ECG-Gated Three-dimensional Intravascular Ultrasound

Background Automated systems for the quantitative analysis of three-dimensional (3D) sets of intravascular ultrasound (IVUS) images have been developed to reduce the time required to perform volumetric analyses; however, 3D image reconstruction by these nongated systems is frequently hampered by cyclic artifacts. Methods and Results We used an ECG-gated 3D IVUS image acquisition workstation and a dedicated pullback device in atherosclerotic coronary segments of 30 patients to evaluate (1) the feasibility of this approach of image acquisition, (2) the reproducibility of an automated contour detection algorithm in measuring lumen, external elastic membrane, and plaque+media cross-sectional areas (CSAs) and volumes and the cross-sectional and volumetric plaque+media burden, and (3) the agreement between the automated area measurements and the results of manual tracing. The gated image acquisition took 3.9±1.5 minutes. The length of the segments analyzed was 9.6 to 40.0 mm, with 2.3±1.5 side branches per segment. The minimum lumen CSA measured 6.4±1.7 mm2, and the maximum and average CSA plaque+media burden measured 60.5±10.2% and 46.5±9.9%, respectively. The automated contour-detection required 34.3±7.3 minutes per segment. The differences between these measurements and manual tracing did not exceed 1.6% (SD<6.8%). Intraobserver and interobserver differences in area measurements (n=3421; r=.97 to.99) were <1.6% (SD<7.2%); intraobserver and interobserver differences in volumetric measurements (n=30; r=.99) were <0.4% (SD<3.2%). Conclusions ECG-gated acquisition of 3D IVUS image sets is feasible and permits the application of automated contour detection to provide reproducible measurements of the lumen and atherosclerotic plaque CSA and volume in a relatively short analysis time

Определение интервалов квазистационарности экономических систем

В работе рассмотрен вопрос определения оптимального интервала адаптации алгоритма динамического управления капиталом для нестационарного случая методами расчета показателя Херста и построения автокорреляционной функции для анализа временных рядов. Проведен анализ влияния выбора интервала адаптации на эффективность алгоритма. Из анализа полученных результатов следует, что метод расчета показателя Херста позволяет более эффективно, чем метод построения автокорреляционной функции, определить интервал стационарности модели функционирования экономической системы.Робота присвячена питанню визначення оптимального інтервалу адаптації алгоритму динамічного керування капіталом для нестаціонарного випадку за допомогою методів розрахунку показника Херста і побудови автокореляційної функції задля аналізу часових рядів. Проведено аналіз впливу вибору інтервалу адаптації на ефективність алгоритму. Порівняння результатів проведеного аналізу дозволяє стверджувати, що метод розрахунку показника Херста дозволяє більш ефективно, ніж метод побудови автокореляційної функції, визначити інтервал стаціонарності моделі функціонування економічної системи

Simpson's rule for the volumetric ultrasound assessment of atherosclerotic coronary arteries: a study with ECG-gated three-dimensional intravascular ultrasound.

BACKGROUND: Volumetric intravascular ultrasound (IVUS) assessment provides complementary information on atherosclerotic plaques. The volumes can be calculated by applying Simpson's rule to cross-sectional area data of multiple IVUS images, acquired with a fixed sample spacing, which is the distance (along the vessel's axis) between two images. OBJECTIVE: To evaluate the effect of different sample spacings on the results of volumetric IVUS measurements. METHODS: A stepwise electrocardiographically gated IVUS image-acquisition and automated three-dimensional analysis approach was applied to 26 patients. Twenty-eight coronary segments with mild-to-moderate coronary atherosclerosis were examined. Volumetric measurements of five images per mm (i.e. sample spacing 0.2 mm), representing a complete scanning of the coronary segment, were considered the optimal standard, against which volumetric measurements of three, one, and one-half images per mm (i.e. larger sample spacings) were compared. RESULTS: The lumen, total vessel, an

Ticagrelor or prasugrel versus clopidogrel in elderly patients with an acute coronary syndrome : Optimization of antiplatelet treatment in patients 70years and older-rationale and design of the POPular AGE study

