Circulation: Clinical Summaries
Original Research Put Into Perspective for the Practicing Clinician
- Marked Variability in Susceptibility to Ventricular Fibrillation in an Experimental Commotio Cordis Model
- High Levels of Systemic Myeloperoxidase Are Associated With Coronary Plaque Erosion in Patients With Acute Coronary Syndromes : A Clinicopathological Study
- Influence of Age on Associations Between Childhood Risk Factors and Carotid Intima-Media Thickness in Adulthood : The Cardiovascular Risk in Young Finns Study, the Childhood Determinants of Adult Health Study, the Bogalusa Heart Study, and the Muscatine Study for the International Childhood Cardiovascular Cohort (i3C) Consortium
- Lifetime Fruit and Vegetable Consumption and Arterial Pulse Wave Velocity in Adulthood : The Cardiovascular Risk in Young Finns Study
- Inhibition and Genetic Ablation of the B7/CD28 T-Cell Costimulation Axis Prevents Experimental Hypertension
- Myocardial Steatosis and Biventricular Strain and Strain Rate Imaging in Patients With Type 2 Diabetes Mellitus
- Economic Evaluation of Fractional Flow Reserve–Guided Percutaneous Coronary Intervention in Patients With Multivessel Disease
- Migraine and Functional Outcome From Ischemic Cerebral Events in Women
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Marked Variability in Susceptibility to Ventricular Fibrillation in an Experimental Commotio Cordis Model
The data reported in this article demonstrate for the first time that an individual susceptibility to commotio cordis exists. Whether individuals are more or less susceptible to chest wall blow–induced ventricular fibrillation has been a clinical question for quite some time, and individual susceptibility may partially explain the rarity of the condition. Yet, despite its rarity, commotio cordis is the second leading cause of sudden cardiac death on the playing field for young athletes. It also is of major concern to parents, coaches, and organizations such as US Lacrosse and Little League Baseball. These data also have clinical implications for the decision of whether return to sports for individuals who have survived a commotio cordis event is wise. See p 2499.
High Levels of Systemic Myeloperoxidase Are Associated With Coronary Plaque Erosion in Patients With Acute Coronary Syndromes : A Clinicopathological Study
This study reports a significant elevation in the levels of circulating myeloperoxidase in patients with an acute coronary syndrome presenting with culprit plaque erosion (assessed by optical coherence tomography) compared with those with culprit plaque rupture. It also reports that examination of culprit plaques from sudden coronary deaths shows that luminal thrombi associated with erosion contain a higher density of myeloperoxidase-positive cells than thrombi superimposed to ruptures. Myeloperoxidase can exert prothrombotic activity via the generation of oxidant reactive species as it catalyzes lipid peroxidation in vivo, thus leading to tissue factor activation and tissue factor pathway inhibitor inactivation. Furthermore, myeloperoxidase reacts with hydrogen peroxide to form an enzyme substrate complex with strong oxidant activity and can bind firmly to negatively charged glycosaminoglycans and proteoglycans in the extracellular matrix. The concordance of information provided in our study by coronary imaging and postmortem analyses highlights the notion that mechanisms of coronary instability are heterogeneous. The only therapeutic target in acute coronary syndromes is currently represented by coronary thrombosis. It is unlikely, however, that more potent antithrombotic drugs can further improve the outcome of acute coronary syndromes because of the associated increased hemorrhagic risk. Our study suggests that coronary thrombosis can be triggered by different stimuli and mechanisms and that a smart treatment of acute coronary syndromes can possibly be guided by intravascular imaging. See p 2505.
Influence of Age on Associations Between Childhood Risk Factors and Carotid Intima-Media Thickness in Adulthood : The Cardiovascular Risk in Young Finns Study, the Childhood Determinants of Adult Health Study, the Bogalusa Heart Study, and the Muscatine Study for the International Childhood Cardiovascular Cohort (i3C) Consortium
The pediatric origin of atherosclerosis is now well accepted, with several authorities issuing guidelines and consensus statements for the assessment and management of cardiovascular disease risk factors, including lipids and lipoprotein, blood pressure, and adiposity, in childhood. Despite this, there have been scant data that have assessed the optimal age when childhood risk exposure begins to associate with adult atherosclerosis, and thus the optimal age for risk factor screening. In the present analyses based on 4 population-based, prospective childhood cohorts—the Cardiovascular Risk in Young Finns Study (Finland), the Childhood Determinants of Adult Health study (Australia), the Bogalusa Heart Study (United States), and the Muscatine Study (United States)—we examined the influence of age on the associations between childhood risk factors and adult carotid artery intima-media thickness, a subclinical marker of atherosclerosis, among 4380 participants 3 to 18 years old at baseline who were reexamined 13 to 28 years later. On the basis of our findings, risk factors measured before the age of 9 years had only weak or nonsignificant associations with carotid intima-media thickness measured more than 20 years later, whereas analysis among subjects 9 to 18 years of age showed significant associations between childhood risk exposure and increased adult intima-media thickness. Our data have direct clinical and public health importance because they suggest that risk factor screening from the age of 9 years onward allows youth who are at increased risk of subclinical atherosclerosis in adulthood to be identified. However, care providers need to keep in mind that although the optimal age for pediatric risk factor screening may commence at 9 years of age, primordial prevention of cardiovascular disease should begin earlier in the life course. See p 2514.
