Is lipoprotein(a) measurement important for cardiovascular risk stratification in children and adolescents?

BACKGROUND: Elevated lipoprotein (Lp(a)) levels are associated with increased risk of atherosclerotic processes and cardiovascular events in adults. The amount of Lp(a) is mainly genetically determined. Therefore, it is important to identify individuals with elevated Lp(a) as early as possible, particularly if other cardiovascular risk factors are present. The purpose of the study was to investigate whether, in a population of children and adolescents already followed for the presence of one or more cardiovascular risk factors (elevated blood pressure (BP), and/or excess body weight, and/or dyslipidemia), the measurement of Lp(a) can be useful for better stratifying their risk profile. METHODS: In a sample of 195 children and adolescents, height, body weight, waist circumference and systolic (SBP) and diastolic (DBP) BP were measured. Body Mass Index (BMI) and SBP and DBP z-scores were calculated. Plasma Lp(a), total cholesterol, high-density lipoprotein (HDL), triglycerides, glucose, insulin, uric acid and creatinine were assessed. Low-density lipoprotein (LDL) cholesterol was calculated with the Friedewald formula. High Lp(a) was defined as ≥ 75 nmol/L and high LDL cholesterol as ≥ 3.37 mmol/L. RESULTS: Our sample of children and adolescents (54.4% males, mean age 11.5 years) had median LDL cholesterol and Lp(a) values equal to 2.54 (interquartile range, IQR: 2.07-3.06) mmol/L and 22 (IQR: 7.8-68.6) nmol/L respectively. 13.8% of children had LDL cholesterol ≥ 3.37 mmol/L and 22.6 Lp(a) values ≥ 75 nmol/L. Lp(a) values were higher in children of normal weight than in those with excess weight (p = 0.007), but the difference disappeared if normal weight children referred for dyslipidemia only were excluded from the analysis (p = 0.210). 69.4% of children had normal Lp(a) and LDL cholesterol values and only 6.2% showed both elevated Lp(a) and LDL cholesterol levels. However, 16.6% of the sample, despite having normal LDL cholesterol, had elevated Lp(a) values. Multivariable analyses showed a significant association of LDL cholesterol both with Lp(a) values, and with the presence of elevated Lp(a) levels. For each mmol/L increase in LDL cholesterol the risk of having an elevated Lp(a) value increased by 73%. There was an inverse correlation between BMI z-score and Lp(a). Neither BP z-scores, nor other biochemical parameters were associated with Lp(a). CONCLUSIONS: In our population more than one out of five children had elevated Lp(a) values, and in about 17% of children elevated Lp(a) values were present in the absence of increased LDL cholesterol. Our results suggest that Lp(a) measurement can be useful to better define the cardiovascular risk profile in children and adolescents already followed for the presence of other cardiovascular risk factors such as elevated BP, excess body weight and high LDL cholesterol.

Non-Pharmacological Treatment for Cardiovascular Risk Prevention in Children and Adolescents with Obesity.

In younger generations, excess weight has reached very alarming levels. Excess weight in adults is associated with increased mortality and morbidity from cardiovascular disease. However, it is not easy to distinguish to what extent these effects are the result of obesity itself or how much is due to the various cardiovascular risk factors that often accompany excess weight. Several risk factors, such as hypertension, dyslipidemia, hyperuricemia, glucose intolerance, and type 2 diabetes mellitus, are already present in pediatric age. Therefore, early intervention with the goal of correcting and/or eliminating them is particularly important. In the child and adolescent with obesity, the first approach to achieve weight reduction and correct the risk factors associated with severe excess weight should always be non-pharmacologic and based on changing poor eating habits and unhealthy lifestyles. The purpose of this review is to give an update on non-pharmacological interventions to be implemented for cardiovascular prevention in children and adolescents with obesity, and their effectiveness. In particular, interventions targeting each individual cardiovascular risk factor will be discussed.

Coronary Artery Disease in Patients Undergoing Hemodialysis: A Problem that Sounds the Alarm.

