Correlation of Cardiac Troponin I with Left Ventricular Systolic Function in Patients with Acute ST-segment Elevated Myocardial Infarction

Myocardial infarction is one of the leading cause of death globally and following acute myocardial infarction prognosis depends on extent of myocardial damage. This study was aimed to correlate cardiac troponin I level with the left ventricular systolic function in patients with acute ST-elevated myocardial infarction. A total of 104 patients of acute ST-segment elevated myocardial infarction receiving streptokinase therapy within 12 hours of onset of chest pain were studied. Cardiac troponin I concentration was measured by immunometric assay and echocardiographic left ventricular ejection fraction was calculated by modified biplane Simpson's method. Left ventricular ejection fraction (LVEF) was compared with serum cardiac troponin I concentration. Study subjects were divided into two groups on the basis of LVEF. In group I, there were 54 patients with LVEF < 50% and in group II, there were 50 patients with LVEF >_ 50%. The mean cTnI within 12 hours of onset was 129 ± 8.7 ng/ml in group I and11 ± 2.1 ng/ml group II and the difference was statistically significant (p<0.001). Serum cardiac troponin I concentration has a strong negative correlation with left ventricular ejection fraction after first acute myocardial infarction. A level of serum cardiac troponin I >_ 6.6 ng/ml provided a good indication for LVEF <50% and this can be used to detect patients with higher risk. Faridpur Med. Coll. J. 2021;16(1):34-38

COVID-19, cardiovascular diseases and cardiac troponins

There has been strong evidence of myocardial injury in coronavirus disease 2019 (COVID-19) patients with significantly elevated serum cardiac troponin (cTn). While the exact mechanism of injury is unclear, possible suggested pathological mechanisms of injury are discussed. These include increased susceptibility of the myocardium and endothelium to viral invasion, underlying hyperinflammatory state and subsequent cytokine storm, a hypercoagulable and prothrombotic state, and indirect myocardial injury due to hypoxemia. As a result of these pathological mechanisms in COVID-19 patients, cTn may be elevated largely due to myocarditis, microangiopathy or myocardial infarction. The utility of cTn as a biomarker for measuring myocardial injury in these patients and assessing its ability as a prognostic factor for clinical outcome is also discussed.

Associations between cardiac troponin I and cardiovascular parameters after 12-week endurance training in young moderately trained amateur athletes

BackgroundPrevious studies were conducted only on elite athletes, and they investigate acute training responses of cardiac troponin I (CTnI). However, cardiac troponin was found to be elevated in young and inexperienced athletes than adults, and immature myocardium is more susceptible to injury, which needs further consideration.AimTherefore, we aimed to observe the association between CTnI and cardiovascular parameters in response to chronic endurance training adaptation in young athletes.MethodsFifteen participants aged (19.5±1.3) years were selected and placed in endurance running at 70%–80% HRmax intensity for 35 min per training for the first week and additional 2 min each week from the second to the last week for 12 weeks. Serum cardiac troponin and cardiovascular parameters were assessed at pre-training and after 12 weeks of training.ResultWe find a significant CTnI level (p<0.05) and it is positively correlated with systolic blood pressure (BP) (r=0.425). Moreover, CTnI was statistically significant (p<0.01) and positively associated with mean arterial pressure (r=0.516) with a moderate correlation. Besides, CTnI showed a significant (p<0.001) and positive relationship with resting heart rate (r=0.605) and a moderate correlation. We did not find a significant relationship between CTnI and diastolic BP in response to endurance training adaptation.ConclusionIn conclusion, serum CTnI was significantly and positively associated with cardiovascular parameters in young amateur athletes in response to 12-week endurance training adaptation.

Effect of an Eight-week High-intensity Interval Training Program on Serum Cardiac Troponin I Level of Streptozotocin-induced Diabetic Rats

Background: One of the complications of diabetes, as a chronic metabolic disorder, is cardiovascular diseases. Objective This study aims to investigate the effect of an eight-week High-Intensity Interval Training (HIIT) program on serum Cardiac troponin I (CtnI) level in streptozotocin-induced diabetic rats. Methods: In this experimental clinical trial, 30 rats were randomly assigned into three groups of healthy Control (C), Diabetic (D), and diabetic+training (D+T). The third group performed the training which included a treadmill running at an intensity of 85%-90% of maximum speed in 6-12 sessions of 2 min for 8 weeks, 5 days per week. Blood glucose level and high-sensitive CtnI levels were measured 48 hours after the last training session and 12 hours of fasting. One-way ANOVA and Tukey’s test were used to analyze the collected data, considering a significance level of P<0.05. Findings: The induction of diabetes caused a significant increase in blood glucose (P=0.01) and high-sensitive CtnI (P=0.01) levels in the D group. Also, a significant difference was observed in the blood glucose level of D+T group compared to the D group (P=0.001). The CtnI level also slightly reduced (11%) in the D+T group compared to the D group, but it was not statistically significant (P=0.591). Conclusion: he HIIT program can reduce the fasting blood glucose and increase the serum level of high-sensitive CtnI to some extent in diabetic rats; therefore, it can be an appropriate strategy for diabetics. However, there is a need for more studies in this area.