The Effect Of First Fasting Glucose On Prognosis Of Acute Coronary Syndrome Patients

Objective: Type 2 diabetes is an independent risk factor for coronary heart disease, which has been supported by abundant epidemiological and clinical research evidence. The relationship between abnormal glucose metabolism and cardiovascular disease, especially that between ACS and the first discovered abnormal glucose metabolism, in recent years, has always been a subject of much concern in the field of cardiovascular. Recent studies found that admission blood glucose (ABG) and the first fasting blood glucose (FBG) could predict poor prognosis of the patients with ACS. However, the patients with ACS were admitted to hospital in different times, and ABG was influenced by many factors. And the value of FBG on the prognosis of patients with ACS was less reported. So the purpose of this study was to ensure whether FBG could be considered as a fast, easy and economical predictor of cardiac events in patients with ACS by comparing FBG with ABG and discussing the predictive value of FBG on cardiac events within 30 days.Methods: The study involved 129 patients without diabetes mellitus who were admitted to the Second Hospital of Hebei Medical University with a diagnosis of ACS from October 2008 to November 2009. They also had ischemic chest pain before admission in 24 hours without eating from last meal for at least 3 hours and never had cardio pulmonary resuscitation out of hospital and malignant tumors. According to the first fasting blood glucose (FBG) and admission blood glucose (ABG), the patients were respectively divided into two groups: normal glucose group (<7.0mmol/L) and elevated glucose group (≥7.0mmol/L). According to"the Acute Myocardial Infarction Diagnosis and Treatment Guidelines"(2001, China) and"the Unstable Angina and Non-ST-segment Elevation Myocardial Infarction Diagnosis and Treatment Guidelines"(2007, China), the patients were treated by regular treatments and observed for 30 days. The relationships between FBG and ABG and other risk factors such as coronary artery lesion, blood pressure, blood lipids, etc. were also observed.Samples collection and measurement methods:1. FBG: The next morning after admission, we took fingertip (the ring finger) blood to measure the first fasting blood glucose (fasting more than 8 hours) with Optium Xceed glucometer made in USA. The first drop of blood was abandoned. The second drop of the blood was used for measurement. Avoid squeezing the finger in the measure process.2. ABG: The same method was used to measure the admission blood glucose.3. hs-CRP: The next morning after admission when the patients were empty stomach, 2ml blood was drawn to measure hs-CRP. The supernatant was collected by centrifugation immediately (3500rpm, 10min), then it was stored at -20℃refrigerator. Using the kit produced by RD Company, the blood samples were measured by enzyme-linked immunosorbent assay.4. HbA1c: The next morning after admission when the patients were empty stomach, 2ml blood was drawn to measure HbA1c. Using BIO-RAD D10 glycohemoglobin detector in Endocrine Laboratory of our hospital, the blood samples were treated with EDTA-K2 and measured by high pressure liquid method.5. Blood lipids, kidney function, and serum glucose: The next morning after admission when the patients were empty stomach, 5ml blood was drawn to measure these testing items. The samples were placed in special INSEPACK blood vacuum tube. The supernatant was collected by centrifugation (3500rpm, 2min), and were measured using the Hitachi 7600-020 automatic biochemical analyzer.6. Epinephrine: The next morning after admission when the patients were empty stomach and in a rest state, 2ml blood was drawn to measure epinephrine. The supernatant was collected by centrifugation immediately (3500rpm, 10min), then it was stored at -20℃refrigerator. Using the kit produced by RD Company, the blood samples were measured by enzyme-linked immunosorbent assay.7. LVEF: It was completed by the Ultrasonic's doctors using the color Doppler ultrasound diagnosis system of the Siemens (ACUSON sequoia 512).8. Coronary angiography: Completed by cardiovascular physicians with intervention qualification.9. 