Chronic kidney disease (CKD) is affecting more and more individuals over time. The importance of the increased prevalence is enhanced by the close association with the increased risk of poor individual outcomes such as death, fatal and non-fatal cardiovascular (CV) events and progression to end stage kidney disease (ESKD). ESKD requires replacement treatment such as hemodialysis (HD), a particular and complex context that unfortunately has been rarely considered in observational studies in the last few decades. The current perspective of HD as a bridge to kidney transplant requires greater attention from observational and experimental research both in the prevention and treatment of CV events in ESKD patients. We present a narrative review by performing a literature review to extrapolate the most significant articles exploring the CV risk, in particular coronary artery disease (CAD), in ESKD and evaluating possible innovative diagnostic and therapeutic tools in these patients. The risk of CAD increases linearly when the estimated glomerular filtration rate (eGFR) declines and reached the most significant level in ESKD patients. Several diagnostic techniques have been evaluated to predict CAD in ESKD such as laboratory tests (Troponin-T, N-terminal pro b-type natriuretic peptide, alkaline phosphatase), echocardiography and imaging techniques for vascular calcifications evaluation. Similarly, treatment is based on lifestyle changes, medical therapy and invasive techniques such as coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). Unfortunately in the literature there are no clear indications of the usefulness and validity of biomarkers and possible treatments in ESKD patients. Considering the ESKD weight in terms of prevalence and costs it is necessary to implement clinical research in order to develop prognostic reliable biomarkers for CV and CAD risk prediction, in patients with ESKD. It should be highlighted that HD is a peculiar setting that offers the opportunity to implement research and facilitates patient monitoring by favoring the design of clinical trials.

Treatment strategies of the thromboembolic risk in kidney failure patients with atrial fibrillation.

The incidence and prevalence of atrial fibrillation (AF) in patients affected by kidney failure, i.e. glomerular filtration rate <15 ml/min/1.73 m2, is high and probably underestimated. Numerous uncertainties remain regarding how to prevent thromboembolic events in this population because both cardiology and nephrology guidelines do not provide clear recommendations. The efficacy and safety of oral anticoagulant therapy (OAC) in preventing thromboembolism in patients with kidney failure and AF has not been demonstrated for either vitamin K antagonists (VKAs) or direct anticoagulants (DOACs). Moreover, it remains unclear which is more effective and safer, because estimated creatinine clearance <25-30 ml/min was an exclusion criterion in the randomized controlled trials (RCTs). Three RCTs comparing DOACs and VKAs in kidney failure failed to reach the primary endpoint, as they were underpowered. The left atrial appendage is the main source of thromboembolism in the presence of AF. Left atrial appendage closure (LAAC) has recently been proposed as an alternative to OAC. RCTs comparing the efficacy and safety of LAAC versus OAC in kidney failure were terminated prematurely due to recruitment failure. A recent prospective study showed a reduction in thromboembolic events in haemodialysis patients with AF and undergoing LAAC compared with patients taking or not taking OAC. We review current treatment standards and discuss recent developments in managing the thromboembolic risk in kidney failure patients with AF. The importance of shared decision-making with the multidisciplinary team and the patient to consider individual risks and benefits of each treatment option is underlined.

Practical guide on left atrial appendage closure for the non-implanting physician: an international consensus paper.

A significant proportion of patients who suffer from atrial fibrillation (AF) and are in need of thromboembolic protection are not treated with oral anticoagulation or discontinue this treatment shortly after its initiation. This undertreatment has not improved sufficiently despite the availability of direct oral anticoagulants which are associated with less major bleeding than vitamin K antagonists. Multiple reasons account for this, including bleeding events or ischaemic strokes whilst on anticoagulation, a serious risk of bleeding events, poor treatment compliance despite best educational attempts, or aversion to drug therapy. An alternative interventional therapy, which is not associated with long-term bleeding and is as effective as vitamin K anticoagulation, was introduced over 20 years ago. Because of significant improvements in procedural safety over the years, left atrial appendage closure, predominantly achieved using a catheter-based, device implantation approach, is increasingly favoured for the prevention of thromboembolic events in patients who cannot achieve effective anticoagulation. This management strategy is well known to the interventional cardiologist/electrophysiologist but is not more widely appreciated within cardiology or internal medicine. This article introduces the devices and briefly explains the implantation technique. The indications and device follow-up are more comprehensively described. Almost all physicians who care for adult patients will have many with AF. This practical guide, written within guideline/guidance boundaries, is aimed at those non-implanting physicians who may need to refer patients for consideration of this new therapy, which is becoming increasingly popular.

Long-term safety and efficacy of left atrial appendage occlusion in dialysis patients with atrial fibrillation: a multi-center, prospective, open label, observational study.

