Periodic repolarization dynamics: Different methods for quantifying low-frequency oscillations of repolarization

BACKGROUND

Periodic repolarization dynamics (PRD) is an electrocardiographic biomarker that quantifies low-frequency (LF) instabilities of repolarization. PRD is a strong predictor of mortality in patients with ischaemic and non-ischaemic cardiomyopathy. Until recently, two methods for calculating PRD have been proposed. The wavelet analysis has been widely tested and quantifies PRD in deg2 units by application of continuous wavelet transformation (PRDwavelet). The phase rectified signal averaging method (PRDPRSA) is an algebraic method, which quantifies PRD in deg. units. The correlation, as well as a conversion formula between the two methods remain unknown.

METHOD

The first step for quantifying PRD is to calculate the beat-to-beat change in the direction of repolarization, called dT°. PRD is subsequently quantified by means of either wavelet or PRSA-analysis. We simulated 1.000.000 dT°-signals. For each simulated signal we calculated PRD using the wavelet and PRSA-method. We calculated the ratio between PRDwavelet and PRDPRSA for different values of dT° and RR-intervals and applied this ratio in a real-ECG validation cohort of 455 patients after myocardial infarction (MI). We finally calculated the correlation coefficient between real and calculated PRDwavelet. PRDwavelet was dichotomized at the established cut-off value of ≥5.75 deg2.

RESULTS

The ratio between PRDwavelet and PRDPRSA increased with increasing heart-rate and mean dT°-values (p < 0.001 for both). The correlation coefficient between PRDwavelet and PRDPRSA in the validation cohort was 0.908 (95% CI 0.891-0.923), which significantly (p < 0.001) improved to 0.945 (95% CI 0.935-0.955) after applying the formula considering the ratio between PRDwavelet and PRDPRSA obtained from the simulation cohort. The calculated PRDwavelet correctly classified 98% of the patients as low-risk and 87% of the patients as high-risk and correctly identified 97% of high-risk patients, who died within the follow-up period.

CONCLUSION

This is the first analytical investigation of the different methods used to calculate PRD using simulated and clinical data. In this article we propose a novel algorithm for converting PRDPRSA to the widely validated PRDwavelet, which could unify the calculation methods and cut-offs for PRD.

Ultrasonographic assessment and clinical outcomes after deployment of a suture-mediated femoral vascular closure device

INTRODUCTION

Data regarding changes in the arterial vascular wall after the deployment of suture-mediated vascular closure devices (VCD) at the femoral site in patients undergoing percutaneous coronary angiography (CAG) or percutaneous coronary intervention (PCI) are sparse. This study investigated the occurrence of structural vascular changes or adverse vascular complications at the access site in the short term after the deployment of a suture-mediated intravascular VCD.

METHODS

Ninety-three patients (72% males) with a mean age of 62 ± 11 years were enrolled. Duplex sonography was conducted at the access site at baseline, 24 hours and 30 days after femoral puncture in patients with successful VCD deployment. Vessel diameter, flow velocities, the severity of atherosclerosis, and the intravascular or perivascular tissue alterations in both the right common femoral artery (RCFA) and right external iliac artery (REILA) were assessed. Vascular complications were documented.

RESULTS

There were no significant changes regarding the diameter of the RCFA in the transverse and longitudinal view, peak systolic velocity (PSV) of the RCFA, PSV ratio of the RCFA to REILA, the resistive index of the RFCA and the severity of arterial wall abnormalities before femoral puncture, the day following VCD deployment and 30 days after (p = NS for all) in the general population and in patients with diabetes mellitus, on oral anticoagulants or with mild peripheral artery disease (p = NS for all markers). Device failure was observed in four cases. Few (4.4%) patients had vascular complications, which included exclusively major or minor haematomas, most of which did not persist at the 30-day follow up.

CONCLUSION

The use of a suture-mediated VCD was safe and was not associated with adverse vascular wall changes at the femoral access site 30 days after deployment in patients undergoing CAG and/or PCI.

Association of Growth Differentiation Factor 15 with Arterial Stiffness and Endothelial Function in Subpopulations of Patients with Coronary Artery Disease: A Proof-of-Concept Study

BACKGROUND

Growth-differentiation factor-15 (GDF-15) is a biomarker belonging to the transforming growth factor-beta cytokine superfamily, which is linked to many pathological conditions, including inflammation and myocardial injury. Pulse wave velocity (cfPWV) and augmentation index (AIx) are indices of arterial stiffness, which are associated with the severity of coronary artery disease (CAD). Flow-mediated dilatation (FMD) is a well-studied surrogate marker of endothelial-dependent dysfunction and systemic inflammation.

