Impact of Coronary Plaque Characteristics on Late Stent Malapposition after Drug-Eluting Stent Implantation

Purpose

To evaluate the impact of pre-procedural coronary plaque composition assessed by virtual histology intravascular ultrasound (VH-IVUS) on late stent malapposition assessed by optical coherence tomography (OCT) following drug-eluting stent (DES) implantation.

Materials and Methods

The study population consisted of 121 patients (121 lesions) who underwent both pre-procedural VH-IVUS and follow-up OCT after DES implantation. The association between pre-procedural plaque composition [necrotic core (NC), dense calcium (DC), fibrotic (FT), and fibro-fatty (FF) volumes] assessed by VH-IVUS and late stent malapposition (percent malapposed struts) or strut coverage (percent uncovered struts) assessed by follow-up OCT was evaluated.

Results

Pre-procedural absolute total NC, DC, FT, and FF plaque volumes were 22.9±19.0, 7.9±9.6, 63.8±33.8, and 16.5±12.4 mm³, respectively. At 6.3±3.1 months post-intervention, percent malapposed and uncovered struts were 0.8±2.5% and 15.3±16.7%, respectively. Pre-procedural absolute total NC and DC plaque volumes were positively correlated with percent malapposed struts (r=0.44, p<0.001 and r=0.45, p<0.001, respectively), while pre-procedural absolute total FT plaque volume was weakly associated with percent malapposed struts (r=0.220, p=0.015). Pre-procedural absolute total DC plaque volume was the only independent predictor of late stent malapposition on multivariate analysis (β=1.12, p=0.002). There were no significant correlations between pre-intervention plaque composition and percent uncovered struts.

Conclusion

Pre-procedural plaque composition was associated with late stent malapposition but not strut coverage after DES implantation. Larger pre-procedural absolute total DC plaque volumes were associated with greater late stent malapposition.     

败血症弥散性血管内凝血时的白细胞溶血毒性的探讨

分别以凝血活酶和活大肠杆菌诱发家兔DIC,观察到活菌组血浆血红蛋白显著升高。同时WBC、MDA升高,而SOD活性显著下降。另分别以家兔贫白细胞血和富白细胞血与内毒素温育,结果前者溶血轻微,而后者溶血显著,且MDA升高。这表明感染致DIC时,内毒素等物质激活白细胞,可能通过自由基机制表现出溶血毒性。     

Thromboelastography in term neonates

Background: Thromboelastography (TEG) is utilized as a point-of-care test of coagulation function to improve evidence-based blood product replacement in adults. In contrast to standard indices of coagulation, TEG reflects the dynamic interactions among the elements involved in hemostasis, including fibrinolysis. Although normal adult values and various abnormalities have been characterized, normative values for term neonates have not been described. Studies of neonatal TEG remain limited and have small sample sizes with inconsistent methodology. The aim of this study is to provide normative data on healthy term neonates, and to assess the impact of mode of delivery on TEG parameters at term.

Methods: Venous umbilical blood was obtained from the placenta within 10?min of delivery. TEG analysis of citrated kaolin-activated samples was performed for 50 healthy term vaginal and 50 cesarean deliveries. Samples collected for cesarean sections were from scheduled cases or unscheduled ones due to failure of progression of labor.

Results: Healthy neonates with uncomplicated vaginal term deliveries resulted in the following TEG parameters: R: 5.41?±?1.34 (mean?±?SD) min; K: 1.62?±?0.75?min; α-angle: 65.39?±?8.77°; MA: 65.86?±?5.81?mm; and LY30: 1.40?±?1.18%. Results for the cesarean delivery neonatal TEG assays showed: R: 5.51?±?1.74 (mean?±?SD) min; K: 1.52?±?0.47?min; α-angle: 64.15?±?4.61°; MA: 64.15?±?4.61?mm; and LY30: 2.44?±?3.51%. Of note, no statistical differences were observed (p?Conclusion: TEG measurements from term neonates were no different when the neonates were delivered vaginally or by cesarean section. Labor had no effect on neonatal TEG levels. Neonatal TEG values may therefore serve as insight for fetal values at the appropriate postconceptional age.     

