42 research outputs found

    Electrocardiographic predictors of clinical outcome in ST-elevation myocardial infarction

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    Malignant ventricular arrhythmias, particularly ventricular fibrillation (VF), remain an important contributor to mortality in ST-elevation myocardial infarction (STEMI). The size of myocardial injury is one more important factor influencing the prognosis of STEMI patients. The search for new non-invasive markers, which can be relatively simply calculated using conventional ECG recording and can predict the degree of myocardial injury and impending VF, is promising. This work is aimed at investigating cardiac repolarization and depolarization abnormalities and predictors and prognosis of ventricular arrhythmias during the course of STEMI. The thesis is composed of the experimental part (Studies I, II, III) and clinical register-based retrospective studies (Studies IV and V). Closed-chest porcine model of myocardial infarction (MI) was used in the experimental part. Occlusion of left descending artery (LAD) lasted 40 minutes and was followed by reperfusion, and ECG was continuously recorded. QRSduration and morphology, dynamics of ST-segment and T-wave alternans (TWA) were calculated, and myocardial area at risk (MaR) and infarct size (IS) were assessed. Predictors and prognostic impact of early VF in STEMI was assessed in a register-based study of 1,718 consecutive patients admitted for primary PCI during 2007-2009 who were followed up for one year. In experimental MI, the maximal level of TWA during occlusion period was associated with both MaR and IS (Study II). Rapid and marked transient increase in QRS duration associated with appearance of J-wave pattern predicted impending VF in acute ischemia (Study III). Restoration of blood flow in infarct-related artery was accompanied by reperfusion peak in all animals, and the magnitude of ST elevation at reperfusion peak was associated with infarct size (Study I). In clinical studies IV and V, the risk of VF in acute period of STEMI was higher in patients with MI history, cardiovascular risk factors such as smoking and left main stenosis, resulting in a large infarct area. Besides MI history and left main stenosis, the risk of VF at reperfusion was associated with inferior localization of STEMI, hypokalemia, high ST-elevation and shorter symptom-toballoon time. The magnitude of ST-elevation before PCI for STEMI independently predicted reperfusion VF. Patients successfully resuscitated after VF and alive at 48 hours had higher in-hospital mortality (12% vs. 2%, p<0.001). However, in VF patients who were discharged alive, 1-year mortality did not differ compared with patients without V

    Predictors of Ventricular Fibrillation at Reperfusion in Patients With Acute ST-Elevation Myocardial Infarction Treated by Primary Percutaneous Coronary Intervention.

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    Ventricular fibrillation (VF) during reperfusion (rVF) in ST-segment elevation myocardial infarction (STEMI) is an infrequent but serious event that complicates coronary interventions. The aim of this study was to analyze clinical predictors of rVF in an unselected population of patients with STEMI treated with percutaneous coronary intervention (PCI). Consecutive patients with STEMI admitted to a tertiary care hospital for primary PCI from 2007 to 2012 were retrospectively assessed for the presence of rVF. Admission electrocardiograms, stored in a digital format, were analyzed for a maximal ST-segment elevation in a single lead and the sum of ST-segment deviations in all leads. Clinical, electrocardiographic, and angiographic characteristics were tested for associations with rVF using logistic regression analysis. Among 3,724 patients with STEMI admitted from 2007 to 2012, 71 (1.9%) had rVF. In univariate analysis, history of myocardial infarction, aspirin and β-blocker use, VF before PCI, left main coronary artery disease, inferior myocardial infarction localization, symptom-to-balloon time 300 μV, and sum of ST-segment deviations in all leads >1,500 μV were associated with increased risk for rVF. In a multivariate analysis, sum of ST-segment deviations in all leads >1500 μV (odds ratio 3.7, 95% confidence interval 1.45 to 9.41, p = 0.006) before PCI remained an independent predictor of rVF. In-hospital mortality was 18.3% in the rVF group and 3.3% in the group without VF (p <0.001), but rVF was not an independent predictor of in-hospital death. In conclusion, the magnitude of ST-segment elevation before PCI for STEMI independently predicts rVF and should be considered in periprocedural arrhythmic risk assessment. Despite higher in-hospital mortality in patients with rVF, rVF itself has no independent prognostic value for prognosis

    Substantiation of the efficiency of the method for processing viburnum by the method of osmotic dehydration

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    In the process of any food production, it is important not only to obtain a high quality product, but also to minimize industrial waste, reduce energy costs for the process. Recently, buyers are also paying special attention to the biological value, the popularity of organic and natural products is growing. The search for new types of non-traditional raw materials and the choice of a rational way of processing it is an important task for scientists and manufacturers. The subject of the study was the viburnum fruits (Viburnum opulus). The object is the process of osmotic dehydration. The purpose of the study is to substantiate the effectiveness of the method of processing Viburnum opulus fruits by the method of osmotic dehydration. The process of processing viburnum fruits provides for mandatory pre-freezing, defrosting, osmotic dehydration and drying. A method was developed for waste-free processing of viburnum fruits using the process of osmotic dehydration. Products of viburnum processing (osmotic solution and powders) were studied. Analysis of the mineral composition of powders of their derivatives from the processing of viburnum showed the highest content of potassium (5.74&nbsp;%). In addition, vitamin C was found in the products of viburnum processing: in powders – 8.28&nbsp;mg/100&nbsp;g, in an osmotic solution − 1.12&nbsp;mg/100&nbsp;ml. Given that wild berries were used for the study, a study of powders for the presence of microorganisms and heavy metals was carried out. Mesophilic aerobic, facultative anaerobic microorganisms, yeasts and molds were not detected. The content of heavy metals is less than 10&nbsp;ppm&nbsp;Pb. Thus, viburnum fruits are safe raw materials. When using osmotic dehydration, their biological value and organoleptic properties are preserved

    Transient and rapid QRS widening associated with J-wave pattern predicts impending ventricular fibrillation in experimental myocardial infarction.

