Association Between Thrombogenicity Indices and Coronary Microvascular Dysfunction in Patients With Acute Myocardial Infarction

Early prediction of microvascular obstruction prior to percutaneous coronary intervention

Early prediction of microvascular obstruction (MVO) occurrence in acute myocardial infarction (AMI) patients undergoing percutaneous coronary intervention (PCI) can facilitate personalized management and improve prognosis. This study developed a prediction model for MVO occurrence using preoperative clinical data and validated its performance in a prospective cohort. A total of 504 AMI patients were included, with 406 in the exploratory cohort and 98 in the prospective cohort. Feature selection was performed using random forest recursive feature elimination (RF-RFE), identifying five key predictors: High-Sensitivity Troponin T, Neutrophil Count, Creatine Kinase-MB, Fibrinogen, and Left Ventricular Ejection Fraction. Among the models developed, logistic regression demonstrated the highest predictive performance, achieving an AUC score of 0.800 in the exploratory cohort and 0.792 in the prospective cohort. This model has been integrated into a user-friendly online platform, providing a practical tool for guiding personalized perioperative management and improving patient prognosis.

The Role of Circulating Biomarkers in Patients with Coronary Microvascular Disease

Coronary microvascular disease (CMD) comprises a spectrum of conditions characterized by the functional and structural abnormalities of coronary microcirculation, affecting vessels typically smaller than 500 μm. Despite its clinical significance as a contributor to myocardial ischemia, CMD frequently remains underdiagnosed due to the limitations of current diagnostic approaches. Invasive testing, including coronary reactivity assessment, is considered the gold standard, but it is resource-intensive and not always accessible. Non-invasive methods, such as positron emission tomography (PET) and transthoracic Doppler echocardiography (TTDE), offer alternatives but are limited by varying accuracy and accessibility. Amid these diagnostic challenges, there is increasing interest in circulating biomarkers as adjuncts in CMD evaluation. Biomarkers associated with endothelial dysfunction, inflammation, and oxidative stress, detectable through routine blood tests, may assist in CMD diagnosis, risk stratification, and therapeutic monitoring. These biomarkers can offer insights into CMD pathogenesis and enable early, non-invasive screening to identify patients who may benefit from more invasive investigations. This narrative review examines studies assessing biomarkers in CMD patients with diagnoses confirmed through invasive techniques. Our objective is to focus on circulating biomarkers linked to the invasive evaluation of coronary microcirculation, aiming to advance the understanding of the underlying mechanisms of this prevalent condition and enhance diagnostic accuracy and the clinical management of affected patients.

Trimetazidine: Activating AMPK Signal to Ameliorate Coronary Microcirculation Dysfunction after Myocardial Infarction

BACKGROUND

Myocardial ischemia-reperfusion (I/R) injury and coronary microcirculation dysfunction (CMD) are observed in patients with myocardial infarction after vascular recanalization. The antianginal drug trimetazidine has been demonstrated to exert a protective effect in myocardial ischemia-reperfusion injury.

OBJECTIVES

This study aimed to investigate the role of trimetazidine in endothelial cell dysfunction caused by myocardial I/R injury and thus improve coronary microcirculation.

METHODS

The myocardial I/R mouse model was established, and trimetazidine was administered for 7 days before myocardial I/R model establishment. Echocardiography, 2,3,5-triphenyltetrazolium chloride (TTC) staining, hematoxylin-eosin (H&E) staining, and thioflavin S staining were applied to assess myocardial injury and microvascular function. Additionally, the oxygen-glucose deprivation/reperfusion (OGD/R) model was developed in endothelial cells to simulate myocardial I/R injury in vitro. Griess reaction method, immunofluorescence, and western blotting (WB) were employed to detect the expressions of nitric oxide (NO), platelet endothelial cell adhesion molecule-1 (CD31) and vascular endothelial (VE)-cadherin, zonula occludens protein 1 (ZO-1), occludin, vascular endothelial growth factor (VEGF) and adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling-related proteins in endothelial cells and mouse cardiomyocytes. AMPK pathway inhibitor compound C was used for further mechanism validation.

