Evaluation of systemic endothelial-dependent and endothelial-independent microvascular reactivity in metabolically healthy obesity: An observational study

BACKGROUND

Metabolically healthy obesity (MHO), a phenotype of obesity considered to be of lower cardiovascular risk, is still a controversial concept. This study aimed to investigate the presence of subclinical systemic microvascular dysfunction in individuals with MHO.

METHODS

This was a cross-sectional study in which 112 volunteers were allocated into three groups: metabolically healthy normal weight (MHNW), MHO, or metabolically unhealthy obesity (MUO). Obesity was defined as a body mass index (BMI) ≥ 30 kg/m². MHO was defined as the absence of any component of metabolic syndrome, except waist circumference. Microvascular reactivity was evaluated using cutaneous laser speckle contrast imaging.

RESULTS

Mean age was 33.2 ± 7.66 years. The median BMI in the MHNW, MHO and MUO groups was 23.6, 32.8, and 35.8 kg/m², respectively. Baseline microvascular conductance values were lower in the MUO group (0.25 ± 0.08 APU/mmHg) than in MHO (0.30 ± 0.10 APU/mmHg) and MHNW groups (0.33 ± 0.12 APU/mmHg) (P = 0.0008). There were no significant differences regarding endothelial-dependent (acetylcholine stimulation or postocclusive reactive hyperemia) or endothelial-independent (sodium nitroprusside stimulation) microvascular reactivity among the groups.

CONCLUSIONS

Individuals with MUO had lower baseline systemic microvascular flow than those with MHNW or MHO, but endothelium-dependent or endothelium-independent microvascular reactivity were not changed in any of the groups. The relatively young age of the study population, the low frequency of class III obesity, or the strict definition of MHO (absence of any metabolic syndrome criteria) might account for the lack of difference of microvascular reactivity among MHNW, MHO or MUO.

Effects of Whey Protein Isolate on Body Composition, Muscle Mass, and Strength of Chronic Heart Failure Patients: A Randomized Clinical Trial

Heart failure (HF) is associated with a reduction of skeletal muscle mass. Whey protein isolate (WPI) has been beneficial in increasing muscle mass and strength, in addition to improving body composition. The goal of this research was to evaluate the effect of WPI on the body composition, muscle mass, and strength of chronic HF patients. For this purpose, twenty-five patients of both genders with predominantly NYHA I functional class and a median age of 65.5 (60.5-71.0) years were used to conduct a randomized, single-blind, placebo-controlled clinical trial and received 30 g per day of WPI for 12 weeks. Anthropometric measurements, body composition analysis, and biochemical exams were performed at the beginning and end of the study. An increase in skeletal muscle mass was observed in the intervention group after 12 weeks. A reduction in waist circumference, body fat percentage, and an increase in skeletal muscle index was observed when compared to the placebo group. No significant effect on muscle strength was observed after 12 weeks of intervention. These data demonstrate that WPI consumption contributed to the increase of skeletal muscle mass, strength, and reduction of body fat in HF patients.

Long-term assessment of systemic microcirculatory function and plasma cytokines after coronavirus disease 2019 (COVID-19)

Systemic microvascular dysfunction has been shown to be present in COVID-19, and serum cytokines are known to be involved in the regulation of vascular function. We sought to evaluate systemic microvascular endothelial function, with laser doppler perfusion monitoring (LDPM), and plasma levels of cytokines after acute COVID-19. Individuals admitted to a Cardiology hospital with acute COVID-19 and followed for 12-15 months after recovery underwent noninvasive evaluation of systemic endothelium-dependent microvascular reactivity by cutaneous LDPM with local thermal hyperemia (LTH). A multiplex biometric immunoassay panel was used to assess 48 serum cytokines and chemokines. Twenty patients and 14 control volunteers were enrolled. The areas under the curves of vasodilation induced by LTH were significantly increased after recovery (P=0.009) and were not different from values obtained in healthy volunteers (P = 0.85). The peak microvascular flow during LTH did also significantly increase (P = 0.02), and was not different form values obtained in healthy volunteers (P = 0.55). Several cytokines displayed significantly reduced serum concentrations after recovery from COVID-19. In conclusion, endothelium-dependent systemic microvascular reactivity improved after recovery from COVID-19 in patients with cardiovascular diseases, in parallel with a reduction in the levels of several serum cytokines and chemokines involved in the regulation of vascular function and inflammation.

Evaluation of DNA damage induced by ionizing radiation from myocardial perfusion imaging: a pilot study

Background

As patient exposure to ionizing radiation raises concern about malignancy risks, this study evaluated the effect of ionizing radiation on patients undergoing myocardial perfusion imaging (MPI) using the comet assay, a method for detection of DNA damage.

Methods

Patients without cancer, acute or autoimmune diseases, recent surgery or trauma, were studied. Gated single-photon myocardial perfusion imaging was performed with Tc-99m sestamibi. Peripheral blood was collected before radiotracer injection at rest and 60–90 min after injection. Single-cell gel electrophoresis (comet assay) was performed with blood lymphocytes to detect strand breaks, which determine a “comet tail” of variable size, visually scored by 3 observers in a fluorescence microscope after staining (0: no damage, no tail; 1: small damage; 2: large damage; 3: full damage). A damage index was calculated as a weighted average of the cell scores.

Results

Among the 29 individuals included in the analysis, age was 65.3 ± 9.9 years and 18 (62.1%) were male. The injected radiotracer dose was 880.6 ± 229.4 MBq. Most cells (approximately 70%) remained without DNA fragmentation (class 0) after tracer injection. There were nonsignificant increases of classes 1 and 2 of damage. Class 3 was the least frequent both before and after radiotracer injection, but displayed a significant, 44% increase after injection.