30-day follow-up to record adverse cardiac events: death, re-infarction, cardiogenic shock, malignant ventricular arrhythmia (defined as ventricular fibrillation and/or hemodynamic unstable ventricular tachycardia), etc. Statistical analysis: All statistical analysis was performed using SPSS v 16.0 software (SPSS Inc., Chicago, Illinois, USA). Univariate analysis was performed in which categorical variables were expressed as frequencies and percentages and quantitative variables were expressed as means and standard deviations. The comparison of quantitative variables between two groups was performed with t test, and the comparison of categorical variables among groups was performed with theχ2. Logistics was used to analyze the risk factors which influence coronary artery diseases. Receiver operator characteristic (ROC) analysis (using MedCalc software) was used to compare the predictive value of FBG and ABG. Values of P<0.05 were considered statistically significant.Result:1. A total of 129 patients with ACS ( 90 men, 39 women; mean age,61.55±11.40 years; age range, 29 to 85 years old) were involved, of which 56 (43.41%) cases were unstable angina, 56 (43.41%) cases were ST-segment elevation myocardial infarction, 17 (13.18%) were non-ST-segment elevation myocardial infarction. Hospitalized patients with diabetes mellitus were found in 36 cases (27.91%).2. Follow-up 30 days in and out of hospital, adverse cardiac events occurred in 9 cases: death, 4 cases; myocardial infarction or re-infarction, 2 cases, cardiogenic shock, 2 cases, malignant arrhythmia, 1 case. The distribution of adverse cardiac events occurred as follows: normal FBG groups (<7.0mmol/L), 1 case (1.15%); elevated FBG group (≥7.0mmol/L), 8 patients (19.05%); normal ABG group, 1 cases (1.92%); elevated ABG group (≥7.0mmol/L), 8 cases (10.39%). The incidence of adverse events in normal FBG group was higher than that in elevated FBG group (P<0.01). However, there was no significant difference between the incidence of adverse events in normal ABG group and elevated ABG group (P=0.08). (There is no difference between the concentrations of fingertip blood and venous blood glucose, P=0.07)3. ROC analysis showed that, as a predictor of 30-day adverse cardiac events, the accuracy rate of FBG could reach 85% with 95% CI of 0.77-0.90 in patients with ACS. While with regard to ABG, the accuracy rate was 81% with 95% CI of 0.73-0.87. There was no statistic difference between the forecast accuracy of FBG and ABG(P =0.55)。4. Compared with the general data,LVEF and the conventional blood parameters, elevated FBG patients had a larger proportion with diabetes(P<0.01), a higher level of HbA1c (P<0.01) and a lower LVEF (P=0.01). However, there was no significant difference between the former indicators and the general data and the conventional blood parameters such as age, sex, hypertension, myocardial infarction history, smoking history, family history of coronary heart disease, blood lipids, body mass index, waist circumference, etc.With regard to ABG, elevated ABG patients also had a larger proportion with diabetes (P=0.01), a higher level of HbA1c (P<0.01) and a lower LVEF (P=0.01) in addition to an older age (P<0.01). There was also no significant difference between the former indicators and the general data and the conventional blood parameters above.5. Comparison between the levels of FBG, ABG and plasma Epinephrine, hs-CRP. Compared with normal FBG and ABG group respectively, the elevated FBG group and elevated ABG group both had higher levels of plasma Epinephrine (P<0.05). However, compared with normal glucose group regardless of FBG or ABG, there level of plasma hs-CRP was not significantly different in elevated glucose group.6. Comparison between the levels of FBG,ABG and coronary artery lesion. Compared with normal FBG and ABG group respectively, neither the elevated FBG group nor elevated ABG group showed differences (P>0.05). The logistics displayed that risk factors including FBG, ABG, HbA1c, CHOL, LDL, HDL, BMI, age, the history of diabetes, high blood pressure, smoking, myocardial infarction and coronary heart disease family histories, of which, HbA1c, age and history of high blood pressure were independent risk factors which influenced coronary artery lesion.Conclusion:1. FBG and ABG could both predict adverse cardiac events of ACS patients within 30 days after admission.2. HbA1c, age and high blood pressure could affect the severity of coronary artery lesions in patients with ACS.