RESULTS

Our research demonstrated that trimetazidine can alleviate myocardial pathological injury and cardiac function injury during myocardial I/R. Trimetazidine was observed to improve microvascular reflux phenomenon and microvascular function and barrier injury in myocardial I/R and OGD/R models. Additionally, the expressions of AMPK signal-related proteins were found to be inhibited in myocardial I/R and OGD/R models, which were then activated in mice administered trimetazidine. However, the effects of trimetazidine on endothelial cell function and barrier damage were attenuated after co-treatment with compound C and trimetazidine.

CONCLUSION

Trimetazidine ameliorated myocardial I/R-induced CMD by activating AMPK signaling.

Platelet-fibrin clot strength and platelet reactivity predicting cardiovascular events after percutaneous coronary interventions

BACKGROUND AND AIMS

Platelet-fibrin clot strength (PFCS) is linked to major adverse cardiovascular event (MACE) risk. However, the association between PFCS and platelet reactivity and their prognostic implication remains uncertain in patients undergoing percutaneous coronary intervention (PCI).

METHODS

In PCI-treated patients (n = 2512) from registry data from January 2010 to November 2018 in South Korea, PFCS using thromboelastography and platelet reactivity using VerifyNow were measured. High PFCS (PFCSHigh) was defined as thromboelastography maximal amplitude ≥ 68 mm, and high platelet reactivity (HPR) was defined as >208 P2Y12 reaction units. Patients were stratified into four groups according to maximal amplitude and P2Y12 reaction unit levels: (i) normal platelet reactivity (NPR)-PFCSNormal (31.8%), (ii) HPR-PFCSNormal (29.0%), (iii) NPR-PFCSHigh (18.1%), and (iv) HPR-PFCSHigh (21.1%). Major adverse cardiovascular event (all-cause death, myocardial infarction, or stroke) and major bleeding were followed up to 4 years.

RESULTS

High platelet reactivity and PFCSHigh showed an additive effect for clinical outcomes (log-rank test, P < .001). Individuals with NPR-PFCSNormal, NPR-PFCSHigh, HPR-PFCSNormal, and HPR-PFCSHigh demonstrated MACE incidences of 7.5%, 12.6%, 13.4%, and 19.3%, respectively. The HPR-PFCSHigh group showed significantly higher risks of MACE compared with the NPR-PFCSNormal group [adjusted hazard ratio (HRadj) 1.89; 95% confidence interval (CI) 1.23-2.91; P = .004] and the HPR-PFCSNormal group (HRadj 1.60; 95% CI 1.12-2.27; P = .009). Similar results were observed for all-cause death. Compared with HPR-PFCSNormal phenotype, NPR-PFCSNormal phenotype was associated with a higher risk of major bleeding (HRadj 3.12; 95% CI 1.30-7.69; P = .010).

CONCLUSIONS

In PCI patients, PFCS and platelet reactivity demonstrated important relationships in predicting clinical prognosis. Their combined assessment may enhance post-PCI risk stratification for personalized antithrombotic therapy.

Influence of Fibrinogen/Albumin Ratio and Fibrinogen/Pre-Albumin Ratio on Cardiac Autonomic Neuropathy in Type 2 Diabetes

Purpose

Subclinical inflammation may be involved in the pathogenesis of diabetic cardiac autonomic neuropathy (DCAN). The purpose of the study is to explore the relationship between novel inflammation biomarkers fibrinogen-albumin ratio (FAR), fibrinogen-prealbumin ratio (FPR), and DCAN in type 2 diabetes mellitus (T2DM).

Patients and Methods

A total of 715 T2DM patients were enrolled in this retrospective study, divided into non-DCAN (n=565) and DCAN (n=150) groups by Ewing's test. Serum fibrinogen, albumin, prealbumin, routine inflammatory and other biochemical markers were measured.

