Effects and mechanisms of glucose-insulin-potassium on post-procedural myocardial injury after percutaneous coronary intervention.

OBJECTIVE: To evaluate the effects and mechanisms of glucose-insulin-potassium (GIK) on post-procedural myocardial injury (PMI) after percutaneous coronary intervention (PCI). METHODS: A total of 200 non-diabetic patients with documented coronary heart disease (CHD) were divided into the Group GIK and Group G, with 100 patients in each group. Patients in Group G were given intravenous infusion of glucose solution 2 hours before PCI. As compared, patients in Group GIK were given GIK. RESULTS: Both post-procedural creatine phosphokinase isoenzyme MB (CK-MB; 62.1 ± 47.8 vs. 48.8 ± 52.6 U/L, P = 0.007) and cTnI (0.68 ± 0.83 vs. 0.19 ± 0.24 ng/mL, P < 0.001) in Group GIK were significantly higher than those in Group G. In Group G, 9.0% and 4.0% of patients had post-procedural increases in CK-MB 1-3 times and > 3 times, which were significantly lower than those in Group GIK (14.0% and 7.0%, respectively; all P values < 0.01); 13.0% and 7.0% of patients had post-procedural increases in cTnI 1-3 times and > 3 times, which were also significantly lower than those in Group GIK (21.0% and 13.0%, respectively; all P < 0.001). Pre-procedural (10.2 ± 4.5 vs. 5.1 ± 6.3, P < 0.001) and post-procedural rapid blood glucose (RBG) levels (8.9 ± 3.9 vs. 5.3 ± 5.6, P < 0.001) in Group G were higher than those in Group GIK. In adjusted logistic models, usage of GIK (compared with glucose solution) remained significantly and independently associated with higher risk of post-procedural increases in both CK-MB and cTnI levels > 3 times. Furthermore, pre-procedural RBG levels < 5.0mmol/L were significantly associated with higher risk of post-procedural increases in both CK-MB and cTnI levels. CONCLUSIONS: In non-diabetic patients with CHD, the administration of GIK may increase the risk of PMI due to hypoglycemia induced by GIK.

The serum anion gap is associated with disease severity and all-cause mortality in coronary artery disease.

OBJECTIVE: To evaluate the associations between the serum anion gap (AG) with the severity and prognosis of coronary artery disease (CAD). METHODS: We measured serum electrolytes in 18,115 CAD patients indicated by coronary angiography. The serum AG was calculated according to the equation: AG = Na+[(mmol/L) + K+ (mmol/L)] - [Cl- (mmol/L) + HCO3- (mmol/L)]. RESULTS: A total of 4510 (24.9%) participants had their AG levels greater than 16 mmol/L. The serum AG was independently associated with measures of CAD severity, including more severe clinical types of CAD (P < 0.001) and worse cardiac function (P = 0.004). Patients in the 4th quartile of serum AG (≥ 15.92 mmol/L) had a 5.171-fold increased risk of 30 days all-cause death (P < 0.001). This association was robust, even after adjustment for age, sex, evaluated glomerular filtration rate [hazard ratio (HR): 4.861, 95% confidence interval (CI): 2.150-10.993, P < 0.001], clinical diagnosis, severity of coronary artery stenosis, cardiac function grades, and other confounders (HR: 3.318, 95% CI: 1.76-2.27, P = 0.009). CONCLUSION: In this large population-based study, our findings reveal a high percentage of increased serum AG in CAD. Higher AG is associated with more severe clinical types of CAD and worse cardiac function. Furthermore, the increased serum AG is an independent, significant, and strong predictor of all-cause mortality. These findings support a role for the serum AG in the risk-stratification of CAD.

The Impact of Different Plasma Glucose Levels on Heart Rate in Experimental Rats With Acute Myocardial Infarction.

BACKGROUND: The aim of the study was to evaluate the impact of different plasma glucose levels on heart rate (HR) in experimental rats with acute myocardial infarction (AMI). METHODS: One hundred and twenty-one male Wistar rats were randomly divided into AMI group (n = 70) and sham-operation group (n = 51). Both groups had low, normal and high glucose levels, respectively. In the former group, hypertonic glucose was injected into the rats to make their blood glucose levels above 16 mmol/L and insulin below 3.3 mmol/L; then, the left anterior descending artery was ligated. In the later group, the models of different blood glucose levels were the same as the former ones, but false operations, thread without ligating, were given to the rats. Electrocardiogram and troponin I (TnI) confirmed that the models were prepared successfully. Electrocardiogram expression of AMI was the formation of Q-wave in over three adjacent leads and abnormal elevation of TnI. RESULTS: The HR of the rats in the hypoglycemic group is higher than that of the hyperglycemic group and normal blood glucose group before AMI (P < 0.05). The HR of the hyperglycemic rats is higher than that of the hypoglycemic group and normal blood glucose group after AMI (P < 0.05). In the hypoglycemic group, the HR of the rats who suffered from AMI was lower than that of the rats of the sham group (P < 0.05). CONCLUSION: Hypoglycemia allows faster HR and the HR in the rats with hyperglycemia is higher than that in the rats with hypoglycemia among the AMI rats.

