Prognostic Determinants of Coronary Atherosclerosis in Stable Ischemic Heart Disease

Association between R2CHA2DS2-VASc score and three-vessel coronary artery disease in a large population at high cardiovascular risk

Coronary artery disease (CAD), particularly three-vessel coronary disease (3VD), is the main cause of death in industrialized countries. Chronic kidney disease is an independent risk factor for CAD. The CHA2DS2-VASc score shows a good ability to predict CV events in high-risk population independently from atrial fibrillation. The aim of the present study was to evaluate the association between the R2CHA2DS2-VASc score and 3VD in a population of patients at high cardiovascular risk. Monocentric prospective study evaluated 1017 patients undergoing coronary angiography. The R2CHA2DS2-VASc score was obtained by adding 2 points to the CHA2DS2-VASc score in case of eGFR < 60 ml/min/1.73m2. Coronary lesions causing ≥ 50% reduction of a major epicardial vessel diameter were considered significant. Patients were grouped based on R2CHA2DS2-VASc tertiles and according to the severity of CAD: 3VD vs No-3VD. The 3VD group showed significantly higher R2CHA2DS2-VASc score than the No-3VD group (4.20 ± 2.18 vs 3.36 ± 2.06, p < 0.001). The risk of 3VD increased by 21% for every 1-point increase in the score (OR 1.21; 95% CI 1.13-1.28, p < 0.001). The prevalence of 3VD was higher among patients belonging to higher tertiles of R2CHA2DS2-VASc (17.2% vs 26.7% vs 33.6% for first, second, and third tertile respectively, p < 0.001) with a risk more than doubled for the third tertile compared to the first one (OR 2.45; 95% CI 1.71-3.49, p < 0.001). The R2CHA2DS2-VASc score is independently associated with 3VD in patients at high cardiovascular risk. The score could be considered a useful tool for clinicians to identify patients who are at high risk of 3VD.

The Role of TPM3 in Protecting Cardiomyocyte from Hypoxia-Induced Injury via Cytoskeleton Stabilization

Ischemic heart disease (IHD) remains a major global health concern, with ischemia-reperfusion injury exacerbating myocardial damage despite therapeutic interventions. In this study, we investigated the role of tropomyosin 3 (TPM3) in protecting cardiomyocytes against hypoxia-induced injury and oxidative stress. Using the AC16 and H9c2 cell lines, we established a chemical hypoxia model by treating cells with cobalt chloride (CoCl2) to simulate low-oxygen conditions. We found that CoCl2 treatment significantly upregulated the expression of hypoxia-inducible factor 1 alpha (HIF-1α) in cardiomyocytes, indicating the successful induction of hypoxia. Subsequent morphological and biochemical analyses revealed that hypoxia altered cardiomyocyte morphology disrupted the cytoskeleton, and caused cellular damage, accompanied by increased lactate dehydrogenase (LDH) release and malondialdehyde (MDA) levels, and decreased superoxide dismutase (SOD) activity, indicative of oxidative stress. Lentivirus-mediated TPM3 overexpression attenuated hypoxia-induced morphological changes, cellular damage, and oxidative stress imbalance, while TPM3 knockdown exacerbated these effects. Furthermore, treatment with the HDAC1 inhibitor MGCD0103 partially reversed the exacerbation of hypoxia-induced injury caused by TPM3 knockdown. Protein-protein interaction (PPI) network and functional enrichment analysis suggested that TPM3 may modulate cardiac muscle development, contraction, and adrenergic signaling pathways. In conclusion, our findings highlight the therapeutic potential of TPM3 modulation in mitigating hypoxia-associated cardiac injury, suggesting a promising avenue for the treatment of ischemic heart disease and other hypoxia-related cardiac pathologies.

Predictive value of serum creatinine and total bilirubin for long-term death in patients with ischemic heart disease: A cohort study

BACKGROUND

Ischemic heart disease (IHD) has a high mortality in the population. Although serum creatinine (Cr) and serum total bilirubin (TBil) are rapid and readily available biomarkers in routine blood tests, there is a lack of literature on the prognostic value of combined Cr and TBil tests for IHD. This study aimed to evaluate a combined equation based on Cr and TBil to predict the long-term risk of death in IHD and to find indicators sensitive to the prognosis of IHD patients.