Background: The prevalence of atrial fibrillation (AF) in end stage kidney disease (ESKD) patients undergoing dialysis is high, however, the high risk of bleeding often hampers with a correct anticoagulation in ESKD patients with AF, despite high thromboembolic risk. Left atrial appendage (LAA) occlusion is a anticoagulation (OAT) for thromboembolism prevention in AF populations with high hemorrhagic risk. Methods and Results: The purpose of the study was to evaluate the efficacy and safety of LAA occlusion in a cohort of dialysis patients undergoing the procedure (LAA occlusion cohort, n = 106), in comparison with two other ESKD cohorts, one taking warfarin (Warfarin cohort, n = 114) and the other without anticoagulation therapy (No-OAT cohort, n = 148). After a median follow-up of 4 years, a Cox regression model, adjusted for possible confounding factors, showed that the hazard ratios (HRs) of thromboembolic events in the LAA occlusion cohort were 0.19 (95%CI 0.04-0.96; p = 0.045) and 0.16 (95%CI 0.04-0.66; p = 0.011) as compared with Warfarin and No-OAT cohorts, respectively. The HR of bleeding in the LAA occlusion cohort was 0.37 (95%CI 0.16-0.83; p = 0.017) compared to Warfarin cohort, while there were no significant differences between the LAA occlusion and the No-OAT cohort (HR 0.51; 95%CI 0.23-1.12; p = 0.094). Adjusted Cox regression models showed lower mortality in patients undergoing LAA occlusion as compared with both the Warfarin cohort (HR 0.60; 95%CI 0.38-0.94; p = 0.027) and no-OAT cohort (HR 0.52; 95%CI 0.34-0.78; p = 0.002). Thromboembolic events in the LAA occlusion cohort were lower than expected according to the CHA2DS2VASc score (1.7 [95%CI 0.3-3.0] vs 6.7 events per 100 person/years, p < 0.001). Conclusion: In ESKD patients with AF, LAA occlusion is safe and effective and is associated with reduced mortality compared with OAT or no therapy.

Wall Properties of Elastic and Muscular Arteries in Children and Adolescents at Increased Cardiovascular Risk.

BACKGROUND: Pulse wave velocity (PWV) assessment represents a simple method to estimate arterial distensibility. At present, carotid-femoral PWV (cf-PWV) is considered the gold standard method in the non-invasive evaluation of the elastic properties of the aorta. On the other hand, the mechanical properties of muscular arteries can be evaluated on the axillo-brachial-radia axis by estimating the carotid-radial PWV (cr-PWV). While a number of studies have addressed these issues in adults, limited information is available on the respective features of cf-PWV and cr-PWV and on their modulating factors in children and adolescents at increased cardiovascular risk. METHODS: The mechanical properties of the predominantly elastic (aorta) and muscular (axillo-brachial-radial axis) arteries were evaluated in a pediatric population characterized by either elevated blood pressure (BP) or excess body weight, and the main factors affecting cf-PWV and cr-PWV values in these individuals were investigated. RESULTS: 443 children and adolescents (median age 11.5 years, 43.3% females) were enrolled; 25% had BP values >90th percentile and 81% were excess weight. The cf-PWV values were significantly lower than the cr-PWV values: median (Q1-Q3) = 4.8 m/s (4.3-5.5) and 5.8 m/s (5.0-6.5), respectively (p < 0.001). The pubertal development (p < 0.03), systolic BP and diastolic BP z-scores (p = 0.002), heart rate (p < 0.001), and waist-to-height ratio (p < 0.005) were significantly associated with cf-PWV values. No significant association was found between BMI z-score and cf-PWV. Predictors of high cf-PWV (>95th percentile) were the heart rate (OR 1.07, 95%CI 1.04-1.10, p < 0.001) and waist-to-height ratio (OR 1.06, 95%CI 1.0-1.13, p = 0.04). The variables significantly related with cr-PWV values were diastolic BP z-score (p = 0.001), heart rate (p < 0.01), and HOMA index (p < 0.02). No significant association was found between the cr-PWV and BMI z-score or waist-to-height ratio. CONCLUSIONS: Systolic and diastolic BP values and central obesity are associated with aortic stiffness in a population of children and adolescents at increased cardiovascular risk. In contrast, diastolic BP, heart rate, and levels of insulin resistance appear to be related to distensibility of the upper limb vascular district.

