Heart disease and stroke statistics--2012 update: a report from the American Heart Association

Nitrite and nitric oxide metabolism in peripheral artery disease

Peripheral artery disease (PAD) represents a burgeoning form of cardiovascular disease associated with significant clinical morbidity and increased 5 year cardiovascular disease mortality. It is characterized by impaired blood flow to the lower extremities, claudication pain and severe exercise intolerance. Pathophysiological factors contributing to PAD include atherosclerosis, endothelial cell dysfunction, and defective nitric oxide metabolite physiology and biochemistry that collectively lead to intermittent or chronic tissue ischemia. Recent work from our laboratories is revealing that nitrite/nitrate anion and nitric oxide metabolism plays an important role in modulating functional and pathophysiological responses during this disease. In this review, we discuss experimental and clinical findings demonstrating that nitrite anion acts to ameliorate numerous pathophysiological events associated with PAD and chronic tissue ischemia. We also highlight future directions for this promising line of therapy.

Gene therapy for ventricular tachyarrhythmias

Cardiac arrest is the leading cause of death in the United States and other developed countries. Ventricular tachyarrhythmias are the most prominent cause of cardiac arrest, and patients with structural heart disease are at increased risk for these abnormal heart rhythms. Drug and device therapies have important limitations that make them inadequate to meet this challenge. We and others have proposed development of arrhythmia gene therapy as an alternative to current treatment methods. In this review, I discuss the basic mechanisms of ventricular arrhythmias and summarize the literature on the use of gene therapy for ventricular tachyarrhythmias.

Myocardial ischemia, reperfusion, and infarction in chronically instrumented, intact, conscious, and unrestrained mice

In the United States alone, the National Heart, Lung, and Blood Institute (NHLBI) has invested several hundred million dollars in pursuit of myocardial infarct-sparing therapies. However, due largely to methodological limitations, this investment has not produced any notable clinical application or cardioprotective therapy. Among the major methodological limitations is the reliance on animal models that do not mimic the clinical situation. In this context, the limited use of conscious animal models is of major concern. In fact, whenever possible, studies of cardiovascular physiology and pathophysiology should be conducted in conscious, complex models to avoid the complications associated with the use of anesthesia and surgical trauma. The mouse has significant advantages over other experimental models for the investigation of infarct-sparing therapies. The mouse is inexpensive, has a high throughput, and presents the ability of one to create genetically modified models. However, successful infarct-sparing therapies in anesthetized mice or isolated mouse hearts may not be successful in more complex models, including conscious mice. Accordingly, a conscious mouse model of myocardial ischemia and reperfusion has the potential to be of major importance for advancing the concepts and methods that drive the development of infarct-sparing therapies. Therefore, we describe, for the first time, the use of an intact, conscious, and unrestrained mouse model of myocardial ischemia-reperfusion and infarction. The conscious mouse model permits occlusion and reperfusion of the left anterior descending coronary artery in an intact, complex model free of the confounding influences of anesthetics and surgical trauma. This methodology may be adopted for advancing the concepts and ideas that drive cardiovascular research.

Periodontal disease and atherosclerotic vascular disease: does the evidence support an independent association?: a scientific statement from the American Heart Association

A link between oral health and cardiovascular disease has been proposed for more than a century. Recently, concern about possible links between periodontal disease (PD) and atherosclerotic vascular disease (ASVD) has intensified and is driving an active field of investigation into possible association and causality. The 2 disorders share several common risk factors, including cigarette smoking, age, and diabetes mellitus. Patients and providers are increasingly presented with claims that PD treatment strategies offer ASVD protection; these claims are often endorsed by professional and industrial stakeholders. The focus of this review is to assess whether available data support an independent association between ASVD and PD and whether PD treatment might modify ASVD risks or outcomes. It also presents mechanistic details of both PD and ASVD relevant to this topic. The correlation of PD with ASVD outcomes and surrogate markers is discussed, as well as the correlation of response to PD therapy with ASVD event rates. Methodological issues that complicate studies of this association are outlined, with an emphasis on the terms and metrics that would be applicable in future studies. Observational studies to date support an association between PD and ASVD independent of known confounders. They do not, however, support a causative relationship. Although periodontal interventions result in a reduction in systemic inflammation and endothelial dysfunction in short-term studies, there is no evidence that they prevent ASVD or modify its outcomes.