Conclusion

While lymphocytes mostly remained in class 0, an increase in class 3 DNA damage was detected. This may suggest that, despite a probable lack of biologically relevant DNA damage, there is still a need for tracer dose reductions in MPI.

Feasibility and Safety of Ipsilateral Ulnar Access in Cases of Impossibility or Failure of Radial Access for Coronary Angiography or Percutaneous Coronary Intervention

OBJECTIVES

To evaluate the feasibility and safety of using the ulnar access in coronary angiography and percutaneous coronary intervention, in the failure or contraindication of ipsilateral radial access.

METHODS

We prospectively evaluated, in a quaternary hospital, patients undergoing coronary angiography or percutaneous coronary intervention by transulnar approach, in case of failure or contraindication to the ipsilateral radial access.

RESULTS

Between August 2018 and March 2020, of the 5,916 invasive coronary procedures performed, 2.2% were by transulnar approach. In the 130 patients evaluated, the indication for use of the transulnar approach was predominantly the low-amplitude or difficult to palpate radial pulse when compared to the ulnar artery (39.2%), followed by occlusion of the ipsilateral radial artery (33.1%). Complications of using the transulnar approach were superficial hematoma or low-degree muscle infiltration with extension ≤10 cm, in 6 patients (4.5%), and in 5 cases (3.8%) hematoma >10 cm. There was a case of transient ischemia of the hand due to forearm hematoma, treated conservatively. No cases of arterial thrombosis, pseudoaneurysm, arteriovenous fistula, symptomatic ulnar artery occlusion or ulnar nerve injury were observed after 30-day follow-up.

CONCLUSION

The use of ipsilateral transulnar access is a feasible and safe alternative in cases where radial access would be impossible. This access site is associated with a low incidence of complications, which, when present, are most commonly associated with the occurance of spasm after the attempted radial puncture.

Generative adversarial networks for generating synthetic features for Wi-Fi signal quality

Wireless networks are among the fundamental technologies used to connect people. Considering the constant advancements in the field, telecommunication operators must guarantee a high-quality service to keep their customer portfolio. To ensure this high-quality service, it is common to establish partnerships with specialized technology companies that deliver software services in order to monitor the networks and identify faults and respective solutions. A common barrier faced by these specialized companies is the lack of data to develop and test their products. This paper investigates the use of generative adversarial networks (GANs), which are state-of-the-art generative models, for generating synthetic telecommunication data related to Wi-Fi signal quality. We developed, trained, and compared two of the most used GAN architectures: the Vanilla GAN and the Wasserstein GAN (WGAN). Both models presented satisfactory results and were able to generate synthetic data similar to the real ones. In particular, the distribution of the synthetic data overlaps the distribution of the real data for all of the considered features. Moreover, the considered generative models can reproduce the same associations observed for the synthetic features. We chose the WGAN as the final model, but both models are suitable for addressing the problem at hand.

Impact of COVID-19 Pandemic on Cardiovascular Testing in Asia

Background

The coronavirus disease-2019 (COVID-19) pandemic significantly affected management of cardiovascular disease around the world. The effect of the pandemic on volume of cardiovascular diagnostic procedures is not known.

Objectives

This study sought to evaluate the effects of the early phase of the COVID-19 pandemic on cardiovascular diagnostic procedures and safety practices in Asia.

Methods

The International Atomic Energy Agency conducted a worldwide survey to assess changes in cardiovascular procedure volume and safety practices caused by COVID-19. Testing volumes were reported for March 2020 and April 2020 and were compared to those from March 2019. Data from 180 centers across 33 Asian countries were grouped into 4 subregions for comparison.

Results

Procedure volumes decreased by 47% from March 2019 to March 2020, showing recovery from March 2020 to April 2020 in Eastern Asia, particularly in China. The majority of centers cancelled outpatient activities and increased time per study. Practice changes included implementing physical distancing and restricting visitors. Although COVID testing was not commonly performed, it was conducted in one-third of facilities in Eastern Asia. The most severe reductions in procedure volumes were observed in lower-income countries, where volumes decreased 81% from March 2019 to April 2020.

Conclusions

The COVID-19 pandemic in Asia caused significant reductions in cardiovascular diagnostic procedures, particularly in low-income countries. Further studies on effects of COVID-19 on cardiovascular outcomes and changes in care delivery are warranted.

Cardiovascular autonomic neuropathy in diabetes: Pathophysiology, clinical assessment and implications

Cardiovascular autonomic neuropathy (CAN) is a debilitating condition that mainly occurs in long-standing type 2 diabetes patients but can manifest earlier, even before diabetes is diagnosed. CAN is a microvascular complication that results from lesions of the sympathetic and parasympathetic nerve fibers, which innervate the heart and blood vessels and promote alterations in cardiovascular autonomic control. The entire mechanism is still not elucidated, but several aspects of the pathophysiology of CAN have already been described, such as the production of advanced glycation end products, reactive oxygen species, nuclear factor kappa B, and pro-inflammatory cytokines. This microvascular complication is an important risk factor for silent myocardial ischemia, chronic kidney disease, myocardial dysfunction, major cardiovascular events, cardiac arrhythmias, and sudden death. It has also been suggested that, compared to other traditional cardiovascular risk factors, CAN progression may have a greater impact on cardiovascular disease development. However, CAN might be subclinical for several years, and a late diagnosis increases the mortality risk. The duration of the transition period from the subclinical to clinical stage remains unknown, but the progression of CAN is associated with a poor prognosis. Several tests can be used for CAN diagnosis, such as heart rate variability (HRV), cardiovascular autonomic reflex tests, and myocardial scintigraphy. Currently, it has already been described that CAN could be detected even during the subclinical stage through a reduction in HRV, which is a non-invasive test with a lower operating cost. Therefore, considering that diabetes mellitus is a global epidemic and that diabetic neuropathy is the most common chronic complication of diabetes, the early identification and treatment of CAN could be a key point to mitigate the morbidity and mortality associated with this long-lasting condition.