Results

Patients with versus without DCAN had higher FAR (10.29 ± 4.83 vs 7.22 ± 2.56 g/g, P < 0.001) and FPR (2.19 ± 1.85 vs 1.43 ± 0.93 g/mg, P < 0.001). As FAR and FPR quartiles increased, the incidence of DCAN increased (Quartile 1 vs Quartile 4: 8.4 vs 42.7%, 9.6 vs 39.2%, respectively, P < 0.001), heart rate variability parameters decreased (P < 0.001); the incidence of diabetic nephropathy, retinopathy and peripheral neuropathy tended to be higher and inflammation factors were more active (P < 0.01). FAR (OR, 95% CI: 1.16, 1.08-1.25, P < 0.001) and FPR (OR, 95% CI: 1.22, 1.03-1.44, P = 0.021) were independent determinants of DCAN; the risk of DCAN increased by approximately 65% and 27% with each increase in the standard deviation (SD) of FAR (OR per SD, 95% CI: 1.65, 1.29-2.11, P < 0.001) and FPR (OR per SD, 95% CI: 1.27, 1.04-1.56, P = 0.021).

Conclusion

FAR and FPR are independent risk factors and may influence DCAN development through inflammation.

Circulating Biomarkers in Coronary Microvascular Dysfunction

Coronary microvascular dysfunction is an underdiagnosed pathologic process that is associated with adverse clinical outcomes. Biomarkers, molecules measurable in the blood, could inform the clinician by aiding in the diagnosis and management of coronary microvascular dysfunction. We present an updated review of circulating biomarkers in coronary microvascular dysfunction representing key pathologic processes, including inflammation, endothelial dysfunction, oxidative stress, coagulation, and other mechanisms.

Artificial Intelligence and Cardiovascular Risk Prediction: All That Glitters is not Gold

Artificial intelligence (AI) is a broad term referring to any automated systems that need 'intelligence' to carry out specific tasks. During the last decade, AI-based techniques have been gaining popularity in a vast range of biomedical fields, including the cardiovascular setting. Indeed, the dissemination of cardiovascular risk factors and the better prognosis of patients experiencing cardiovascular events resulted in an increase in the prevalence of cardiovascular disease (CVD), eliciting the need for precise identification of patients at increased risk for development and progression of CVD. AI-based predictive models may overcome some of the limitations that hinder the performance of classic regression models. Nonetheless, the successful application of AI in this field requires knowledge of the potential pitfalls of the AI techniques, to guarantee their safe and effective use in daily clinical practice. The aim of the present review is to summarise the pros and cons of different AI methods and their potential application in the cardiovascular field, with a focus on the development of predictive models and risk assessment tools.

Relationships between indicators of prothrombotic activity and coronary microvascular dysfunction in patients with myocardial infarction with obstructive and non-obstructive coronary artery disease

The relationship between prothrombotic activity and coronary microvascular dysfunction (MVD) is limited. This study aimed to perform a comparative analysis of the relationship between prothrombotic activity and MVD in patients with myocardial infarction without obstructive coronary artery disease (MINOCA) and myocardial infarction with obstructive coronary artery disease (MI-CAD).

MATERIAL AND METHODS

A total of 37 patients were enrolled in the study; the main group included 16 MINOCA patients, and 21 MI-CAD patients were included in the control group. Blood samples for protein C, antithrombin, WF, plasminogen, and homocysteine were performed on the 4th ± 1 day of admission. CZT-SPECT data were used to determine the standard indices of myocardial perfusion dis-orders (SSS, SRS, and SDS), as well as stress and rest myocardial blood flow (MBF), myocardial flow reserve (MFR), and difference flows (DF). MVD was defined as MFR (≤ 1.91 ml/min); coronary slow flow (CSF) was defined as corrected TIMI frame count (21 ± 3).

