Serum alkaline phosphatase levels are associated with coronary artery calcification patterns and plaque vulnerability

Phosphoglycerate Dehydrogenase Overexpression Inhibits Ferroptosis to Repress Calcification of Human Coronary Artery Vascular Smooth Muscle Cells via the P53/SLC7A11 Pathway

Background

Coronary artery calcification (CAC) is in almost all patients with coronary artery disease and requires more effective therapies. We aim to explore the effects of phosphoglycerate dehydrogenase (PHGDH) on CAC.

Methods

We identified the differentially expressed genes through bioinformatic analysis and selected PHGDH for further verification. Human coronary artery smooth muscle cells (HCASMCs) cultured with calcifying medium were used as models of CAC in vitro. Erastin was administered to induce ferroptosis. We determined the cell viability by the cell count kit-8 assay. The alkaline phosphatase activity, calcium content, and the expression of glutathione were evaluated by the corresponding detection kits. The calcification level was detected by alizarin red staining. Then we performed Western blot to examine the expression of runt-related transcription factor 2, bone morphogenetic protein 2, cyclooxygenase 2, glutathione peroxidase 4, P53, and solute carrier family 7a member 11 (SLC7A11).

Results

We acquired 201 differentially expressed genes and selected PHGDH to verify. In calcifying medium-induced HCASMCs, PHGDH overexpression increased the cell viability and decreased the alkaline phosphatase activity, calcium content, calcification level, and the expression of bone morphogenetic protein 2 and runt-related transcription factor 2. Additionally, we found higher levels of glutathione, glutathione peroxidase 4, and SLC7A11 and lower levels of cyclooxygenase 2 and P53 after up-regulating PHGDH. Erastin reversed the effects of PHGDH on calcification of HCASMCs.

Conclusion

PHGDH overexpression suppresses the calcification level of HCASMCs by inhibiting ferroptosis through the P53/SLC7A11 signaling pathway, suggesting PHGDH as a promising therapeutic target of CAC.

Coronary Artery Calcification: Current Concepts and Clinical Implications

Coronary artery calcification (CAC) accompanies the development of advanced atherosclerosis. Its role in atherosclerosis holds great interest because the presence and burden of coronary calcification provide direct evidence of the presence and extent of coronary artery disease; furthermore, CAC predicts future events independently of concomitant conventional cardiovascular risk factors and to a greater extent than any other noninvasive biomarker of this disease. Nevertheless, the relationship between CAC and the susceptibility of a plaque to provoke a thrombotic event remains incompletely understood. This review summarizes the current understanding and literature on CAC. It outlines the pathophysiology of CAC and reviews laboratory, histopathological, and genetic studies, as well as imaging findings, to characterize different types of calcification and to elucidate their implications. Some patterns of calcification such as microcalcification portend increased risk of rupture and cardiovascular events and may improve prognosis assessment noninvasively. However, contemporary computed tomography cannot assess early microcalcification. Limited spatial resolution and blooming artifacts may hinder estimation of degree of coronary artery stenosis. Technical advances such as photon counting detectors and combination with nuclear approaches (eg, NaF imaging) promise to improve the performance of cardiac computed tomography. These innovations may speed achieving the ultimate goal of providing noninvasively specific and clinically actionable information.

Serum Angiopoietin-like Protein 3 Levels Are Associated with Endothelial Function in Patients with Maintenance Hemodialysis

Angiopoietin-like protein 3 (ANGPTL3) plays an important role in lipid and lipoprotein trafficking and metabolism and is positively correlated with cardiovascular disease. Our objective was to evaluate the association between serum ANGPTL3 levels and endothelial function in patients on maintenance hemodialysis (MHD). We enrolled 116 patients on MHD and obtained their blood test results from their medical records. Using a noninvasive digital thermal monitor, we determined the vascular reactivity index (VRI) as a measure of endothelial function. Serum ANGPTL3 concentration was measured by a commercial-enzyme-linked immunosorbent assay. Vascular reactivity was classified as poor in 17 (14.7%) patients, intermediate (1.0 ≤ VRI < 2.0) in 50 (43.1%) patients, and high (VRI ≥ 2.0) in 49 (42.2%) patients. Serum levels of ANGPTL3 (p < 0.001) and alkaline phosphatase (ALP, p = 0.025) increased significantly as the VRI decreased. The log-transformed serum ALP (log-ALP, r = -0.187, p = 0.045) and log-ANGPTL3 (r = -0.319, p < 0.001) showed a negative correlation with the VRI on univariate linear regression analysis. A significant negative correlation was found between log-ANGPTL3 and VRI (p < 0.001) on multivariate stepwise linear regression analysis. The findings of our investigation showed that, in patients with MHD, the ANGPTL3 concentration had a negative correlation with the VRI.