OBJECTIVE

In this proof-of-concept study, we aimed to investigate the relationship between circulating GDF-15, endothelial dysfunction, and indices of arterial stiffness in different settings of coronary artery disease and myocardial injury.

METHODS

In this cross-sectional single-center study, we enrolled patients (n = 22) after interventional treatment for acute myocardial infarction (AMI), patients (n = 11) admitted with chest pain and elevated cardiac enzymes but without evidence of obstructing CAD (MI-NOCAD) in percutaneous coronary angiography (CAG), and patients (n = 20) who underwent CAG according to indications without evident obstructive CAD in CAG (NOCAD). FMD was assessed at the brachial artery. AIx of the central aortic pressure and cfPWV were estimated by applanation tonometry at the radial and carotid-femoral site, respectively, with a validated acquisition system (Sphygmo- Cor, AtCor Medical, Sydney (NSW), Australia). ELISA was used to determine circulating GDF- 15 serum levels (R&D Systems, Minneapolis, MN). Clinical and demographic data and values of routine biochemical biomarkers were obtained. The highest high-sensitive cardiac Troponin I (hsTpnI) value during hospitalization was also recorded. Left ventricular ejection fraction (LVEF) was assessed with a transthoracic echocardiogram.

RESULTS

Patients with AMI were older, had worse LVEF, higher values of hsTpnI and increased circulating GDF-15 levels. Importantly, AMI patients had increased cfPWV values, deteriorated AIx values, blunted FMD and worse serum creatinine levels compared to MI-NOCAD and NOCAD patients, respectively, whereas MI-NOCAD and NOCAD did not differ from each other significantly on these biomarkers. Both AMI and MI-NOCAD patients presented a higher but comparable white blood cell count than NOCAD patients. A strong linear correlation between GDF-15 and cfPWV, hsTpnI, AIx, white blood cell count and creatinine but not with FMD was demonstrated in the general study population.

CONCLUSION

This proof-of-concept study showed that higher circulating levels of GDF-15, an inflammatory biomarker, were associated significantly with increased arterial stiffness only in AMI patients, whereas elevated GDF-15 demonstrated a linear relationship with the severity of the myocardial injury.

The prognostic role of galectin-3 and endothelial function in patients with heart failure according to left ventricular ejection fraction classification HF group

Background

Heart failure (HF) is nowadays classified in HF with reduced ejection fraction (HFrEF), HF with mildly-reduced EF (HFmrEF) and HF with preserved EF (HFpEF). Endothelial dysfunction, increased arterial stiffness and galectin-3, a biomarker of myocardial fibrosis, have been linked to major adverse cardiovascular events (MACE) in patients with ischemic HF.

Purpose

The purpose of this prospective, follow-up study was to investigate in patients with stable ischemic HF the prognostic role of circulating galectin-3 levels, endothelial function and arterial stiffness according to left ventricular ejection fraction classification.

Methods

In this study we prospectively enrolled 340 patients with stable ischemic HF. Patients were categorized in HFrEF (when EF below or equal to 40%), HFmrEF (when EF is more than 40%&lt;ef≤49%)&gt; and below/equal to 49%) and HFpEF (when EF is more/equal to 50% along with the presence of structural or functional dysfunction and/or elevated natriuretic peptides) according to recent guidelines upon 2D echocardiographic assessment. We evaluated flow-mediated dilatation (FMD) of brachial artery as a marker of endothelial function, carotid-femoral pulse-wave velocity (PWV) as a marker of arterial stiffness and galectin-3 levels as a biomarker of fibrosis. Patients were followed-up for MACE and the primary endpoint was defined as cardiovascular death, myocardial infarction, coronary revascularization, stroke, and hospitalization due to HF. &lt;ef≤49%)&gt;

Results

Interestingly, FMD values exhibited a stepwise improvement according to LVEF (HFrEF: 4.74±2.35% vs. HFmrEF: 4.97±2.81% vs. HFpEF: 5.94±3.46%, p=0.01) which remained statistically significant after the evaluation of possible confounders including age, sex, cardiovascular risk factors and number of significantly stenosed epicardial coronary arteries (b coefficient: 0.990, 95% CI: 0.166–1.814, p=0.019). Multivessel coronary artery disease (CAD) was more frequent in the group of HFrEF (HFrEF: 56% vs. HFmrEF: 64% vs. HFpEF: 73%, p=0.049). Nevertheless, PWV did not display any association with LVEF. Patients who presented MACE exhibited worse FMD values (4.51±2.35% vs. 5.32±2.67%, p=0.02) and the highest tertile of galectin-3 was linked to more MACEs (36% vs. 5.9%, p=0.01).