Obesity-Related Inflammation and Endothelial Dysfunction in COVID-19: Impact on Disease Severity

The coronavirus disease 2019 (COVID-19) pandemic has put into evidence another pandemic – obesity. Currently, several studies have documented the association between obesity and COVID-19 severity. The mechanisms underlying the increased risk of complications and mortality in obese patients with COVID-19 are of diverse nature. Inflammation plays a central role in obesity. Metabolic alterations seen in obese patients are related to an inflammatory response, and several studies report elevated levels of circulating inflammatory cytokines in obese patients. Also, deregulated expression of adipokines, such as leptin and resistin, increase the expression of vascular adhesion molecule 1 and intercellular adhesion molecule 1 that contribute to increased vascular leukocyte adhesiveness and additional oxidative stress. Additionally, it is now recognized that the chronic impairment of systemic vascular endothelial function in patients with cardiovascular and metabolic disorders, including obesity, when intensified by the detrimental effects of SARS-CoV-2 over the endothelium, may explain their worse outcomes in COVID-19. In fact, vascular endothelial dysfunction may contribute to a unfavorable response of the endothelium to the infection by SARS-CoV-2, whereas alterations in cardiac structure and function and the prothrombotic environment in obesity may also provide a link to the increased cardiovascular events in these patients.

Automatic Search-and-Replace From Examples With Coevolutionary Genetic Programming

We describe the design and implementation of a system for executing search-and-replace text processing tasks automatically, based only on examples of the desired behavior. The examples consist of pairs describing the original string and the desired modified string. Their construction, thus, does not require any specific technical skill. The system constructs a solution to the specified task that can be used unchanged on popular existing software for text processing. The solution consists of a search pattern coupled with a replacement expression: the former is a regular expression which describes both the strings to be replaced and their portions to be reused in the latter, which describes how to build the modified strings. Our proposed system is internally based on genetic programming and implements a form of cooperative coevolution in which two separate populations are evolved independently, one for search patterns and the other for replacement expressions. We assess our proposal on six tasks of realistic complexity obtaining very good results, both in terms of absolute quality of the solutions and with respect to the challenging baselines considered.

Systemic microvascular endothelial dysfunction is associated with left ventricular ejection fraction reduction in chronic Chagas disease patients

OBJECTIVE

This study compares microvascular reactivity (MR) in chronic Chagas disease (CD) patients with healthy individuals, matched for sex and age. In addition, we evaluated the association between MR and left ventricular ejection fraction (LVEF) in patients.

METHODS

Acetylcholine iontophoresis was performed on the forearm skin, using laser speckle contrast imaging, to evaluate endothelium-dependent vasodilation. Clinical data were obtained from medical records.

RESULTS

Thirty-six patients were compared to 25 healthy individuals (controls). Vasodilation was higher in controls, when compared to patients (p < .0001). There was a significant association between LVEF, stratified into quartiles, and MR (p-value for linear trend = .002). In addition, there was no difference in MR between patients with normal LVEF and the control group. In patients, MR was independent of the presence of arterial hypertension or diabetes.

CONCLUSIONS

We have shown for the first time that the reduction of MR is associated with a decrease of LVEF in a cohort of chronic CD patients. The results were not affected by comorbidities, such as hypertension or diabetes. The evaluation of systemic endothelial function may be useful to tailor therapeutic and preventive approaches, targeted at systolic left ventricular failure associated with chronic CD cardiomyopathy.

Systemic microvascular dysfunction in COVID-19

COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), while having lung injury as its most prominent feature, has been increasingly shown to affect endothelial cell function and the microvasculature. In this report, a woman with COVID-19, cardiac valve disease and spherocytosis was assessed with laser Doppler perfusion monitoring. Systemic microvascular reactivity was impaired during a worsening phase of COVID-19, but improved after clinical recovery; microcirculatory dysfunction paralleled systemic inflammation and pulmonary involvement. The assessment of systemic microcirculatory function may therefore provide insights on COVID-19 pathophysiology.

Emerging concepts in metabolically healthy obesity

Obesity is a major risk factor for noncommunicable diseases that is responsible for more than 70% of early deaths in the world. In the 1980's decade, some studies started to describe a "benign" obesity phenotype, named "metabolically healthy obesity" (MHO), which represents obesity without comorbidities such as hypertension, cardiovascular diseases, insulin resistance, diabetes, dyslipidemia or metabolic syndrome. However, it is still unclear if this "benign" obesity phenotype is really favorable or just a transition status to unhealthy obesity and if these subjects presented subclinical levels of cardiovascular risk that are not commonly detected. To further elucidate these issues, the investigation of pathophysiological mechanisms that can increase cardiovascular risk in MHO individuals, such as hormones and cytokines, may offer some responses. In parallel, the evaluation of subclinical cardiovascular derangement, using the systemic microcirculation as a proxy, may be an alternative to anticipate overt cardiovascular disease. Overall, further studies are needed to better understand the pathophysiology of MHO as well as to identify high-risk individuals who deserve more intensive management.

Acute cardiac injury in patients with COVID-19

INTRODUCTION

Cardiac complications of COVID-19 are potentially life-threatening. The occurrence of myocardial injury in the context of COVID-19 is multifactorial and has generated increasing interest.

METHODS

A systematic review with a meta-analysis of the literature was performed. MEDLINE and EMBASE were searched. Two independent reviewers evaluated the selected manuscripts for the outcome "myocardial injury", defined by troponin elevation above the 99th percentile. The study heterogeneity and risk of bias were evaluated.

RESULTS

Eight studies, with a total of 1,229 patients, were included. The frequency of myocardial injury was 16% (95% CI: 9%-27%). The heterogeneity among the studies was high (93%).

