1,373 research outputs found

    Flow resistance of perforated plates in tangential flow

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    Changes in acoustic properties of perforated plates resulting from interaction of flows normal and tangential to plate surfac

    Expert review on coronary calcium

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    While there is no doubt that high risk patients (those with >20% ten year risk of future cardiovascular event) need more aggressive preventive therapy, a majority of cardiovascular events occur in individuals at intermediate risk (10%ā€“20% ten year risk). Accurate risk assessment may be helpful in decreasing cardiovascular events through more appropriate targeting of preventive measures. It has been suggested that traditional risk assessment may be refined with the selective use of coronary artery calcium (CAC) or other methods of subclinical atherosclerosis measurement. Coronary calcification is a marker of atherosclerosis that can be quantified with the use of cardiac CT and it is proportional to the extent and severity of atherosclerotic disease. The published studies demonstrate a high sensitivity of CAC for the presence of coronary artery disease but a lower specificity for obstructive CAD depending on the magnitude of the CAC. Several large clinical trials found clear, incremental predictive value of CAC over the Framingham risk score when used in asymptomatic patients. Based on multiple observational studies, patients with increased plaque burdens (increased CAC) are approximately ten times more likely to suffer a cardiac event over the next 3ā€“5 years. Coronary calcium scores have outperformed conventional risk factors, highly sensitive C-reactive protein (CRP) and carotid intima media thickness (IMT) as a predictor of cardiovascular events. The relevant prognostic information obtained may be useful to initiate or intensify appropriate treatment strategies to slow the progression of atherosclerotic vascular disease. Current data suggests intermediate risk patients may benefit most from further risk stratification with cardiac CT, as CAC testing is effective at identifying increased risk and in motivating effective behavioral changes. This article reviews information pertaining to the clinical use of CAC for assessing coronary atherosclerosis as a useful predictor of coronary artery disease (CAD) in certain population of patients

    800-5 Improving Accuracy of Ultrafast Computed Tomography in the Detection of Angiographically Significant Coronary Artery Disease

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    In differentiating coronary calcium from artifact by ultrafast computed tomography (UFCT), many different thresholds have been proposed. UFCT has demonstrated a high sensitivity and only modest specificity to detect coronary calcifications when compared to angiography. The Agatston method is most widely used today, utilizing a minimum CT number of 130 Hounsfield units (HU). In an attempt to improve specificity without markedly reducing sensitivity, we evaluated 272 coronary vessels from 68 patients with angiography and UFCT coronary scanning. All patients underwent coronary angiography for clinical indications, and had UFCT scanning done within three months of the angiogram. A blinded reader evaluated all the UFCT scans. We then varied the minimum CT number to assess whether 130 HU was truly the best threshold. Sensitivity, specificity and accuracy for different thresholds are listed.Threshold130 HU150 HU170 HU200 HUSensitivity95%92%89%87%Specificity65%72%75%78%Accuracy72%77%78%79%The results above indicate that 130 HU is too low a threshold to maximize accuracy of this test when compared with angiography. Sensitivity is reduced as the threshold is improved, however this result is not significant (p=0.61). The improved specificity from 130 to 150 represents a significant improvement (p<0.0001), although a larger study must be performed before widespread use of this new threshold is employed

    Association Between Chronic Hepatitis C Virus Infection and Myocardial Infarction Among People Living With HIV in the United States.