Clinical Approach in the Management of Paediatric Patients with Familial Hypercholesterolemia: A National Survey Conducted by the LIPIGEN Paediatric Group.

Detection and treatment of patients with familial hypercholesterolemia (FH) starting from childhood is fundamental to reduce morbidity and mortality. The activity of National realities such as the LIPIGEN (LIpid transPort disorders Italian GEnetic Network) Paediatric Group, founded in 2018, is a milestone in this context. The aim of this exploratory survey, conducted in October 2021 among Italian lipid clinics included in the LIPIGEN Paediatric Group, was to investigate the current clinical approach in the management and treatment of paediatric patients with suspected FH. A digital questionnaire composed of 20 questions investigating nutritional treatment and nutraceutical and pharmacological therapy for children and adolescents with FH was proposed to the principal investigators of 30 LIPIGEN centres. Twenty-four centres responded to the section referring to children aged < 10 years and 30 to that referring to adolescents. Overall, 66.7% of children and 73.3% of adolescents were given lipid-lowering nutritional treatment as the first intervention level for at least 3-4 months (29.2% and 23.3%) or 6-12 months (58.3% and 53.3%). Nutraceuticals were considered in 41.7% (regarding children) and 50.0% (regarding adolescents) of the centres as a supplementary approach to diet. Lipid-lowering drug therapy initiation was mainly recommended (91.7% and 80.0%). In 83.3% of children and 96.7% of adolescents, statins were the most frequently prescribed drug. We highlighted several differences in the treatment of paediatric patients with suspected FH among Italian centres; however, the overall approach is in line with the European Atherosclerosis Society (EAS) recommendations for FH children and adolescents. We consider this survey as a starting point to reinforce collaboration between LIPIGEN centres and to elaborate in the near future a consensus document on the management of paediatric patients with suspected FH so as to improve and uniform detection, management, and treatment of these patients in our country.

Association between lifestyle modifications and improvement of early cardiac damage in children and adolescents with excess weight and/or high blood pressure.

BACKGROUND: It is not known whether, in children and adolescents with alterations in weight and/or blood pressure (BP), lifestyle modifications are associated with an improvement of early cardiac damage. METHODS: In a pediatric population referred for excess weight, high BP, or both (n = 278, 10.6 (2.3) years), echocardiography was performed at enrollment and after 15 months of follow-up, during which participants received nonpharmacological treatment, based on correcting unhealthy lifestyles and improving dietary habits. Left ventricular mass was indexed for height (g/m2.7, LVMI), and an LVMI value higher than or equal to age- and gender-specific 95th percentile was the criterion for defining left ventricular hypertrophy (LVH). Multiple linear and logistic regression analyses were carried out to determine associations between changes in BMI and BP z-scores and changes of LVMI values and LVH prevalence, from baseline to follow-up. RESULTS: At baseline, 33.1% of study participants were hypertensive, 52.9% obese, and 36.3% had LVH. At follow-up, the prevalence of hypertension, obesity, and LVH was 18.7%, 30.2%, and 22.3%, respectively (p < 0.001 for all). A decrease in LVMI from 37.1 to 35.2 g/m2.7 (p < 0.001) was observed. Only delta BMI z-score positively related to an improvement of LVMI. Reductions of BMI (OR = 0.22, 95% CI 0.07-0.64) and diastolic BP (OR = 0.64, 95% CI 0.42-0.93) z-scores from baseline to follow-up and family history of hypertension (OR = 0.36, 95% CI 0.16-0.78) were associated with a lower prevalence of LVH. CONCLUSIONS: In a pediatric population at cardiovascular risk, changing incorrect lifestyle and dietary habits is associated with both reduction of BMI and BP values and regression of early cardiac damage. A higher resolution version of the Graphical abstract is available as Supplementary information.

Elevated Serum Urea-to-Creatinine Ratio and In-Hospital Death in Patients with Hyponatremia Hospitalized for COVID-19.