RATIONALE: Dual antiplatelet therapy with acetylsalicylic acid in combination with a more potent P2Y12- inhibitor (ticagrelor or prasugrel) is recommended in patients with acute coronary syndrome without ST-segment elevation (NSTE-ACS) to prevent atherothrombotic complications. The evidence on which this recommendation is based shows that ticagrelor and prasugrel reduce atherothrombotic events at the expense of an increase in bleeding events when compared with clopidogrel. However, it remains unclear whether ticagrelor or prasugrel has a better net clinical benefit in elderly patients with NSTE-ACS when compared with clopidogrel. The POPular AGE trial is designed to address the optimal antiplatelet strategy in elderly NSTE-ACS patients. STUDY DESIGN: POPular AGE is a multicenter, open-label, randomized controlled trial that aims to include 1000 patients ≥70years of age with NSTE-ACS. Patients are randomly assigned to receive either clopidogrel or a more potent P2Y12 inhibitor (ticagrelor or prasugrel). The first primary end point is any bleeding event requiring medical intervention. The second primary end point is the net clinical benefit, a composite of all-cause mortality, nonfatal myocardial infarction, nonfatal stroke, "PLATelet inhibition and patient Outcomes" major bleeding, or "PLATelet inhibition and patient Outcomes" minor bleeding. Patients will be followed for 1 year after randomization, and analyses will be performed on the basis of intention to treat. CONCLUSION: The POPular AGE is the first randomized controlled trial that will assess whether the treatment strategy with clopidogrel will result in fewer bleeding events without compromising the net clinical benefit in patients ≥70years of age with NSTE-ACS when compared with a treatment strategy with ticagrelor or prasugrel

Multivariable analysis including patients within 3 hours of symptom onset (n = 197).

<p>Clinical model: Age, sex, hypertension, hypercholesterolemia, family history of CVD, current and former smoking, diabetes mellitus, and history of MI, PCI or CABG, and ECG. Abbreviations: hs-cTnT, high-sensitive cardiac troponin; PlGF, placental growth factor; sFlt-1, soluble Fms-like tyrosine kinase-1; NT-proBNP, N-terminal prohormone B-type Natriuretic Peptide; GDF-15, growth differentiation factor-15; AUC, area under the receiver operating curve (ROC); CI, confidence interval.</p><p>*adjusted for over-optimism</p><p>** compared to the Clinical model</p><p>*** compared to the Clinical model + hs-cTnT</p><p>Multivariable analysis including patients within 3 hours of symptom onset (n = 197).</p

Sensitivity, specificity, predictive values and AUCs of hs-cTnT, myoglobin and 5 novel biomarkers in patients with symptom onset within 3 hours.

<p>Values are given as percentage or number (95%CI)</p><p>Abbreviations: hs-cTnT, high-sensitive cardiac troponin; PlGF, placental growth factor; sFlt-1, soluble Fms-like tyrosine kinase-1; NT-proBNP, N-terminal prohormone B-type Natriuretic Peptide; GDF-15, growth differentiation factor-15; PPV, positive predictive value; NPV, negative predictive value; AUC, area under the receiver operating curve (ROC).</p><p>Sensitivity, specificity, predictive values and AUCs of hs-cTnT, myoglobin and 5 novel biomarkers in patients with symptom onset within 3 hours.</p

Median biomarker concentrations and inter quartile ranges stratified by ACS status.

<p>Values are given as median (Inter Quartile Range); p-value calculated with Mann-Whitney <i>U</i>-test</p><p>Abbreviations: hs-cTnT, high-sensitive cardiac troponin; PlGF, placental growth factor; sFlt-1, soluble Fms-like tyrosine kinase-1; NT-proBNP, N-terminal prohormone B-type Natriuretic Peptide; GDF-15, growth differentiation factor-15.</p><p>Median biomarker concentrations and inter quartile ranges stratified by ACS status.</p

Multivariable analysis including all patients (n = 453).

<p>Clinical model: Age, sex, hypertension, hypercholesterolemia, family history of CVD, current and former smoking, diabetes mellitus, and history of MI, PCI or CABG and ECG. Abbreviations: hs-cTnT, high-sensitive cardiac troponin; PlGF, placental growth factor; sFlt-1, soluble Fms-like tyrosine kinase-1; NT-proBNP, N-terminal prohormone B-type Natriuretic Peptide; GDF-15, growth differentiation factor-15; AUC, area under the receiver operating curve (ROC); CI, confidence interval.</p><p>*adjusted for over-optimism</p><p>** compared to the Clinical model</p><p>*** compared to the Clinical model + hs-cTnT</p><p>Multivariable analysis including all patients (n = 453).</p