Background More elderly patients undergo coronary artery bypass surgery (CABG) than younger patients. Whether tranexamic acid (TA) is still effective and safe in elderly patients undergoing CABG surgeries is still unclear. Methods In this study, a cohort of 7,224 patients ≥70 years undergoing CABG surgery were included. Patients were categorized into the no TA group, TA group, high-dose group, and low-dose group according whether TA was administered and the dose administered. The primary endpoint was blood loss and blood transfusion after CABG. The secondary endpoints were thromboembolic events and in-hospital death. Results The blood loss at 24 and 48 h and the total blood loss after surgery in patients in the TA group were 90, 90, and 190 ml less than those in the no-TA group, respectively ( p < 0.0001). The total blood transfusion was reduced 0.38-fold with TA administration compared to that without TA (OR = 0.62, 95% CI 0.56–0.68, p < 0.0001). Blood component transfusion was also reduced. High-dose TA administration reduced the blood loss by 20 ml 24 h after surgery ( p = 0.032) but had no relationship with the blood transfusion. TA increased the risk of perioperative myocardial infarction (PMI) by 1.62-fold [ p = 0.003, OR = 1.62, 95% CI (1.18–2.22)] but reduced the hospital stay time in patients who were administered TA compared to that of patients who did not receive TA ( p = 0.026). Conclusion We revealed that elderly patients undergoing CABG surgeries had better hemostasis after TA administration but increased the risk of PMI. High-dose TA was effective and safe compared with low-dose TA administration in elderly patients undergoing CABG surgery.

Abstract Background Sex differences present in the blood management of patients after coronary artery bypass grafts (CABG) surgeries. Tranexamic acid (TXA) performed well in maintaining hemostasis during and after surgeries. However, the impact of sex differences on blood control after CABG in patients who received TXA was not investigated. Methods Overall, 29,536 patients undergoing CABG with TXA administration from 2009 to 2019 in our hospital were included. Propensity score matching was performed. Finally, 6808 males and 6808 females were matched based on 23 covariates. Results Female patients had a 0.36-fold lower incidence of reoperations due to major hemorrhage or cardiac tamponade compared to males (1.3% vs. 2.0%, p = 0.001, OR = 0.64, 95%CI = 0.49–0.84). Females had a median of 100 ml less blood loss in 24 h (median 360 vs. 460 ml, p < 0.0001), 150 ml less in 48 h (median 580 vs. 730 ml, p < 0.0001), and 180 ml less in total (median 760 vs. 940 ml, p < 0.0001) than male patients. The red blood cell (RBC) transfusion rate in female was 1.53-fold higher than that in male (33.0% vs. 21.6%, OR = 1.53, 95% CI = 1.43–1.63, p < 0.0001). Females also had higher morbidities than males after CABGs. Conclusions Females had less blood loss than males after CABG with the TXA treatment. Females still had a higher RBC transfusion rate after surgery. Morbidities in women were also higher than that in men.

Background Tranexamic acid (TXA) administered during off-pump coronary artery bypass (OPCAB) surgeries has achieved good blood control in small cohorts. We aimed to investigate the safety issues and hemostasis associated with TXA administration during OPCAB in a large retrospective cohort study. Methods This study included 19,687 patients with OPCAB from 2009 to 2019. A total of 1,307 patients were excluded because they were younger than 18 years or certain values were missing. Among the remaining 18,380 patients, 10,969 were in the TXA group and 7,411 patients were in the no-TXA group. There were 4,889 patients whose TXA dose was ≥50 mg/kg, and the remaining 6,080 patients had a TXA dose of <50 mg/kg. Propensity score matching (PSM) was performed between the TXA and no-TXA groups and between the high-dose and low-dose groups, and statistical analysis was performed. Results Tranexamic acid administration did not increase the risk of hospital death or thromboembolic events. Patients who administered TXA had less blood loss at 24 h (478.32 ± 276.41 vs. 641.28 ± 295.09, p < 0.001) and 48 h (730.59 ± 358.55 vs. 915.24 ± 390.13, p < 0.001) and total blood loss (989.00 ± 680.43 vs. 1,220.01 ± 720.68, p < 0.001) after OPCAB than the patients with non-TXA. Therefore, the risk of total blood exposure [odds ratio (OR) = 0.50, 95% CI 0.47–0.54, p < 0.001] or blood component exposure (p < 0.001) was decreased significantly in the patients who administered TXA. The TXA dosage did not impact the patient survival, thromboembolic events, or blood management. Conclusions The application of TXA was safe and provided blood control in patients with OPCAB, and the dosage did not affect these parameters.