Hyponatremia is associated with adverse outcomes in hospitalized patients. An elevated value of the serum urea-to-creatinine ratio (UCR) has been proposed as a proxy of hypovolemia. The aim of this study was to investigate the relationship between the UCR and in-hospital death in patients hospitalized with COVID-19 and hyponatremia. We studied 258 patients admitted for COVID-19 between January 2020 and May 2021 with serum sodium at < 135 mmol/L. The primary end-point was all-cause mortality. A 5-unit increase in the serum UCR during hospital stays was associated with an 8% increase in the hazard of all-cause death (HR = 1.08, 95% CI: 1.03-1.14, p = 0.001) after adjusting for potential confounders. In patients with a UCR > 40 at baseline, a > 10 mmol/L increase in serum sodium values within the first week of hospitalization was associated with higher odds of in-hospital death (OR = 2.93, 95% CI: 1.03-8.36, p = 0.044) compared to patients who experienced a < 10 mmol/L change. This was not observed in patients with a UCR < 40. Hypovolemia developing during hospital stays in COVID-19 patients with hyponatremia detected at hospital admission bears an adverse prognostic impact. Moreover, in hypovolemic patients, a > 10 mmol/L increase in serum sodium within the first week of hospital stays may further worsen the in-hospital prognosis.

Evidence and Uncertainties on Lipoprotein(a) as a Marker of Cardiovascular Health Risk in Children and Adolescents.

Lipoprotein(a) (Lp(a)) is made up of apoprotein(a) (apo(a)) and an LDL-like particle. The LPA gene encodes apo(a) and thus determines the characteristics and amount of apo(a) and Lp(a). The proportion of Lp(a) in each individual is genetically determined and is only minimally modifiable by the environment or diet. Lp(a) has important pro-atherosclerotic and pro-inflammatory effects. It has been hypothesized that Lp(a) also has pro-coagulant and antifibrinolytic actions. For these reasons, high Lp(a) values are an important independent risk factor for cardiovascular disease and calcific aortic valve stenosis. Numerous studies have been performed in adults about the pathophysiology and epidemiology of Lp(a) and research is under way for the development of drugs capable of reducing Lp(a) plasma values. Much less information is available regarding Lp(a) in children and adolescents. The present article reviews the evidence on this topic. The review addresses the issues of Lp(a) changes during growth, the correlation between Lp(a) values in children and those in their parents, and between Lp(a) levels in children, and the presence of cardiovascular disease in the family. Gaining information on these points is particularly important for deciding whether Lp(a) assay may be useful for defining the cardiovascular risk in children, in order to plan a prevention program early.

Role of Insulin Resistance as a Mediator of the Relationship between Body Weight, Waist Circumference, and Systolic Blood Pressure in a Pediatric Population.

Excess weight and high waist circumference (WC) are associated with increased blood pressure (BP), starting from the pediatric age. Insulin resistance is associated with elevated BP in childhood. The aim of the study was to assess the role of insulin resistance in mediating the relationship between body mass index (BMI), WC, and BP values in a pediatric population referred to a cardio-pediatric center for the presence of one or more cardiovascular risk factors. In 419 children (mean age 10.7 [standard deviation, SD 2.5] years), the following parameters were collected both in basal conditions and after 18.6 (SD 9.3) months of follow-up during which a treatment based on lifestyle and dietary modifications was given: systolic and diastolic BP (SBP and DBP), WC, plasma glucose, and insulin values. The HOMA (Homeostasis Model Assessment)-index was considered as an expression of insulin resistance. At baseline there was a significant correlation between HOMA-index and SBP z-score (ß = 0.081, p = 0.003), and insulin resistance was a mediator of the relationship between BMI and SBP z-score (p = 0.015), and between waist circumference to height (WtHr) and SBP z-score (p = 0.008). The effect of BMI z-score modifications on SBP z-score changes from baseline to follow-up was totally mediated by HOMA-index changes (p = 0.008), while HOMA-index only partially mediated the effect of WtHr modifications on SBP z-score changes (p = 0.060). Our study strongly suggests that, in a pediatric population at cardiovascular risk, the HOMA-index is an important mediator of the relationship between BMI, WC and SBP.

Negative prognostic impact of electrolyte disorders in patients hospitalized for Covid-19 in a large multicenter study.