The relationship between insulin resistance, serum alkaline phosphatase, and left ventricular dysfunction following myocardial infarction

The occurrence of heart failure following acute myocardial infarction (AMI) significantly increases the risk of post-infarction mortality. Alkaline phosphatase (AP) is considered to be an independent predictor of cardiovascular disease (CVD) and adverse outcomes. Furthermore, in recent years, alkaline phosphatase has been associated with insulin resistance (IR). Our aim was to investigate the correlation between IR substitutes (triglyceride-glucose (TyG) index, triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio), AP, and LV dysfunction in patients admitted after AMI. The retrospective study included 810 patients who underwent coronary angiography for myocardial infarction at the First Hospital of Hebei Medical University from August 2018 to December 2021. Patients were categorized into three groups based on their serum AP levels. Clinical characteristics at admission, cardiac echocardiography findings, coronary angiography results, and biochemical markers such as serum AP levels and triglycerides (TG) were recorded during hospitalization. Left ventricular ejection fraction (LVEF) was assessed using cardiac echocardiography conducted from the time of admission until the coronary angiography procedure. A total of 774 patients with AMI were included in this study. The TyG index is significantly correlated with the TG/HDL-C ratio. (R = 0.739, P < 0.001). Binary logistic regression analysis revealed that elevated serum AP (OR 2.598, 95% CI 1.331-5.071, P = 0.005), presence of the left anterior descending (LAD) artery as the infarct-related artery (IRA) (OR 2.452, 95% CI 1.352-4.449, P = 0.003), and triglyceride (TG) levels (OR 0.652, 95% CI 0.429-0.992, P = 0.046) were protective risk factor for an admission LVEF < 40% following AMI. The serum alkaline phosphatase and LAD as IRA are independent risk factors for severe reduction in LVEF during hospitalization for AMI. Conversely, triglyceride are independent protective factor for severe reduction in LVEF during AMI hospitalization.

Positive association between alkaline phosphatase and arteriosclerosis: a cross-sectional study

AIMS

Serum alkaline phosphatase (ALP) is known to be associated with cardiovascular events and cerebral arteriosclerosis. However, the link between ALP and early arteriosclerosis remains unclear. This study investigated the relationship between ALP and early arteriosclerosis assessed by brachial-ankle pulse wave velocity (Ba-PWV).

METHODS

This retrospective analysis included 5011 participants who underwent health examinations, including ALP and Ba-PWV measurement, at the Second Hospital of Hebei Medical University from 2012 to 2017. Regression analysis, smoothing function analysis in the generalized additive model (GAM), threshold effect analysis, and subgroup analyses were performed.

RESULTS

Multivariate regression analysis identified a significantly positive association between serum ALP and arteriosclerosis [odds ratio (OR) = 1.008, 95% confidence interval (CI) 1.004-1.011, P  < 0.001]. Smoothing function analysis indicated a two-stage association between ALP and arteriosclerosis. Furthermore, threshold effect analysis determined an inflection point at 135 U/l, below which the relationship was linearly positive and above which the risk of arteriosclerosis did not increase prominently with increasing ALP (OR = 1.009, 95% CI: 1.005-1.013, P  < 0.001; OR = 0.976, 95% CI: 0.952-1.002, P  = 0.068). However, ALP was not associated with arteriosclerosis only in participants with diabetes (OR = 0.996, 95% CI: 0.979-1.014, P  = 0.690). A positive association between Ba-PWV and arteriosclerosis was observed for both the arteriosclerosis and nonarteriosclerosis groups ( β  = 9.10, 95% CI: 4.67-13.54, P  < 0.001; β  = 8.02, 95% CI: 5.67-10.37, P  < 0.001).

