The aims of the present study were: 1) to investigate the contribution of the extent of luminal stenosis and other lesion composition-related factors in predicting invasive fractional flow reserve (FFR); and 2) to explore the distribution of various combinations of morphological characteristics and the severity of stenosis among lesions demonstrating normal and abnormal FFR.
Background
In patients with stable ischemic heart disease, FFR-guided revascularization, as compared with medical therapy alone, is reported to improve outcomes. Because morphological characteristics are the basis of plaque rupture and acute coronary events, a relationship between FFR and lesion characteristics may exist.
Methods
This is a subanalysis of NXT (HeartFlowNXT: HeartFlow Analysis of Coronary Blood Flow Using Coronary CT Angiography), a prospective, multicenter study of 254 patients (age 64 ± 10 years, 64% male) with suspected stable ischemic heart disease; coronary computed tomography angiography including plaque morphology assessment, invasive angiography, and FFR were obtained for 383 lesions. Ischemia was defined by invasive FFR ≤0.80. Computed tomography angiography–defined morphological characteristics of plaques and their vascular location were used in univariate and multivariate analyses to examine their predictive value for invasive FFR. The distribution of various combinations of plaque morphological characteristics and the severity of stenosis among lesions demonstrating normal and abnormal FFR were examined.
Results
The percentage of luminal stenosis, low-attenuation plaque (LAP) or necrotic core volume, left anterior descending coronary artery territory, and the presence of multiple lesions per vessel were the predictors of FFR. When grouped on the basis of degree of luminal stenosis, FFR-negative lesions had consistently smaller LAP volumes compared with FFR-positive lesions. The distribution of plaque characteristics in lesions with normal and abnormal FFR demonstrated that whereas FFR-negative lesions excluded likelihood of stenotic plaques with moderate to high LAP volumes, only one-third of FFR-positive lesions demonstrated obstructive plaques with moderate to high LAP volumes.
Conclusions
In addition to the severity of luminal stenosis, necrotic core volume is an independent predictor of FFR. The distribution of plaque characteristics among lesions with varying luminal stenosis and normal and abnormal FFR may explain the outcomes associated with FFR-guided therapy. 相似文献
PURPOSE: To examine if excessive in-stent neointimal formation causing a subcritical stenosis may indicate enhanced vascular reactivity in response to injury, thus predicting late cardiovascular events. METHODS: One hundred consecutive patients (64 men; median age 71 years) with high-grade internal carotid artery stenoses (68 asymptomatic, 32 symptomatic) underwent carotid artery stenting (CAS). High-sensitivity C-reactive protein (hs-CRP) was measured before CAS. Patients were monitored with duplex ultrasound for excessive in-stent neointimal formation (flow-compromising lumen diameter reduction >/=50%), critical restenosis (>/=70%), or the occurrence of late major adverse cardiovascular events (MACE) defined as myocardial infarction (MI), stroke, and death occurring later than 30 days poststenting. RESULTS: Over a median 23-month follow-up, excessive neointimal formation was observed in 14 (14%) patients, restenosis in 2 (2%), and 30 late MACE in 25 [25%: 4 MIs, 2 ipsilateral strokes (in the patients with restenosis), 8 contralateral strokes, and 16 cardiovascular deaths]. Cumulative MACE-free survival rates at 6, 12, and 24 months were 92%, 84%, and 77%, respectively. Baseline hs-CRP levels were associated both with neointimal hyperplasia (p=0.024) and MACE (p=0.021). Patients with excessive neointimal formation exhibited a significantly increased adjusted risk for MACE (hazard ratio 3.56, p=0.010). CONCLUSIONS: Excessive in-stent neointimal formation after CAS indicates an increased risk for late MACE, potentially reflecting a state of exaggerated vascular reactivity in response to injury. Inflammation, which is associated both with neointimal hyperplasia and MACE, seems a common characteristic of different vascular pathologies. 相似文献
BackgroundAlthough DNA of high quality can be easily prepared from cultured cells with commercially available kits, many studies involve a large number of samples which increases the cost drastically. We optimized two simple and inexpensive methods for preparing DNA suitable for digital PCR from a small number of cells directly from wells of 96‐well plates.MethodsCells (number: 103‐104) were lysed with a Direct PCR® lysis buffer or a 10% Chelex100® solution. The lysates were further purified and concentrated by means of DNA precipitation with a blue‐colored glycogen as a carrier. PCR and digital PCR were used to evaluate the efficiency of the two methods.ResultsFor 1000 cells from one primary culture and two tumor cell lines, DNA was reproducible and obtained with recovery rate (obtained/expected amount of DNA) in the range of 50%‐90% as measured by the fluorometer dyes instrument Qubit. Using 8 out of a total of 10 µL DNA solution for 1000 cells, both conventional PCR and digital PCR were successful. For digital PCR, more than 1600 positive droplets were obtained for DNA from 1000 cells using the Direct PCR® method, corresponding to a yield efficiency of approximately 80%. Further reducing the number of cells down to 100 would be possible with 160 positive droplets expected. Both reagents are inexpensive (0.08€/sample).ConclusionsTwo methods are efficient, especially the Direct PCR® reagent‐based method provides a simple and inexpensive method for preparing DNA suitable for digital PCR from small number of cells. 相似文献
