Akiko Kada

National Hospital Organization Nagoya Medical Center, Nagoya, Aichi, Japan

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Publications (33)122.73 Total impact

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    ABSTRACT: Background:The geographic distribution of cardiovascular (CV) health-care services has not been assessed systematically.Methods and Results:Data of the Japanese Circulation Society (JCS) annual survey were provided to the JCS working group with the permission of the JCS Scientific Committee. The status of CV practice in 2010 was then assessed in 47 prefectures retrospectively, along with national census and gross domestic product (GDP) data. The surveyed indices included resources (hospitals, beds and cardiologists), burden (number of inpatients), and outcome (CV mortality and autopsy) in each prefecture, which correlated well with respective populations or GDP. Inequality of geographic distribution was evident for pediatrics among the 47 prefectures, according to Lorenz curve, Gini coefficient or the maximum/minimum ratio for each index. According to the Gini coefficients, only the number of inpatients (medical or acute myocardial infarction) and beds for the total number of general hospitals or the hospitals surveyed in the present JCS study were lower than expected with regard to GDP.Conclusions:Geographic disparity of CV resources or burden was larger in pediatrics than in CV medicine or surgery. Improvement of equality in CV practice with regard to appropriateness and quality are the coming challenges for the JCS.
    Full-text · Article · Feb 2015
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    ABSTRACT: Aldosterone is one of the major factors to cause organ damage during an acute phase of heart failure (HF), and many reports have demonstrated that patients with acute decompensated HF (ADHF) have high blood aldosterone concentrations, and the high aldosterone concentrations predict poor prognosis in patients with HF. These findings suggest that eplerenone, an antagonist of aldosterone receptors may provide a new concept and strategy for the treatment of ADHF, protecting the heart and other organs during chronic phases, depending on the restoration of hemodynamic abnormalities. EARLIER is an event-driven clinical trial with an estimated enrolment of 300 patients hospitalized with ADHF with reduced left ventricular ejection fraction. ADHF includes ischemic or non-ischemic HF, and patients can be enrolled within 72 h after the visit to the hospital. We randomize the patients taking standard therapies for ADHF to the eplerenone and placebo groups. Eplerenone, either 25 or 50 mg, is administered for 6 months in the eplerenone group, and the corresponding placebo is administered in the placebo group on top of the standard care. We set the primary endpoint as the incidence of the composite endpoint (cardiac death or first re-hospitalization due to cardiac disease) 6 months after the enrollment, and also check the quality of life, i.e., exercise capacity and safety features of eplerenone. EARLIER is a clinical trial of eplerenone targeting ADHF and also the first multicenter investigator-initiated phase III trial in the cardiovascular field in Japan, funded by the Japanese government.
    No preview · Article · Jan 2015 · Cardiovascular Drugs and Therapy
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    ABSTRACT: To investigate patient background and current trends in the treatment of brain tumor patients, we analyzed a patient dataset using the Diagnosis Procedure Combination (DPC) database. The DPC data of all inpatients treated between April 2013 and March 2014 in the 327 core and branch hospitals enrolled in the Japan Neurosurgical Society training program were collected. Using ICD-10 code, we could extract 6,142 primary malignant brain tumor patients, 2,538 secondary malignant brain tumor patients, 2,043 pituitary tumor patients, 3,854 meningioma patients, and 5,666 other benign brain tumor patients from amongst a total of 501,609 patients. In this study, we focused on the primary and secondary malignant brain tumor patients. Using a K-code, we could extract 1,564 primary malignant brain tumor patients and 1,072 secondary malignant brain tumor patients who underwent surgery. Treatment modalities were analyzed for these patients. This study provides a general picture of the current trend of treatment for malignant brain tumors in Japan. But further study is needed to validate this patient dataset.