BACKGROUND: The prognostic impact of electrolyte disorders in hospitalized COVID-19 patients is unclear. METHODS: The study included all adult patients hospitalized for COVID-19 in four hospitals in Northern Italy between January 2020 and May 2021 with at least one serum potassium and sodium measurement performed within 3 days since admission. Primary outcome was in-hospital death; secondary outcome was Intensive Care Unit (ICU) admission. A cause-specific Cox proportional-hazards regression model was used for investigating the association between potassium and sodium (as either categorical or continuous variables) and mortality or admission to ICU. RESULTS: Analyses included 3,418 adult hospitalized COVID-19 patients. At multivariable analysis, both hyperkalemia (Hazard Ratio, [HR] 1.833, 95% Confidence Interval [CI] 1.371-2.450) and sK above the median (K 5.1 vs 4.1 mmol/L: HR 1.523, 95% CI 1.295-1.798), and hypernatremia (HR 2.313, 95%CI 1.772-3.018) and sNa above the median (Na 149 vs 139 mmol/L: HR 1.442, 95% CI 1.234-1.686), were associated with in-hospital death, whereas hypokalemia and hyponatremia were not. Hyponatremia was associated with increased hazard of ICU admission (HR 1.884, 95%CI 1.389-2.556). CONCLUSIONS: Electrolyte disorders detected at hospital admission may allow early identification of COVID-19 patients at increased risk of adverse outcomes.

The conundrum of the complex relationship between acute kidney injury and cardiac arrhythmias.

Acute kidney injury (AKI) is defined by a rapid increase in serum creatinine levels, reduced urine output or both. Death may occur in 16-49% of patients admitted to an intensive care unit with severe AKI. Complex arrhythmias are a potentially serious complication in AKI patients with pre-existing or AKI-induced heart damage and myocardial dysfunction, with fluid overload, especially electrolyte and acid-base disorders, representing the pathogenetic mechanisms of arrhythmogenesis. Cardiac arrhythmias, in turn, increase the risk of poor renal outcomes, including AKI. Arrhythmic risk in AKI patients receiving kidney replacement treatment may be reduced by modifying dialysis/replacement fluid composition. The most common arrhythmia observed in AKI patients is atrial fibrillation. Severe hyperkalaemia, sometimes combined with hypocalcaemia, causes severe bradyarrhythmias in this clinical setting. Although the likelihood of life-threatening ventricular arrhythmias is reportedly low, the combination of cardiac ischaemia and specific electrolyte or acid-base abnormalities may increase this risk, particularly in AKI patients who require kidney replacement treatment. The purpose of this review is to summarize the available epidemiological, pathophysiological and prognostic evidence aiming to clarify the complex relationships between AKI and cardiac arrhythmias.

Prognostic Impact of Percutaneous Coronary Intervention in Chronic Dialysis Patients with Acute Myocardial Infarction: Findings from the Lombardy Health Database.

Background: Patients on chronic dialysis are less likely to be treated with percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). This is due to the lack of evidence from randomized trials, concerns about possible PCI-related side effects, and multimorbidity. Therefore, routine use of PCI for treatment of dialysis patients with AMI remains an unresolved issue. Methods: We analyzed data of patients on chronic dialysis hospitalized with AMI from 2003 to 2018, by using the administrative Lombardy Health Database (Italy). Patients were grouped according to whether they underwent or not PCI during index hospitalization. The primary outcome was in-hospital mortality, 1-year mortality was the secondary endpoint. Results: During the study period, 265,048 patients were hospitalized with AMI. Of them, 3206 (1.2%) were on chronic dialysis (age 71 ± 11; 72% males). Among dialysis patients, 44% underwent PCI, while 54% underwent PCI among non-dialysis patients (p < 0.0001). Dialysis was an independent predictor of treatment with medical therapy only (OR 0.75 [95% CI 0.70-0.81]). In-hospital mortality in the dialysis cohort was 15%, significantly lower in patients treated with PCI than in those not treated with PCI (11% vs. 19%; p < 0.0001). One-year mortality was 47% and it was lower in PCI-treated patients (33% vs. 52%; p < 0.0001). The adjusted risk of the study endpoints was significantly lower in dialysis patients undergoing PCI: OR 0.62 (95% CI 0.50-0.76) for in-hospital mortality; HR 0.63 (95% CI 0.56-0.71) for 1-year mortality. Conclusions: This study showed that in AMI patients on chronic dialysis, PCI is associated with a significant in-hospital and 1-year survival benefit. Yet, they underwent PCI less frequently than patients with preserved renal function.

Association of obesity phenotypes with left ventricular mass index and left ventricular hypertrophy in children and adolescents.