Comparisons of the effects of stent eccentricity on the neointimal hyperplasia between sirolimus-eluting stent versus paclitaxel-eluting stent

Purpose

Previous studies suggested that asymmetric stent expansion did not affect suppression of neointimal hyperplasia (NIH) after sirolimus-eluting stents (SES) implantation. The aim of this study was to evaluate the effects of stent eccentricity (SE) on NIH between SES versus paclitaxel-eluting stents (PES) using an intravascular ultrasound (IVUS) analysis from the randomized trial.

Materials and Methods

Serial IVUS data were obtained from Post-stent Optimal Expansion (POET) trial, allocated randomly to SES or PES. Three different SE (minimum stent diameter divided by maximum stent diameter) were evaluated; SE at the lesion site with maximal %NIH area (SE-NIH), SE at the minimal stent CSA [SE-minimal stent area (SE-MSA)], and averaged SE through the entire stent (SE-mean). We classified each drug-eluting stents (DES) into the concentric (≥ mean SE) and eccentric groups (< mean SE) based on the mean value of SE.

Results

Among 301 enrolled patients, 233 patients [SES (n = 108), PES (n = 125)] underwent a follow-up IVUS. There was no significant correlation between %NIH area and SE-NIH (r = - 0.083, p = 0.391) or SE-MSA (r = - 0.109, p = 0.259) of SES. However, SE-NIH of PES showed a weak but significant correlation with %NIH area (r = 0.269, p < 0.01). As to the associations between SE-mean and NIH volume index, SES revealed no significant correlation (r = - 0.001, p = 0.990), but PES showed a weak but significant correlation (r = 0.320, p < 0.01). However, there was no difference in the restenosis rate between the eccentric versus concentric groups of both DES.

Conclusion

This study suggests that lower SE of both SES and PES, which means asymmetric stent expansion, may not be associated with increased NIH.     

妊娠期凝血功能障碍与产科多器官功能障碍综合征

妊娠期弥漫性血管内凝血(DIC)是病理妊娠的严重并发症,常与产科出血、重度子痫前期及子痫、羊水栓塞、妊娠期急性脂肪肝和感染等相关。出血、高血压和感染等可启动瀑布式病理生理反应,即全身炎症反应综合征(SIRS),致使孕产妇全身低灌注、低血流,最终导致多器官功能障碍综合征(MODS)、DIC的发生。只有尽早明确病因,评估母胎血流动力学的继发改变,及时正确地在治疗窗处理凝血功能障碍,纠正低容量、低血供和低灌注,维持血流动力学稳定,才能降低孕产妇的病死率。     

血同型半胱氨酸与危重新生儿弥漫性血管内凝血相关性研究

目的 探讨血同型半胱氨酸与危重新生儿弥漫性血管内凝(DIC)的相关性.方法 2004年8月至2007年1月收住我院NICU的危重新生儿共157例,其中诊断为DIC的36例为试验组,其余无合并DIC的危重新生儿中随机选取40例为对照组.对两组的血清同型半胱氨酸的水平进行对比,而且将试验组根据所处的时期分为A、B两组,A组20例,为DIC早中期,B组16例,为DIC晚期,研究在DIC早中期与晚期的疾病的转归及血清同型半胱氨酸的水平的相关性.结果 DIC新生儿组患儿血清同型半胱氨酸的水平明显高于无合并DIC的危重新生儿,而且DIC早中期血清同型半胱氨酸的水平明显升高,病情进展为DIC晚期血清同型半胱氨酸的水平迅速下降,而病情逐渐好转者,则逐渐下降.结论 血清同型半胱氨酸的水平与危重新生儿DIC是密切相关的.而且血清同型半胱氨酸的水平随DIC早中期病情的进展的不同而发生动态的变化.     