Association of dysglycemia and all-cause mortality across the spectrum of coronary artery disease.

OBJECTIVE: To assess the association between fasting plasma glucose (FPG) and all-cause mortality across the spectrum of coronary artery disease (CAD). PATIENTS AND METHODS: The study included 18,999 patients during a study period of April 1, 2004, through October 31, 2010. The primary end points were in-hospital and follow-up all-cause mortality. According to the quartiles of FPG levels, patients were categorized into 4 groups: quartile 1, less than 5.1 mmol/L; quartile 2, 5.1 to less than 5.9 mmol/L; quartile 3, 5.9 to less than 7.5 mmol/L; and quartile 4, 7.5 mmol/L or greater. The conversion factor for units of plasma glucose is 1.00 mmol/L equals 18 mg/dL. Presented as mg/dL, the 4 quartile ranges of plasma glucose concentrations used in our data analysis are ≤90.0 mg/dL, 90.1-106.0 mg/dL, 106.1 mg/dL-135.0 mg/dL and ≥135.1 mg/dL. Quartile 1 was recognized as the lower glycemic group, quartiles 2 and 3 as the normoglycemic groups, and quartile 4 as the higher glycemic group. RESULTS: In patients with acute myocardial infarction, all-cause mortality for the dysglycemic groups was higher than for the normoglycemic groups: in-hospital mortality for quartiles 1, 2, 3, and 4 was 1.0%, 0.9%, 0.2%, and 1.5%, respectively (P=.001); follow-up mortality for quartiles 1, 2, 3, and 4 was 1.7%, 0.9%, 0.3%, and 1.8%, respectively (P<.001). In patients with stable CAD, no significant differences in mortality were found among groups. However, in patients with unstable angina pectoris, the normoglycemic groups had lower follow-up mortality and roughly equal in-hospital mortality compared with the dysglycemic groups. After adjusting for confounding factors, this observation persisted. CONCLUSION: The association between lower FPG level and mortality differed across the spectrum of CAD. In patients with acute myocardial infarction, there was a U-shaped relationship. In patients with stable CAD or unstable angina pectoris, mildly to moderately decreasing FPG level was associated with neither higher nor lower all-cause mortality.

[Comparative study of gene mutation between Chinese patients with familial and sporadic hypertrophic cardiomyopathy].

OBJECTIVE: To compare the gene mutation between Chinese patients with familial and sporadic hypertrophic cardiomyopathy (HCM). METHODS: Peripheral blood samples were collected from 36 patients with familial HCM (FHCM) and 50 patients with sporadic HCM (SHCM), all un-related and from different provinces of China. PCR was used to amplify the 26 protein-coding axons of beta-myosin heavy chain (MYH7), 16 exons for cardiac troponin T (TNNT2), and 38 exons for cardiac myosin-binding protein C (MYBPC3). The amplified products were sequenced and compared with the standard sequence in the genBank so as to determine the potential mutation sites. RESULTS: (1) 13 of the 36 FHCM patients (36.1%) harbored 3 different mutations in MYH7 gene: Arg663His in exon18, Glu924Lys in exon 23, and Ile736Thr in exon 20. Of the 50 SHCM patients, only 1 (2%) harbored MYH7 gene missence mutation: Ile736Thr located in exon 20. (2) TNNT2 was not identified in all SHCM patients and FHCM patients. (3) MYBPC3 was not identified in all SHCM patients. Four FHCM patients harbored 2 different mutations: Arg502Trp in exon 18 and Arg346fs in exon 13 respectively. CONCLUSION: MYH7 and MYBPC3 may be the dominant disease-causing genes in Chinese familial HCM patients; however the mutation rate of MYH7 and MYBPC3 genes is significantly lower in the SHCM patients compared with the FHCM patients. TNNT2 seems not the predominant disease-causing gene in all Chinese patients with HCM.