CONCLUSIONS

Myocardial injury may occur in patients with COVID-19, with a frequency of 16% according to current studies. Continuous research is needed to update these findings as the pandemic evolves and to define the implications of myocardial injury in the context of this infection.

Importance of the evaluation of systemic microvascular flow and reactivity in critically ill patients with coronavirus disease 2019 - COVID-19

Amidst the pandemic that has mesmerized the entire world, as it has not spared anyone according to any specific characteristic, some conditions have, in fact, emerged as risk factors for a complicated evolution of COVID-19. Older age, cardiovascular disease including hypertension, diabetes and pulmonary disease, have been associated with more severe presentations and/or adverse prognosis. In this letter to the editor, we propose that the link between cardiovascular and metabolic diseases and the higher incidence and worse prognosis of COVID-19 patients is the (micro) vascular endothelium.

Increased systemic endothelial-dependent microvascular reactivity after ingestion of a high-carbohydrate snack in young, healthy volunteers

OBJECTIVE

This study evaluated the acute effect of a high-carbohydrate snack (HCS) on systemic microvascular function of healthy, young volunteers, using laser speckle contrast imaging (LSCI).

METHODS

Cutaneous microvascular blood flow was assessed in the forearm with LSCI coupled to iontophoresis of acetylcholine, using increasing anodal currents, before and after (25 min) the ingestion of a HCS or water (control). Twenty volunteers (10 male) received a single HCS (70 g of carbohydrates) in the fasting state in the morning.

RESULTS

The area under the curve (AUC) of acetylcholine-induced microvascular vasodilation increased from 17,847 ± 4539 to 20,315 ± 7168 arbitrary perfusion units/s (P = 0.03) after ingestion of a HCS, but was unchanged after the ingestion of water (P = 0.22).

CONCLUSION

A single snack consisting on an acute oral load of carbohydrates induced a significant increase of endothelium-dependent microvascular vasodilation in healthy, young subjects.

Budget Impact of Cryoablation Versus Radiofrequency Ablation of Atrial Fibrillation in the Brazilian Public Healthcare System

BACKGROUND

Cryoablation is a new technology for ablation of atrial fibrillation (AF), effective and safe when compared with standard radiofrequency (RF) ablation. Nevertheless, the economic impact of its incorporation is unknown, especially considering the public health system of a developing country. This study analyzed the budget impact of cryoablation incorporation for treatment of paroxysmal AF in the Brazilian public health system.

METHODS

The budget impact was calculated as the cost difference between the current scenario (RF ablation guided by electroanatomic mapping) and the new scenario (cryoablation). The cost of each intervention was obtained by multiplying the price of a single procedure by the number of candidates for it. Other technologies (RF ablation guided by intracardiac echocardiography or with a nonirrigated catheter) were considered in a sensitivity analysis.

RESULTS

The budget impact showed savings of $43 097 096.84 with cryoablation. In the sensitivity analysis, cryoablation resulted in cost savings compared with RF ablation guided by intracardiac echocardiography, whereas in comparison to RF ablation with the nonirrigated catheter, cryoablation was more expensive. A market share assessment, performed using an incorporation rate of 3% per year, indicated savings of approximately $800 000 per 5 years.

CONCLUSIONS

Cryoablation of AF resulted in cost savings compared with the current scenario (RF ablation guided by electroanatomic mapping). When alternative technologies were considered, cryoablation was more expensive than RF ablation with a nonirrigated catheter, but it also resulted in savings compared with RF ablation guided by intracardiac echocardiography. Overall, cryoablation of AF may reduce expenditures in the Brazilian public health system.

Mortality and morbidity of patients on the waiting list for coronary artery bypass graft surgery

OBJECTIVES

The public health care system in Brazil has extensive waiting lists of patients requiring complex operations such as coronary artery bypass grafting (CABG). The purpose of this study was to identify the mortality and morbidity rates of the patients awaiting CABG and identify predictors of adverse events and their association with perioperative outcomes.

METHODS

We conducted a retrospective analysis of outpatient medical records of patients referred for this elective procedure in Rio de Janeiro, Brazil. Excluded from the study were records of patients with any of the following: an indication for urgent surgery, unstable angina or concomitant surgical valvular disease or subsequent transfer to clinical or percutaneous therapy.

RESULTS

A total of 274 patients were identified and met the inclusion criteria, with a median waiting time for an operation of 142.7 days. While waiting for CABG surgery, 31 (11.3%) patients died of any cause and 42 (15.3%) patients had a serious cardiac event (death, myocardial infarction or unstable angina). Of the 22 (8%) incidents of acute myocardial infarction, 8 (2.9%) were non-fatal and 14 (5.1%) were fatal. There was a greater risk of death awaiting CABG surgery in patients with a left ventricular ejection fraction below 45% (hazard ratio = 2.33, 95% confidence interval 1.02-5.32; P = 0.039). The operative mortality rate was 5.8%. Although there was no evidence of worse perioperative outcomes in patients with prolonged waiting times for an operation, there was an association between waiting more than 16 weeks for an operation and death while on the list.

CONCLUSIONS

Extensive waiting periods for CABG contribute to higher mortality and morbidity rates, especially in patients with left ventricular dysfunction.

Effects of Riot Control Training on Systemic Microvascular Reactivity and Capillary Density

Introduction

The main aim of the present study is to evaluate the effects of strenuous exercise, related to special military training for riot control, on systemic microvascular endothelial function and skin capillary density.

Materials and Methods

Endothelium-dependent microvascular reactivity was evaluated in the forearm skin of healthy military trainees (age 23.4 ± 2.3 yr; n = 15) using laser speckle contrast imaging coupled with cutaneous acetylcholine (ACh) iontophoresis and post-occlusive reactive hyperemia (PORH). Functional capillary density was assessed using high-resolution, intra-vital color microscopy in the dorsum of the middle phalanx. Capillary recruitment (capillary reserve) was evaluated using PORH. Microcirculatory tests were performed before and after a 5-wk special military training for riot control.