METHOD

In this study, 2625 patients with IHD were included, and the combined value and combined equations of Cr and TBil were obtained by logistic regression analysis based on Cr and TBil collected at the time of admission. Patients were divided into four groups according to the quartiles of the combined value. COX proportional hazard regression model was used to analyze the risk factors for long-term death in IHD patients. Receiver operating characteristic (ROC) curves were used to evaluate the prognostic effect of Cr, TBil and combined value on long-term death events.

RESULTS

Logistic regression analysis was performed for long-term death events with Cr and TBil as independent variables, and the logit regression model was Logit(P) = 0.0129×TBil+0.007×Cr-0.417. Multifactorial Cox regression analysis showed that high values of the equation were independent risk factors for long-term death events (all-cause death: HR 1.457, 95% CI 1.256-1.689, P<0.001; cardiovascular death: HR 1.452, 95% CI 1.244-1.695, P<0.001). Combined Cr and TBil value are more valuable in predicting long-term death (AUC: 0.609, 95% CI 0.587-0.630, P<0.001).

CONCLUSION

Combined Cr and TBil assay is superior to single biomarkers for predicting long-term death in patients with IHD. High values of the equation are independent predictors of long-term death and can be used to identify patients at high risk for IHD.

Accumulation of endogenous adenosine improves cardiomyocyte metabolism via epigenetic reprogramming in an ischemia-reperfusion model

Adenosine kinase (ADK) plays the major role in cardiac adenosine metabolism, so that inhibition of ADK increases myocardial adenosine levels. While the cardioprotective actions of extracellular adenosine against ischemia/reperfusion (I/R) are well-established, the role of cellular adenosine in protection against I/R remains unknown. Here we investigated the role of cellular adenosine in epigenetic regulation on cardiomyocyte gene expression, glucose metabolism and tolerance to I/R. Evans blue/TTC staining and echocardiography were used to assess the extent of I/R injury in mice. Glucose metabolism was evaluated by positron emission tomography and computed tomography (PET/CT). Methylated DNA immunoprecipitation (MeDIP) and bisulfite sequencing PCR (BSP) were used to evaluate DNA methylation. Lentiviral/adenovirus transduction was used to overexpress DNMT1, and the OSI-906 was administered to inhibit IGF-1. Cardiomyocyte-specific ADK/IGF-1-knockout mice were used for mechanistic experiments.Cardiomyocyte-specific ADK knockout enhanced glucose metabolism and ameliorated myocardial I/R injury in vivo. Mechanistically, ADK deletion caused cellular adenosine accumulation, decreased DNA methyltransferase 1 (DNMT1) expression and caused hypomethylation of multiple metabolic genes, including insulin growth factor 1 (IGF-1). DNMT1 overexpression abrogated these beneficial effects by enhancing apoptosis and decreasing IGF-1 expression. Inhibition of IGF-1 signaling with OSI-906 or genetic knocking down of IGF-1 also abrogated the cardioprotective effects of ADK knockout, revealing the therapeutic potential of increasing IGF-1 expression in attenuating myocardial I/R injury. In conclusion, the present study demonstrated that cardiomyocyte ADK deletion ameliorates myocardial I/R injury via epigenetic upregulation of IGF-1 expression via the cardiomyocyte adenosine/DNMT1/IGF-1 axis.

Coronary stenosis is a risk marker for impaired cardiac function on cardiopulmonary exercise test

Background

Cardiac function varies in different ways in ischemic heart disease (IHD). We aimed to evaluate the characteristics of cardiac function on cardiopulmonary exercise test (CPET) in IHD with different coronary stenoses.

Methods

Totally 614 patients with IHD were divided into non-obstructive coronary artery disease (NOCAD) (stenosis < 50%), obstructive coronary artery disease (OCAD) (stenosis 50-90%) and severe OCAD ( stenosis > 90%) according to the coronary angiography. And 101 healthy volunteers as controls. All participants performed CPET to assess cardiac function by oxygen uptake (VO₂), estimated cardiac output (CO), and heart rate (HR).

Results

Generally, the values of VO₂, CO, and HR in IHD were significantly lower than in healthy volunteers. Among 289 NOCAD, 132 OCAD, and 193 severe OCAD, significantly decreased values of VO₂, CO, HR were observed (VO₂ peak: 16.01 ± 4.11 vs. 15.66 ± 4.14 vs. 13.33 ± 3.4 mL/min/kg; CO: 6.96 ± 2.34 vs. 6.87 ± 2.37 vs. 6.05 ± 1.79 L/min; HR: 126.44 ± 20.53 vs. 115.15 ± 18.78 vs. 109.07 ± 16.23 bpm, P < 0.05). NOCAD had significantly lower VO₂ at anaerobic threshold (-1.35, 95%CI -2.16 - -0.54) and VO₂ peak (-2.05, 95%CI -3.18 - -0.93) compared with healthy volunteers after adjustment. All IHD patients were associated with low stroke volume and inefficient gas exchange (P < 0.05).

