Impact of Elevated Plasma Total Homocysteine Concentration on Coronary Atherosclerosis in Chinese Patients With Acute Myocardial Infarction Undergoing Primary Coronary Intervention

Association between homocysteine and coronary artery disease-trend over time and across the regions: a systematic review and meta-analysis

BACKGROUND

The association of homocysteine with coronary artery disease (CAD) has been explored previously with mixed findings. The present Systematic Review and Meta-Analysis (SRMA) has assessed the pooled estimate of association between homocysteine (Hcy) and CAD, and its variation over the period and geography.

METHODS

Systematic literature search was done in PubMed, Scopus and Cochrane to identify the observational studies that have reported mean Hcy among cases (CAD) and control. The SRMA was registered in PROSPERO (ID-CRD42023387675).

RESULTS

Pooled standardized mean difference (SMD) of Hcy levels between the cases and controls was 0.73 (95% CI 0.55-0.91) from 59 studies. Heterogeneity was high (I2 94%). The highest SMD was found among the Asian studies (0.85 [95% CI 0.60-1.10]), while the European studies reported the lowest SMD between the cases and controls (0.32 [95% CI 0.18-0.46]). Meta-regression revealed that the strength of association was increasing over the years (Beta = 0.0227, p = 0.048).

CONCLUSIONS

Higher homocysteine levels might have a significant association with coronary artery diseases, but the certainty of evidence was rated low, owing to the observational nature of the studies, high heterogeneity, and publication bias. Within the population groups, Asian and African populations showed a greater strength of association than their European and American counterparts, and it also increased over the years.

Biochemical Association of MTHFR C677T Polymorphism with Myocardial Infarction in the Presence of Diabetes Mellitus as a Risk Factor

Myocardial infarction (MI) is a cardiovascular disease that occurs due to the blockage of the coronary artery. Subsequently, cardiac muscles receive a lower oxygen supply, which leads to the death of cardiac muscles. The etiology of MI is linked to various environmental, occupational, and genetic factors. Various studies have been conducted on the polymorphism of genes involved in MI. Previous studies have shown that different variants of the methylene tetrahydrofolate reductase (MTHFR) gene are involved in causing MI by altering the metabolism of folate and homocysteine. However, the genetic polymorphism of MTHFR C677T (rs1801133) and its association with MI in the presence of diabetes mellitus (DM) as a risk factor still needs to be investigated. This study recruited 300 participants who were divided into three groups, i.e., the control, MI, and MI-DM. The blood samples collected from the study participants were subjected to various biochemical tests and their clinical parameters were monitored. MTHFR C677T (rs1801133) genotyping was performed by Tetra ARMS PCR using predetermined primers. The MTHFR C677T (rs1801133) polymorphism was associated with MI in the presence of DM as a risk factor among the participants. The MTHFR C677T (rs1801133) T/T homozygous genotype was found to be significant among MI patients in the presence of DM as a risk factor.

S-Adenosylmethionine Alleviates Amyloid-β-Induced Neural Injury by Enhancing Trans-Sulfuration Pathway Activity in Astrocytes

BACKGROUND

Glutathione (GSH) is an important endogenous antioxidant protecting cells from oxidative injury. Cysteine (Cys), the substrate limiting the production of GSH, is mainly generated from the trans-sulfuration pathway. S-adenosylmethionine (SAM) is a critical molecule produced in the methionine cycle and can be utilized by the trans-sulfuration pathway. Reductions in GSH and SAM as well as dysfunction in the trans-sulfuration pathway have been documented in the brains of Alzheimer's disease (AD) patients. Our previous in vivo study revealed that SAM administration attenuated oxidative stress induced by amyloid-β (Aβ) through the enhancement of GSH.

OBJECTIVE

To investigate the effect of Aβ-induced oxidative stress on the trans-sulfuration pathway in astrocytes and neurons, respectively, and the protective effect of SAM on neurons.

METHODS

APP/PS1 transgenic mice and the primary cultured astrocytes, neurons, and HT22 cells were used in the current study.

RESULTS

SAM could rescue the low trans-sulfuration pathway activity induced by Aβ only in astrocytes, accompanying with increasing levels of Cys and GSH. The decrease of cellular viability of neurons caused by Aβ was greatly reversed when co-cultured with astrocytes with SAM intervention. Meanwhile, SAM improved cognitive performance in APP/PS1 mice.

CONCLUSION

In terms of astrocyte protection from oxidative stress, SAM might be a potent antioxidant in the therapy of AD patients.

