Method of differentiating stable angina pectoris from acute coronary syndrome and diagnostic kit thereof

A method of differentiating stable angina pectoris from acute coronary syndrome, comprising:

• obtaining a blood plasma sample from a patient;
• measuring a relative concentration of at least one metabolic biomarker in the blood plasma sample, wherein the at least one metabolic biomarker is selected from the group consisting of malic acid, taurine, arachidonic acid, citramalic acid, methionine, and pentadecanoic acid;
• wherein, the step of measuring a relative concentration of at least one metabolic biomarker in the blood plasma sample further comprises the following steps:
• a), adding an internal standard of 2-isopropyl malic acid into the blood plasma to obtain the blood plasma having the internal standard at a concentration of 1 μg/ml;
• b), preparing the blood plasma having the internal standard into a sample solution, using a solvent;
• c), dissolving a reference mixture using the solvent to prepare a reference solution, wherein the reference mixture includes 2-isopropyl malic acid and the at least one metabolic biomarker, and the purities of the 2-isopropyl malic acid and the at least one metabolic biomarker are no less than 98%;
• and d), analyzing the sample solution and the reference solution by UPLC-Q/TOF-MS, measuring a peak area of extracted ion chromatogram of the at least one metabolic biomarker and a peak area of extracted ion chromatogram of the 2-isopropyl malic acid in the sample solution, and using a ratio of the peak area of the extracted ion chromatogram of the at least one metabolic biomarker to the peak area of the extracted ion chromatogram of the 2-isopropyl malic acid as a relative concentration of the at least one metabolic biomarker;
• obtaining a differentiating value according to the relative concentration of at least one metabolic biomarker;
• wherein the differentiating value is a value calculated by a formula;
• and
• comparing the differentiating value with a predefined critical value, if the differentiating value is more than the predefined critical value, the patient has the acute coronary syndrome, otherwise, the patient has the stable angina pectoris, wherein the predefined critical value is determined according to the at least one metabolic biomarker.