Conclusion

IHD with increasing atherosclerotic burdens were associated with impaired cardiac output and chronotropic response on CPET. NOCAD should be given more early prevention and rigorous follow-up.

Annotating regulatory elements by heterogeneous network embedding

MOTIVATION

Regulatory elements (REs), such as enhancers and promoters, are known as regulatory sequences functional in a heterogeneous regulatory network to control gene expression by recruiting transcription regulators and carrying genetic variants in a context specific way. Annotating those REs relies on costly and labor-intensive next-generation sequencing and RNA-guided editing technologies in many cellular contexts.

RESULTS

We propose a systematic Gene Ontology Annotation method for Regulatory Elements (RE-GOA) by leveraging the powerful word embedding in natural language processing. We first assemble a heterogeneous network by integrating context specific regulations, protein-protein interactions and gene ontology (GO) terms. Then we perform network embedding and associate regulatory elements with GO terms by assessing their similarity in a low dimensional vector space. With three applications, we show that RE-GOA outperforms existing methods in annotating TFs' binding sites from ChIP-seq data, in functional enrichment analysis of differentially accessible peaks from ATAC-seq data, and in revealing genetic correlation among phenotypes from their GWAS summary statistics data.

AVAILABILITY AND IMPLEMENTATION

The source code and the systematic RE annotation for human and mouse are available at https://github.com/AMSSwanglab/RE-GOA.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Integrating Coronary Plaque Information from CCTA by ML Predicts MACE in Patients with Suspected CAD

Conventional prognostic risk analysis in patients undergoing noninvasive imaging is based upon a limited selection of clinical and imaging findings, whereas machine learning (ML) algorithms include a greater number and complexity of variables. Therefore, this paper aimed to explore the predictive value of integrating coronary plaque information from coronary computed tomographic angiography (CCTA) with ML to predict major adverse cardiovascular events (MACEs) in patients with suspected coronary artery disease (CAD). Patients who underwent CCTA due to suspected coronary artery disease with a 30-month follow-up for MACEs were included. We collected demographic characteristics, cardiovascular risk factors, and information on coronary plaques by analyzing CCTA information (plaque length, plaque composition and coronary artery stenosis of 18 coronary artery segments, coronary dominance, myocardial bridge (MB), and patients with vulnerable plaque) and follow-up information (cardiac death, nonfatal myocardial infarction and unstable angina requiring hospitalization). An ML algorithm was used for survival analysis (CoxBoost). This analysis showed that chest symptoms, the stenosis severity of the proximal anterior descending branch, and the stenosis severity of the middle right coronary artery were among the top three variables in the ML model. After the 22nd month of follow-up, in the testing dataset, ML showed the largest C-index and AUC compared with Cox regression, SIS, SIS score + clinical factors, and clinical factors. The DCA of all the models showed that the net benefit of the ML model was the highest when the treatment threshold probability was between 1% and 9%. Integrating coronary plaque information from CCTA based on ML technology provides a feasible and superior method to assess prognosis in patients with suspected coronary artery disease over an approximately three-year period.

Effect and mechanism of "Danggui-kushen" herb pair on ischemic heart disease

AIMS

The purpose of this study was to investigate the mechanism and effects of "Danggui-kushen" herb pair (DKHP) better than single drug in ischemic heart disease (IHD).

METHODS

IHD model was established by left anterior descending branch of coronary artery in rats. Rats were randomized into six groups and oral administration for 7 days: control, model, Danshen dripping pills (DS) (5.103 g/kg), Danggui (DG) (2.7 g/kg), Kushen (KS) (2.7 g/kg) and DKHP (2.7 g/kg). Electrocardiogram (ECG), myocardial infarction and damage assessment, histological inspection analysis, and various biochemical indexes of myocardial tissue were measured to evaluate the myocardial damage and the protective effects of drugs. The inflammatory levels were identified by HE staining and serum cytokine, and the expression of hypoxia-inducible factor 1α (HIF-1α), inhibitor kappa B kinaseβ (IKKβ) and nuclear transcription factor kappa B (NF-κB) were measured by immunohistochemistry.