Results

Microvascular endothelium-dependent vasodilatory responses were markedly and significantly reduced after training, compared with values obtained before training. The peak values of microvascular conductance obtained during iontophoresis of ACh or PORH before training (0.84 ± 0.22 and 0.94 ± 0.72 APU/mmHg, respectively) were markedly reduced after training (0.47 ± 0.11 and 0.71 ± 0.14 APU/mmHg; p < 0.0001 and p = 0.0037, respectively). Endothelium-dependent capillary recruitment was significantly reduced after training (before 101 ± 9 and after 95 ± 8 capillaries/mm2; p = 0.0007).

Conclusions

The present study showed that a 5-wk strenuous military training, performed in unfavorable climatic conditions, induces marked systemic microvascular dysfunction, mainly characterized by reduced endothelium-dependent microvascular vasodilation and blunted capillary recruitment.

Clinical, Anthropometric and Biochemical Characteristics of Patients with or without Genetically Confirmed Familial Hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is a common autosomal dominant disorder, characterized by a high level of low-density lipoprotein cholesterol (LDL-C) and a high risk of premature cardiovascular disease.

OBJECTIVE

To evaluate clinical and anthropometric characteristics of patients with the familiar hypercholesterolemia (FH) phenotype, with or without genetic confirmation of FH.

METHODS

Forty-five patients with LDL-C > 190 mg/dl were genotyped for six FH-related genes: LDLR, APOB, PCSK9, LDLRAP1, LIPA and APOE. Patients who tested positive for any of these mutations were considered to have genetically confirmed FH. The FH phenotype was classified according to the Dutch Lipid Clinic Network criteria.

RESULTS

Comparing patients with genetically confirmed FH to those without it, the former had a higher clinical score for FH, more often had xanthelasma and had higher LDL-C and apo B levels. There were significant correlations between LDL-C and the clinical point score for FH (R = 0.382, p = 0.037) and between LDL-C and body fat (R = 0.461, p = 0.01). However, patients with mutations did not have any correlation between LDL-C and other variables, while for those without a mutation, there was a correlation between LDL-C and the clinical point score.

CONCLUSIONS

LDL-C correlated with the clinical point score and with body fat, both in the overall patient population and in patients without the genetic confirmation of FH. In those with genetically confirmed FH, there were no correlations between LDL-C and other clinical or biochemical variables in patients.

Research proposal: inflammation and oxidative stress in coronary artery bypass surgery graft: comparison between diabetic and non-diabetic patients

BACKGROUND

Diabetes mellitus patients (DM) have more severe progression of atherosclerotic disease than non-diabetic (NDM) individuals. In situ inflammation and oxidative stress are key points in the pathophysiology of atherosclerosis, a concept largely based on animal model research. There are few studies comparing inflammation and oxidative stress parameters in medium-sized arteries between DM and NDM patients. A fragment of the internal mammary artery used in coronary artery bypass grafting (CABG) will be employed for this purpose OBJECTIVE: To assess the expression of inflammatory markers tumor necrosis factor-α, transforming growth factor-β1, nuclear factor kappa B, the enzymes superoxide dismutase, and catalase in the vascular wall of the arterial graft used in CABG, comparing DM and NDM patients RESULTS: The present study will add information to the vascular degenerative processes occurring in diabetic patients.

Associations between endothelial progenitor cells, clinical characteristics and coronary restenosis in patients undergoing percutaneous coronary artery intervention

Objective

Endothelial progenitor cells (EPCs) are produced in the bone marrow and mobilized to the peripheral blood playing a key role in endothelial repair. The objective of this study was to evaluate circulating EPC before and after percutaneous coronary intervention (PCI) with stent implantation and their associations with coronary restenosis and adverse cardiovascular events. Venous blood was obtained before and the day after PCI. Quantification of total white blood count and identification of EPCs (CD45⁻CD34⁺CD31⁺CD133/2⁺CD309⁺) through immunophenotyping by flow cytometry was performed. The primary outcome was either restenosis detected by new coronary angiography or angina with myocardial ischemia at the territory of the stented coronary artery. Secondary outcomes were angina without demonstrable myocardial ischemia, acute coronary syndrome or all-cause death.

Results

37 patients were followed for 1 year. The median EPC count before PCI was 320 cells/mcl and after PCI 286 cells/mcl. A decrease of EPC count was found in 65% of the patients, while 35% displayed an increase. Primary outcomes occurred in 10.8% and the secondary in 37.8% of the patients. Despite a higher level of EPC before (402 cell/mcl) and after PCI (383 cell/mcl) in patients with the secondary outcomes, there was no significant association between EPC and cardiovascular events.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3401-y) contains supplementary material, which is available to authorized users.

High-intensity interval training or continuous training, combined or not with fasting, in obese or overweight women with cardiometabolic risk factors: study protocol for a randomised clinical trial

INTRODUCTION

Physical inactivity and increased caloric intake play important roles in the pathophysiology of obesity. Increasing physical activity and modifying eating behaviours are first-line interventions, frequently hampered by lack of time to exercise and difficulties in coping with different diets. High-intensity interval training (HIIT) may be a time-efficient method compared with moderate-intensity continuous training (CT). Conversely, diets with a fasting component may be more effective than other complex and restrictive diets, as it essentially limits caloric intake to a specified period without major diet composition changes. Therefore, the combination of HIIT and fasting may provide incremental benefits in terms of effectiveness and time efficiency in obese and sedentary populations. The aim of this study is to determine the effect of HIIT versus CT, combined or not with fasting, on microcirculatory function, cardiometabolic parameters, anthropometric indices, cardiorespiratory fitness and quality of life in a population of sedentary overweight or obese women with cardiometabolic risk factors.