It has been argued that metabolically healthy obesity (MHO) does not increase the risk of cardiovascular disease. The aim of this study is to evaluate whether, in a population of obese children/adolescents, the metabolically unhealthy obesity (MUO) phenotype is associated with higher left ventricular mass index and/or higher prevalence of left ventricular hypertrophy than the MHO phenotype. We also tested whether the addition of an insulin resistance index (HOMA-index >90th percentile by sex and age) and the presence of hyperuricemia (serum uric acid >90th percentile by sex and age) to the definition of MUO better identified obese children with early cardiac damage. Left ventricular hypertrophy was defined as the presence of left ventricular mass index greater than or equal to the age- and sex-specific 95th percentile. The study population included 459 obese children (males 53.2%, mean age 10.6 [standard deviation, 2.6] years), of whom 268 (58.4%) were MUO. The left ventricular mass index was higher in MUO children than in MHO children (37.8 vs 36.3 g/m2.7, p=0.015), whereas the percentage of MUO children presenting left ventricular hypertrophy was only slightly higher in MUO children (31.1 vs 40%, p=0.06). Multiple linear regression analyses showed that the variables significantly associated with higher left ventricular mass index were male gender (p<0.01), Body Mass Index z-score (p<0.001) and Waist-to-Height-ratio (p<0.001). Multiple logistic regression analyses showed that the presence of left ventricular hypertrophy was only significantly associated with higher Body Mass Index z-score (p<0.05) and Waist-to-Height-ratio (p<0.05). In spite of the higher left ventricular mass index of MUO as compared to MHO children, the MUO phenotype was not a significant predictor of either higher left ventricular mass index or higher left ventricular hypertrophy prevalence. The MUO phenotype had a low predictive ability on the presence of left ventricular hypertrophy. The area under the receiver operating characteristic curve was 0.57 (sensitivity 0.64, 1-specificity 0.55). The addition of insulin resistance and hyperuricemia to the definition of MUO did not change the results observed with the standard definition of MUO at multivariable analysis. The MUO phenotype appears to be of little usefulness in identifying the early presence of cardiac damage in a large population of obese children and adolescents. Excess weight and abdominal obesity are confirmed as an important determinant of early organ damage in obese children.

Uric acid and arterial stiffness in children and adolescents: Role of insulin resistance and blood pressure.

Several studies describe the association between serum uric acid (SUA) and arterial stiffness in adults. Uric acid contributes through several mechanisms to the increase in blood pressure (BP) and adversely affects the insulin signaling pathway. Moreover, SUA predict the development of hypertension and insulin resistance up to type 2 diabetes. Early arterial stiffening, estimated by carotid-femoral pulse wave velocity (PWV), may already be present in pediatric age. Aim of our study was to investigate the relationship between SUA and PWV in a pediatric population and its interaction with insulin resistance and BP. In 322 children and adolescents (56.2% male, mean age 11.3 [SD 2.8] years), we measured weight, height, waist circumference, BP and PWV. We also assayed SUA and estimated glomerular filtration rate (eGFR) and calculated HOMA-index as a marker of insulin resistance. Simple and multiple regression analyses were performed to assess variables associated with PWV. Mediation models were applied to identify the direct and indirect effects of individual variables on PWV. On univariate analysis, age (p < 0.001), waist circumference-to-height ratio (p = 0.036), systolic and diastolic BP (SBP and DBP) z-score (p < 0.001), heart rate (p = 0.028), SUA (p = 0.002), HOMA-index (p < 0.001), and eGFR (p = 0.014) were significantly associated with PWV. The multiple regression model showed that only age (p = 0.028), SBP z-score (p = 0.006), and heart rate (p = 0.001) were significantly associated with PWV. The results were superimposable when the DBP z-score replaced the SBP z-score in the model. Mediation models showed that the effect of eGFR on PWV was fully mediated by SUA (p = 0.015) and that the effect of SUA on PWV was totally mediated by HOMA-index (p < 0.001). Both SUA (p < 0.01) and HOMA-index (p < 0.01) had a significant association with higher SBP (DBP) z-scores. The double mediation model including both BP and HOMA-index showed that the SUA effect on PWV was totally mediated by both variables (p = 0.005, for HOMA-index, p = 0.004, for SBP z-score and p = 0.007, for combined effect). The results were superimposable when the DBP z-score replaced the SBP z-score in the model. In conclusion, insulin resistance and BP are both important mediators of the association between SUA and vascular stiffness in pediatric age.