KEY FINDINGS

The results suggested that: compared with the control group, model group showed significantly myocardial tissue abnormalities, and increased levels of inflammatory cytokine. Treatment with drugs inhibited the increase of α-hydroxybutyrate dehydrogenase (α-HBDH), creatine kinase (CK), creatinekinase isoenzyme (CK-MB), interleukin 1 (IL-1) and interleukin 6 (IL-6). The results of immunohistochemical showed that drugs-treatment inhibited the expression of IKKβ and the P-p65, increased the expression of HIF-1α, which demonstrated that the anti-inflammatory effects of DKHP was achieved by suppressing of NF-κB signaling.

CONCLUSION

These observations indicated that DKHP can ameliorate myocardial injury better than single. And these are related to the inhibition of NF-κB and actives HIF-1α signaling.

Investigation of Lipid Metabolism in Dynamic Progression of Coronary Artery Atherosclerosis of Humans by Time-of-Flight Secondary Ion Mass Spectrometry

Alterations in lipid metabolites in coronary artery tissues are phenotypic changes in the progression of atherosclerosis (AS). A full picture of the spatiotemporal distribution of lipid metabolites in coronary AS is needed for a deeper understanding of its pathology and the identification of potential biomarkers of disease progression. In this work, the changes in species, quantity, and distribution of lipid metabolites at different stages of AS, which were standardized by the disease areas, were analyzed through the high spatial resolution- and high sensitivity-time-of-flight secondary ion mass spectrometry (ToF-SIMS) under delayed extraction mode. Based on high lateral resolution imaging, we further analyzed the ToF-SIMS data extracted from the subregions of AS lesion tissues at different disease progression stages by semiquantitative comparison, clustering analysis (t-stochastic neighbor embedding and HCA), and KEGG enrichment. Thus, a much-detailed description of lipids' features in coronary AS was achieved. We constructed a ToF-SIMS mass spectrometry database of coronary AS lipids. 40 specific lipid metabolites with distinctive patterns between different pathological stages were obtained. Chemical imaging unveiled further details regarding the spatial distribution of lipids. Moreover, linoleic acid and arachidonic acid metabolic pathway were predicted to be critical in AS progression.

Epidemiology and pathophysiologic insights of coronary atherosclerosis relevant for contemporary non-invasive imaging

In the past few years significant changes have taken place in the diagnostic and therapeutic approach to patients with coronary artery disease (CAD) and/or ischemic heart disease (IHD). New discoveries about the development and progression of coronary atherosclerosis have changed the clinical landscape. At the same time a marked decrease in cardiovascular (CV) mortality and CAD incidence have been observed in many Countries but particularly in the most industrialized ones. This fall has been also observed in the incidence of stroke, sudden death, myocardial ischemia, myocardial infarction (MI), and prevalence of CAD. As a consequence, an increasing number of patients with chest pain exhibits non-significant stenosis at both invasive and non-invasive coronary angiography and the rate of coronary vessels revascularizations has greatly reduced. Coronary atherosclerosis and its characteristics have shown to be both diagnostic and therapeutic targets beyond obstructive CAD. The decreased prevalence of CAD in the general population has modified the pre-test probability (PTP) of disease. In this landscape the conventional stress imaging tests appear to have limited accuracy making the diagnosis of obstructive CAD very challenging. These diagnostic tests have been introduced and tested in a population with a much higher probability of disease and therefore the contemporary accuracy of these old tests appear much lower than in the past. In addition, in the past few years the relevance of the traditional ischemia guided coronary intervention strategy has been questioned. Given the low CV events granted by an optimal medical therapy in CAD the major attention has been directed on detecting coronary atherosclerosis. The earlier the better. At the same time, a growing number of data from clinical studies have shown a significant prognostic role for non-obstructive CAD and coronary atherosclerosis. All these facts have shifted the clinicians' attention from the functional evaluation of the coronary circulation to the anatomic burden of disease.

Mildly Abnormal Lipid Levels, but Not High Lipid Variability, Are Associated With Increased Risk of Myocardial Infarction and Stroke in “Statin-Naive” Young Population A Nationwide Cohort Study

Rationale:

In young adults, the role of mildly abnormal lipid levels and lipid variability in the risk of atherosclerotic cardiovascular diseases remains uncertain.

