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- Shao, Yangzhen, 1981, et al.
(författare)
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A mouse model reveals an important role for catecholamine-induced lipotoxicity in the pathogenesis of stress-induced cardiomyopathy.
- 2013
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Ingår i: European journal of heart failure. - : Wiley. - 1879-0844 .- 1388-9842. ; 15:1, s. 9-22
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Tidskriftsartikel (refereegranskat)abstract
- AimStress-induced cardiomyopathy (SIC), also known as takotsubo cardiomyopathy, is an acute cardiac syndrome with substantial morbidity and mortality. The unique hallmark of SIC is extensive ventricular dysfunction (akinesia) involving apical segments with preserved function in basal segments. Adrenergic overstimulation plays an important role in initiating SIC, but the pathomechanisms involved are unknown. We tested the hypothesis that excessive catecholamines cause perturbation of myocardial lipid metabolism and that cardiac lipotoxicity is responsible for the pathogenesis of SIC. METHODS AND RESULTS: A single dose injection of isoprenaline (ISO; 400 mg/kg) induced SIC-like regional akinesia in mice. Oil red O staining revealed severe lipid accumulation in the heart 2 h post-ISO. Both intramyocardial lipid accumulation and cardiac function were normalized within 1 week post-ISO and no significant amount of fibrosis was detected. We found that gene expression of lipid importers and exporters (ApoB lipoprotein) was depressed 2 h post-ISO. These results were confirmed by similar findings in SIC patients and in ISO/patient serum-stressed HL-1 cardiomyocytes. Moreover, overexpression of ApoB in the heart was found to protect against the development of ISO-induced cardiac toxicity and cardiac dysfunction. We also found that ISO-induced intramyocardial lipid accumulation caused electrophysiological disturbance and stunning in ISO/patient serum-stressed HL-1 cardiomyocytes. CONCLUSIONS: The present study demonstrates that lipotoxicity is closely associated with catecholamine-induced myocardial dysfunction, including neurogenic stunning, metabolic stunning, and electrophysiological stunning. Cardiac lipotoxicity may originate from direct inhibition of myocardial ApoB lipoprotein and subsequent decreased lipid export, caused by supraphysiological levels of catecholamines.
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- Shao, Yangzhen, 1981, et al.
(författare)
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Novel rat model reveals important roles of β-adrenoreceptors in stress-induced cardiomyopathy.
- 2013
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Ingår i: International journal of cardiology. - : Elsevier BV. - 1874-1754 .- 0167-5273. ; 168:3, s. 1943-1950
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Stress-induced cardiomyopathy (SIC), also known as Takotsubo cardiomyopathy, is an acute cardiac syndrome with substantial morbidity and mortality. The unique hallmark of SIC is extensive ventricular akinesia involving apical segments with preserved function in basal segments. Adrenergic overstimulation plays an important role in initiating SIC but the pathophysiological pathways and receptors involved are unknown. METHODS: Sprague Dawley rats (~300g) were injected with a single dose of the β-adrenergic agonist isoprenaline (ISO, i.p.) and echocardiography was used to study cardiac function. The akinetic part of the left ventricle was biopsied in six SIC patients. Amount of intracellular lipid and glycogen as well as degree of permanent cardiac damage were assessed by histology. RESULTS: In rats, ISO at doses ≥50mg/kg induced severe SIC-like regional akinesia that completely resolved within seven days. Intracellular lipid content was higher in akinetic, but not in normokinetic myocardium in both SIC patients and rats. β2-receptor blockade or Gi-pathway inhibition was associated with less widespread akinesia and low lipid accumulation but significantly increased acute mortality. CONCLUSIONS: We provide a novel rat model of SIC that supports the hypothesis of circulating catecholamines as initiators of SIC. We propose that the β-adrenoreceptor pathway is important in the setting of severe catecholamine overstimulation and that perturbations of cardiac metabolism occur in SIC.
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- Thygesen, Kristian, et al.
(författare)
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Recommendations for the use of cardiac troponin measurement in acute cardiac care
- 2010
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 0195-668X .- 1522-9645. ; 31:18, s. 2197-2204
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Tidskriftsartikel (refereegranskat)abstract
- The release of cardiomyocyte components, i.e. biomarkers, into the bloodstream in higher than usual quantities indicates an ongoing pathological process. Thus, detection of elevated concentrations of cardiac biomarkers in blood is a sign of cardiac injury which could be due to supply-demand imbalance, toxic effects, or haemodynamic stress. It is up to the clinician to determine the most probable aetiology, the proper therapeutic measures, and the subsequent risk implied by the process. For this reason, the measurement of biomarkers always must be applied in relation to the clinical context and never in isolation. There are a large number of cardiac biomarkers, but they can be subdivided into four broad categories, those related to necrosis, inflammation, haemodynamic stress, and/or thrombosis. Their usefulness is dependent on the accuracy and reproducibility of the measurements, the discriminatory limits separating pathology from physiology, and their sensitivity and specificity for specific organ damage and/or disease processes. In recent years, cardiac biomarkers have become important adjuncts to the delivery of acute cardiac care. Therefore, the Working Group on Acute Cardiac Care of the European Society of Cardiology established a committee to deal with ongoing and newly developing issues related to cardiac biomarkers. The intention of the group is to outline the principles for the application of various biomarkers by clinicians in the setting of acute cardiac care in a series of expert consensus documents. The first of these will focus on cardiac troponin, a pivotal marker of cardiac injury/necrosis.