    Preview · Article · Jan 2015 · Japanese Journal of Neurosurgery
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    ABSTRACT: In recent years, the utilization of big data to visualize the real-world status of medical care has received greater attention. Since 2011, the authors have studied a nationwide cohort study named the J-ASPECT Study based on the Japanese Diagnosis Procedure Combination (DPC) and claim database. Here we first describe the overall profile of the joint project conducted by this study group and the Japan Neurosurgical Society as the special project of the 34th Annual Meeting of the Japanese Congress of Neurological Surgeons. Briefly, we built a large scale database of the patients who were admitted for the treatment of neurosurgical diseases, and other cerebrovascular disorders from hospitalization until discharge. Next, we focused on the current status of surgical and endovascular management for patients with subarachnoid hemorrhage, unruptured aneurysms, and carotid stenosis treated during the period of April 2012 to March 2013 in the hospitals participating in this study.
    Preview · Article · Jan 2015 · Japanese Journal of Neurosurgery
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    ABSTRACT: In clinical investigator initiated clinical trials, we frequently encounter the situation where it is very difficult to estimate the effect size and the clinically meaningful difference between the treatment and control groups. In this paper we explore various two-phase, three-stage adaptive designs which can be applied to this situation. The first phase determines whether the trial should proceed or not. If the decision is to proceed, then the sample size is re-estimated. The second phase consists of two stages, but the sample size is not re-estimated. We introduce hybrid and alpha-split designs, adding to two existing adaptive designs: Bauer-Köhne design and Lehmacher-Wassmer design. Main findings are: 1) the differences in the overall powers and the average sample number (ASN)s among these designs are small, except for the design which includes O’Brien-Fleming boundaries and the alpha-split design, 2) the two-phase, three-stage design suffers a relative loss of power by 15% but the ASN is less than 50%, as compared to the single stage design under the optimal condition, 3) two-phase, three-stage design compares with the three-stage group sequential design. We conclude that the design can be a candidate when there is no useful information on the effect size.
    Preview · Article · Jan 2015
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    ABSTRACT: Background Poor outcomes have been reported for stroke patients admitted outside of regular working hours. However, few studies have adjusted for case severity. In this nationwide assessment, we examined relationships between hospital admission time and disabilities at discharge while considering case severity. Methods and Results We analyzed 35 685 acute stroke patients admitted to 262 hospitals between April 2010 and May 2011 for ischemic stroke (IS), intracerebral hemorrhage (ICH), or subarachnoid hemorrhage (SAH). The proportion of disabilities/death at discharge as measured by the modified Rankin Scale (mRS) was quantified. We constructed 2 hierarchical logistic regression models to estimate the effect of admission time, one adjusted for age, sex, comorbidities, and number of beds; and the second adjusted for the effect of consciousness levels and the above variables at admission. The percentage of severe disabilities/death at discharge increased for patients admitted outside of regular hours (22.8%, 27.2%, and 28.2% for working‐hour, off‐hour, and nighttime; P<0.001). These tendencies were significant in the bivariate and multivariable models without adjusting for consciousness level. However, the effects of off‐hour or nighttime admissions were negated when adjusted for consciousness levels at admission (adjusted OR, 1.00 and 0.99; 95% CI, 1.00 to 1.13 and 0.89 to 1.10; P=0.067 and 0.851 for off‐hour and nighttime, respectively, versus working‐hour). The same trend was observed when each stroke subtype was stratified. Conclusions The well‐known off‐hour effect might be attributed to the severely ill patient population. Thus, sustained stroke care that is sufficient to treat severely ill patients during off‐hours is important.
