Background: Non-ST Elevated Myocardial Infarction (NSTEMI) diagnosis is dependent on elevation of high sensitivity troponin (hs-troponin). The current cutoff point for hs-troponin is highly sensitive but not specific for detecting obstructive myocardial infarction. Our aim is to better risk stratify patients by determining the significance of the current cut off point hs-troponin in determining obstructive myocardial infarction.
Methods: We studied 202 patients. All patients were assessed for their demographics, clinical history, laboratory and imaging results. Using SPSS version 22, the pooled cohort of patients were analyzed at significant level <0.05 and the data were test for significant correlations between two predetermined groups; A and B. Group A included patients with positive coronary angiography (CAG) results who had obstructive coronary artery disease and required intervention, and group B included patients with negative CAG results who had normal or near normal coronary arteries that required no intervention.
Results: Group A comprised 87.6% of the patients. Both groups had a median age of 53 years. In Group A, 91% were males, 54% were diabetics, 54% hypertensives and median hs-troponin was 145 ng/L. While in group B, 88% were males, 39% were diabetics, 60% hypertensives, and median hs-troponin was 54 ng/L. There is significant correlation between the two groups in the percentage of diabetes and median troponin level (p < 0.05).
Conclusions: A ROC curve was generated and identified a level of 127 ng/dL as the best cutoff of hs-troponin in detecting obstructive myocardial infarction (p=0.03). Interestingly, 60% of patients in group B had alternative diagnosis.