Myocardial Injury in Mechanically Ventilated Cases in Intensive Care Unit

General anesthesia and tracheal intubation activate the sympathetic nervous system that might affect the innervation of the heart. The aim of study is to look for the incidence of myocardial injury (MI) in intubated adult patients in the Intensive Care Unit (ICU).

This cross-sectional study was conducted on all intubated patients during four months in Imam AL Sadeq Teaching Hospital's ICU, from January 2022 to May 2022. Patients were‎ selected by the census sampling method. Electrocardiograms (ECG), echocardiograms (echo), blood pressure monitoring, other vital signs, and high-sensitivity serum troponin I testing were used to detect myocardial damage. Patients were divided to normal and high troponin groups. Primary diagnosis of admission to ICU was recorded.  Patients were followed after 60 days by visits or phone call.

This study included 40 patients with a mean age of 56.6±7.3 years. There were 17 (42.5%) cases of new MI in the ICU. Troponin levels were found to be significantly associated with age, hypertension, and atrial fibrillation (p<0.05), but not with gender or the type of illness. Patients with elevated troponin levels were three times more likely to experience mortality within 60 days compared to those with normal levels (0.0247). Logistic regression analysis confirmed a significant positive association between troponin levels and mortality, controlling for age, hypertension, and atrial fibrillation (odds ratio=5.49, 95% CI= 1.15-27.15, p=0.033). Age, hypertension, and atrial fibrillation were not significant predictors of mortality.

In conclusion, our study showed a high rate of MI in non-cardiac ICU patients and also a significant association between elevated troponin levels and increased mortality within 60 days in ICU patients. The findings of this study show the importance of monitoring troponin levels as a prognostic indicator in critically ill patients.