    Full-text · Article · Oct 2014 · Journal of the American Heart Association
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    ABSTRACT: The effectiveness of comprehensive stroke center (CSC) capabilities on stroke mortality remains uncertain. We performed a nationwide study to examine whether CSC capabilities influenced in-hospital mortality of patients with ischemic and hemorrhagic stroke. Of the 1,369 certified training institutions in Japan, 749 hospitals responded to a questionnaire survey regarding CSC capabilities that queried the availability of personnel, diagnostic techniques, specific expertise, infrastructure, and educational components recommended for CSCs. Among the institutions that responded, data on patients hospitalized for stroke between April 1, 2010 and March 31, 2011 were obtained from the Japanese Diagnosis Procedure Combination database. In-hospital mortality was analyzed using hierarchical logistic regression analysis adjusted for age, sex, level of consciousness on admission, comorbidities, and the number of fulfilled CSC items in each component and in total. Data from 265 institutions and 53,170 emergency-hospitalized patients were analyzed. Mortality rates were 7.8% for patients with ischemic stroke, 16.8% for patients with intracerebral hemorrhage (ICH), and 28.1% for patients with subarachnoid hemorrhage (SAH). Mortality adjusted for age, sex, and level of consciousness was significantly correlated with personnel, infrastructural, educational, and total CSC scores in patients with ischemic stroke. Mortality was significantly correlated with diagnostic, educational, and total CSC scores in patients with ICH and with specific expertise, infrastructural, educational, and total CSC scores in patients with SAH. CSC capabilities were associated with reduced in-hospital mortality rates, and relevant aspects of care were found to be dependent on stroke type.
    Full-text · Article · May 2014 · PLoS ONE
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    ABSTRACT: Burnout is common among physicians and affects the quality of care. We aimed to determine the prevalence of burnout among Japanese physicians working in stroke care and evaluate personal and professional characteristics associated with burnout. A cross-sectional design was used to develop and distribute a survey to 11 211 physicians. Physician burnout was assessed using the Maslach Burnout Inventory General Survey. The predictors of burnout and the relationships among them were identified by multivariable logistic regression analysis. A total of 2724 (25.3%) physicians returned the surveys. After excluding those who were not working in stroke care or did not complete the survey appropriately, 2564 surveys were analyzed. Analysis of the participants' scores revealed that 41.1% were burned out. Multivariable analysis indicated that number of hours worked per week is positively associated with burnout. Hours slept per night, day-offs per week, years of experience, as well as income, are inversely associated with burnout. Short Form 36 mental health subscale was also inversely associated with burnout. The primary risk factors for burnout are heavy workload, short sleep duration, relatively little experience, and low mental quality of life. Prospective research is required to confirm these findings and develop programs for preventing burnout.
    Full-text · Article · May 2014 · Circulation Cardiovascular Quality and Outcomes
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    ABSTRACT: Aims Diabetes is a major risk factor for heart failure (HF). We examined whether baseline HbA1c level predicts HF incidence independent of other HF risk factors, including baseline cardiac structural and functional abnormalities. Methods In patients with type 2 diabetes, multivariable Cox regression models were constructed to examine the independent association between baseline HbA1c and future HF hospitalization. Results In 608 subjects (mean age, 66.5 years; men, 68%; mean HbA1c, 9.1% (76 mmol/mol)), 92 were hospitalized for HF during a median follow-up of 6 years. For a 1% (11 mmol/mol) increase in baseline HbA1c, the hazard ratio for HF was 1.23 (95% confidence interval, 1.1–1.7, p < 0.001) with adjustment for age, sex, body mass index, blood pressure and plasma B-type natriuretic peptide (BNP) level. The effect of HbA1c on HF was independent of baseline left ventricular (LV) ejection fraction, the ratio of peak early to late diastolic filling velocity, and prevalent/incident coronary heart disease (CHD), and was more evident in patients with enlarged LV, decreased systolic function, prevalent CHD, or prevalent HF. Conclusion In patients with type 2 diabetes, HbA1c significantly predicts future HF hospitalization independent of baseline BNP level or echocardiographic parameters.