Magnitude and management of hypercholesterolemia in the adult population of Spain, 2008-2010: The ENRICA Study

INTRODUCTION AND OBJECTIVES

Only a few studies have reported nationwide population-based data on the magnitude and control of hypercholesterolemia. This work examines the prevalence and management of hypercholesterolemia in Spain.

METHODS

Cross-sectional study conducted from June 2008 to October 2010 on 11,554 individuals representative of the population aged ≥ 18 years in Spain. Study participants provided 12-h fasting blood samples, which were analyzed in a central laboratory with standardized methods.

RESULTS

In the whole population, 50.5% had hypercholesterolemia (total cholesterol ≥ 200 mg/dL or drug treatment) and 44.9% high levels of low-density lipoprotein cholesterol (≥ 130 mg/dL or drug treatment), with no substantial sex-related differences. Moreover, 25.5% of men showed high-density lipoprotein cholesterol < 40 mg/dL and 26.4% of women high-density lipoprotein cholesterol <50mg/dL. Also, 23.2% of men and 11.7% of women had triglycerides ≥ 150 mg/dL. Frequency of dyslipidemia increased up to 65 years, except for low high-density lipoprotein cholesterol which did not vary with age. Among those with high low-density lipoprotein cholesterol, 53.6% knew of it and 44.1% of them received lipid-lowering treatment; among the latter, 55.7% had a controlled level (13.2% of all hypercholesterolemics). Control of high low-density lipoprotein cholesterol increased with age and with the number of visits to the specialist physician, but was lower among diabetics (odds ratio=0.38; 95% confidence interval, 0.28-0.53) and patients with cardiovascular disease (odds ratio=0.55; 95% confidence interval, 0.33-0.92).

CONCLUSIONS

About half of the Spanish population has elevated serum cholesterol; moreover, cholesterol control is poor, particularly among those with highest cardiovascular risk, such as diabetics or patients with cardiovascular disease.

Animal models of organic heart valve disease

Heart valve disease is a frequently encountered pathology, related to high morbidity and mortality rates in industrialized and developing countries. Animal models are interesting to investigate the causality, but also underlying mechanisms and potential treatments of human valvular diseases. Recently, animal models of heart valve disease have been developed, which allow to investigate the pathophysiology, and to follow the progression and the potential regression of disease with therapeutics over time. The present review provides an overview of animal models of primary, organic heart valve disease: myxoid age-related, infectious, drug-induced, degenerative calcified, and mechanically induced valvular heart disease.

Future Perspectives on Percutaneous Coronary Interventions in Women

In the United States alone, more than 1 million cardiac catheterizations are performed each year, with approximately 600,000 patients undergoing percutaneous coronary intervention (PCI). A meaningful perspective on the future of PCI in women requires not only reflection on some of the major developments in interventional cardiology but also a look back more generally at the changing patterns in the burden of coronary disease in the population and at the gains accrued in understanding and combating cardiovascular disease in women.

A novel stroke therapy of pharmacologically induced hypothermia after focal cerebral ischemia in mice

Compelling evidence from preclinical and clinical studies has shown that mild to moderate hypothermia is neuroprotective against ischemic stroke. Clinical applications of hypothermia therapy, however, have been hindered by current methods of physical cooling, which is generally inefficient and impractical in clinical situations. In this report, we demonstrate the potential of pharmacologically induced hypothermia (PIH) by the novel neurotensin receptor 1 (NTR1) agonist ABS-201 in a focal ischemic model of adult mice. ABS-201 (1.5-2.5 mg/kg, i.p.) reduces body and brain temperature by 2-5°C in 15-30 min in a dose-dependent manner without causing shivering or altering physiological parameters. Infarct volumes at 24 h after stroke are reduced by ∼30-40% when PIH therapy is initiated either immediately after stroke induction or after 30-60 min delay. ABS-201 treatment increases bcl-2 expression, decreases caspase-3 activation, and TUNEL-positive cells in the peri-infarct region, and suppresses autophagic cell death compared to stroke controls. The PIH therapy using ABS-201 improves recovery of sensorimotor function as tested 21 d after stroke. These results suggest that PIH induced by neurotensin analogs represented by ABS-201 are promising candidates for treatment of ischemic stroke and possibly for other ischemic or traumatic injuries.