METHODS AND ANALYSIS

Sedentary women aged 30-50 years, with a body mass index ≥25 kg/m2 and cardiometabolic risk factors, will be randomised to HIIT performed in the fasting state, HIIT performed in the fed state, CT in the fasting state or CT in the fed state. Cardiometabolic parameters, anthropometric indices, cardiorespiratory fitness, quality of life and microvascular function (cutaneous capillary density and microvascular reactivity evaluated by laser speckle contrast imaging) will be evaluated before initiation of the interventions and 16 weeks thereafter.

ETHICS AND DISSEMINATION

The trial complies with the Declaration of Helsinki and has been approved by the local ethics committee (Instituto Nacional de Cardiologia, Rio de Janeiro, Brazil). All patients provide written informed consent before enrolment and randomisation. The study's results will be disseminated to the healthcare community by publications and presentations at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT03236285.

Active Learning of Regular Expressions for Entity Extraction

We consider the automatic synthesis of an entity extractor, in the form of a regular expression, from examples of the desired extractions in an unstructured text stream. This is a long-standing problem for which many different approaches have been proposed, which all require the preliminary construction of a large dataset fully annotated by the user. In this paper, we propose an active learning approach aimed at minimizing the user annotation effort: the user annotates only one desired extraction and then merely answers extraction queries generated by the system. During the learning process, the system digs into the input text for selecting the most appropriate extraction query to be submitted to the user in order to improve the current extractor. We construct candidate solutions with genetic programming (GP) and select queries with a form of querying-by-committee, i.e., based on a measure of disagreement within the best candidate solutions. All the components of our system are carefully tailored to the peculiarities of active learning with GP and of entity extraction from unstructured text. We evaluate our proposal in depth, on a number of challenging datasets and based on a realistic estimate of the user effort involved in answering each single query. The results demonstrate high accuracy with significant savings in terms of computational effort, annotated characters, and execution time over a state-of-the-art baseline.

Prognostic Assessment of Diabetics Using Myocardial Perfusion Imaging: Diabetes Mellitus is Still a Coronary Artery Disease Equivalent

Background

Even though diabetes mellitus (DM) has been considered a "Coronary Artery Disease (CAD) equivalent", that is still controversial, especially in a contemporary population subject to optimized treatment.

Objective

We aimed to assess the cardiovascular risk of diabetics by myocardial perfusion scintigraphy (MPS).

Methods

Consecutive patients who underwent MPS from 2008 to 2012 were studied. Perfusion scores were calculated, and abnormal MPS was defined as a summed stress score >3. Patients were followed for 3±1 years for all-cause death, which was compared between patients with DM (without known CAD) and patients with known CAD but without DM.

Results

Among 3409 patients, 471 (13.8%) were diabetics without known CAD (DM group) and 638 (18.7%) had CAD without diabetes (CAD group). Annualized death rates were not significantly different between DM or CAD patients (0.9 vs 1.5%, p=0.09). With normal MPS, death rates were 0.7% for DM and 0.6% for CAD (p=0.8). With abnormal MPS, death rates increased similarly in the DM and CAD groups.

Conclusions

In diabetic patients without known CAD, the rate of death was not significantly different from patients with prior CAD and without DM. Abnormal MPS increased risk similarly in diabetic patients and in those with CAD. These findings suggest that DM may still be considered a high-risk condition, comparable to known CAD, and effectively stratified by MPS.

"Metabolically Healthy" Obesity: Fact or Threat?

INTRODUCTION

Obesity is a serious, worldwide and growing problem, with associated complications ranging from cardiovascular disease to cancer. It has been suggested that a subgroup of obese patients- the "metabolically healthy" (MH)- would constitute a phenotype whose cardiovascular risk would be closer to that of normal weight individuals and lower than that of obese patients with other risk factors. The definitions of MH obesity are heterogeneous, what makes the estimation of its prevalence quite difficult. Besides that, data are still controversial about the risk of incident cardiovascular disease in these patients and therefore this remains an unresolved matter. In parallel, the possibly lower risk of MH obesity may raise questions about the need for weight loss in MH obese patients.

CONCLUSION

This issue should be carefully addressed, and evidence for a "benign" profile of MH obesity critically evaluated, as obesity is a risk factor for numerous health outcomes, and weight loss in obese people additionally offers protection against these nonmetabolic diseases.

Clinical, scintigraphic, and angiographic predictors of oxygen pulse abnormality in patients undergoing cardiopulmonary exercise testing

BACKGROUND

The oxygen (O₂ ) pulse curve obtained at cardiopulmonary exercise testing provides information on cardiorespiratory fitness and the presence of cardiovascular disease. O₂ pulse abnormalities have been attributed to myocardial ischemia, among other conditions, but the predictors of abnormal O₂ pulse curves are not completely known.

HYPOTHESIS

Perfusion abnormalities detected by myocardial perfusion scintigraphy (MPS) may be associated with abnormal O₂ pulse curves.

METHODS

Forty patients with normal left ventricular function underwent cardiopulmonary exercise testing with radiotracer injection at peak exercise, followed by MPS. The O₂ pulse curves were classified as (A) normal; (B) probably normal (normal slope with lower peak value); (C) probably abnormal (flat, with low peak value); or (D) definitely abnormal (descending slope), and analyzed as A/B vs C/D. Coronary artery disease (CAD) was defined as >50% stenosis. MPS perfusion scores were calculated (summed rest score [SRS], indicating myocardial fibrosis; summed difference score, indicating ischemia).

RESULTS

Comparing patients with A/B vs C/D curves, the latter were more frequently female and had higher SRS. The prevalence of ischemic MPS, of any CAD, or multivessel CAD was not significantly different among patients with A/B or C/D curve patterns. On logistic regression, female sex, body mass index, and the SRS were significantly associated with C/D curves.