Objective:

To investigate the association of these abnormalities in lipid profiles with the risk of myocardial infarction (MI) and stroke in young population.

Methods and Results:

From the Korean National Health Insurance Service, a nationwide population-based cohort of 1 934 324 statin-naive adults aged 20 to 39 years, with ≥3 lipid profile measurements and without a history of MI and stroke, were followed-up until the date of MI or stroke, or December 31, 2017. The primary measure of lipid variability was variability independent of the mean. Higher baseline total cholesterol, LDL-C (low-density lipoprotein-cholesterol), and triglycerides and lower HDL-C (high-density lipoprotein-cholesterol) levels were significantly associated with increased MI risk; respective adjusted hazard ratios and 95% CIs comparing the highest versus lowest quartiles were 1.35 (1.20–1.53) for total cholesterol, 1.41 (1.25–1.60) for LDL-C, 1.28 (1.11–1.47) for triglycerides, and 0.82 (0.72–0.94) for HDL-C. Adjusted analyses for deciles of lipid profiles showed that MI risk was significantly elevated among participants with total cholesterol ≥223.4 mg/dL, LDL-C ≥139.5 mg/dL, HDL-C ≤41.8 mg/dL, and triglycerides ≥200.1 mg/dL. The associations between lipid levels and stroke risk were less prominent. Multivariable-adjusted restricted cubic spline analysis demonstrated that the increase in MI risk was not exclusively driven by extreme values of lipid profiles. Similar results were obtained on sensitivity analyses of baseline lipid levels. However, associations between lipid variability and the risk of MI and stroke varied depending on the measure of lipid variability used.

Conclusions:

Mildly abnormal baseline lipid levels were associated with an increased future risk of atherosclerotic cardiovascular disease events, particularly MI, whereas measures of lipid variability were not. Therefore, in young adults, achieving optimal lipid levels could be valuable in the prevention of atherosclerotic cardiovascular disease.

Clinical significance of presenting syndromes on outcome after coronary artery bypass grafting

OBJECTIVES

Evidence of an association between postoperative survival and the presenting syndrome following coronary artery bypass grafting (CABG) is limited. Our goal was to evaluate whether the presenting symptoms of acute coronary syndrome (ACS) or stable ischaemic heart disease were associated with mid-term survival in patients undergoing CABG.

METHODS

We performed a single-centre retrospective study involving consecutive CABG operations from 2011 to 2016. Post-discharge survival was ascertained via patient-level data linkage with the State of Connecticut vital statistics. Baseline and postoperative variables were compared between the two groups. The multivariate Cox proportional hazard model, adjusted for demographics and comorbidity, was used to show whether the presenting syndrome category was independently associated with mid-term survival.

RESULTS

A total of 1631 patients were included: 794 with stable ischaemic heart disease and 837 with ACS. Patients with ACS who underwent CABG showed more comorbidities. The overall 30-day mortality rate was 1.8% (ACS 2.3% vs stable ischaemic heart disease 1.3%; P = 0.12). In-hospital, postoperative outcomes revealed higher rates of prolonged ventilation (11.7% vs 4.8%; P < 0.001), pneumonia (6.6% vs 3.9%; P = 0.016) and stay in the intensive care unit (3.7 ± 4.0 vs 3.2 ± 2.7 days; P = 0.014) in patients with ACS. The overall mean duration of the long-term follow-up period was 27.9 ± 16.5 months, during which 117 deaths occurred. The multivariable Cox proportional hazard model adjusted for demographics and comorbidity showed that ACS was not a predictor of mid-term mortality [hazard ratio (HR) 1.26, 95% confidence interval (CI) 0.84-1.90; P = 0.26]. Other significant predictors were cardiogenic shock (HR 2.12, 95% CI 1.04-4.33; P = 0.039) and history of congestive heart failure (HR 1.78, 95% CI 1.18-2.69; P = 0.0062).

CONCLUSIONS

The presenting syndrome was not an independent predictor of the mid-term mortality rate. The results indicate that the classification of the presenting syndrome may be fluid and that clinical decision-making for postoperative care of patients who have CABG directed by category of presenting syndrome needs careful consideration. These data should be interpreted in the context of the limitations of this study.

Megakaryocytic Leukemia 1 Bridges Epigenetic Activation of NADPH Oxidase in Macrophages to Cardiac Ischemia-Reperfusion Injury

BACKGROUND

Excessive accumulation of reactive oxygen species (ROS), catalyzed by the NADPH oxidases (NOX), is involved in the pathogenesis of ischemia-reperfusion (IR) injury. The underlying epigenetic mechanism remains elusive.