Trends in cardiovascular health metrics and associations with all-cause and CVD mortality among US adults

CONTEXT

Recent recommendations from the American Heart Association aim to improve cardiovascular health by encouraging the general population to meet 7 cardiovascular health metrics: not smoking; being physically active; having normal blood pressure, blood glucose and total cholesterol levels, and weight; and eating a healthy diet.

OBJECTIVE

To examine time trends in cardiovascular health metrics and to estimate joint associations and population-attributable fractions of these metrics in relation to all-cause and cardiovascular disease (CVD) mortality risk.

DESIGN, SETTING, AND PARTICIPANTS

Study of a nationally representative sample of 44,959 US adults (≥20 years), using data from the National Health and Nutrition Examination Survey (NHANES) 1988-1994, 1999-2004, and 2005-2010 and the NHANES III Linked Mortality File (through 2006).

MAIN OUTCOME MEASURES

All-cause, CVD, and ischemic heart disease (IHD) mortality.

RESULTS

Few participants met all 7 cardiovascular health metrics (2.0% [95% CI, 1.5%-2.5%] in 1988-1994, 1.2% [95% CI, 0.8%-1.9%] in 2005-2010). Among NHANES III participants, 2673 all-cause, 1085 CVD, and 576 IHD deaths occurred (median follow-up, 14.5 years). Among participants who met 1 or fewer cardiovascular health metrics, age- and sex-standardized absolute risks were 14.8 (95% CI, 13.2-16.5) deaths per 1000 person-years for all-cause mortality, 6.5 (95% CI, 5.5-7.6) for CVD mortality, and 3.7 (95% CI, 2.8-4.5) for IHD mortality. Among those who met 6 or more metrics, corresponding risks were 5.4 (95% CI, 3.6-7.3) for all-cause mortality, 1.5 (95% CI, 0.5-2.5) for CVD mortality, and 1.1 (95% CI, 0.7-2.0) for IHD mortality. Adjusted hazard ratios were 0.49 (95% CI, 0.33-0.74) for all-cause mortality, 0.24 (95% CI, 0.13-0.47) for CVD mortality, and 0.30 (95% CI, 0.13-0.68) for IHD mortality, comparing participants who met 6 or more vs 1 or fewer cardiovascular health metrics. Adjusted population-attributable fractions were 59% (95% CI, 33%-76%) for all-cause mortality, 64% (95% CI, 28%-84%) for CVD mortality, and 63% (95% CI, 5%-89%) for IHD mortality.

CONCLUSION

Meeting a greater number of cardiovascular health metrics was associated with a lower risk of total and CVD mortality, but the prevalence of meeting all 7 cardiovascular health metrics was low in the study population.

Multiple biomarkers and risk of clinical and subclinical vascular brain injury: the Framingham Offspring Study

BACKGROUND

Several biomarkers have been individually associated with vascular brain injury, but no prior study has explored the simultaneous association of a biologically plausible panel of biomarkers with the incidence of stroke/transient ischemic attack and the prevalence of subclinical brain injury.