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    Hepatitis C virus (HCV) infection is common among people living with human immunodeficiency virus (PLWH). Extrahepatic manifestations of HCV, including myocardial infarction (MI), are a topic of active research. MI is classified into types, predominantly atheroembolic type 1 MI (T1MI) and supply-demand mismatch type 2 MI (T2MI). We examined the association between HCV and MI among patients in the Centers for AIDS Research (CFAR) Network of Integrated Clinical Systems, a US multicenter clinical cohort of PLWH. MIs were centrally adjudicated and categorized by type using the Third Universal Definition of Myocardial Infarction. We estimated the association between chronic HCV (RNA+) and time to MI while adjusting for demographic characteristics, cardiovascular risk factors, clinical characteristics, and history of injecting drug use. Among 23,407 PLWH aged ā‰„18 years, there were 336 T1MIs and 330 T2MIs during a median of 4.7 years of follow-up between 1998 and 2016. HCV was associated with a 46% greater risk of T2MI (adjusted hazard ratio (aHR) = 1.46, 95% confidence interval (CI): 1.09, 1.97) but not T1MI (aHR = 0.87, 95% CI: 0.58, 1.29). In an exploratory cause-specific analysis of T2MI, HCV was associated with a 2-fold greater risk of T2MI attributed to sepsis (aHR = 2.01, 95% CI: 1.25, 3.24). Extrahepatic manifestations of HCV in this high-risk population are an important area for continued research

    Insomnia as an Independent Predictor of Incident Cardiovascular Disease in HIV: Data from the Veterans Aging Cohort Study

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    Background: Insomnia is associated with increased cardiovascular disease (CVD) risk in the general population and is highly prevalent in people with HIV. The CVD risk conferred by insomnia in the HIV population is unknown. Methods: Using the Veterans Aging Cohort Study-Survey Cohort, insomnia symptoms were measured and dummy coded with the item, ā€œDifficulty falling or staying asleep?ā€ (5-point scale from no difficulty to bothers a lot). Incident CVD event ICD-9 codes (acute myocardial infarction, stroke, or coronary artery revascularization) were identified with VA and Medicare administrative data and VA fee-for-service data. Those with baseline CVD were excluded. Results: HIV-infected (N=3,108) veterans had a median follow-up time of 10.8 years, during which 267 CVD events occurred. Compared to HIV-infected veterans with no difficulty falling or staying asleep, HIV-infected veterans bothered a lot by insomnia symptoms had an increased risk of incident CVD after adjusting for demographics (HR=1.64, 95%CI=1.16-2.31, p=.005), CVD risk factors (HR=1.62, 95%CI=1.14-2.30, p=.007), additional potential confounders (hepatitis C infection, renal disease, anemia, alcohol use, cocaine use; HR=1.70, 95%CI=1.19-2.43, p=.003), and HIV-specific factors (HIV-1 RNA, CD4+ T-cell count, ART; HR=1.66, 95%CI=1.16-2.37, p=.005). Additional adjustment for non-benzodiazepine sleep medication (HR=1.62, 95%CI=1.13-2.32, p=.009) did not attenuate the association; however, it fell short of significance at p < .01 after adjustment for depressive symptoms (HR=1.51, 95%CI=0.98-2.32, p=.060) or antidepressant medication (HR=1.51, 95%CI=1.04-2.19, p=.031). Conclusion: Highly bothersome insomnia symptoms were significantly associated with incident CVD in HIV-infected veterans, suggesting that insomnia may be a novel, modifiable risk factor for CVD in HIV

    Ectopic cardiovascular fat in middle-aged men: effects of race/ethnicity, overall and central adiposity. The ERA JUMP study.

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    Background/objectivesHigher volumes of ectopic cardiovascular fat (ECF) are associated with greater risk of coronary heart disease (CHD). Identifying factors that are associated with ECF volumes may lead to new preventive efforts to reduce risk of CHD. Significant racial/ethnic differences exist for overall and central adiposity measures, which are known to be associated with ECF volumes. Whether racial/ethnic differences also exist for ECF volumes and their associations with these adiposity measures remain unclear.Subjects/methodsBody mass index (BMI), computerized tomography-measured ECF volumes (epicardial, pericardial and their summation) and visceral adipose tissue (VAT) were examined in a community-based sample of 1199 middle-aged men (24.2% Caucasians, 7.0% African-Americans, 23.6% Japanese-Americans, 22.0% Japanese, 23.2% Koreans).ResultsSignificant racial/ethnic differences existed in ECF volumes and their relationships with BMI and VAT. ECF volumes were the highest among Japanese-Americans and the lowest among African-Americans. The associations of BMI and VAT with ECF differed by racial/ethnic groups. Compared with Caucasians, for each 1-unit increase in BMI, African-Americans had lower, whereas Koreans had higher increases in ECF volumes (P-values&lt;0.05 for both). Meanwhile, compared with Caucasians, for each 1-unit increase in log-transformed VAT, African-Americans, Japanese-Americans and Japanese had similar increases, whereas Koreans had a lower increase in ECF volumes (P-value&lt;0.05).ConclusionsRacial/ethnic groups differed in their propensity to accumulate ECF at increasing level of overall and central adiposity. Future studies should evaluate whether reducing central adiposity or overall weight will decrease ECF volumes more in certain racial/ethnic groups. Evaluating these questions might help in designing race-specific prevention strategy of CHD risk associated with higher ECF