Conclusions

FMD values have a linear improvement according to LVEF increase in patients with ischemic HF and worse values are linked to more MACEs. Higher levels of galectin-3 might be used for risk stratification of patients with ischemic HF.

Funding Acknowledgement

Type of funding sources: None.

The prognostic role of galectin-3 and endothelial function in patients with heart failure

BACKGROUND

Heart failure (HF) is nowadays classified as HF with reduced ejection fraction (HFrEF), HF with mildly reduced EF (HFmrEF), and HF with preserved EF (HFpEF). Endothelial dysfunction (assessed by flow-mediated dilatation [FMD]), increased arterial stiffness (assessed by carotid-femoral pulse-wave velocity [PWV]), and galectin-3, a biomarker of myocardial fibrosis, have been linked to major adverse cardiovascular events (MACE) in patients with ischemic HF.

METHODS

In this study we prospectively enrolled 340 patients with stable ischemic HF. We assessed the brachial artery FMD, carotid-femoral PWV, and galectin-3 levels, and patients were followed up for MACE according to HF group.

RESULTS

Interestingly, the FMD values exhibited a stepwise improvement according to left ventricular ejection fraction (LVEF) (HFrEF: 4.74 ± 2.35% vs. HFmrEF: 4.97 ± 2.81% vs. HFpEF: 5.94 ± ± 3.46%, p = 0.01), which remained significant after the evaluation of possible confounders including age, sex, cardiovascular risk factors, and number of significantly stenosed epicardial coronary arteries (b coefficient: 0.990, 95% confidence interval: 0.166-1.814, p = 0.019). Single-vessel coronary artery disease was more frequent in the group of HFpEF (HFrEF: 56% vs. HFmrEF: 64% vs. HFpEF: 73%, p = 0.049). PWV did not display any association with LVEF. Patients who presented MACE exhibited worse FMD values (4.51 ± 2.35% vs. 5.32 ± 2.67%, p = 0.02), and the highest tertile of galectin-3 was linked to more MACEs (36% vs. 5.9%, p = 0.01).

CONCLUSIONS

Flow-mediated dilatation displayed a linear improvement with LVEF in patients with ischemic HF. Deteriorated values are associated with MACE. Higher levels of galectin-3 might be used for risk stratification of patients with ischemic HF.

Development of severe intrapulmonary shunting in a patient with carcinoid heart disease after closure of a persistent foramen ovale: a case report

Background

Neuroendocrine tumours (NETs) can affect the cardiopulmonary system causing carcinoid heart disease (CHD) and valve destruction. Persistent foramen ovale (PFO) occlusion is indicated in patients with CHD and shunt-related left heart valve involvement.

Case summary

We report the case of a 54-year-old female patient with metastatic NET originating from the small bowel. The patient was on medication with octreotide and telotristat. One year after diagnosis, cardiac involvement of carcinoid developed with regurgitation of right-sided and, due to PFO, left-sided heart valves. Closure of PFO was performed (Occlutech 16/18 mm). One year later, she presented with recurrent severe dyspnoea. The PFO occluder was in situ without residual shunt. Valvular heart disease, including left-sided disease, and metastatic spread of NET were stable. Blood gas analysis revealed arterial hypoxaemia (pO₂ = 44 mmHg/5.87 kPa), which was related to extensive intrapulmonary shunting (31% shunt fraction) confirmed using contrast-enhanced echocardiography. The patient was prescribed long-term oxygen supplementation as symptomatic therapy and anti-tumoural therapy was intensified with selective internal radiotherapy (SIRT) of the liver metastases to improve biochemical control of the carcinoid syndrome. At a follow-up visit 4 months after SIRT, the patient-reported stable dyspnoea; however, magnetic resonance imaging revealed progression of osseous metastases.

Discussion

An echocardiographic assessment of the presence of a PFO is recommended in patients with NET as PFO closure minimizes the risk of left-sided carcinoid valve disease. Deterioration of symptomatic status in metastasized NET might also be due to a hepatopulmonary-like physiology with intrapulmonary shunting and arterial desaturation thought to be caused by vasoactive substances secreted by the tumour. This is a rare case describing the development of this syndrome after PFO closure.