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    Certain types of the early repolarization (ER) phenomenon, previously considered to be benign, have been reported to be associated with ventricular fibrillation (VF), both in population-based studies and in the myocardial infarction (MI) settings

    What are new opportunities for clinical practice the VERIFY study opens and which values for native diabetes patients? Joint conclusion on the advisory board results. November 6, 2019

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    According to key diabetic studies, the early use of metformin glucose lowering therapy is associated with a reduced risk of developing micro- and, in the long term, 10-year follow-up, macrovascular complications and cardiovascular mortality. Short-term studies results on combined glucose lowering therapy with metformin suggests that combination therapy can have several advantages on the one side from the effectiveness of glycemic control and on another side from positive effect on the development of complications of type 2 diabetes. The question of the start time of combined hypoglycemic therapy remains open. According to the results of recent large-scale studies, real world evidence data, careful glycemic control during the first year from the moment of diagnosis of type 2 diabetes is crucial for further management of the disease and slow the progression of complications. However, due to the fact that the clinical benefits of early combination therapy were not demonstrated in randomized clinical trials, this approach, despite the theoretical background, was not recommended for widespread use in international guidelines for the treatment diabetes patients. Russian algorithms on the treatment diabetes patients recommend combined glucose lowering therapy at the start of treatment at a HbA1c level of 1% higher than the target. A 5-year VERIFY study results were demonstrated long-term sustained glycemic control in combination with vildagliptin + metformin prescribed for native diabetes patients with relatively low HbA1c values, as well as the advantages of this approach in comparison with the standard strategy for phased intensification of monotherapy. The results of the VERIFY study provided a wealth of information to discuss early treatment intensification, the clinical benefits of this approach and a possible review of the treatment strategy for native diabetes patients

    Prolonged repolarization in the early phase of ischemia is associated with ventricular fibrillation development in a porcine model

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    Background: Repolarization prolongation can be the earliest electrophysiological change in ischemia, but its role in arrhythmogenesis is unclear. The aim of the present study was to evaluate the early ischemic action potential duration (APD) prolongation concerning its causes, expression in ECG and association with early ischemic ventricular fibrillation (phase 1A VF).Methods: Coronary occlusion was induced in 18 anesthetized pigs, and standard 12 lead ECG along with epicardial electrograms were recorded. Local activation time (AT), end of repolarization time (RT), and activation-repolarization interval (ARIc) were determined as dV/dt minimum during QRS-complex, dV/dt maximum during T-wave, and rate-corrected RT–AT differences, respectively. Patch-clamp studies were done in enzymatically isolated porcine cardiomyocytes. IK(ATP) activation and Ito1 inhibition were tested as possible causes of the APD change.Results: During the initial period of ischemia, a total of 11 pigs demonstrated maximal ARIc prolongation &gt;10 ms at 1 and/or 2.5 min of occlusion (8 and 6 cases at 1 and 2.5 min, respectively) followed by typical ischemic ARIc shortening. The maximal ARIc across all leads was associated with VF development (OR 1.024 95% CI 1.003–1.046, p = 0.025) and maximal rate-corrected QT interval (QTc) (B 0.562 95% CI 0.346–0.775, p &lt; 0.001) in logistic and linear regression analyses, respectively. Phase 1A VF incidence was associated with maximal QTc at the 2.5 min of occlusion in ROC curve analysis (AUC 0.867, p = 0.028) with optimal cut-off 456 ms (sensitivity 1.00, specificity 0.778). The pigs having maximal QTc at 2.5 min more and less than 450 ms significantly differed in phase 1A VF incidence in Kaplan-Meier analysis (log-rank p = 0.007). In the patch-clamp experiments, 4-aminopyridine did not produce any effects on the APD; however, pinacidil activated IK(ATP) and caused a biphasic change in the APD with initial prolongation and subsequent shortening.Conclusion: The transiently prolonged repolarization during the initial period of acute ischemia was expressed in the prolongation of the maximal QTc interval in the body surface ECG and was associated with phase 1A VF. IK(ATP) activation in the isolated cardiomyocytes reproduced the biphasic repolarization dynamics observed in vivo, which suggests the probable role of IK(ATP) in early ischemic arrhythmogenesis

    Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

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    Background: Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke. Methods: We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30–50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515. Findings: Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68–0·90), which indicated that albiglutide was superior to placebo (p&lt;0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (&lt;1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (&lt;1%) deaths in the albiglutide group. Interpretation: In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes. Funding: GlaxoSmithKline
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