METHODS AND RESULTS

In 3127 stroke-free Framingham offspring (age, 59±10 years; 54% female), we related a panel of 8 biomarkers assessing inflammation (C-reactive protein), hemostasis (D-dimer and plasminogen activator inhibitor-1), neurohormonal activity (aldosterone-to-renin ratio, B-type natriuretic peptide, and N-terminal proatrial natriuretic peptides), and endothelial function (homocysteine and urinary albumin/creatinine ratio) measured at the sixth examination (1995-1998) to risk of incident stroke/transient ischemic attack. In a subset of 1901 participants with available brain magnetic resonance imaging (1999-2005), we further related these biomarkers to total cerebral brain volume, covert brain infarcts, and large white-matter hyperintensity volume. During a median follow-up of 9.2 years, 130 participants experienced incident stroke/transient ischemic attack. In multivariable analyses adjusted for stroke risk factors, the biomarker panel was associated with incident stroke/transient ischemic attack and with total cerebral brain volume (P<0.05 for both) but not with covert brain infarcts or white-matter hyperintensity volume (P>0.05). In backward elimination analyses, higher log-B-type natriuretic peptide (hazard ratio, 1.39 per 1-SD increment; P=0.002) and log-urinary albumin/creatinine ratio (hazard ratio, 1.31 per 1-SD increment; P=0.004) were associated with increased risk of stroke/transient ischemic attack and improved risk prediction compared with the Framingham Stroke Risk Profile alone; when the <5%, 5% to 15%, or >15% 10-year risk category was used, the net reclassification index was 0.109 (P=0.037). Higher C-reactive protein (β=-0.21 per 1-SD increment; P=0.008), D-dimer (β=-0.18 per 1-SD increment; P=0.041), total homocysteine (β=-0.21 per 1-SD increment; P=0.005), and urinary albumin/creatinine ratio (β=-0.15 per 1-SD increment; P=0.042) were associated with lower total cerebral brain volume.

CONCLUSION

In a middle-aged community sample, we identified multiple biomarkers that were associated with clinical and subclinical vascular brain injury and could improve risk stratification.

The role of neuregulin/ErbB2/ErbB4 signaling in the heart with special focus on effects on cardiomyocyte proliferation

The signaling complex consisting of the growth factor neuregulin-1 (NRG1) and its tyrosine kinase receptors ErbB2 and ErbB4 has a critical role in cardiac development and homeostasis of the structure and function of the adult heart. Recent research results suggest that targeting this signaling complex may provide a viable strategy for treating heart failure. Clinical trials are currently evaluating the effectiveness and safety of intravenous administration of recombinant NRG1 formulations in heart failure patients. Endogenous as well as administered NRG1 has multiple possible activities in the adult heart, but how these are related is unknown. It has recently been demonstrated that NRG1 administration can stimulate proliferation of cardiomyocytes, which may contribute to repair failing hearts. This review summarizes the current knowledge of how NRG1 and its receptors control cardiac physiology and biology, with special emphasis on its role in cardiomyocyte proliferation during myocardial growth and regeneration.

Management of hypertension in the elderly

Hypertension is the most-prevalent modifiable risk factor for cardiovascular morbidity and mortality worldwide. Hypertension is highly prevalent among older adults (≥65 years), and aging of the population will substantially increase the prevalence of this condition. Age-related endothelial dysfunction and increased arterial stiffness contribute to the increased prevalence of hypertension, particularly systolic hypertension, among the elderly. The incidence of some forms of secondary hypertension also increases with age, mainly owing to the use of drugs (especially NSAIDs that have pressor effects) and the presence of chronic kidney disease, obstructive sleep apnea, and renal artery stenosis. Guidelines differ in thresholds and goals for antihypertensive drug therapy in the elderly because of a paucity of high-level evidence from randomized controlled trials and inconsistencies in the definition of 'elderly'. Medical treatment of hypertension reduces cardiovascular morbidity and mortality in the elderly, and all guidelines recommend lifestyle modifications and medical treatment for elderly patients whose blood pressure exceeds prescribed thresholds and who are at moderate or high cardiovascular disease risk. In the absence of comorbidities, which constitute 'compelling indications' for the use of specific antihypertensive drugs or drug classes, no clear evidence exists to support recommendations for the use of particular antihypertensive-drug classes in older adults.

Nutrition in the primary and secondary prevention of stroke

Stroke is a worldwide major health issue. As some of the risk factors are modifiable, it is of high importance to understand how we can minimize the risk for stroke. Multifactorial interventions should be provided to patients in the frame of primary and secondary prevention. Obesity is a well-established modifiable factor as well as the dietary pattern that mostly depends on the social environment, the lifestyle and the habits of each individual. So, dietary changes should be part of the holistic approach which includes improvements in the regulation of hypertension, hyperlipidaemia and hyperglycaemia. In the present review, we try to provide a global approach on how diet can influence the risk of stroke and especially the nutritional influence on lipid profile and vessel disease and the role of dietary modification in the secondary stroke prevention. The importance of salt restriction, DASH and Mediterranean diet low in saturated and high in polyunsaturated fats, and the management of obesity seem to be the most important dietary priorities.