Adropin is associated with hyperhomocysteine and coronary atherosclerosis

Homocysteine has been recognized as a risk factor for atherosclerosis and cardiovascular diseases. Adropin is a newly-identified energy homeostasis protein with a potential protective effect against coronary artery disease (CAD). This study attempted to measure the correlation between serum homocysteine and adropin levels in patients with CAD, and to ascertain how the two hormones could affect the severity of coronary atherosclerosis. A cohort of CAD patients who had undergone coronary angiography was prospectively recruited. The serum homocysteine and adropin levels of the patients were measured and the severity of coronary atherosclerosis was quantified with the SYNTAX score. The data were analyzed with a generalized structural equation model. In total, 170 consecutive patients were recruited with a mean serum homocysteine level of 15.9±8.3 µmol/l, and 76 (44.7%) patients were identified as hyperhomocysteinemic with a serum homocysteine level >15 µmol/l. Serum homocysteine level was found to be significantly negatively correlated with serum adropin level (r=-0.169, P=0.028). Patients with hyperhomocysteinemia had lower serum adropin levels and higher SYNTAX scores than patients without hyperhomocysteinemia. Further analysis with a generalized structural equation model showed that adropin was significantly associated with hyperhomocysteinemia (adjusted odds ratio: 0.95, 95% confidence interval: 0.93 to 0.98; P=0.002), which in turn was significantly associated with the SYNTAX score (coefficient: 4.71, 95% confidence interval: 1.39 to 8.03; P=0.005). In conclusion, the serum homocysteine level was inversely correlated with the serum adropin level in patients with CAD. A low serum adropin level was associated with hyperhomocysteinemia and more severe coronary atherosclerosis, as reflected by a higher SYNTAX score.

Value and level of plasma homocysteine in patients with angina pectoris undergoing coronary angiographic study

This study tested whether the plasma level of total homocysteine (tHcy) was predictive of obstructive coronary artery disease (CAD) and clinical outcome in patients undergoing coronary angiographic (CAG) study. From September 2002 to October 2004, 1,305 consecutive patients with angina pectoris undergoing CAG study were consecutively enrolled. Blood samples were prospectively collected to assess the plasma level of tHcy from each patient before catheterization. Of these 1305 patients, 676 (51.8%) had multivessel disease (group 1), 367 (28.1%) had single-vessel disease (group 2), and 262 (20.1%) had normal coronary artery or insignificant coronary artery disease (group 3). The plasma level of tHcy was notably higher in group 1 than in groups 2 and 3 (11.6 ± 4.4 versus 10.9 ± 4.0 versus 10.4 ± 3.8, P < 0.001). Univariate binary logistic regression analysis demonstrated that the plasma tHcy level was strongly associated with multiple-vessel disease (MVD) (defined as ≥ 2 vessel disease) (P < 0.001). Multivariate binary logistic regression analysis showed that tHcy level, fasting blood sugar, diabetes mellitus, and age were significantly and independently predictive of MVD (all P < 0.03). Univariate Cox regression analysis demonstrated that tHcy level was predictive of long-term mortality (P = 0.042). However, the tHcy level was not an independent predictor of long-term mortality on multivariate Cox regression analysis (P > 0.05). The results of our study support the hypothesis that tHcy level is an independent predictor of MVD in patients with chest pain undergoing CAG study. Conversely, our study did not support the tHcy level as an independent predictor of long-term mortality in this clinical setting.

Homocysteine predicts adverse clinical outcomes in unstable angina and non-ST elevation myocardial infarction: implications from the folate intervention in non-ST elevation myocardial infarction and unstable angina study

BACKGROUND

Unstable angina and non-ST elevation myocardial infarction (NSTEMI) are common acute coronary events. Homocysteine is a novel risk factor for coronary heart diseases. Together with the conventional risk factors, they may affect the outcome of non-ST coronary events.

OBJECTIVE

This study aims to determine the effect of clinical risk factors that are responsible for the occurrence of mortality, and the composite outcome of mortality, nonfatal myocardial infarction and serious rehospitalization within 6 months after the onset of non-ST acute coronary syndromes.

METHODS

A total of 124 Filipino patients were interviewed and tested for blood homocysteine levels and lipid profiles. Outcomes were assessed after 6 months.

RESULTS

Homocysteinemia (>16 micromol/l) is associated with increased mortality and composite outcomes (mortality, nonfatal reinfarction, and serious rehospitalization), even if adjusted for conventional risk factors. No association was detected for the conventional risk factors. Earlier acute coronary syndrome was found to be positively associated with mortality and the composite outcomes. Early stroke is associated with increased composite outcomes, whereas greater mortality and adverse outcomes were observed in NSTEMI compared with intermediate-risk unstable angina.

CONCLUSION

Increased homocysteine level is associated with mortality and serious nonfatal outcomes in patients with unstable angina and NSTEMI.

Predictive factors of TIMI-3 flow before percutaneous coronary intervention in facilitated percutaneous coronary intervention for acute myocardial infarction

The outcome for facilitated percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) is known to be more favorable in cases in which TIMI-3 flow is obtained before PCI. We investigated factors that affect the acquisition of TIMI-3 flow before PCI. Facilitated PCI was performed on 178 patients divided into two groups, a group in which TIMI-3 flow was acquired before conducting PCI and another in which it was not, and their background factors and short-term outcomes were investigated. The hemoglobin concentrations, white blood cell (WBC) counts, and HbA1c values were significantly lower in the group in which TIMI-3 flow was acquired before PCI and significantly more had a history of past smoking. According to the results of logistic analysis, WBC count (odds ratio [OR], 0.865, P = 0.0077), hemoglobin concentration (OR, 0.77, P = 0.0257), and smoking history (OR, 0.266, P = 0.0021) were independent factors that predicted acquisition of TIMI-3 flow. The WBC count and hemoglobin value on arrival at the emergency room and history of smoking were shown to be independent factors for acquisition of TIMI-3 flow before PCI in facilitated PCI.