MicroRNAs in the Management of Heart Failure

BACKGROUND

In recent years much research has been devoted to the deployment of biomarkers in the field of heart failure; Objectives: To study the potential of post-transcriptional regulation by microRNAs on the diagnosis, management and therapy of heart failure.

METHODS

Literature search focus on the role of microRNAs in heart failure.

RESULTS

MicroRNAs are expressed and regulated in the course of the pathological manifestations of heart failure (HF). This wide and uncharted area of genetic imprints consisting of small non-coding RNA molecules, is upregulated and released into blood stream from organs under certain conditions and or stress. The use of genetically based strategies for the management of HF have gained great interest in the field of biomedical science because they can be used as biomarkers providing information regarding cardiac status and function. They also appear as promising tools with therapeutic potential because of their ability to induce changes at the cellular level without creating alterations in the gene sequence. In addition, with the advances in genomic sequencing, quantification and synthesis in technologies of microRNAs identification as well as the growing knowledge of the biology of miRNAs and their involvement in HF, it is expected to favorably affect the prognosis of HF patients.

CONCLUSION

MicroRNAs are involved in the regulation of multi biological processes involved in the progress of heart failure. More studies are needed to achieve a clinical valuable implementation of microRNAs in the management of HF.

Lipoprotein-associated phospholipase A2 levels, endothelial dysfunction and arterial stiffness in patients with stable coronary artery disease

BACKGROUND

Lipoprotein-associated Phospholipase A2 (Lp-PLA2), can exert proinflammatory as well as proatherogenic properties on the vascular wall. The current study sought to evaluate the influence of high Lp-PLA2 levels on indices of arterial wall properties in patients with stable coronary artery disease (CAD).

METHODS

Three hundred seventy-four consecutive patients with stable CAD (mean age 61 ± 11 years, 89% males) were enrolled in this single-center cross-sectional study. Flow-mediated dilation (FMD) was used to assess endothelial function and augmentation index (AIx) of the central aortic pressure was used to assess reflected waves. ELISA was used to determine Lp-PLA2 serum levels.

RESULTS

After dividing the participants in 3 equal groups based on the tertiles of circulating Lp-PLA2 values, no significant differences were demonstrated between those in the 3rd tertile with Lp-PLA2 values > 138 μg/L, in the 2nd tertile with Lp-PLA2 values between 101 and 138 μg/L and in the 1st tertile (Lp-PLA2 values < 101 μg/L) regarding age, male gender, smoking habits, family history of CAD or history of a previous myocardial infarction, diabetes mellitus, arterial hypertension, hyperlipidemia, duration of CAD and treatment with relevant medication. Importantly, subjects with Lp-PLA2 values in the highest tertile, had significantly reduced FMD values compared to the middle and lower tertile (4.43 ± 2.37% vs. 4.61 ± 1.97% vs. 5.20 ± 2.52% respectively, P = 0.03). Patients in the highest tertile of Lp-PLA2 values had significantly higher AIx values (24.65 ± 8.69% vs. 23.33 ± 9.65%, P = 0.03), in comparison to the lowest tertile, with Lp-PLA2 values < 101 μg/L. A linear regression analysis showed that Lp-PLA2 values > 138 μg/L negatively correlated to FMD [b = - 0.45 (95% CI: - 0.79 - -0.11), P = 0.01] and AIx values [b = 1.81 (95% CI: 0.57-3.05), P < 0.001] independently of cofounders like gender, age, diabetes mellitus, arterial hypertension, dyslipidemia, smoking habits, family history of CAD, history of previous myocardial infarction, serum glucose, circulating lipid levels, duration of CAD, antihypertensive medication, antidiabetic drugs, statin therapy and treatment with β-blockers.

CONCLUSIONS

Elevated Lp-PLA2 levels relate to endothelial dysfunction and arterial stiffness in patients with stable CAD independently from classical risk factors for CAD, statin use, antihypertensive treatment, and duration of the disease.

Osteoprotegerin and Osteopontin Serum Levels are Associated with Vascular Function and Inflammation in Coronary Artery Disease Patients

BACKGROUND

Osteoprotegerin and osteopontin have recently emerged as key factors in both vascular remodelling and atherosclerosis progression. Interleukin-6 (IL-6) is an inflammatory cytokine with a key role in atherosclerosis. The relationship of osteoprotegerin, osteopontin, and IL-6 serum levels with endothelial function and arterial stiffness was evaluated in patients with coronary artery disease (CAD).