Background: The safety and blood management effects of Tranexamic acid (TXA) and its dose effects in coronary artery bypass graft (CABG) were still ambiguous. This study aimed to analyze these TXA effects. Methods: Overall, 42,010 patients undergoing CABG were enrolled in this retrospective cohort study. Patients were assigned to the TXA group (n = 29,536) and the no-TXA group (n = 12,474). Furthermore, the TXA group was divided into the high-dose (>= 50 mg/kg) (16,488) and the low-dose (<50 mg/kg) (13,048) subgroup. Propensity score matching was performed in both groups respectively. The primary endpoint after CABG was composed of hospital death, perioperative myocardial infarction (PMI), stroke, acute kidney injury (AKI), and pulmonary embolism. The secondary endpoint included blood loss and blood transfusion after surgery. Results: TXA led to a 1.40-fold risk of PMI (p < 0.001). Patients in the TXA group had fewer re-operations for bleeding or tamponade [Odd ratio (OR) = 0.82, p = 0.044], less blood loss after surgery (p < 0.001), and a lower risk for blood transfusion exposure (OR = 0.45, p < 0.001) than those in the no-TXA group. The high-dose TXA reduced blood loss after cardiac surgery compared to the low-dose TXA (p < 0.001) with no associations with blood exposure or adverse events. Conclusions: The use of TXA during CABG increased the risk of PMI despite better blood control after surgery. The high dose of TXA acquired better bleeding management. Meanwhile, it did not increase the risk of primary endpoint.

BACKGROUND: Vein graft occlusion is deemed a major challenge in coronary artery bypass grafting. Previous studies implied that the no-touch technique for vein graft harvesting could reduce occlusion rate compared with the conventional approach; however, evidence on the clinical benefit and generalizability of the no-touch technique is scare. METHODS: From April 2017 to June 2019, we randomly assigned 2655 patients undergoing coronary artery bypass grafting at 7 hospitals in a 1:1 ratio to receive no-touch technique or conventional approach for vein harvesting. The primary outcome was vein graft occlusion on computed tomography angiography at 3 months and the secondary outcomes included 12-month vein graft occlusion, recurrence of angina, and major adverse cardiac and cerebrovascular events. The generalized estimate equation model was used to account for the cluster effect of grafts from the same patient. RESULTS: During the follow-up, 2533 (96.0%) participants received computed tomography angiography at 3 months after coronary artery bypass grafting and 2434 (92.2%) received it at 12 months. The no-touch group had significantly lower rates of vein graft occlusion than the conventional group both at 3 months (2.8% versus 4.8%; odds ratio, 0.57 [95% CI, 0.41-0.80]; P<0.001) and 12 months (3.7% versus 6.5%; odds ratio, 0.56 [95% CI, 0.41-0.76]; P<0.001). Recurrence of angina was also less common in the no-touch group at 12 months (2.3% versus 4.1%; odds ratio, 0.55 [95% CI, 0.35-0.85]; P<0.01). Rates of major adverse cardiac and cerebrovascular events were of no significant difference between the 2 groups. The no-touch technique was associated with higher rates of leg wound surgical interventions at 3-month follow-up (10.3% versus 4.3%; odds ratio, 2.55 [95% CI, 1.85-3.52]; P<0.001). CONCLUSIONS: Compared with the conventional vein harvesting approach in coronary artery bypass grafting, the no-touch technique significantly reduced the risk of vein graft occlusion and improved patient prognosis.