    Reduction in downstream test utilization following introduction of coronary computed tomography in a cardiology practice

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    To compare utilization of non-invasive ischemic testing, invasive coronary angiography (ICA), and percutaneous coronary intervention (PCI) procedures before and after introduction of 64-slice multi-detector row coronary computed tomographic angiography (CCTA) in a large urban primary and consultative cardiology practice. We utilized a review of electronic medical records (NotesMDĀ®) and the electronic practice management system (MegawestĀ®) encompassing a 4-year period from 2004 to 2007 to determine the number of exercise treadmill (TME), supine bicycle exercise echocardiography (SBE), single photon emission computed tomography (SPECT) myocardial perfusion stress imaging (MPI), coronary calcium score (CCS), CCTA, ICA, and PCI procedures performed annually. Test utilization in the 2Ā years prior to and 2Ā years following availability of CCTA were compared. Over the 4-year period reviewed, the annual utilization of ICA decreased 45% (2,083 procedures in 2004 vs. 1,150 procedures in 2007, PĀ <Ā 0.01) and the percentage of ICA cases requiring PCI increased (19% in 2004 vs. 28% in 2007, PĀ <Ā 0.001). SPECT MPI decreased 19% (3,223 in 2004 vs. 2,614 in 2007 PĀ <Ā 0.02) and exercise stress treadmill testing decreased 49% (471 in 2004 vs. 241 in 2007 PĀ <Ā 0.02). Over the same period, there were no significant changes in measures of practice volume (office and hospital) or the annual incidence of PCI (405 cases in 2004 vs. 326 cases in 2007) but a higher percentage of patients with significant disease undergoing PCI 19% in 2004 vs. 29% in 2007 PĀ <Ā 0.01. Implementation of CCTA resulted in a significant decrease in ICA and a corresponding significant increase in the percentage of ICA cases requiring PCI, indicating that CCTA resulted in more accurate referral for ICA. The reduction in unnecessary ICA is associated with avoidance of potential morbidity and mortality associated with invasive diagnostic testing, reduction of downstream SPECT MPI and TME as well as substantial savings in health care dollars

    Pulmonary function is associated with distal aortic calcium, not proximal aortic distensibility. MESA lung study

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    Forced expiratory volume in one second strongly predicts mortality from cardiovascular disease. FEV1 has been associated with aortic stiffness a strong independent predictor of cardiovascular mortality. However, the anatomical site and possible mechanisms linking aortic stiffness and lung function are unknown. We therefore examined if FEV1 and CT percent emphysema were associated with calcification of the abdominal aorta or reduced distensibility of the proximal thoracic aorta.The Multi-Ethnic Study of Atherosclerosis (MESA) measured aortic calcification on cardiac and abdominal CT scans and proximal aortic distensibility using magnetic resonance among participants aged 45ā€“84 years without clinical cardiovascular disease. Spirometry was measured following ATS/ERS guidelines and percent emphysema was measured in the lung fields of cardiac CT scans. Multivariate analyses adjusted for age, sex, race/ethnicity and cardiovascular risk factors. Of 1,917 participants with aortic distensibility measures, 13% were current and 38% were former smokers. Eighteen percent had airflow limitation without asthma. FEV1 was associated with the extent of distal aortic calcification (0.76; 95%CI 0.60ā€“0.97, p = 0.02) but not proximal aortic calcification or proximal aortic distensibility (āˆ’0.04 mmHgāˆ’1; 95%CI āˆ’0.16ā€“0.09 mmHgāˆ’1, p = 0.60). Percent emphysema was associated with neither measure. FEV1 was associated with severity of distal aortic calcification where it was present independently of smoking and other cardiovascular risk factors but not with distensibility or calcification of the proximal aorta

