Autonomic Function in Obese Children and Adolescents: Systematic Review and Meta-Analysis.

Background: Obesity is invariably accompanied by autonomic dysfunction, although data in pediatric populations are conflicting. Methods: We conducted a systematic review and meta-analysis of 12 studies (totaling 1102 participants) comparing obese and normal-weight subjects (5-18 years of age), defined as body mass index >95th or <85th percentile, respectively. Using a random-effects model, we report the standardized mean differences (SMD) of sympathetic and vagal indices of heart rate variability. Results: Autonomic dysfunction was present in the obesity group, based on the average SMD in the standard deviation of sinus intervals (at -0.5340), and on the ratio of low (LF)- to high (HF)-frequency spectra (at 0.5735). There was no difference in sympathetic activity, but the heterogeneity among the relevant studies weakens this result. SMD in HF (at 0.5876), in the root mean square of successive differences between intervals (at -0.6333), and in the number of times successive intervals exceeded 50 ms divided by the total number of intervals (at -0.5867) indicated lower vagal activity in the obesity group. Conclusions: Autonomic dysfunction is present in obese children and adolescents, attributed to lower vagal activity. Further studies are needed in various pediatric cohorts, placing emphasis on sympathetic activity.

Absolute zero-contrast percutaneous coronary interventions: An intravascular ultrasound-guided case series and literature review.

PURPOSE: Contrast media (CM)-associated adverse effects including mainly acute kidney injury and hypersensitivity reactions still remain a significant treatment burden to vulnerable patients requiring percutaneous coronary intervention (PCI). The complete omission of CM administration accompanied by intravascular ultrasound (IVUS) guidance may offer an appropriate revascularization treatment. METHODS: We hereby present a case series of four patients with challenging coronary lesions and relative/absolute contraindications to CM use [(hypersensitivity reaction owning to CM, history of contrast-induced acute kidney injury, solitary kidney, or advanced chronic kidney disease (CKD)] who underwent absolute zero-contrast IVUS-guided PCI following a predetermined protocol. RESULTS: The initial diagnostic angiography was reviewed for landmark identification, and multiple guidewires created a metallic road map providing additional landmarks and protected side branches. IVUS imaging was performed to determine lesion length, reference segments and landing zones, assess stent expansion/apposition and identify major complications. All procedures were successfully completed without any CM administration, renal function deterioration, pericardial effusion, or stent edge dissection. CONCLUSIONS: We demonstrated the feasibility of absolute zero-contrast IVUS-guided PCI in patients with complex coronary lesions susceptible to CM-associated adverse effects. Since the safety of this strategy is well-documented in patients with CKD and challenging lesions morphology even in acute settings, evidence-based validation of this approach is capable of changing the otherwise conservative treatment of vulnerable patients where even minimum doses of CM may have detrimental effects. SUMMARY FOR THE ANNOTATED TABLE OF CONTENTS: Patients with vulnerable renal function as well as former hypersensitivity reaction to contrast media encounter a significant treatment burden regarding coronary artery disease. Zero-contrast IVUS-guided strategy based on a predetermined protocol provides a feasible alternative approach in patients susceptible to contrast media-associated adverse effects even in the presence of complex coronary lesions.

Renal Complications after Percutaneous Coronary Interventions on Concurrent Metformin Therapy: A Systematic Review with Meta-Analysis.