    No preview · Article · May 2014 · Diabetes research and clinical practice
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    ABSTRACT: The association between comprehensive stroke care capacity and hospital volume of stroke interventions remains uncertain. We performed a nationwide survey in Japan to examine the impact of comprehensive stroke care capacity on the hospital volume of stroke interventions. A questionnaire on hospital characteristics, having tissue plasminogen activator (t-PA) protocols, and 25 items regarding personnel, diagnostic, specific expertise, infrastructure, and educational components recommended for comprehensive stroke centers (CSCs) was sent to 1369 professional training institutions. We examined the effect of hospital characteristics, having a t-PA protocol, and the number of fulfilled CSC items (total CSC score) on the hospital volume of t-PA infusion, removal of intracerebral hemorrhage, and coiling and clipping of intracranial aneurysms performed in 2009. Approximately 55% of hospitals responded to the survey. Facilities with t-PA protocols (85%) had a significantly higher likelihood of having 23 CSC items, for example, personnel (eg, neurosurgeons: 97.3% versus 66.1% and neurologists: 51.3% versus 27.7%), diagnostic (eg, digital cerebral angiography: 87.4% versus 43.2%), specific expertise (eg, clipping and coiling: 97.2% and 54% versus 58.9% and 14.3%, respectively), infrastructure (eg, intensive care unit: 63.9% versus 33.9%), and education (eg, professional education: 65.2% versus 20.7%). On multivariate analysis adjusted for hospital characteristics, total CSC score, but not having a t-PA protocol, was associated with the volume of all types of interventions with a clear increasing trend (P for trend < .001). We demonstrated a significant association between comprehensive stroke care capacity and the hospital volume of stroke interventions in Japan.
    Full-text · Article · Oct 2013 · Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association

  • No preview · Article · Oct 2013 · Journal of Cardiac Failure
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    ABSTRACT: The J-ASPECT Study, a nationwide Japanese study was conducted regarding the acute stroke care capacities of professional training institutions and the prevalence of burnout and quality of life amongst board-certified neurosurgeons and neurologists in Japan. We found that significant disparities existed in the fulfillment of the recommended items for comprehensive stroke centers, and a high prevalence of burnout among those professionals who worked for stroke care. The study group also analyzed the risk of in-hospital mortality for 53,170 acute stroke cases using nationwide administrative data based on the Diagnosis Procedure Combination (DPC) payment system. © 2013, Japanese Congress of Neurological Surgeons. All rights reserved.
    No preview · Article · Sep 2013 · Japanese Journal of Neurosurgery
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    ABSTRACT: Purpose: Atrial fibrillation (AF) is associated with an increased risk of mortality and stroke. However, few prospective studies have examined the association of smoking and drinking on AF in Western populations. No studies have examined the two combined effects on the risk of AF. We assessed the combined effect of smoking and drinking status on the risk of incident AF in a 12.6-year prospective study of an urban general population in Japan. Methods: A total of 6,798 participants (30 to 79 years old) in the Suita Study were initially free of AF and prospectively followed up for incident AF. Participants were diagnosed with AF if AF or atrial flutter was present on an electrocardiogram from a routine health check-up examination (every 2 years) or if AF was indicated as a present illness by questionnaires or by registration of cardiovascular disease events during follow-up. Smoking status was classified into 3 categories: nonsmokers and former and current smokers. Alcohol consumption was classified into 5 categories: nondrinkers and former and current drinkers, which were divided into further three categories: weekly alcohol consumption of 1 to 160 g/week (moderate drinkers; <1 gou/day in average, a Japanese unit), 161 to 321 g/week, and ≥322 g/week (excessive drinkers; ≥2 gous/day). Blood pressure (BP) categories were defined by the following criteria: optimal, normal, and high-normal BP, and hypertension. Cox proportional hazard ratios (HRs; 95% confidence intervals, CIs) were analyzed after adjusting for age, sex, BP categories, diabetes, hyperlipidemia, body mass index, (and smoking and drinking status) at baseline. Results: During 12.6 years of follow-up, 237 incident AF events occurred (4.05 and 1.68 per 1,000 person-years for men and women, respectively). Compared with nonsmokers, the adjusted HR (95% CIs) of incident AF for smokers was 1.46 (1.00 to 2.12). Adjusted hazard ratio for AF was 1.14 (1.02 to 1.28) per 10 cigarettes a day. Compared with nondrinkers, the adjusted HRs (95% CIs) of incident AF for moderate and excessive drinkers were 1.00 (0.70 to 1.41) and 1.63 (1.05 to 2.53), respectively. Compared with nonsmoker with non-excessive drinking, the adjusted HRs (95% CIs) of incident AF for smokers with non-excessive drinking and nonsmokers and smokers with excessive drinking were 1.42 (1.01 to 1.98), 1.97 (1.17 to 3.32), and 2.07 (1.27 to 3.37), respectively. Conclusions: Cigarette smoking and excessive drinking are important risk factors for incidence of AF. Lifestyle modifications for moderate drinking and smoking cessation are important for preventing AF in general population.