    Efficacy and Safety of Ertugliflozin in Patients With Type 2 Diabetes Mellitus and Established Cardiovascular Disease Treated With Metformin and Sulfonylurea

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    Abstract Introduction: Ertugliflozin (ERTU), a sodium-glucose cotransporter 2 (SGLT2) inhibitor, is approved as an adjunct to diet and exercise to improve glycemic control in patients with type 2 diabetes mellitus (T2DM). Aim: As a pre-specified sub-study of the Phase 3 VERTIS CV trial (NCT01986881), the efficacy and safety of ERTU were assessed in patients with T2DM and established atherosclerotic cardiovascular disease (ASCVD) inadequately controlled with metformin and sulfonylurea (SU). Methods: Patients with T2DM, established ASCVD, and HbA1c 7.0ā€“10.5% on stable metformin (ā‰„1500 mg/day) and SU doses as defined per protocol were randomized to once-daily ERTU (5 mg or 15 mg) or placebo. The primary sub-study objectives were to assess the effect of ERTU on HbA1c compared with placebo and to evaluate safety and tolerability during 18-week follow-up. Key secondary endpoints included proportion of patients achieving HbA1c &lt;7%, fasting plasma glucose (FPG), body weight, and systolic blood pressure. Changes from baseline at Week 18 for continuous efficacy endpoints were assessed using a constrained longitudinal data analysis model. Results: Of the 8246 patients enrolled in the VERTIS CV trial, 330 patients were eligible for this sub-study (ERTU 5 mg, n=100; ERTU 15 mg, n=113; placebo, n=117). Patients had a mean (SD) age of 63.2 (8.4) years, T2DM duration 11.4 (7.4) years, estimated glomerular filtration rate 83.5 (17.8) mL/min/1.73 m2, and HbA1c 8.3% (1.0) (67.4 [10.6] mmol/mol). At Week 18, ERTU 5 mg and 15 mg were each associated with a significantly greater least squares mean (95% CI) HbA1c reduction from baseline versus placebo; the placebo-adjusted differences for ERTU 5 mg and 15 mg were ā€“0.7% (ā€“0.9, ā€“0.4) and ā€“0.8% (ā€“1.0, ā€“0.5), respectively (P&lt;0.001). A higher proportion of patients in each ERTU group achieved HbA1c &lt;7% relative to placebo (P&lt;0.001). ERTU significantly reduced FPG and body weight (P&lt;0.001, for each dose versus placebo), but not systolic blood pressure. Adverse events were reported in 48.0%, 54.9%, and 47.0% of patients in the ERTU 5 mg, 15 mg, and placebo groups, respectively. Genital mycotic infections were experienced by significantly higher proportions of male patients who received ERTU 5 mg and 15 mg (4.2% and 4.8%, respectively) versus placebo (0.0%; Pā‰¤0.05) and by a numerically, but not significantly, higher proportion of female patients who received ERTU 15 mg (10.3%) compared with placebo (3.8%) (P=0.36). The incidences of symptomatic hypoglycemia were 11.0% (5 mg), 12.4% (15 mg), and 7.7% (placebo), and of severe hypoglycemia 2.0% (5 mg), 1.8% (15 mg), and 0.9% (placebo). Conclusion: Among patients with T2DM and ASCVD, ERTU (5 mg and 15 mg) added to metformin and SU for 18 weeks improved glycemic control (HbA1c and FPG) and reduced body weight, and was generally well tolerated with a safety profile consistent with the SGLT2 inhibitor class
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