CONCLUSIONS

Female sex, increasing body mass index, and myocardial fibrosis were significant predictors of abnormal O₂ pulse curves. Myocardial ischemia and the presence and extent of CAD were not associated with the abnormal patterns of the O₂ pulse curve.

Microvascular Function and Endothelial Progenitor Cells in Patients with Severe Hypercholesterolemia and the Familial Hypercholesterolemia Phenotype

Objective: To evaluate endothelial progenitor cells (EPCs) and systemic microvascular function in patients with severe hypercholesterolemia, comparing patients with the definite familial hypercholesterolemia (FH) phenotype (DFH) or probable/possible FH phenotype (PFH). There is a large spectrum of atherosclerotic disease between these two clinical phenotypes of FH, and to acquire further knowledge of the pathophysiology of vascular disease in both is desirable. Methods: Subjects with severe hypercholesterolemia, defined as low-density lipoprotein cholesterol (LDL-C) >190 mg/dL, were classified as DFH or PFH and underwent measurement of the number of EPCs by flow cytometry and evaluation of cutaneous microvascular reactivity using a laser speckle contrast-imaging system with iontophoresis of acethylcholine (ACh) or sodium nitroprusside. EPCs were defined as CD45- or CD45low, CD34+CD133+CD309+ cells. Categorical variables were compared using Fisher test and continuous variables with Student t test or Mann-Whitney test, and a value of p < 0.05 was considered statistically significant. Results: Patients with DFH had higher LDL-C than those with PFH. There was no difference in the median number of EPCs between patients with DFH or PFH, but there was a significant reduction of endothelial-dependent, ACh-induced vasodilatation in the former. Conclusion: Patients with DFH have impaired microvascular endothelial-dependent vasodilatation compared to those with PFH, indicating more severe vascular disease in the former.

Budget impact of applying appropriateness criteria for myocardial perfusion scintigraphy: The perspective of a developing country

Myocardial perfusion imaging is widely used for the risk stratification of coronary artery disease. In view of its cost, besides radiation issues, judicious evaluation of the appropriateness of its indications is essential to prevent an unnecessary economic burden on the health system. We evaluated, at a tertiary-care, public Brazilian hospital, the appropriateness of myocardial perfusion scintigraphy indications, and estimated the budget impact of applying appropriateness criteria. An observational, cross-sectional study of 190 patients with suspected or known coronary artery disease referred for myocardial perfusion imaging was conducted. The appropriateness of myocardial perfusion imaging indications was evaluated with the Appropriate Use Criteria for Cardiac Radionuclide Imaging published in 2009. Budget impact analysis was performed with a deterministic model. The prevalence of appropriate requests was 78%; of inappropriate indications, 12%; and of uncertain indications, 10%. Budget impact analysis showed that the use of appropriateness criteria, applied to the population referred to myocardial perfusion scintigraphy within 1 year, could generate savings of $ 64,252.04 dollars. The 12% inappropriate requests for myocardial perfusion scintigraphy at a tertiary-care hospital suggest that a reappraisal of MPI indications is needed. Budget impact analysis estimated resource savings of 18.6% with the establishment of appropriateness criteria for MPI.

"Metabolically healthy" obesity: Prevalence, clinical features and association with myocardial ischaemia

OBJECTIVE

To evaluate the prevalence of the "metabolically healthy" (MH) or "metabolically unhealthy" (MU) obesity phenotypes and their association with cardiorespiratory fitness and inducible myocardial ischaemia.

METHODS

Individuals without known coronary artery disease undergoing myocardial perfusion single-photon emission computed tomography (MPS) were studied. Those without dyslipidemia, hypertension, or diabetes were considered MH, and when ≥1 of these was present, MU status was considered present. Summed stress and difference perfusion scores (SSS and SDS, respectively) were calculated; a SDS >1 defined ischaemic MPS.

RESULTS

MH patients were 35.0% of the nonobese population and 23.5% of the obese (p<0.001). The prevalence of ischaemia was not significantly different between MH patients with obesity or MH patients without obesity (10.9% vs 9.1%, p=0.3), except for patients with body mass index ≥40kg/m² (21.9%). MH obese patients were less frequently able to exercise and had lower exercise capacity than the nonobese patients.

CONCLUSIONS

The prevalence of myocardial ischaemia was not significantly different between MH obese or nonobese individuals, supporting the concept of the "metabolically healthy obesity". However, there are other factors involved, such as the ability to exercise, that influence the risk of myocardial ischaemia, limiting the "safety" of that obesity phenotype.

Regex-based entity extraction with active learning and genetic programming

We consider the long-standing problem of the automatic generation of regular expressions for text extraction, based solely on examples of the desired behavior. We investigate several active learning approaches in which the user annotates only one desired extraction and then merely answers extraction queries generated by the system.

The resulting framework is attractive because it is the system, not the user, which digs out the data in search of the samples most suitable to the specific learning task. We tailor our proposals to a state-of-the-art learner based on Genetic Programming and we assess them experimentally on a number of challenging tasks of realistic complexity. The results indicate that active learning is indeed a viable framework in this application domain and may thus significantly decrease the amount of costly annotation effort required.

We consider the long-standing problem of the automatic generation of regular expressions for text extraction, based solely on examples of the desired behavior. We investigate several active learning approaches in which the user anno- tates only one desired extraction and then merely answers extraction queries generated by the system.

The resulting framework is attractive because it is the sys- tem, not the user, which digs out the data in search of the samples most suitable to the specific learning task. We tailor our proposals to a state-of-the-art learner based on Genetic Programming and we assess them experimentally on a num- ber of challenging tasks of realistic complexity. The results indicate that active learning is indeed a viable framework in this application domain and may thus significantly decrease the amount of costly annotation effort required.