RESULTS

We performed a step-by-step analysis of prothrombotic activity of the hemostasis system in binary logistic regression for MINOCA patients to identify factors associated with MVD (MFR ≤ 1.91 ml/min). A predictive model was developed to estimate the probability of reduced MFR. A low MFR is related to only plasminogen in MINOCA patients, whereas only wall motion score index (WMSI) in MI-CAD group was associated with a low MFR.

CONCLUSION

This small-scale study revealed the relationship between indicators of prothrombotic activity and MVD. The key factors that affect MVD in MINOCA patients was plasminogen, whereas, in patients with MI-CAD, WMSI was the key factor. Measurements of MVD may enhance the risk stratification and facilitate future targeting of adjunctive antithrombotic therapies in MINOCA and MI-CAD patients.

Portal vein thrombosis associates with high platelet-fibrin clot strength and platelet activation in decompensated cirrhosis: A retrospective study

BACKGROUND AND AIMS

Alteration of platelet status associates with decompensation and death in cirrhosis, while its effect on portal vein thrombosis (PVT) remains unclear. We aimed to retrospectively investigate whether PVT associates with platelet-fibrin clot strength and platelet activation in decompensated cirrhosis.

METHODS

Platelet-fibrin clot strength (G) was measured by thromboelastography (TEG). Platelet activation was reflected by plasma concentrations of soluble p-selectin (sPs) and a platelet aggregation test adjusted for platelet counts.

RESULTS

Among 166 patients, 45 had PVT. The platelet count was significantly lower in PVT. While the G value was positively correlated with platelet count (ρ = 0.74, P < 0.01), increased G was associated with PVT after adjusting for platelet count in the logistic regression (P = 0.04). The normalized G value according to the linear relation with platelet count was calculated as follows: G_platelet = [(G - 2622)/platelet count]. This coefficient had no correlation with platelet count and was an independent risk factor of PVT (OR = 1.03, CI_95%: 1.01-1.05, P = 0.012). In two subanalyses, the collagen-induced platelet aggregation (n = 37, P = 0.029) and plasma concentration of sPs (n = 56, P = 0.001) adjusted for platelet count were significantly higher in PVT.

CONCLUSION

This study showed a positive correlation of high platelet-fibrin clot strength detected via TEG and platelet activation with PVT in decompensated cirrhosis.

Ligustrazine prevents coronary microcirculation dysfunction in rats via suppression of miR-34a-5p and promotion of Sirt1

INTRODUCTION

The coronary microembolization contributes to coronary microvascular dysfunction (CMD), in which miR-34a-5p may play a critical role. Ligustrazine has been reported to improve CMD. The present study was designed to discuss the role of miR-34a-5p/Sirt1 pathway in CMD and explore the underlying mechanism of ligustrazine.

METHODS

Coronary microembolization (CME) was induced by left ventricle injection of sodium laurate in rats. CME formation and cardiac function were examined by HE staining and hemodynamic tests to evaluate CMD. The expressions of miR-34a-5p, Sirt1 and the downstream proteins were detected by RT-qPCR and western blot. Dual-luciferase reporter (DLR) assay was performed to confirm the connection between miR-34a-5p and Sirt1. The blood markers of endothelial dysfunction, platelet activation and inflammation were examined with ELISA.

RESULTS

Overt CME and cardiac dysfunction as well as up-regulated miR-34a-5p and down-regulated Sirt1 were observed in CME rats. Overexpressing miR-34a-5p aggravated while silencing miR-34a-5p inhibited CME formation. DLR assay confirmed that miR-34a-5p directly inhibited Sirt1 mRNA expression. Ligustrazine pretreatment suppressed miR-34a-5p and promoted Sirt1 expression, which alleviated endothelial dysfunction, inhibited platelet activation and inflammation, and in turn reduced CME. Overexpressing miR-34a-5p diminished the positive effects of ligustrazine; while after silencing miR-34a-5p, ligustrazine failed to further promote Sirt1 expression and inhibit CME formation.