METHODS

We enrolled 219 patients with stable CAD and 112 control subjects. Osteoprotegerin, osteopontin and IL-6 serum levels were measured using an ELISA assay. Endothelial function was evaluated by flow-mediated dilation (FMD) in the brachial artery and carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness.

RESULTS

There was no significant difference between control subjects and CAD patients according to age and sex. Compared with control subjects, CAD patients had significantly impaired FMD (p<0.001) and increased PWV (p=0.009). CAD patients also had significantly higher levels of osteoprotegerin (p<0.001), osteopontin (p<0.001) and IL-6 (p=0.03), compared with control subjects. Moreover, IL-6 levels were correlated with osteoprotegerin (r=0.17, p=0.01) and osteopontin (r=0.30, p<0.001) levels. FMD was correlated with osteoprotegerin levels independent of possible confounders [b coefficient= - 0.79, 95% CI (-1.54, -0.05), p=0.04].

CONCLUSION

CAD patients have increased osteoprotegerin, osteopontin and IL-6 levels. Moreover, there is a consistent association between osteoprotegerin and osteopontin serum levels, vascular function and inflammation in CAD patients. These findings suggest another possible mechanism linking osteoprotegerin and osteopontin serum levels with CAD progression through arterial wall stiffening and inflammation.

Lipoprotein-associated phospholipase A2 levels, endothelial dysfunction and arterial stiffness in patients with stable coronary artery disease

Background

Lipoprotein-associated Phospholipase A2 (Lp-PLA2), has inflammatory and atherogenic actions in the vascular wall. We investigate the impact of high Lp-PLA2 levels on endothelial function and arterial stiffness on patients with coronary artery disease (CAD).

Methods

We enrolled 374 consecutive patients with stable CAD (mean age 61±11 years). Endothelial function was evaluated by flow-mediated dilation (FMD) and reflected waves with augmentation index (AIx) of the central aortic pressure. Serum levels of Lp-PLA2 were measured with ELISA.

Results

In the studied population the median values of Lp-PLA2 levels was 125 (96–152) μg/L. There was no difference between subjects with Lp-PLA2 levels above and below 125μg/L concerning classical risk factors for CAD. Importantly, subjects with Lp-PLA2 values ≥125μg/L had significantly impaired FMD (4.44±2.19% vs. 4.89±2.07%, p=0.04) and AIx values (25.21±8.70% vs. 23.06±9.47%, p=0.03), compared to participants with lower Lp-PLA2 serum levels. A linear regression analysis revealed that Lp-PLA2 ≥125μg/L negatively relates to impaired FMD [b=−0.54 (95% CI: −1.05 to −0.02), p=0.04] and AIx values [b=2.14 (95% CI: 0.18–4.01), p=0.03] independently of cofounders.

Conclusions

Elevated Lp-PLA2 relates to endothelial dysfunction and arterial stiffness in CAD patients. These findings highlight the significant role of Lp-PlA2 in the process of atherosclerosis.

Funding Acknowledgement

Type of funding source: None

The Effect of DPP-4i on Endothelial Function and Arterial Stiffness in Patients with Type 2 Diabetes: A Systematic Review of Randomized Placebo-controlled Trials

We systematically reviewed the literature regarding the impact of dipeptidyl peptidase-4 inhibitors (DPP-4i) on vascular function, including endothelial function and arterial stiffness, as predictors of atherosclerosis progression and cardiovascular disease in patients with type 2 diabetes mellitus (T2DM). We searched PubMed in order to identify clinical trials that investigated the effect of DPP-4i on vascular function in patients with T2DM when compared with placebo. Although 168 articles were initially found, only 6 studies (total 324 patients) investigated the effect of DPP-4i in comparison with placebo, specifically linagliptin and sitagliptin, and satisfied the inclusion criteria. There are scarce data to indicate that linagliptin may enhance endothelial function and exert a slight beneficial effect on arterial wall properties. Sitagliptin seems to have a neutral effect on these variables. Further trials are needed to elucidate the topic. The standards of reporting were in accordance with the PRISMA guidelines.

Pro-inflammatory Cytokines in Acute Coronary Syndromes

BACKGROUND

Over the last decades, the role of inflammation and immune system activation in the initiation and progression of coronary artery disease (CAD) has been established.