Currently there are no growth charts based on local norms available for infants in Iran, and their growth is assessed by the National Centre for Health Statistics (NCHS) reference data, which is misleading. Growth charts for a cohort of 317 infants (164 girls and 153 boys) born in Shiraz (Southern Iran) in 1996 and followed for 2 years from birth are presented. All the centiles of length and weight charts are slightly above those of the NCHS charts under the age of 6 months and fall substantially below those over the age of 6 months. However, the spread is similar, so there is no suggestion that the difference is due to the prevalence of gross malnutrition. The difference shows that the use of locally based growth charts are essential for assessing the growth of children in Iran. The representativeness of our data leads us to conclude that the charts presented here are likely to be applied to the urban infant population of Iran.Gegenwärtig stehen im Iran für Kleinkinder keine auf lokalen Normdaten basierende Wachstumsdiagramme zur Verfügung. Das Wachstum dieser Kinder wird anhand der Referenzdaten des Nationalen Zentrums für Gesundheitsstatistik (NCHS) eingeschätzt, was zu Fehleinschätzungen führt. Es werden Wachstumsdiagramme für eine Kohorte von 317 Kleinkindern (164 Mädchen und 153 Jungen) vorgestellt, die 1996 in Shiraz (Südiran) geboren wurden und nach ihrer Geburt 2 Jahre lang untersucht wurden. Alle Längen- und Gewichtszentilen liegen bis zu einem Alter von unter 6 Monaten leicht über denjenigen der NCHS-Diagramme und fallen ab einem Alter von 6 Monaten beträchtlich unterhalb diese. Allerdings ist die Spannweite ähnlich und daher gibt es kein Anzeichen dafür, dass der Unterschied auf das Vorliegen einer schweren Unterernährung zurückzuführen ist. Die Unterschiede zeigen, dass die Verwendung von lokalen Wachstumsdiagrammen für die Einschätzung des Wachstums von Kindern im Iran notwendig ist. Die Tatsache, dass unsere Daten als repräsentativ anzusehen sind, veranlasst uns zu der Schlussfolgerung, dass die hier vorgestellten Charts wahrscheinlich für die städtische Kleinkinderpopulation im Iran anwendbar sind.On ne dispose pas actuellement en Iran de tables normatives de la croissance établies sur des données locales, si bien que la croissance des enfants iraniens est inadéquatement observéeen référence aux données du National Centre for Health Statistics (NCHS). On présente ici des courbes de croissance établies à partir d'une cohorte de 317 enfants (164 filles et 153 garçons) nés à Shiraz (Iran méridional) en 1996 et suivis pendant leurs deux premières années. Tous les centiles de taille et de poids sont légèrement supérieurs à ceux des tables NCHS avant l'âge de six mois, puis leurs deviennent nettement inférieurs par la suite. L'évolution des courbes étant similaire, il n'y a donc pas raison de suspecter que la différence est due à de la malnutrition. Cet écart entre les deux tables montre que l'utilisation de courbes fondées sur des données locales est essentielle pour le suivi de la croissance des enfants en Iran. La représentativité de nos données nous conduit à estimer que les tables présentées dans ce travail sont applicables à la population infantile urbaine en Iran. 相似文献
A new model for prediction of the effective permeability of gases in mixed matrix membranes (MMMs), considering the effects of particle shape and the interfacial layer, is presented. The proposed model treats core filler particles and interfacial shell layers as complex particles. Moreover, the Bruggman mathematical procedure is used to improve the accuracy of the presented model for high concentrations of fillers in MMMs. Also, an appropriate uniform criterion is established to make efficient use of the new model for various experimental data to avoid the need for curve‐fitting procedures. Finally, the proposed model is examined for several sets of experimental data.
Clinical Oral Investigations - This study aimed to compare the efficacy of silver nanoparticles (AgNPs) irrigating solution alone and following activation with photon-induced photoacoustic... 相似文献
Atherosclerotic plaque characteristics may affect downstream myocardial perfusion, as well as coronary lesion severity.
Objectives
This study sought to evaluate the association between quantitative plaque burden and plaque morphology obtained using coronary computed tomography angiography (CTA) and quantitative myocardial perfusion obtained using [15O]H2O positron emission tomography (PET), as well as fractional flow reserve (FFR) derived invasively.
Methods
Two hundred eight patients (63% men; age 58 ± 8.7 years) with suspected coronary artery disease were prospectively included. All patients underwent 256-slice coronary CTA, [15O]H2O PET, and invasive FFR measurements. Coronary CTA-derived plaque burden and morphology were assessed using commercially available software and compared with PET perfusion and FFR.
Results
Atherosclerotic plaques were present in 179 patients (86%) and 415 of 610 (68%) evaluable coronary arteries. On a per-vessel basis, traditional coronary plaque burden indexes, such as plaque length and volume, minimal lumen area, and stenosis percentage, were significantly associated with impaired hyperemic myocardial blood flow (MBF) and FFR. In addition, morphological features, such as partially calcified plaques, positive remodeling (PR), and low attenuation plaque, displayed a negative impact on hyperemic MBF and FFR. Multivariable analysis revealed that the morphological feature of PR was independently related to impaired hyperemic MBF as well as an unfavorable FFR (p = 0.004 and p = 0.007, respectively), next to stenosis percentage (p = 0.001 and p < 0.001, respectively) and noncalcified plaque volume (p < 0.001 and p = 0.010, respectively).
Conclusions
PR and noncalcified plaque volume are associated with detrimental downstream hyperemic myocardial perfusion and FFR, independent of lesion severity. 相似文献