Acute cellular rejection and HLA mismatch in heart transplantation: insights from a developing country

The notable evolution of heart transplant (HTX) has paralleled the capacity of diagnosing rejection and, consequently, initiating timely treatment. Acute cellular rejection, diagnosed by endomyocardial biopsy, is the most frequent in the first 6 months after HTX. HLA matching is not routinely performed in HTX due to the absence of consensus regarding its usefulness. However, the use of HLA typing might be underscored if it could predict an increased risk of rejection. Therefore, the aim of this study was to evaluate, at a public cardiology center in Brazil, the association between HLA mismatches and the incidence of acute cellular rejection in the first 6 months after HTX. Data were obtained from hospital records and from the National Transplant System. Overall, there was no association between the number of HLA mismatches and the frequency of acute cellular rejection, but there was a tendency toward a higher incidence of rejection with HLA-DR incompatibility.

Abstract 557: Gene Polymorphisms in IL-10, INF-γ and TGF-β are Associated with Early-Onset Coronary Artery Disease and Microvascular Function

The influence of genetics on atherosclerosis development remains unclear. Association of single-nucleotide polymorphisms (SNPs) with early-onset coronary artery disease (EOCAD), as well as with carotid intima-media thickness (CIMT), and systemic microvascular reactivity was examined in 52 patients with EOCAD (45 ±3 years old) and 35 age-matched controls. SNPs in ACE, TNF-α (-308G/A, -238 G/A), IFN-γ (+874 A/T), MMP-9 (-1562 C/T), IL-10 (-1082 A/G, -819 C/T, 592 C/A), NOS3 (894 G/T), ApoA1 (rs964184), and TGF-β (codon 10 T/C) genes were genotyped by automatic sequencing. CIMT was determined by ultrasound and capillary density by intravital video-microscopy. Microvascular reactivity was evaluated using laser speckle contrast imaging, cutaneous blood flow was assessed at rest and during post-occlusive reactive hyperemia (PORH), and acetylcholine (Ach) or sodium nitroprusside (SNP) iontophoresis. Genotype distribution was: ACE: 31 DD, 12 II, 43 DI; TNF-α: 56 GG, 20 GA, 3 AA at position -308, and 76 GG, 3 GA at position -238; IFN-γ: 8 subjects with high producer TT genotype; MMP-9: 62 CC, 23 CT; IL-10: 8 high producer haplotype, 35 intermediate, and 43 low; NOS3: 41 GG, 34 GT, 11 TT; ApoA1: 47 CC, 29 CG, 10 GG; TGF-β (cd 25): 75 GG, 10 GC; TGF-β (cd 10): 66 high producer genotype, 19 low producer. IFN-γ, IL-10 haplotype, and TGF-β were significantly related to EOCAD. CIMT was increased (0.93 ±0.02 mm, p<0.0001), while capillary density (87 ±3 capillaries/mm2, p=0.029) was reduced in EOCAD. CC genotype of TGF-β showed higher CIMT (p=0.004) and lower capillary density (p=0.019) than TT. High IL-10 haplotype reduced vasodilator response after PORH (0.32 APU/mmHg, p=0.0316), while high IFN-γ genotype reduced the response induced by both Ach (0.19 APU/mmHg) and SNP (0.13 APU/mmHg) in relation to low producer (0.44, 0.31, and 0.24 APU/mmHg, respectively). TT genotype of TGF-β showed lower vasodilator response after SNP than CC. In conclusion, IFN-γ, IL-10 and TGF-β genotypes were associated with EOCAD, as well as with systemic microvascular response, CIMT, and capillary rarefaction. The results suggest that IFN-γ, IL-10 and TGF-β genotypes could influence EOCAD, affecting microvascular reactivity through endothelium-dependent and -independent pathways.

Association between Carotid Intima-media Thickness and Early-onset Coronary Artery Disease: Does the site of Sonographic Evaluation Matter?

BACKGROUND

Intima-media thickness (IMT) is frequently used for risk stratification (RS) due to the association with coronary artery disease (CAD). Nonetheless, the best carotid site to scan is uncertain, especially in the young. The aim of this study was to evaluate the diagnostic performance of IMT measurements performed at different carotid sites.

METHODS

Eighty-nine subjects ≤45 years were studied (55 with known CAD and 34 controls). IMT measurements were performed at the common carotid (CC), bulb and internal branch (IB) of both carotid arteries, (2112 measures). The diagnostic performance of IMT measurements performed at different sites, regarding the presence of CAD, was evaluated with ROC curves.

RESULTS

Carotid plaques were found in 20.0% of the patients and 6.0% of the controls. The diagnostic performance of carotid IMT measures obtained at the CC, bulb or IB was not significantly different, with the CC and IB being slightly better (AUC ROC =0.82 and 0.80 respectively).

CONCLUSIONS

IMT measures obtained at different carotid sites are associated with CAD in young (≤45 years) individuals. The diagnostic performance of IMT measured at the CC and IB is the more accurate measure, and this may be the most adequate for the measurement of IMT in this population.

Screening for silent coronary artery disease in diabetics- or not?

The association between diabetes mellitus and coronary artery disease (CAD) is wellknown. Being the leading cause of death in diabetics, CAD is a target for prevention, diagnosis and treatment. In that sense, silent CAD in diabetics has long been a matter of concern, leading both to continued attempts at its diagnosis as well as to the persisting challenge of defining if screening for CAD in the diabetic population is useful and/or warranted. The most frequent and stronger point in favor of screening rests on the assumption that early diagnosis of CAD may lead to early treatment and therefore improved outcomes. Nonetheless, screening for CAD in diabetics is a controversial issue, since studies have not yielded evidence supporting better outcomes in diabetics screened for CAD compared to nonscreened diabetics. For several reasons, current tests that detect inducible ischemia or assess atherosclerotic burden may not be able to identify those patients at increased risk. Therefore a cautious look should be taken (once more) at that question.