OBJECTIVES

The study aimed to present the interplay between cytokines and their actions preceding and shortly after ACS.

METHODS

We searched in a systemic manner the most relevant articles to the topic of inflammation, cytokines, vulnerable plaque and myocardial infarction in MEDLINE, COCHRANE and EMBASE databases.

RESULTS

Different classes of cytokines (intereleukin [IL]-1 family, Tumor necrosis factor-alpha (TNF-α) family, chemokines, adipokines, interferons) are implicated in the entire process leading to destabilization of the atherosclerotic plaque, and consequently, to the incidence of myocardial infarction. Especially IL-1 and TNF-α family are involved in inflammatory cell accumulation, vulnerable plaque formation, platelet aggregation, cardiomyocyte apoptosis and adverse remodeling following the myocardial infarction. Several cytokines such as IL-6, adiponectin, interferon-γ, appear with significant prognostic value in ACS patients. Thus, research interest focuses on the modulation of inflammation in ACS to improve clinical outcomes.

CONCLUSION

Understanding the unique characteristics that accompany each cytokine-cytokine receptor interaction could illuminate the signaling pathways involved in plaque destabilization and indicate future treatment strategies to improve cardiovascular prognosis in ACS patients.

Microsurgical reconstruction of complex oromandibular defects: An update

Free flaps are the gold standard for reconstruction of the mandible, tongue and floor of the mouth. Free fibular flaps are the most preferable option for reconstruction of complex mandibular defects, as well as for tongue and mouth floor reconstruction, since they are harvested easily, present excellent sculptability and good functional outcomes. Alternative options for bone reconstruction include the fibular and iliac crest free flap, and for soft tissue reconstruction include the anterolateral thigh, the radial forearm free flap, and the nasolabial island flap. The principles of the surgical approach include resection of the mandibular segment, intraoperative evaluation of the defect, and various surgical manipulations of the flap on site to reconstruct the defect. Advances in computerized preoperative planning have allowed virtual simulation of the defect and fabrication of an individualized stereolithic mandibular model. This short review discusses the current trends of bone and soft tissue flaps for complex oromandibular reconstructions aiming to present a comprehensive review that the readers would find interesting and informative.

Coronary Microcirculation and the No-reflow Phenomenon

The no-reflow phenomenon refers to the post-percutaneous coronary intervention condition in which, despite re-establishing epicardial coronary vessel patency, the flow to the previously ischemic myocardium is markedly reduced. When it does occur, it attenuates the beneficial effect of reperfusion therapy and substantial regions of the myocardium fail to receive adequate perfusion. The pathophysiology of this phenomenon is not completely understood. The possible mechanisms could be related to alterations in the microvascular circulation. Various mechanisms such as activation of inflammatory pathways, vascular damage and hemorrhage, leukocyte infiltration, and cellular edema may be responsible. As the no-reflow phenomenon is associated with adverse clinical consequences, it is of great importance to identify exact responsible mechanisms and apply effective preventive and therapeutic strategies. In this review, we describe an updated overview of the pathophysiological mechanisms and the current preventive tools for no-reflow as well as therapeutic interventions in order to improve coronary blood flow and consequently the prognosis for these patients.

Interrelationship between diabetes mellitus and heart failure: the role of peroxisome proliferator-activated receptors in left ventricle performance

Heart failure (HF) is a common cardiac syndrome, whose pathophysiology involves complex mechanisms, some of which remain unknown. Diabetes mellitus (DM) constitutes not only a glucose metabolic disorder accompanied by insulin resistance but also a risk factor for cardiovascular disease and HF. During the last years though emerging data set up, a bidirectional interrelationship between these two entities. In the case of DM impaired calcium homeostasis, free fatty acid metabolism, redox state, and advance glycation end products may accelerate cardiac dysfunction. On the other hand, when HF exists, hypoperfusion of the liver and pancreas, b-blocker and diuretic treatment, and autonomic nervous system dysfunction may cause impairment of glucose metabolism. These molecular pathways may be used as therapeutic targets for novel antidiabetic agents. Peroxisome proliferator-activated receptors (PPARs) not only improve insulin resistance and glucose and lipid metabolism but also manifest a diversity of actions directly or indirectly associated with systolic or diastolic performance of left ventricle and symptoms of HF. Interestingly, they may beneficially affect remodeling of the left ventricle, fibrosis, and diastolic performance but they may cause impaired water handing, sodium retention, and decompensation of HF which should be taken into consideration in the management of patients with DM. In this review article, we present the pathophysiological data linking HF with DM and we focus on the molecular mechanisms of PPARs agonists in left ventricle systolic and diastolic performance providing useful insights in the molecular mechanism of this class of metabolically active regiments.