CONCLUSION

MiR-34a-5p contributes to CMD by inhibiting Sirt1 expression. Ligustrazine exerts endothelial-protective, anti-platelet and anti-inflammatory effects to prevent CMD via suppressing miR-34a-5p and promoting Sirt1.

Association between kaolin-induced maximum amplitude and slow-flow/no-reflow in ST elevation myocardial infarction patients treated with primary percutaneous coronary intervention

BACKGROUND

ST-segment elevation myocardial infarction (STEMI) patients with a high thrombus burden have a relatively high slow-flow/no-reflow risk. However, the association between kaolin-induced maximum amplitude (MA_thrombin) and slow-flow/no-reflow has been scarcely explored.

METHODS

STEMI patients treated with primary percutaneous coronary intervention (PCI) were retrospectively enrolled from January 2015 to December 2019 at China-Japan Friendship Hospital. MA_thrombin levels were measured using thromboelastography before the PCI procedure. The patients were divided into two groups according to thrombolysis in myocardial infarction (TIMI) flow grade after primary PCI: the normal flow group (TIMI flow grade = 3) and slow-flow/no-reflow (TIMI flow grade ≤ 2). The logistic regression model and restricted cubic spline regression (RCS) were used to analyze the predictive value of MA_thrombin for slow-flow/no-reflow. All patients were followed up after discharge and observed the adverse cardiovascular events between the two groups.

RESULTS

A total of 690 patients were enrolled, with 108(15.7%) having slow-flow/no-reflow. The multivariate logistic regression model analysis showed that MA_thrombin level was an independent risk factor for slow-flow/no-reflow. The RCS analysis showed a nonlinear relationship between MA_thrombin levels and slow-flow/no-reflow. The cut-off value of MA_thrombin levels for predicting slow-flow/no-reflow was 68 mm. During a median follow-up time of 4.4 years, slow-flow/no-reflow (hazard ratio 1.93, 95% confidence interval 1.27-2.93, P = 0.002) and MA_thrombin levels (hazard ratio 1.06, 95% confidence interval 1.03-1.08, P < 0.001) were independent risk factors for predicting the long-term of adverse clinical cardiovascular events.

CONCLUSION

MA_thrombin was an independent risk factor for predicting slow-flow/ no-reflow in STEMI patients who underwent primary PCI.

Relationship between the Soluble F11 Receptor and Annexin A5 in African Americans Patients with Type-2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is characterized by endothelial dysfunction, increased thrombogenicity, and inflammation. The soluble human F11 receptor (sF11R) and annexin A5 (ANXA5) play crucial roles in inflammatory thrombosis and atherosclerosis. We examined the relationship between circulating sF11R and ANXA5 and their impact on endothelial function. The study included 125 patients with T2DM. Plasma levels of sF11R and ANXA5 were quantified by ELISA. Microvascular function was assessed using the vascular reactivity index (VRI). Large artery stiffness was assessed by carotid-femoral pulse wave velocity (PWV). Carotid intima-media thickness (CIMT) was assessed by B-mode ultrasound imaging. The mean age of patients in the study was 59.7 ± 7.8 years, 78% had hypertension, 76% had dyslipidemia, and 12% had CKD. sF11R correlated positively with ANXA5 levels (β = 0.250, p = 0.005), and correlated inversely with VRI and total nitic oxide (NO), (β = −0.201, p = 0.024; β = −0.357, p = 0.0001, respectively). Multivariate regression analysis revealed that sF11R was independently associated with ANXA5 in the total population and in patients with HbA1c > 6.5% (β = 0.366, p = 0.007; β = 0.425, p = 0.0001, respectively). sF11R and ANXA5 were not associated with vascular outcome, suggesting that they may not be reliable markers of vascular dysfunction in diabetes. The clinical significance of sF11R/ANXA5 association in diabetes warrants further investigation in a larger population.