponin positivity (p=0.036), with the highest proportions in cardiovascular disease (3/3, 100.0%), inborn errors of metabolism (2/3, 66.7%), and sepsis (3/7, 42.9%). Echocardiographic abnormality was present in 13/112 children and all 13 were troponin positive (Fisher exact p=0.0005). ECG abnormality (20/33 vs 23/79, p=0.002) and chest X-ray abnormality (20/33 vs 28/79, p=0.014) were also significantly more frequent in troponin-positive children. Mortality was higher in the troponin-positive group (26/33, 78.8%) than in the troponin-negative group (12/79, 15.2%; p=0.0005). Troponin positivity was also associated with need for mechanical ventilation (31/33, 93.9%; p=0.0005) and inotropic support (32/33, 97.0%; p=0.0005). Mean recorded stay was longer in the troponin-positive group, but the difference was not statistically significant (9.82±11.19 vs 6.75±7.68 days; p=0.156).

Conclusion: Admission troponin T positivity identified a clinically vulnerable subgroup of critically ill children with higher echocardiographic, ECG, and radiographic abnormalities, greater need for organ support, and markedly higher mortality. A bedside cardiac assessment pathway combining troponin T with echocardiography and ECG may help earlier recognition of myocardial involvement in PICU, although serial biomarker and imaging studies with adjustment for illness severity are needed before routine prognostic use can be generalized.