Relationship of national institutes of health stroke scale to 30-day mortality in medicare beneficiaries with acute ischemic stroke

Background

The National Institutes of Health Stroke Scale (NIHSS), a well-validated tool for assessing initial stroke severity, has previously been shown to be associated with mortality in acute ischemic stroke. However, the relationship, optimal categorization, and risk discrimination with the NIHSS for predicting 30-day mortality among Medicare beneficiaries with acute ischemic stroke has not been well studied.

Methods and Results

We analyzed data from 33102 fee-for-service Medicare beneficiaries treated at 404 Get With The Guidelines-Stroke hospitals between April 2003 and December 2006 with NIHSS documented. The 30-day mortality rate by NIHSS as a continuous variable and by risk-tree determined or prespecified categories were analyzed, with discrimination of risk quantified by the c-statistic. In this cohort, mean age was 79.0 years and 58% were female. The median NIHSS score was 5 (25th to 75th percentile 2 to 12). There were 4496 deaths in the first 30 days (13.6%). There was a strong graded relation between increasing NIHSS score and higher 30-day mortality. The 30-day mortality rates for acute ischemic stroke by NIHSS categories were as follows: 0 to 7, 4.2%; 8 to 13, 13.9%; 14 to 21, 31.6%; 22 to 42, 53.5%. A model with NIHSS alone provided excellent discrimination whether included as a continuous variable (c-statistic 0.82 [0.81 to 0.83]), 4 categories (c-statistic 0.80 [0.79 to 0.80]), or 3 categories (c-statistic 0.79 [0.78 to 0.79]).

Conclusions

The NIHSS provides substantial prognostic information regarding 30-day mortality risk in Medicare beneficiaries with acute ischemic stroke. This index of stroke severity is a very strong discriminator of mortality risk, even in the absence of other clinical information, whether used as a continuous or categorical risk determinant. (J Am Heart Assoc. 2012;1:42-50.)

Multimodal MRI of nonhuman primate stroke

Stroke is the fourth leading cause of death. Despite decades of research, no neuroprotective drug has proven to be effective clinically. One widely accepted view to account for this negative outcome is that the rodent stroke model simply does not adequately reflect the complexity of human stroke. Recent failures of several high-profile neuroprotective drugs for stroke treatment in phase III clinical trials further underscore the importance of developing adequate animal models for stroke research. The brain organization and vascular circuitry of nonhuman primates (NHPs) are more homologous with humans than the widely used rodent for stroke modeling. The Stroke Therapy Academic Industry Roundtable, a national committee commissioned by the American Heart Association, recommended that clinically relevant NHP stroke models be established for developing and assessing neuroprotective drugs. The aim of this article is to review the challenges and applications of magnetic resonance imaging studies of NHP stroke models.

Comparison of nutritional intake in US adolescent swimmers and non-athletes

Swimming is a very popular sport among adolescents in the US. Little is known about the diet of competitive adolescent swimmers in the US but data from other countries indicate several inadequacies, including excessive intake of fat and lower than recommended intake of carbohydrate and several micronutrients that may affect athletic performance and bone accrual. We assessed usual diet, using a food frequency questionnaire and calcium checklist, among 191 adolescent males and females [91 swimmers (mean 13.7, s = 2.5 years) and 100 non-athletes (mean 14.4, s = 2.8 years)]. For both males and females, swimmers and non-athletes generally had similar average intakes of macro- and micro-nutrients, including higher than recommended amounts of total fat (36%) and saturated fat (12%), and inadequate amounts of calcium, vitamin D, and daily servings of fruits, vegetables, grains, and dairy products. This first study of nutritional intake among adolescent swimmers in the US suggests that dietary habits of adolescents who swim competitively may jeopardize optimal athletic performance and place them at risk for future chronic diseases, including osteoporosis.