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- Montalescot, Gilles, et al.
(författare)
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Prehospital Ticagrelor in ST-Segment Elevation Myocardial Infarction
- 2014
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Ingår i: New England Journal of Medicine. - : Massachusetts Medical Society. - 0028-4793 .- 1533-4406. ; 371:11, s. 1016-1027
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND The direct-acting platelet P2Y(12) receptor antagonist ticagrelor can reduce the incidence of major adverse cardiovascular events when administered at hospital admission to patients with ST-segment elevation myocardial infarction (STEMI). Whether prehospital administration of ticagrelor can improve coronary reperfusion and the clinical outcome is unknown. METHODS We conducted an international, multicenter, randomized, double-blind study involving 1862 patients with ongoing STEMI of less than 6 hours duration, comparing prehospital (in the ambulance) versus in-hospital (in the catheterization laboratory) treatment with ticagrelor. The coprimary end points were the proportion of patients who did not have a 70% or greater resolution of ST-segment elevation before percutaneous coronary intervention (PCI) and the proportion of patients who did not have Thrombolysis in Myocardial Infarction flow grade 3 in the infarct-related artery at initial angiography. Secondary end points included the rates of major adverse cardiovascular events and definite stent thrombosis at 30 days. RESULTS The median time from randomization to angiography was 48 minutes, and the median time difference between the two treatment strategies was 31 minutes. The two coprimary end points did not differ significantly between the prehospital and in-hospital groups. The absence of ST-segment elevation resolution of 70% or greater after PCI (a secondary end point) was reported for 42.5% and 47.5% of the patients, respectively. The rates of major adverse cardiovascular events did not differ significantly between the two study groups. The rates of definite stent thrombosis were lower in the prehospital group than in the in-hospital group (0% vs. 0.8% in the first 24 hours; 0.2% vs. 1.2% at 30 days). Rates of major bleeding events were low and virtually identical in the two groups, regardless of the bleeding definition used. CONCLUSIONS Prehospital administration of ticagrelor in patients with acute STEMI appeared to be safe but did not improve pre-PCI coronary reperfusion.
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- Stebbins, Amanda, et al.
(författare)
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A Model for Predicting Mortality in Acute ST-Segment Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention : Results From the Assessment of Pexelizumab in Acute Myocardial Infarction Trial
- 2010
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Ingår i: Circulation: Cardiovascular Interventions. - 1941-7640. ; 3:5, s. 414-422
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Tidskriftsartikel (refereegranskat)abstract
- Background-Accurate models to predict mortality are needed for risk stratification in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Methods and Results-We examined 5745 patients with STEMI undergoing primary PCI in the Assessment of Pexelizumab in Acute Myocardial Infarction Trial within 6 hours of symptom onset. A Cox proportional hazards model incorporating regression splines to accommodate nonlinearity in the log hazard ratio (HR) scale was used to determine baseline independent predictors of 90-day mortality. At 90 days, 271 (4.7%) of 5745 patients died. Independent correlates of 90-day mortality were (in descending order of statistical significance) age (HR, 2.03/10-y increments; 95% CI, 1.80 to 2.29), systolic blood pressure (HR, 0.86/10-mm Hg increments; 95% CI, 0.82 to 0.90), Killip class (class 3 or 4 versus 1 or 2) (HR, 4.24; 95% CI, 2.97 to 6.08), heart rate (>70 beats per minute) (HR, 1.45/10-beat increments; 95% CI, 1.31 to 1.59), creatinine (HR, 1.23/10-mu mol/L increments >90 mu mol/L; 95% CI, 1.13 to 1.34), sum of ST-segment deviations (HR, 1.25/10-mm increments; 95% CI, 1.11 to 1.40), and anterior STEMI location (HR, 1.47; 95% CI, 1.12 to 1.93) (c-index, 0.82). Internal validation with bootstrapping confirmed minimal overoptimism (c-index, 0.81). Conclusions-Our study provides a practical method to assess intermediate-term prognosis of patients with STEMI undergoing primary PCI, using baseline clinical and ECG variables. This model identifies key factors affecting prognosis and enables quantitative risk stratification that may be helpful in guiding clinical care and for risk adjustment for observational analyses. (Circ Cardiovasc Interv. 2010;3:414-422.)
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