A paradoxical thrombogenic mutation in factor II at the target site of arthropod bleeding toxin

Loss-of-function mutations in coagulation cascade proteins lead to bleeding diasthesis. In contrast, gain-of-function mutations in these proteins, which are exceptionally rare, lead to hereditary thrombosis. This is best exemplified by Factor V (i.e., Factor V Leiden) and Factor II (i.e., p.Arg596Leu). Here, we report a family with hereditary thrombosis. The proposita presented with cerebral venous thrombosis accompanied by infarction at the age of 12 years. Despite anticoagulation therapy with oral warfarin, she later developed deep venous thrombosis in her hepatic portal veins at the age of 27 years. A medical exome analysis identified a de novo heterozygous mutation p.Tyr434His in Factor II, which was segregated within the family. A retrospective molecular diagnosis was made using a preserved surgical specimen from the proposita's mother, who had died 10 years earlier. The p.Tyr434 residue, which was substituted in the presently reported family, was located in “exosite I” of thrombin, a critical recognition site for fibrinogen, protein C, and thrombin aptamer. Therefore, the mutant thrombin likely exerted its thrombophilic effect by altering the affinity of thrombin to downstream substrates. Furthermore, the “exosite I” domain of thrombin was inhibited by the arthropod bleeding toxin Triabin (a protein discovered from the saliva of the blood-sucking triatomine bug Triatoma pallidipennis). Our observation that patients with a p.Tyr434His mutation exhibited recurrent thrombosis provides the first proof-of-concept in humans that a pharmacologic agent targeting “exosite I” could be an effective means of specifically modulating the thrombogenic-side of the coagulation system via the inhibition of factor II.     

外周动脉腔内超声显像的形态学研究

血管内超声是利用安装在心导管顶端的微型超声探头从管腔内观察血管形态学的新技术，为了解其对人体动脉实时显像的能力及定量定性的准确性，在自行设计的实验模型装置上的对９段经生理压力固定的人离体外周动脉进行超声显像，然后将血管组织对应切片观察，对比二者结果发现：（１）血管内超声可准确测定动脉腔面积，周长，直径和厚度等重要参数，与组织学测值相关系数均在０．９５以上（Ｐ〈０．００１）；（２）肌性和弹性动脉组织     

Familial high factor VIII level in a child with necrotizing fasciitis complicating primary varicella infection

This article describes an unusual association of familial high plasma factor VIII level and necrotizing fasciitis in a 4-year-old girl with primary varicella infection.     

Disseminated intravascular coagulation in pediatric patients: clinical and laboratory features and prognostic factors influencing the survival

Although disseminated intravascular coagulation (DIC) has been a well-known disorder for many years, there is lack of sufficient number of clinical trials about incidence, frequency of underlying disorders, and prognosis of DIC in children. The aim of this study was to evaluate the frequency, etiologic factors, and clinical and laboratory findings of DIC and to determine the prognostic factors influencing the mortality in hospitalized pediatric patients. Medical records of 5535 children who were hospitalized were investigated. Sixty-two patients who were diagnosed as acute DIC were enrolled. The frequency of DIC was 1.12%. The underlying etiologic factors were infection in 59 patients (95.2%) and major trauma in 3 patients (4.8%). The frequency of bleeding and thrombosis was 48.8 and 4.8%. Respiratory, cardiovascular, hepatic, renal, neurologic, and gastrointestinal dysfunction was present in 71, 67.7, 35.5, 16.1, 16.1 and 11.3% of patients, respectively. Respiratory and cardiovascular dysfunctions were significantly associated with mortality. Multiorgan dysfunction syndrome (MODS) was present in 85.5% of the patients, and 54.8% of the patients had developed acute respiratory distress syndrome (ARDS). Mortality rate was significantly high in patients with MODS and ARDS. In multivariete logistic regression analysis, only ARDS and cardiovascular dysfunction had predictive and prognostic value on mortality. None of the diagnostic laboratory tests had predictive or prognostic value and the degree of abnormality of these tests did not show any correlation with mortality. In conclusion, DIC is not a rare disorder in hospitalized children, especially in patients with sepsis, and MODS, ARDS, and respiratory and cardiovascular system dysfunctions are poor prognostic factors.