KINETIC CHANGES OF HIGH-SENSITIVITY CARDIAC TROPONIN T IN ACUTE CORONARY SYNDROME WITH CHRONIC KIDNEY DISEASE

Abstract

Acute coronary syndrome is used to cover a group of clinical symptoms compatible with acute myocardial ischemia and comprises various forms of angina pectoris, AMI, and sudden cardiac death. It is the leading cause of death among adults and one of the most common reasons for ED visits worldwide. Chronic kidney disease is an independent risk factor for the development of ACS; it is also associated with adverse outcomes in those with existing cardiovascular disease. In addition; patients with CKD are more likely to present with typical symptoms, which may delay diagnosis and adversely affect outcomes. The diagnosis for AMI patients with CKD and AMI patients only was made by clinical history, ECG, imaging techniques, estimation of GFR by MDRD equation and blood tests including creatinine and cardiac enzymes (total CK, CK-MB, cTnI and hs-cTnT) at admission and after 6 hours. In this regard, our study aimed to evaluate kinetic changes of hs-cTnT in patients with CKD suffering from AMI and to compare these kinetic changes with patients suffering from AMI only. Our study was conducted on 45 patients presenting to the ED of Ain Shams University Hospitals with acute chest pain and 10 healthy subjects as a control group. Patients will be further classified to groupI including patients with AMI and groupII including AMI patients with CKD. All patients included in this study were subjected to full medical history, clinical examination, ECG and laboratory investigations including measurement of GFR by MDRD equation, measurement of cardiac markers including total CK, CK-MB and troponin I and measurement of hs-cTnT at admission and after 6 hours. Patients known to have acute pericarditis, acute pulmonary embolism, acute or severe heart failure, myocarditis and sepsis were not included in the study. Results of the current study did not show any statistically significant difference between the two studied groups as regards the positive family history and DM. As regards creatinine, a highly significant difference was found between the two studied groups. Data of the present study revealed that CK levels at admission exhibited a statistically highly significant difference between CKD patients with AMI and those with AMI only (p<0.05). However, no statistically significant difference was found as regards the rest of the measured cardiac markers for both samples those taken at admission and after 6 hours (p>0.05, respectively). Fortunately, all measured cardiac markers showed a highly statistical significant difference between admission and after 6 hours in the two studied groups (p<0.001, respectively). Concerning the relative kinetic changes of the hs-troponin, no statistically significant difference was detected between the two studied groups (p>0.05, respectively). On assessment of the diagnostic performance for the relative kinetic changes of hs-troponin using ROC curve analysis in patients with CKD and AMI versus patients with AMI only, The best diagnostic performance was recorded at ROC cut off 37.2% which had a diagnostic efficacy of 62%, sensitivity 75%, specificity 52%, PPV 56% and 72% NPV. In conclusion, our study demonstrated that hs-cTnT at values below or close to the 99th percentile upper reference limit, increases above the upper reference limit with relative increases of at least >50% within 2 hours suggest a rising pattern and optimize the overall accuracy of AMI diagnosis. A dynamic change in cardiac troponins of ≥ 20% after presentation should be used to define ACS in CKD patients who present with possible ACS.