Non-natriuretic peptide biomarkers in heart failure with preserved and reduced ejection fraction

Heart failure (HF) with reduced and preserved ejection fraction constitutes two entities with distinct pathogenetic backgrounds sharing common features. Beyond natriuretic peptides, several novel biomarkers have been proven useful in the diagnosis, prognosis and treatment of HF. Biomarkers of myocardial fibrosis have a low diagnostic yield in subjects with acute HF but may add prognostic information, especially in patients with HF and preserved ejection fraction. Biomarkers of renal impairment identify subjects with worse prognosis independently of left ventricle ejection fraction while inflammatory markers have not been proven useful in patients with systolic or diastolic impairment. In this review article, we summarize the main differences and application of non-natriuretic peptide biomarkers in HF patients with preserved and reduced ejection fraction.

Mitochondria and cardiovascular diseases-from pathophysiology to treatment

Mitochondria are the source of cellular energy production and are present in different types of cells. However, their function is especially important for the heart due to the high demands in energy which is achieved through oxidative phosphorylation. Mitochondria form large networks which regulate metabolism and the optimal function is achieved through the balance between mitochondrial fusion and mitochondrial fission. Moreover, mitochondrial function is upon quality control via the process of mitophagy which removes the damaged organelles. Mitochondrial dysfunction is associated with the development of numerous cardiac diseases such as atherosclerosis, ischemia-reperfusion (I/R) injury, hypertension, diabetes, cardiac hypertrophy and heart failure (HF), due to the uncontrolled production of reactive oxygen species (ROS). Therefore, early control of mitochondrial dysfunction is a crucial step in the therapy of cardiac diseases. A number of anti-oxidant molecules and medications have been used but the results are inconsistent among the studies. Eventually, the aim of future research is to design molecules which selectively target mitochondrial dysfunction and restore the capacity of cellular anti-oxidant enzymes.

Genotyping, Platelet Activation, and Cardiovascular Outcome in Patients after Percutaneous Coronary Intervention: Two Pieces of the Puzzle of Clopidogrel Resistance

OBJECTIVES

Individual platelet responses to antiplatelet therapy depend on genetic, cellular, and clinical factors. CYP2C19 and P2Y12 receptor polymorphisms are implicated in platelet responses to antiplatelet treatment. We aimed to evaluate the impact of CYP2C19 and C34T P2Y12 genotyping on platelet reactivity and cardiovascular outcome in patients after percutaneous coronary intervention (PCI) on clopidogrel treatment.

METHODS

We enrolled 408 patients with stable coronary artery disease (CAD) receiving aspirin and clopidogrel (75 mg/day) 1 month after PCI. High on-treatment platelet reactivity was evaluated using the VerifyNow Assay in a subset of patients. CYP2C19*2 and C34T P2Y12 genotyping was performed by real-time polymerase chain reaction. The primary end point was the composite of death or hospitalization for cardiovascular causes, and patients were followed for a median time of 13 months.

RESULTS

In the total study population, 37% were carriers of at least 1 CYP2C19*2 loss-of-function allele, and 53% were carriers of at least 1 C34T loss-of-function allele. Interestingly, homozygotes of the CYP2C19*2 loss-of-function allele had significantly increased P2Y12 reaction units (PRU) (p = 0.007). However, PRU did not differ between carriers and noncarriers of the C34T loss-of-function allele (p = 0.41). Moreover, carriers of CYP2C19*2 had an increased hazard ratio (HR) for the occurrence of the primary end point (for carriers HR = 1.96, 95% CI 1.05-3.66, p = 0.03), whereas the C34T polymorphism had no impact on the cardiovascular outcome (p = 0.17). Finally, PRU was associated with cardiovascular outcome even after adjustment for the presence of any reduced function allele polymorphism.

CONCLUSIONS

We documented a different effect of CYP2C19 and P2Y12 receptor polymorphisms on platelet reactivity and cardiovascular outcome in CAD patients after PCI on clopidogrel treatment. Importantly, increased platelet reactivity adversely affects the cardiovascular outcome independently of the studied polymorphisms.