METHODS

We evaluated the potential role of megakaryocytic leukemia 1 (MKL1), as a bridge linking epigenetic activation of NOX to ROS production and cardiac ischemia-reperfusion injury.

RESULTS

Following IR injury, MKL1-deficient (knockout) mice exhibited smaller myocardial infarction along with improved heart function compared with wild-type littermates. Similarly, pharmaceutical inhibition of MKL1 with CCG-1423 also attenuated myocardial infarction and improved heart function in mice. Amelioration of IR injury as a result of MKL1 deletion or inhibition was accompanied by reduced ROS in vivo and in vitro. In response to IR, MKL1 levels were specifically elevated in macrophages, but not in cardiomyocytes, in the heart. Of note, macrophage-specific deletion (MϕcKO), instead of cardiomyocyte-restricted ablation (CMcKO), of MKL1 in mice led to similar improvements of infarct size, heart function, and myocardial ROS generation. Reporter assay and chromatin immunoprecipitation assay revealed that MKL1 directly bound to the promoters of NOX genes to activate NOX transcription. Mechanistically, MKL1 recruited the histone acetyltransferase MOF (male absent on the first) to modify the chromatin structure surrounding the NOX promoters. Knockdown of MOF in macrophages blocked hypoxia/reoxygenation-induced NOX transactivation and ROS accumulation. Of importance, pharmaceutical inhibition of MOF with MG149 significantly downregulated NOX1/NOX4 expression, dampened ROS production, and normalized myocardial function in mice exposed to IR injury. Finally, administration of a specific NOX1/4 inhibitor GKT137831 dampened ROS generation and rescued heart function after IR in mice.

CONCLUSIONS

Our data delineate an MKL1-MOF-NOX axis in macrophages that contributes to IR injury, and as such we have provided novel therapeutic targets in the treatment of ischemic heart disease.

Association of Isoprostanes-Related Oxidative Stress with Vulnerability of Culprit Lesions in Diabetic Patients with Acute Coronary Syndrome

Urinary excretion of 8-iso-prostaglandin F_2α (8-iso-PGF_2α), a reliable biomarker for enhanced oxidant stress in vivo, has been described in association with diabetes and coronary heart disease. The aim of this study was to evaluate the relationship between urinary 8-iso-PGF_2α levels and the characteristics of coronary culprit lesion in diabetic patients with acute coronary syndrome (ACS). A total of 79 diabetic patients with ACS were included. iMAP intravascular ultrasound (iMAP-IVUS) was performed to evaluate the characteristics of culprit plaques. Fasting urinary 8-iso-PGF_2α level was measured and corrected by creatinine clearance. iMAP-IVUS data showed culprit plaques in high urinary 8-iso-PGF_2α level patients had a greater percentage of necrotic core and less fibrous components. High urinary 8-iso-PGF_2α levels were correlated with increased necrotic plaque components (r = 0.325, P = 0.003). Meanwhile, the presence of thin-capped fibroatheroma (50.0% versus 11.5%, P = 0.003), ruptured plaques (30.8% versus 7.7%, P = 0.035), and thrombus (38.5% versus 7.7%, P = 0.008) were significantly more frequent in the upper tertile of urinary 8-iso-PGF_2α levels than in the low tertile. Multivariate analysis showed high levels of urinary 8-iso-PGF_2α (OR 4.240, P = 0.007) was independently associated with the presence of vulnerable culprit plaque in diabetic ACS patients. Urinary 8-iso-PGF_2α also displayed a significant value in predicting vulnerable plaques in diabetic patients with ACS by constructing the receiver-operating characteristic (ROC) curve (Area under the ROC curve: 0.713, P = 0.001). Urinary 8-iso-PGF_2α levels are associated with the vulnerability of the coronary culprit lesion in diabetic patients with ACS and may provide additional information for risk assessment in suspected vulnerable patients.