BACKGROUND:We validated the performance of seven different reagents of peroxidase method for sdLDL-C in two automatic analyzers that are common in Chinese laboratories. METHODS:Seven commercially available sdLDL-C assays were analyzed with the Beckman AU5400 and Mindray BS2000 automatic analyzers. A total of 336 blood samples were collected and the reference interval was also validated in 298 apparently healthy individuals. Serum samples were used for method comparison of precision, recovery, lower limit of detection, comparison and concurrence analysis, as well as reference interval for the Mindray reagent. RESULTS:The repeatability CV% of the seven sdLDL-C assays were 0.81%~3.66% for Mindray BS2000 and 0.76%~3.91% for Beckman AU5400, while Total CVs for Mindray BS2000 sdLDL-C assay were 1.34%~4.81%, and that of Beckman AU5400 were 2.25%~10.33%. The measured recovery rates of sdLDL-C assays were within the allowable ±10% deviation range. There was no obvious difference between the reagents in the lower limit detection. There was a difference between the validation results of the reference range and the manufacturer's.BSBE, Mindray, and Dongou had a high degree of association with DENKA SEIKEN on Mindray BS2000, while BSBE, Mindray, Dongou and Merit Choice had a high degree of association with DENKA SEIKEN on Beckman AU5400. Passing-Bablok regression showed excellent linear correlation between BSBE and Mindray and DENKA SEIKEN and on Beckman AU5400. CONCLUSIONS:Our results indicate that the basic performance can meet the testing requirements, but the comparability between them is still insufficient.

目的 探讨血清载脂蛋白E(ApoE)水平与颈动脉粥样硬化斑块的关系,评价ApoE在颈动脉粥样硬化中的作用.方法 选择2019年2-5月首都医科大学附属北京安贞医院体检中心行颈动脉超声的体检者300例为研究对象,根据体检结果 分为颈动脉内膜中层厚度(IMT)异常组(182例,包括IMT增厚组65例和颈动脉粥样硬化斑块组117例)和双侧颈动脉正常的对照组(118例).所有受试者均收集基本资料,检测空腹三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、ApoE水平.结果IMT异常组与对照组的性别构成、体质量指数(BMI)及部分既往史(吸烟、饮酒、运动、高血压和冠心病患病率)比较,差异无统计学意义(P>0.05);IMT异常组患者的年龄、糖尿病患病率高于对照组,差异有统计学意义(P<0.05).颈动脉粥样硬化斑块组、IMT增厚组与对照组的性别构成、BMI、部分既往史(吸烟、饮酒、运动、高血压和冠心病患病率)比较,3组间差异均无统计学意义(P>0.05).颈动脉粥样硬化斑块组和IMT增厚组的年龄高于对照组(P<0.01).IMT增厚组的糖尿病患病率高于颈动脉粥样硬化斑块组和对照组(P<0.01),颈动脉粥样硬化斑块组与对照组糖尿病患病率比较差异无统计学意义(P>0.05).LDL-C水平在IMT异常组高于对照组[(3.13±0.77)mmol/L vs.(2.89±0.75)mmol/L,P<0.05],在颈动脉粥样硬化斑块组、IMT增厚组与对照组3组间差异无统计学意义(P>0.05).ApoE水平在IMT异常组低于对照组[40.69±11.38)mg/Lvs.(46.84±13.46)mg/L,P<0.05];ApoE水平在颈动脉粥样硬化斑块组[(38.82±14.82)mg/L]低于IMT增厚组[(44.93±10.24)mg/L]和对照组(P<0.05).结论 ApoE水平与颈动脉粥样硬化斑块相关,ApoE水平不仅在IMT异常与健康者之间有差别,且随着斑块严重程度的发展可进一步识别出颈动脉粥样硬化斑块患者.

Giant coronary artery aneurysms (CAAs) are rare coronary artery anomalies. The management of CAAs is still controversial because of the different possible pathophysiologies. In our case, tricuspid stenosis resulting from compression of the giant CAA was successfully relieved by CAA repair. As far as we know, this is the first reported case of compression by a giant CAA resulting in tricuspid stenosis. (C) 2019 by The Society of Thoracic Surgeons

Hypoplastic right heart syndrome(HRHS) is characterized by hypoplastic right ventricle (RV); Numerous transcriptional cascades in the second heart field (SHF) regulate RVdevelopment. The relationship of SHF gene variants with human HRHS remains unknown. The whole lengths of 17 SHF genes were sequenced in 16 HRHS, and the selected single-nucleotide variants (SNVs) were then genotyped in HRHS, other congenital heart disease (CHD) and healthy control. Luciferase assay was performed to verify the effect of FOXC2: rs34221221A>GandTBX20: rs59854940C>Gat the transcription level. There were 151 (12.86%) novel SNVs after sequence analysis, of which three were in exons (one was synonymous SNV and two were nonsynonymous SNVs), two in promoter, and most SNVs (89.95%) were in intronic regions. Genotype analyses revealed that the minor alleles of FOXC2: rs34221221 A>G and TBX20: rs59854940 C>G could increase HRHS risk (P<0.05), but not in other CHD or healthy control. Luciferase assay showed that the minor G allele in rs34221221 significantly increased FOXC2 transcription while in rs59854940 it decreased TBX20 transcription significantly. Novel variants of SHF gene associated with HRHS were identified. Minor alleles in two variants from FOXC2 and TBX20 could increase the risk of HRHS.