Objective: Metformin, commonly prescribed in diabetic patients, can cause lactic acidosis. Although generally rare, this side effect remains a source of concern in procedures requiring contrast media, due to the risk of contrast-induced nephropathy. Temporarily withdrawing metformin during the peri-procedural period is often practiced, but clinical decisions are difficult in emergency situations, such as acute coronary syndromes. In this systematic review with meta-analysis, we aimed to further investigate the safety of percutaneous coronary interventions in patients on concurrent metformin therapy.Design, Setting and Participants: We analyzed studies in patients undergoing (elective or emergency) percutaneous coronary interventions with or without concurrent metformin administration, reporting on the incidence of metformin-associated lactic acidosis and peri-procedural renal function.Methods: PubMed, ClinicalTrials.gov, Cochrane Library, and Scopus were systematically searched without language restrictions throughout August 2022. Randomized clinical trials and observational studies were assessed with the Revised Cochrane Collaboration Risk of Bias tool and the Newcastle-Ottawa quality scale, respectively. Data synthesis addressed the mean drop in estimated glomerular filtration rate (eGFR) and the incidence of contrast-induced nephropathy, in addition to lactic acidosis.Results: Nine studies were included, totaling 2235 patients (1076 continuing metformin during the peri-procedural period), mostly with eGFR above 30 mL/min/1.73m2 No cases of lactic acidosis were reported. The mean post-procedural drop in eGFR was 6.81mL/min/1.73m2 (95% confidence interval [CI]: 3.41 to 10.21) in the presence of metformin and 5.34 mL/min/1.73m2 (95% CI: 2.98 to 7.70) in its absence. The incidence of contrast-induced nephropathy was not affected by concurrent metformin, as shown by a (between-groups) standardized mean difference of 0.0007 (95% CI: -0.1007 to 0.1022).Conclusion: Concurrent metformin during percutaneous coronary interventions in patients with relatively preserved renal function is safe, without added risk of lactic acidosis or contrast-induced nephropathy. Thus, emergency revascularization in the context of acute coronary syndromes should not be deferred. More data from clinical trials in patients with severe renal disease are needed.

Exercise-mediated adaptations in vascular function and structure: Beneficial effects in coronary artery disease.

Exercise exerts direct effects on the vasculature via the impact of hemodynamic forces on the endothelium, thereby leading to functional and structural adaptations that lower cardiovascular risk. The patterns of blood flow and endothelial shear stress during exercise lead to atheroprotective hemodynamic stimuli on the endothelium and contribute to adaptations in vascular function and structure. The structural adaptations observed in arterial lumen dimensions after prolonged exercise supplant the need for acute functional vasodilatation in case of an increase in endothelial shear stress due to repeated exercise bouts. In contrast, wall thickness is affected by rather systemic factors, such as transmural pressure modulated during exercise by generalized changes in blood pressure. Several mechanisms have been proposed to explain the exercise-induced benefits in patients with coronary artery disease (CAD). They include decreased progression of coronary plaques in CAD, recruitment of collaterals, enhanced blood rheological properties, improvement of vascular smooth muscle cell and endothelial function, and coronary blood flow. This review describes how exercise via alterations in hemodynamic factors influences vascular function and structure which contributes to cardiovascular risk reduction, and highlights which mechanisms are involved in the positive effects of exercise on CAD.

Should Deferred Stenting Still Be Considered in ST-Elevation Myocardial Infarction with High Thrombus Burden?

Patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) may demonstrate distal microvascular embolization of thrombotic materials. We retrospectively examined 20 cases displaying extensive thrombus in the infarct-related artery (IRA), treated either with a two-step procedure, with interim tirofiban infusion, or immediate stent implantation. Distal embolization tended to be more common in the latter strategy, but, overall, the outcome was comparable. Thus, a two-staged procedure may be considered in selected cases of primary PCI associated with high thrombus burden.

Treatment of Mobile Right Heart Thrombi.

Right heart thrombi are detected in approximately 4% of patients with pulmonary embolism. The associated mortality is high, but the optimal strategy remains controversial. We report a case of a large mobile right heart thrombus, complicated by embolism of the right pulmonary artery, which was successfully treated with half-dose alteplase. We briefly review the literature and discuss the therapeutic options, focusing on the advantages of thrombolysis. LEARNING POINTS: Mobile right heart thrombi require rapid therapeutic choices between surgical thrombectomy and thrombolysis.Half-dose alteplase may be effective, even in the presence of an extensive thrombus burden.