Testosterone, myocardial function, and mortality

The cardiovascular system is particularly sensitive to androgens, but some controversies exist regarding the effect of testosterone on the heart. While among anabolic abusers, cases of sudden cardiac death have been described, recently it was reported that low serum level of testosterone was correlated with increased risk of cardiovascular diseases (CVD) and mortality rate. This review aims to evaluate the effect of testosterone on myocardial tissue function, coronary artery disease (CAD), and death. Low testosterone level is associated with increased incidence of CAD and mortality. Testosterone administration in hypogonadal elderly men and women has a positive effect on cardiovascular function and improved clinical outcomes and survival time. Although at supraphysiologic doses, androgen may have a toxic effect, and at physiological levels, testosterone is safe and exerts a beneficial effect on myocardial function including mechanisms at cellular and mitochondrial level. The interaction with free testosterone and estradiol should be considered. Further studies are necessary to better understand the interaction mechanisms for an optimal androgen therapy in CVD.

Urinary 8-iso-prostaglandin F2α as a risk marker for the vulnerability of culprit plaque in diabetic patients with stable coronary artery disease

We evaluated the association of urinary excretion of 8-iso-prostaglandin F_2α (8-iso-PGF_2α) with the vulnerability of culprit lesions in 156 age- and sex-matched diabetic stable coronary artery disease (CAD) patients with or without thin-capped fibroatheroma (TCFA) identified by iMAP intravascular ultrasound. Fasting urinary 8-iso-PGF_2α level was measured and corrected by creatinine clearance. Compared to non-TCFA group, patients with TCFA had higher urinary 8-iso-PGF_2α levels [114.6 (71.1, 181.5) vs. 83.0 (63.2, 138.2) pmol/mmolCr, P = 0.012]. Urinary 8-iso-PGF_2α level was positively correlated with percent necrotic volume of culprit lesion (r = 0.218, P = 0.006). High urinary 8-iso-PGF_2α level (OR 2.941, P = 0.009) was independently associated with the presence of TCFA and displayed a significant value in predicting TCFA plaques in study patients. The current study indicated that urinary 8-iso-PGF_2α may be an important surrogate marker for the vulnerability of culprit lesion in diabetic patients with CAD.

Is there a role for fractional flow reserve in coronary artery bypass graft (CABG) planning?

The concept of significant lesions has substantially evolved over the last decade. With growing evidence for use of fractional flow reserve (FFR) as a determinant of lesion-specific ischemia and its superiority to angiography-guided revascularization and medical therapy, the field of percutaneous revascularization has shifted to rely exclusively on FFR instead of luminal stenosis alone in guiding revascularization. This transition to physiological assessment has not yet made it to the realm of surgical revascularization. FFR-guided therapy has been shown to be superior to angiography-guided therapy mainly by safe deferral of about 1/3rd of lesions, leading to less periprocedural events and better outcomes. Is it possible that utilization of FFR-guided CABG would lead to less complicated procedures, shorter operating times, more frequent off pump CABG procedures and more hybrid procedures? Can FFR-guided CABG improve the cardiovascular outcomes as compared to current standard of practice? In the following paragraphs we review the concept of FFR, the evidence behind FFR-guided therapy, the emerging data regarding use FFR-guided CABG and discuss where the revascularization field is headed.

Maximization of the usage of coronary CTA derived plaque information using a machine learning based algorithm to improve risk stratification; insights from the CONFIRM registry

INTRODUCTION

Machine learning (ML) is a field in computer science that demonstrated to effectively integrate clinical and imaging data for the creation of prognostic scores. The current study investigated whether a ML score, incorporating only the 16 segment coronary tree information derived from coronary computed tomography angiography (CCTA), provides enhanced risk stratification compared with current CCTA based risk scores.

METHODS

From the multi-center CONFIRM registry, patients were included with complete CCTA risk score information and ≥3 year follow-up for myocardial infarction and death (primary endpoint). Patients with prior coronary artery disease were excluded. Conventional CCTA risk scores (conventional CCTA approach, segment involvement score, duke prognostic index, segment stenosis score, and the Leaman risk score) and a score created using ML were compared for the area under the receiver operating characteristic curve (AUC). Only 16 segment based coronary stenosis (0%, 1-24%, 25-49%, 50-69%, 70-99% and 100%) and composition (calcified, mixed and non-calcified plaque) were provided to the ML model. A boosted ensemble algorithm (extreme gradient boosting; XGBoost) was used and the entire data was randomly split into a training set (80%) and testing set (20%). First, tuned hyperparameters were used to generate a trained model from the training data set (80% of data). Second, the performance of this trained model was independently tested on the unseen test set (20% of data).