    Full-text · Article · Aug 2013 · European Heart Journal
  • Akiko Kada · Zhihong Cai · Manabu Kuroki
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    ABSTRACT: Evaluating the performance of a medical diagnostic test is an important issue in disease diagnosis. Youden [Index for rating diagnostic tests, Cancer 3 (1950), pp. 32–35] stated that the ideal measure of performance is to ensure that the control group resembles the diseased group as closely as possible in all respects except for the presence of the disease. To achieve this aim, this paper introduces the potential test result approach and proposes a new measure to evaluate the performance of medical diagnostic tests. This proposed measure, denoted as , can be interpreted as a probability that a test result T would respond to a disease status D (D∈{D 0, D 1}) for a given threshold T, and therefore evaluates both the sufficiency and necessity of the performance of a medical diagnostic test. This new measure provides a total different interpretation for the Youden index and thus helps us to better understand the essence of the Youden index and its properties. We further propose non-parametric bounds on the proposed measure based on a variety of assumptions and illustrate our results with an example from the neonatal audiology study.
    No preview · Article · Aug 2013 · Journal of Applied Statistics
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    ABSTRACT: Aim: It has been uncertain whether patients with acute heart failure syndromes (AHFSs) benefit from a lower heart rate (HR) itself or from treatment for heart failure (HF) that reduces sympathetic tone with consequent HR reduction (HRR). The present study investigated the influence of HRR during hospitalization on the prognosis of AHFS patients. Methods and results: In 421 AHFS patients, we analyzed the relationship between HRR during hospitalization and the prognosis after discharge. During a mean follow-up period of 1.9 years, 76 and 55 patients died or were re-hospitalized for HF, respectively. Although HR at discharge did not influence cardiac events (hazard ratio [HR]: 1.00 [95% CI; 0.99-1.02], p=0.22), the extent of HRR was a predictor of cardiac events (HR: 0.89 [0.84-0.96], p<0.001). Kaplan-Meier analysis revealed that the cardiac event rate of the HRR-positive group (≥ 27 bpm reduction of HR from 114 ± 24 at admission to 65 ± 11 bpm at discharge) was significantly lower than that of the HRR-negative group (≤ 26 bpm (=median value) reduction of HR from 74 ± 14 to 71 ± 14 bpm). In the HRR-positive group, the cardiac event rate was significantly lower in patients receiving beta-blockers. Furthermore, the extent of HR change was an important predictor of cardiac events among other markers, compared with the change in systolic blood pressure or B-type natriuretic peptide. Conclusion: The HR itself at discharge was not associated with the prognosis, but the extent of HRR achieved by treatment of HF with beta-blockers was a strong predictor for the clinical outcome in AHFS patients.