CONCLUSION

In this study, the serum ALP level was positively associated with early arteriosclerosis, with a saturation effect beyond ALP = 135 U/l. However, the positive association between ALP and arteriosclerosis was unclear in adults with diabetes.

Acute coronary syndrome screening in patients presenting with arteriosclerosis in health check-ups: a case-control study

OBJECTIVES

This research aimed to develop a simple and effective acute coronary syndrome (ACS) screening model in order to intervene early and focus on prevention in patients presenting with arteriosclerosis.

DESIGN

A case-control study.

SETTING

The study used a cross-sectional survey to collect data from 2243 patients who completed anonymous electronic medical record (EMR) data and coronary angiography was gathered at a hospital in Shandong Province between December 2013 and April 2016.

PARTICIPANTS

Adults 18 years old and above diagnosed as ACS or non-ACS according to the records in hospital EMR database, and with completed basic information (age and sex).

PREDICTORS

54 laboratory biomarkers and demographic factors (age and sex).

STATISTICAL ANALYSIS

A dataset without missing data of all patients' laboratory indicators and demographic factors was divided into training set and validation set after being balanced. After the training set balanced, area under the curve of random forest (AUCRF) and least absolute shrinkage and selection operator (LASSO) regression were used for feature extraction. Then two set random forest models were established with the different feature sets, and the process of comparison and analysis was made to evaluate models for the optimal model including sensitivity, accuracy and AUC receiver operating characteristic curves with the internal validation set.

MAIN OUTCOME MEASURES

To establish an ACS screening model.

RESULTS

An RF model with 31 features selected by LASSO with an AUC of 0.616 (95% CI 0.650 to 0.772), a sensitivity of 0.832 and an accuracy of 0.714 in the validation set. The other RF model with 27 features selected by AUCRF with an AUC of 0.621 (95% CI 0.664 to 0.785), a sensitivity of 0.849 and an accuracy of 0.728 in the validation set.

CONCLUSIONS

The established ACS screening model with 27 clinical features provides a better performance for practical solution in predicting ACS.

Serum marker and CT characteristics of coronary calcified nodule assessed by intravascular ultrasound

Background

Calcified nodule (CN) is a type of potentially vulnerable plaque. Its formation mechanism remains unknown. This study was to assess serum marker and computed tomography angiography (CTA) characteristics of CN validated by intravascular ultrasound (IVUS).

Methods

Patients who underwent coronary CTA followed by invasive coronary angiography and IVUS were retrospectively analyzed. Serum levels of alkaline phosphatase (ALP), gamma-glutamyltransferase, and calcium were collected.

Results

IVUS detected 128 de novo calcified lesions in 79 patients with coronary artery disease (CAD). CNs were identified in 11.4% (9/79) of patients and 9.4% (12/128) of lesions. Compared with patients with non-nodular calcified plaques, CN patients had higher serum level of ALP (82.00 vs 65.00 U/L, P = 0.022) and total plaque volume (673.00 vs 467.50 mm3, P = 0.021). Multivariable analyses revealed that serum ALP level and total plaque volume were independently associated with the prevalence of CN in CAD patients with calcified plaques. At lesion level, the CN group had a higher frequency of moderate to heavy calcification on angiography (75.00% vs 40.52%, P = 0.017). In terms of CTA characteristics, plaques with CN had a more severe diameter stenosis (79.00% vs 63.00%, P = 0.007), higher plaque burden (85.40% vs 77.05%, P = 0.005), total plaque density (398.00 vs 283.50 HU, P = 0.008), but lower lipid percentage (14.65% vs 19.75%, P = 0.010) and fiber percentage (17.90% vs 25.65%, P = 0.011). Mean plaque burden is an independent predictor of the prevalence of CN in calcified plaques (odds ratio = 1.102, 95% confidence interval: 1.025–1.185, P = 0.009). The AUC is 0.753 (95% confidence interval: 0.615–0.890, P = 0.004). When using 84.85% as the best cutoff value, the diagnostic sensitivity and specificity of mean plaque burden for predicting the presence of CN within calcified plaques were 66.7% and 80.2%, respectively.

Conclusions

CN had different CTA imaging features from non-nodular coronary calcification. The presence of a CN was associated with a higher serum ALP level and plaque burden.