目的:验证一种新的脂蛋白磷脂酶A2(Lp-PLA2)质量测定试剂的方法学性能.方法:选取2018年9月3日至27日在首都医科大学附属北京安贞医院就诊患者的新鲜血清标本336例,验证威海威高公司的Lp-PLA2检测试剂的精密度、线性范围、正确度、携带污染率和参考区间,用上海德赛公司Lp-PLA2试剂作为参比试剂,进行临床样本比对及医学决定水平处的偏差评估.结果:Lp-PLA2低(99.18 ng/ml)、中(244.07 ng/ml)、高(446.98 ng/ml)3个浓度样品的批内变异系数(CV)分别为4.61％、3.91％、3.76％;Lp-PLA2低(98.92 ng/ml)、中(239.90 ng/ml)、高(440.22 ng/ml)3个浓度样品的批间变异系数(CV)分别为3.91％、3.41％、2.38％,均小于规定的范围.线性范围验证回归系数a=0.998,相关系数r2=0.9927.Lp-PLA2不同浓度水平血清样品的回收率分别为101.70％、93.40％、92.40％、92.80％、95.60％、100.00％,在允许±10％偏差范围内.生物参考区间及携带污染率均符合要求.收集新鲜血清样本326例,与上海德赛公司的Lp-PLA2活性检测试剂比对,回归方程的截距和斜率分别为2.691(95％CI:-2.459～7.842)和0.336(95％CI:0.323～0.348),r为0.954,相关性良好;在医学决定水平处的预期偏差分别为-14.44％、2.77％、0.64％.结论:该Lp-PLA2化学发光法质量测定试剂盒性能验证满足要求,检测结果与上海德赛公司活性检测试剂一致性良好.

Ligustrazine is one of the alkaloid compounds isolated from the traditional Chinese herb, which shows protective effects on cardiovascular disorders. High homocysteine (Hcy) level can predict cardiovascular-related events including death. In this study, we used Hcy to stimulate the human umbilical vein endothelial cells (HUVECs) and investigated the protective effect of ligustrazine on endothelial dysfunction by assessing the cell apoptosis, oxidative damage, mitochondrial dysfunction, and the potential molecular pathways. Our results clearly showed that ligustrazine increased HUVEC cell viability, decreased the dehydrogenase (LDH) level, and inhibited HUVEC apoptosis, which was associated with the attenuation of attenuated oxidative damage. The mitochondrial-dependent pathway was closely related in the regulation of ligustrazine, reflected by the attenuated mitochondrial membrane potential change and decreased cytochrome c release from the mitochondria to the cytosol. Ligustrazine may protect Hcy-induced apoptosis in HUVECs by attenuating oxidative damage and modulating mitochondrial dysfunction.

Transcriptional factors and signaling factors in the second heart field (SHF) contribute to cardiac development. However, the associations of intronic gene variants in the SHF with congenital heart disease (CHD) remain ununderstood. Ten single nucleotide polymorphisms (SNPs) from our previous sequencing data were selected and then genotyped in 383 CHD patients and 384 healthy controls in a Chinese population. Genotype analyses revealed that minor alleles in TBX1: rs12165908 C > G [odds ratio (OR) = 2.64; 95% confidence interval (CI) = 1.87-3.73, p = 3.03 × 10-8] and GATA6: rs143085291 C > T (OR = 2.49; 95% CI = 1.18-5.29, p = 0.01) increased CHD risk significantly. Meanwhile, FGF10: rs78454549 T > C and GATA4: rs13275657 A>G polymorphisms were significantly associated with increased risk of simple CHDs. The minor allele C in GATA4: rs17153694 T > C increased the risk of tetralogy of Fallot, whereas minor alleles in TBX1: rs41298006 G>A, FGF10: rs75629618 C>T, FGF10: rs10461755 G>A, FGF10: rs75632187 A>G, and FGF10: rs12518964 G > A were associated with increased risk of single ventricle. The minor allele T in rs143085291 in GATA6 enhancer decreased the transcription level in luciferase assay. Our findings suggest that intronic SNPs in transcriptional factors and signaling factors in the SHF are significantly associated with increased risk of different CHD types.