Lifetime Fruit and Vegetable Consumption and Arterial Pulse Wave Velocity in Adulthood : The Cardiovascular Risk in Young Finns Study
The primary prevention of cardiovascular diseases should be started in childhood because the atherosclerotic process develops silently for decades before clinical events such as myocardial infarction or stroke occur. Epidemiological studies have shown that it may be possible to modify cardiovascular disease risk by favorable lifestyle changes (eg, healthy diet, adequate physical activity, smoking restriction). However, a limited amount of information is available on childhood lifestyle risk factors and cardiovascular disease risk in adulthood. The Cardiovascular Risk in Young Finns Study is an ongoing 5-center follow-up study of atherosclerosis risk factors in Finnish children and adolescents. Participants were followed up since 1980 and had lifestyle risk factor data since childhood (3 to 18 years). Arterial pulse wave velocity was determined in young adulthood (aged 30 to 45 years) because it is a marker of arterial stiffness and an independent predictor of cardiovascular events and all-cause mortality. We showed that high fruit and vegetable consumption was associated with lower pulse wave velocity. The decrease in pulse wave velocity was more evident if the consumption of fruits and vegetables remained high from childhood to adulthood. It is also important to modify all lifestyle risk factors (low fruit consumption, low vegetable consumption, low physical activity, and smoking) in childhood because multiple risk factors led to increased arterial stiffness in this study. These findings highlight the importance of emphasizing lifestyle as early as in childhood in the primary prevention of cardiovascular disease. See p 2521.
Inhibition and Genetic Ablation of the B7/CD28 T-Cell Costimulation Axis Prevents Experimental Hypertension
Recent evidence indicates that inflammation, and in particular the adaptive immune response, contributes to hypertension. Hypertensive stimuli such as angiotensin II and mineralocorticoids promote T-cell activation and infiltration into vessels and the kidney. Prior studies have also shown that mice lacking T cells are resistant to hypertensive stimuli. In this study, additional evidence supporting a role of T cells in the genesis of hypertension is provided. Inhibition of T-cell costimulation with the agent CTLA4-Ig or by genetic deletion of the costimulatory molecules CD80 and CD86 markedly lowered the hypertensive response to angiotensin II or DOCA-salt challenge in mice. Moreover, treatment with CTLA4-Ig had blood pressure–lowering effects in experimental animals with established hypertension. These experiments support an immune mechanism for hypertension and point to new treatment strategies for difficult-to-treat cases of hypertension. In particular, CTLA4-Ig might prove beneficial in patients with malignant hypertension, which is often associated with end-organ damage that might be immune mediated. See p 2529.
Myocardial Steatosis and Biventricular Strain and Strain Rate Imaging in Patients With Type 2 Diabetes Mellitus
The underlying origin of diabetic heart disease is likely to be multifactorial, ranging from altered myocardial metabolism to endothelial dysfunction, microvascular disease, autonomic neuropathy, and altered myocardial structure with fibrosis. Increasing evidence is emerging on the role of lipotoxic myocardial injury from lipid oversupply. Using magnetic resonance imaging and proton magnetic resonance spectroscopy, the present study evaluated the association between myocardial triglyceride accumulation and altered biventricular myocardial function by 2-dimensional speckle tracking echocardiography in type 2 diabetic patients. Diabetic patients with high myocardial triglyceride content had significantly more impaired biventricular myocardial functions despite normal volumes and ejection fraction. On multivariate analyses, myocardial triglyceride content was an independent determinant of biventricular myocardial functions. Future studies assessing the effectiveness of antisteatotic therapy in type 2 diabetic patients may include quantifications of myocardial triglyceride content by spectroscopy and assessments of myocardial functions by strain/strain rate imaging on 2-dimensional speckle tracking echocardiography. See p 2538.
Economic Evaluation of Fractional Flow Reserve–Guided Percutaneous Coronary Intervention in Patients With Multivessel Disease
The Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) study demonstrated that performing percutaneous coronary intervention guided by fractional flow reserve measurement in patients with multivessel coronary artery disease leads to improved outcomes at 1 year compared with the traditional approach of using angiography alone to guide percutaneous coronary intervention. In this economic evaluation of the FAME study, we find that a fractional flow reserve–guided strategy not only improves outcomes but also saves money at 1 year. This finding provides further support for the routine measurement of fractional flow reserve in patients with multivessel coronary artery disease undergoing percutaneous coronary intervention. See p 2545.
Migraine and Functional Outcome From Ischemic Cerebral Events in Women
Migraine affects ≈20% of the female population, and up to one third of migraineurs experience transient neurological symptoms, primarily visual disturbances that are known as migraine aura. Previous research has linked migraine with aura with increased risk of ischemic stroke, particularly among women. However, little research has been done on whether the functional outcome from stroke, which can be more severe among women, is affected by migraine status. To explore this association, we used data from the Women's Health Study, a large prospective cohort study of women aged ≥45 years at baseline without a history of stroke, transient ischemic attack, or other major diseases. We found that women who report migraine with aura are at increased risk of transient ischemic attack (relative risk=1.56; 95% confidence interval, 1.03 to 2.36) and of ischemic stroke with good functional outcome, with modified Rankin Scale 0 to 1 (relative risk=2.33; 95% confidence interval, 1.37 to 3.97). However, women who report migraine with aura do not appear to have an increased risk of a more unfavorable functional outcome after ischemic stroke. Women with migraine without aura did not have increased risks for any outcome. Although our data confirm migraine with aura as a risk factor for ischemic cerebrovascular events, results suggest that the functional outcome of these events is good. See p 2551.
- © 2010 American Heart Association, Inc.
- Migraine and Functional Outcome From Ischemic Cerebral Events in Women
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