Scientific Rigor Recommendations for Optimizing the Clinical Applicability of Translational Research

The approval of new therapies to treat neurodegenerative disease conditions by the Food and Drug administration (FDA) has been hindered by many failed clinical trials, which were based upon "significant" efficacy in preclinical or translational studies. Additional problems during drug development related to significant adverse events and unforeseen toxicity have also hampered drug development. Recent reviews of preclinical data suggests that many studies have over-estimated efficacy due to poor or inadequate study design, exclusion of important data (negative or neutral) and lack of study randomization and blinding. This article describes in detail a set of recommendations to improve the quality of science being conducted in laboratories worldwide, with the goal of documenting in the peer-reviewed literature, including Journal of Neurology and Neurophysiology, the scientific basis for the continued development of specific strategies to treat neurodegenerative diseases such as Stroke, Alzheimer's disease, Huntington's disease, Parkinson's disease, Spinal cord injury, and Amyotrophic lateral sclerosis. The minimum recommendations for effective translational research include the need for model justification, study group randomization and blinding, power analysis calculations, appropriate statistical analysis of all data sets, and a conflict of interest statement by investigators. It will also be beneficial to demonstrate reproducible efficacy in multiple species and in studies done by independent laboratories.

Variations in neuromuscular electrical stimulation's ability to increase reach and hand opening during voluntary effort after stroke

Functional Electrical Stimulation (FES) has shown potential as a mechanism to augment functional arm and hand movement after stroke. However, neuroprostheses that combine voluntary effort and FES must account for co-activation patterns (synergies) that limit movement. The goal of this study is to explore the conditions under which voluntary effort and FES can be combined to achieve useful reach and hand opening in different subjects. Subjects performed a reach and hand opening task where different levels of voluntary effort and FES were applied to produce reach and hand opening while measuring the resulting hand opening and distance from a target. Initial results indicate that there are significant variations between participants and how much effort can be exerted while still eliciting effective reach and hand opening.

Three in one: safety, efficacy, and patient acceptability of triple fixed-dose combination medicine in the management of hypertension

Hypertensive patients whose blood pressures are more than 20 mmHg above their goal will often require three or more medications. Careful selection of medications whose actions are complementary or have an improved adverse effect profile when combined can affect not only the blood pressure but also patient acceptance, thus improving persistence in taking the medications as prescribed. This review will highlight the three single-pill three-drug combinations currently available in the US and will address their efficacy, safety, and tolerability. All three include the dihydropyridine calcium-channel blocker, amlodipine, and the thiazide diuretic, hydrochlorothiazide. They each contain a different renin-angiotensin system blocker. One includes the angiotensin-receptor blocker, olmesartan, while another contains valsartan. The third combination includes the direct renin inhibitor, aliskiren. All three fixed-dose combinations (FDC) at maximum doses of each component lowers the blood pressure of patients with stage II hypertension by 37 to 40 mmHg systolic and 21 to 25 mmHg diastolic, which is superior to any two of the components that comprise the three-drug FDC. These drugs are effective in males and females, the elderly, diabetics, minority populations, and patients with metabolic syndrome. Triple-drug FDCs are well tolerated with a low incidence of adverse effects, the most common being peripheral edema related to amlodipine. Extrapolation of data from two-drug FDC suggests that medication compliance (adherence and persistence) should be better with these FDCs than with the individual components taken as separate medications, although additional studies are necessary to confirm this.

Transcranial direct current stimulation and behavioral models of smoking addiction

While few studies have applied transcranial direct current stimulation (tDCS) to smoking addiction, existing work suggests that the intervention holds promise for altering the complex system by which environmental cues interact with cravings to drive behavior. Imaging and repetitive transcranial magnetic stimulation studies suggest that increased dorsolateral prefrontal cortex (DLPFC) activation and integrity may be associated with increased resistance to smoking cues. Anodal tDCS of the DLPFC, believed to boost activation, reduces cravings in response to these cues. The finding that noninvasive stimulation modifies cue induced cravings has profound implications for understanding the processes underlying addiction and relapse. tDCS can also be applied to probe mechanisms underlying and supporting nicotine addiction, as was done in a pharmacologic study that applied nicotine, tDCS, and TMS paired associative stimulation to find that stopping nicotine after chronic use induces a reduction in plasticity, causing difficulty in breaking free from association between cues and cravings. This mini-review will place studies that apply tDCS to smokers in the context of research involving the neural substrates of nicotine addiction.