Basic Mechanisms in Atherosclerosis: The Role of Calcium

In the beginning, atherosclerosis was considered to be the result of passive lipid accumulation in the vascular walls. After tremendous technological advancements in research, we are now able to almost admire the complexity of the atherosclerotic process. Atherosclerosis is a chronicinflammatory condition that begins with the formation of calcified plaque, influenced by a number of different factors inside the vascular wall in large and mid-sized arteries. Calcium mineralization of the lumen in the atherosclerotic artery promotes and solidifies plaque formation causing narrowing of the vessel. Soft tissue calcification associated with tissue denegation or necrosis is a passive precipitation event. The process of atherogenesis is mainly driven by CD4+ T cells, CD40L, macrophages, foam cells with elevated transcription of many matrix metalloproteinases, osteoblasts, cytokines, selectins, myeloperoxidases, vascular adhesion molecules (VCAM), and smooth muscle cells. Our knowledge in the genesis of atherosclerosis has changed dramatically in the last few years. New imaging techniques such as intravascular ultrasound or IVUS have made possible to investigate atherosclerosis in early stages. Arterial calcification emerges from two different types, the medial-elastin dependent and the intimal, both of which are directly related to atherosclerosis due to osteoblast differentiation of vascular smooth muscle cells. The deposition of minerals in the form of calcium (Ca(2+)) initially emerges from the inorganing mineral octacalcium phosphate [Ca8H2(PO4)6.5H2O] to the form of Hydroxylapatite [Ca10(PO4)6(OH)2]. This review is devoted to broaden the understanding regarding atherosclerosis and the central role of calcium in the development of the condition.

Effects of CYP2C19 Polymorphism on Endothelial Function, Arterial Stiffness and Inflammation in Coronary Artery Disease Patients Under Clopidogrel Treatment

BACKGROUND

Clopidogrel's ability to inhibit platelet function determined its clinical usefulness. The role of CYP2C19*2 genotype on antiplatelet treatment is recently under question. Arterial wall properties and inflammation are key players in atherosclerosis development. Hence, we evaluated the impact of CYP2C19*2 genetic polymorphism on endothelial function, arterial stiffness and inflammation in coronary artery disease (CAD) patients receiving clopidogrel treatment.

METHODS AND RESULTS

In this study we enrolled 408 consecutive patients with stable CAD under dual antiplatelet therapy (clopidogrel 75mg/day, aspirin 100mg/day), 30 days after percutaneous coronary intervention. Measurement of flow-mediated dilation (FMD) of the brachial artery was used to evaluate endothelial function. Carotid-femoral pulse wave velocity (PWV) and augmentation index (AIx) was measured to estimate arterial stiffness. Real time polymerase chain reaction was used for the genotyping of CYP2C19*2. Levels of tumor necrosis factor alpha (TNF-a) and interleukin 6 (IL-6) were measured with ELISA. We found no difference in basic clinical and demographic characteristics nor in FMD, PWV, AIx and inflammatory status (p=NS for all) between CYP2C19 homozygotes for the wild type; carriers of reduced function allele and homozygotes for the reduced function allele.

CONCLUSION

CYP2C19*2 loss of action polymorphism causes no impact on vascular function and inflammatory status in stable CAD patients receiving clopidogrel treatment.

Non-cardiogenic pulmonary edema, rhabdomyolysis and myocardial injury following heroin inhalation: a case report

BACKGROUND

Heroin use by non-injecting routes of administration (snorting, swallowing, "chasing the dragon") is considered to be safer but is not risk-free for fatal overdose or serious side effects. We report the case of an adolescent who was transferred unconscious to the emergency department after heroin inhalation. Description of the case: A 17-year-old male was transferred to the emergency department unconscious (Glasgow coma scale: 6/15) after heroin inhalation. He was treated with non-rebreather mask and intravenous infusion of naloxone with gradual improvement of consciousness and arterial blood gasses. The chest computed tomography showed signs of acute respiratory distress syndrome. Laboratory exams on the second day of hospitalization showed elevated creatine kinase (CK) and troponin-I levels while his electrocardiography (ECG) showed J-point elevation in V1, V2, and V3 precordial leads. On the second day of hospitalization the pulmonary infiltrates were not present in his chest X-ray while on the eighth day, troponin-I and CK levels were normalized without dynamic ECG changes and the patient was discharged uneventfully.

CONCLUSION

Heroin inhalation may cause severe complications, such as non-cardiogenic pulmonary edema, rhabdomyolysis or myocardial injury. Hippokratia 2016, 20(1): 84-87.