Objective To explore the association between carotid artery plaque and small dense low-density lipoprotein cholesterol(sdLDL-C)concentrations as well as the probability of sdLDL-C and sdLDL-C/LDL-C ratio as biomarkers of human carotid atherosclerotic plaque.Methods 174 subjects in physical examination center of An Zhen Hospital from November 2015 to February 2016 were enrolled one by one as a cross-sectional study.All subjects were divided into carotid IMT abnormal group(n=92)and control group(n=82)according to carotid ultrasound.According to the thickness of IMT characterized by carotid ultrasound,subjects were divided into the thickened IMT group(n=32), plaques group(n=60), and plaques group were divided into single plaque group(n=33)and multiple plaques group(n=27).Body Mass Index(BMI), fasting serum sdLDL-C, triglyceride(TG), LDL-C and high-density lipoprotein cholesterol(HDL-C)concentrations were measured.Pearson′s and Spearman correlation coefficient analyses and logistic regression analyses were used to examine the relationships between carotid atherosclerotic plaque,sdLDL-C values,and other clinical variables.Area under curve(AUC)was calculated to determine the diagnostic value of sdLDL-C and sdLDL-C/LDL-C ratio in subjects with carotid atherosclerotic plaque. Results Levels of sdLDL-C(1.02 ±0.42 vs.0.97 ±0.46 vs.0.61 ±0.29, F=21.07, P<0.001)and sdLDL-C /LDL-C(0.34 ±0.17 vs.0.34 ±0.17 vs.0.21 ±0.09,F=16.34,P<0.001)in the thickened IMT group and the plaques group were higher than those of the control group).Even in individuals considered to be at low LDL-C(<2.59 mmol/L)level,sdLDL-C(0.94 ±0.41 vs.0.56 ±0.25,t=4.00, P<0.01)and sdLDL-C/LDL-C ratio(0.43 ±0.19 vs.0.24 ±0.08,t=4.45,P<0.01)remained higher in the carotid abnormal group than those in the control group.Age and sdLDL-C were the independent risk factors of carotid artery plaque.AUC of receiver operator characteristic curve(ROC)for serum sdLDL-C and sdLDL-C/LDL-C ratio were 0.882(95% CI:0.819-0.945, P<0.01)and 0.830(95% CI:0.747-0.914,P<0.01)to determine the multiple carotid atherosclerotic plaque,and the cut-off level were 0.90 mmol/L(sensitivity,88.0%;specificity,79.3%)and 0.30(sensitivity,84.0%;specificity,74.5%). Conclusions Carotid atherosclerotic plaque has a close relationship with sdLDL-C concentrations.sdLDL-C and sdLDL-C/LDL-C ratio can be biomarkers when assessing subjects with a carotid atherosclerotic plaque.

The prognosis of tetralogy of Fallot with absent pulmonary valve (TOF/APV) without operation is poor. We evaluated the surgical outcome of TOF/APV in a single center.

Background: Reoperation for congenital heart disease may be associated with cardiac or vascular injuries during repeat sternotomy, resulting in increased mortality and/or morbidity rates. The aim of this study was to determine the frequency of these cardiac injuries and the associated outcome.Methods: Between January 2012 and December 2013, 4256 sternotomy procedures were performed at the Pediatric Cardiac Center in Fuwai Hospital, including 195 repeat sternotomy procedures (RS). We retrospectively studied the clinical data of 195 RS patients and 250 randomly selected primary sternotomy (PS) patients. Demographic and operative details, major injures (MI), and clinical outcomes were compared between the two groups. We also assessed the risk factors for major injury and in-hospital mortality and morbidity.Results: Significant differences were observed between the RS and PS groups in terms of skin incision to cardiopulmonary bypass(CPB) time, overall CPB time, cross-clamp time and blood requirement, and ventilation time (p < 0.001). MI during RS occurred in 7 of the 195 patients (3.6 %), while operative mortality was 1.0 % (2/195). However, in the RS patients, mortality and morbidity rates were not significantly different between the MI subgroup and the non-MI subgroup (p = 1.000 and 0.556, respectively). Additionally, no significant difference was found between the RS and PS groups in terms of mortality (p = 1.000) and morbidity (p = 0.125).Conclusions: Both RS and MI are not associated with increased risk of operative mortality and morbidity. Outcomes for reoperative pediatric operations in contemporary practice are similar with those for primary operations.