RESULTS

In total, 8844 patients (mean age 58.0 ± 11.5 years, 57.7% male) were included. During a mean follow-up time of 4.6 ± 1.5 years, 609 events occurred (6.9%). No CAD was observed in 48.7% (3.5% event), non-obstructive CAD in 31.8% (6.8% event), and obstructive CAD in 19.5% (15.6% event). Discrimination of events as expressed by AUC was significantly better for the ML based approach (0.771) vs the other scores (ranging from 0.685 to 0.701), P < 0.001. Net reclassification improvement analysis showed that the improved risk stratification was the result of down-classification of risk among patients that did not experience events (non-events).

CONCLUSION

A risk score created by a ML based algorithm, that utilizes standard 16 coronary segment stenosis and composition information derived from detailed CCTA reading, has greater prognostic accuracy than current CCTA integrated risk scores. These findings indicate that a ML based algorithm can improve the integration of CCTA derived plaque information to improve risk stratification.

Noninvasive Imaging of the Coronary Vasculature Using Ultrafast Ultrasound

Objectives

The aim of this study was to investigate the potential of coronary ultrafast Doppler angiography (CUDA), a novel vascular imaging technique based on ultrafast ultrasound, to image noninvasively with high sensitivity the intramyocardial coronary vasculature and quantify the coronary blood flow dynamics.

Background

Noninvasive coronary imaging techniques are currently limited to the observation of the epicardial coronary arteries. However, many studies have highlighted the importance of the coronary microcirculation and microvascular disease.

Methods

CUDA was performed in vivo in open-chest procedures in 9 swine. Ultrafast plane-wave imaging at 2,000 frames/s was combined to an adaptive spatiotemporal filtering to achieve ultrahigh-sensitive imaging of the coronary blood flows. Quantification of the flow change was performed during hyperemia after a 30-s left anterior descending (LAD) artery occlusion followed by reperfusion and was compared to gold standard measurements provided by a flowmeter probe placed at a proximal location on the LAD (n = 5). Coronary flow reserve was assessed during intravenous perfusion of adenosine. Vascular damages were evaluated during a second set of experiments in which the LAD was occluded for 90 min, followed by 150 min of reperfusion to induce myocardial infarction (n = 3). Finally, the transthoracic feasibility of CUDA was assessed on 2 adult and 2 pediatric volunteers.

Results

Ultrahigh-sensitive cine loops of venous and arterial intramyocardial blood flows were obtained within 1 cardiac cycle. Quantification of the coronary flow changes during hyperemia was in good agreement with gold standard measurements (r² = 0.89), as well as the assessment of coronary flow reserve (2.35 ± 0.65 vs. 2.28 ± 0.84; p = NS). On the infarcted animals, CUDA images revealed the presence of strong hyperemia and the appearance of abnormal coronary vessel structures in the reperfused LAD territory. Finally, the feasibility of transthoracic coronary vasculature imaging was shown on 4 human volunteers.

Conclusions

Ultrafast Doppler imaging can map the coronary vasculature with high sensitivity and quantify intramural coronary blood flow changes.

Plaque Characteristics in Coronary Artery Disease Patients with Impaired Glucose Tolerance

BACKGROUND

Impaired glucose tolerance (IGT) patients are known to have a high risk of cardiovascular events and their prognosis has been reported to be poor. The present study aimed to compare coronary plaque characteristics among coronary artery disease (CAD) patients with normal glucose tolerance (NGT), those with IGT, and those with diabetes mellitus (DM) by using optical coherence tomography (OCT).

METHODS

The present study included 101 coronary artery disease patients (mean age, 67.9 ± 10.4 years; 82.4% male). OCT was performed for target and non-target vessels during percutaneous coronary intervention. The patients were divided into the following 3 groups: the NGT, IGT, and DM groups.

RESULTS

A total of 136 non-target residual plaques were found in 101 patients (27, 30, and 44 in the NGT, IGT, and DM groups, respectively). The size of the lipid core expressed as the mean angle of the lipid arc was significantly greater in the IGT and DM groups than in the NGT group (163.0 ± 58.7°, 170.1 ± 59.3°, and 130.9 ± 37.7°, respectively, P < 0.05). The fibrous cap covering the lipid core was significantly thinner in the IGT group than in the NGT group (77.0 ± 23.4 μm vs. 105.6 ± 47.0 μm, P = 0.040).

CONCLUSION

The coronary plaques in CAD patients are more vulnerable when having IGT compared to those with NGT, and similar to those with DM. This finding may explain the high risk of cardiovascular events in CAD patients with IGT.