    No preview · Article · Nov 2012 · Journal of Cardiology
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    ABSTRACT: Introduction: No prospective studies have examined the association between blood pressure (BP) and atrial fibrillation (AFib) incidence in Asian general populations. We assessed the association between BP and incident AFib in a Japanese urban population. Methods: In total, 6,693 initially AFib-free participants (mean age 55.7 years at the baseline survey) in the Suita Study were prospectively followed for incident AFib. Participants were diagnosed with AFib if either AFib or atrial flutter was present on an electrocardiogram or if present illness or medical records indicated AFib. Health check-up examinations were conducted every 2 years. BP categories were defined by the ESH/ESC 2007 criteria. BPs were taken as the average of the second and third measurements by sphygmomanometers. Cox proportional hazard model for incident AFib were fit for BP categories and estimated hazard ratios (HRs) and 95% confidence intervals (CIs). Results: During 12.3 years of mean follow-up, 207 incident atrial fibrillation events occurred (3.73 and 1.60 per 1,000 person-years for men and women, respectively). Compared with systolic BP (SBP) <120 mmHg, diastolic BP (DBP) <80 mmHg, and optimal BP subjects, the adjusted HRs (95% CIs) for incident AFib were 1.70 (1.15-2.53) in SBP >140 mmHg, 1.36 (0.98-1.90) in DBP >90 mmHg, and 1.51 (1.02-2.24) in hypertension (SBP>140 mmHg, DBP>90 mmHg, and/or antihypertensive drug users), respectively. The adjusted HRs (95% CIs) for AFib were 1.24 (1.11-1.42) with 20 mm Hg increases in SBP and 1.10 (0.98-1.24) with 10 mm Hg increases in DBP. Conclusion: Systolic hypertensions were identified as important risk factors for incident AFib in Asia.
    No preview · Article · Sep 2012 · Journal of Hypertension

  • No preview · Conference Paper · Nov 2011
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    ABSTRACT: Acute ischaemic stroke patients sometimes receive heparin for treatment and/or prophylaxis of thromboembolic complications. This study was designed to elucidate the incidence and clinical features of heparin-induced thrombocytopenia (HIT) in acute stroke patients treated with heparin. We conducted a prospective multicentre cohort study of 267 patients who were admitted to three stroke centres within 7 d after stroke onset. We examined clinical data until discharge and collected blood samples on days 1 and 14 of hospitalization to test anti-platelet factor 4/heparin antibodies (anti-PF4/H Abs) using an enzyme-linked immunosorbent assay (ELISA); platelet-activating antibodies were identified by serotonin-release assay (SRA). Patients with a 4Ts score ≥4 points, positive-ELISA, and positive-SRA were diagnosed as definite HIT. Heparin was administered to 172 patients (64·4%: heparin group). Anti-PF4/H Abs were detected by ELISA in 22 cases (12·8%) in the heparin group. Seven patients had 4Ts ≥ 4 points. Among them, three patients (1·7% overall) were also positive by both ELISA and SRA. National Institutes of Health Stroke Scale score on admission was high (range, 16-23) and in-hospital mortality was very high (66·7%) in definite HIT patients. In this study, the incidence of definite HIT in acute ischaemic stroke patients treated with heparin was 1·7% (95% confidence interval: 0·4-5·0). The clinical severity and outcome of definite HIT were unfavourable.
    Full-text · Article · Jun 2011 · British Journal of Haematology
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    ABSTRACT: Amiodarone (AMD), used to treat arrhythmia has an iodine content of 37%, therefore, it is believed that this drug may have adverse effects when administered in the early stages of thyroid gland development. Further, amiodarone-induced hypothyroidism (AIH) is frequently caused by chronic thyroiditis. In this study, we sought to elucidate the frequency of AIH and clarify the relation among sex, the age, the blood levels of AMD, the results of thyroid function tests, and the onset of AIH. Further, we determined the time and dosage at which levothyroxine sodium hydrate (LTN) therapy was initiated in patients with AIH. We investigated 372 cases, and LTN therapy was administered concurrently with other agents in 94 cases. The results revealed that AIH occurred frequently in young women. The results also showed that the onset of AIH was not influenced by the blood levels of amiodarone. In a number of cases, AIH was seen in cases in which the thyroid stimulating hormone (TSH) levels were high before AMD was administered. In patients with AIH, LTN was administered at a mean dose of 25 μ g for an average of 12-36 months. However, LTN seemed to be effective in normalizing the levels of TSH when administered at a dose of 50-100 μ g. Therefore, it was thought that it was desirable to observe a thyroid gland function carefully in cases where the TSH level was high before the initiation of AMD therapy.
    No preview · Article · May 2011
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    Preview · Article · Apr 2011 · Journal of the American College of Cardiology