目的：制作患者来源的诱导多能干细胞（hiPSC）株，构建评价不同类型心脏停搏液效果的心肌细胞模型，并对肥厚型心肌病（HCM）术中心脏停搏液的选择进行研究。<br>　　方法：收集了23例接受外科治疗的HCM患者组织样本。外显子测序发现相同的HCM突变MYH7 Arg663His突变2例，和同家系正常基因型对照2例，制作hiPSC，并向心肌细胞分化。分析hiPSC-心肌细胞的形态学和电生理特性，并在细胞缺血再灌注模型中，分析三种不同心脏停搏液对电生理活动、钙通道调控和细胞凋亡的影响。

Tradition considers that mammalian heart consists of about 70% non‐myocytes (interstitial cells) and 30% cardiomyocytes ( CM s). Anyway, the presence of telocytes ( TC s) has been overlooked, since they were described in 2010 (visit www.telocytes.com ). Also, the number of cardiac stem cells ( CSC s) has not accurately estimated in humans during ageing. We used electron microscopy to identify and estimate the number of cells in human atrial myocardium (appendages). Three age‐related groups were studied: newborns (17 days–1 year), children (6–17 years) and adults (34–60 years). Morphometry was performed on low‐magnification electron microscope images using computer‐assisted technology. We found that interstitial area gradually increases with age from 31.3 ± 4.9% in newborns to 41 ± 5.2% in adults. Also, the number of blood capillaries (per mm 2 ) increased with several hundreds in children and adults versus newborns. CM s are the most numerous cells, representing 76% in newborns, 88% in children and 86% in adults. Images of CM s mitoses were seen in the 17‐day newborns. Interestingly, no lipofuscin granules were found in CM s of human newborns and children. The percentage of cells that occupy interstitium were (depending on age): endothelial cells 52–62%; vascular smooth muscle cells and pericytes 22–28%, Schwann cells with nerve endings 6–7%, fibroblasts 3–10%, macrophages 1–8%, TC s about 1% and stem cells less than 1%. We cannot confirm the popular belief that cardiac fibroblasts are the most prevalent cell type in the heart and account for about 20% of myocardial volume. Numerically, TC s represent a small fraction of human cardiac interstitial cells, but because of their extensive telopodes, they achieve a 3D network that, for instance, supports CSC s. The myocardial (very) low capability to regenerate may be explained by the number of CSC s, which decreases fivefold by age (from 0.5% to 0.1% in newborns versus adults).

BACKGROUND:Coronary atherosclerotic unstable plaque is one of the leading causes of cardiovascular death. Macrophage-derived matrix metalloproteinase (MMP) 9 is considered for degrading extracellular matrix and collagen, thereby thinning the fibrous cap in plaques. miR-21 is implicated to play an important role in the progression of atherosclerosis. Nevertheless, miR-21 as the biomarker for coronary atherosclerotic unstable plaque remains unknown. We aimed to investigate the prediction role of miR-21 for unstable plaque by pathway study of miR-21 on MMPs and its inhibitor RECK in macrophages. METHODS:Expression of miR-21 in macrophages and serum miR-21 as well as MMP-9 was measured in patients with coronary non-calcified plaque, calcified plaque and controls. In vitro experiment was done in human macrophages by over-expressing miR-21 or down-regulating RECK. The regulation of RECK and MMP-9 by miR-21 was evaluated by western blotting and siRNA strategy. RESULTS:Patients with non-calcified coronary artery lesions had significantly higher miR-21 in macrophages and lower miR-21 serum levels compared to the control and calcified plaque patients. At the same time, the serum levels of MMP-9 were significantly elevated in non-calcified patients. Experiments in vitro indicated that over-expressing miR-21 could induce the expression and secretion of pro-MMP-9 and active-MMP-9 in human macrophages via targeting gene RECK, and knocking down RECK expression by specific siRNA can resemble that of miR-21 over-expression. CONCLUSIONS:miR-21 might be a biomarker for plaque instability by suppressing target gene RECK to promote the expression and secretion of MMP-9 in macrophages.