Association between NLRP3 inflammasome and periprocedural myocardial injury following elective PCI

Background

Periprocedural myocardial injury (PMI) is a common complication of percutaneous coronary intervention (PCI) associated with poor prognosis. Inflammation has been demonstrated to exert a crucial role in PMI. However, how the inflammation is initiated or sustained in PMI remains elusive.

Methods

RNA-seq in peripheral blood mononuclear cells (PBMCs) from 3 Non-PMI and 6 PMI patients was performed with subsequent bioinformatics analysis. RNA-seq results were verified in a patient cohort. We also established the coronary microembolization (CME) mice model to mimic PMI. The activity of caspase-1 in PBMCs was detected by flow cytometry. The levels of interleukin (IL)-1β, IL-18 and cardiac troponin in plasma were measured by enzyme-linked immunosorbent assay.

Results

We identified a total of 901 differentially expressed genes (DEGs) between Non-PMI and PMI patients. These DEGs participated in several inflammation-related processes. NOD-like receptor signaling pathway was significantly enriched in pathway analysis. All the key genes composed in the NLRP3 inflammasome, including NLRP3, PYCARD, CASP1 and IL1B, were upregulated in PMI patients. The activation of NLRP3 inflammasome was then verified by increased activity of caspase-1 in PBMCs, and elevated levels of IL-1β and IL-18 in plasma in PMI patients. Spearman analysis confirmed tight correlations between caspase-1 activity, IL-1β, IL-18 levels and troponin T level. In addition, caspase-1 activity, IL-1β and IL-18 levels were also enhanced in CME mice.

Conclusions

We discovered that NLRP3 inflammasome was involved in PMI, thus providing evidence supporting the therapeutic value of NLRP3 inflammasome-targeted strategies in PMI.

Longitudinal profile of circulating endothelial cells in post-acute coronary syndrome patients

IntroductionPatients who have experienced an acute coronary syndrome (ACS) are at risk of a recurrent event, but their level of risk varies. Because of their close temporal relationship with vascular injury, longitudinal measurements of circulating endothelial cells (CECs) carry potential to improve individual risk assessment.MethodsWe conducted an explorative nested case-control study within our multicenter, prospective, observational biomarker study (BIOMArCS) of 844 ACS patients. Following an index ACS, high-frequency blood sampling was performed during 1-year follow-up. CECs were identified using flow cytometric analyses in 15 cases with recurrent event, and 30 matched controls.ResultsCases and controls had a median (25^th-75^thpercentile) age of 64.1 (58.1-75.1) years and 80% were men. During the months preceding the endpoint, the mean (95%CI) CEC concentration in cases was persistently higher than in controls (12.8 [8.2-20.0] versus 10.0 [7.0-14.4] cells/ml), although this difference was non-significant (P = 0.339). In controls, the mean cell concentration was significantly (P = 0.030) lower in post 30-day samples compared to samples collected within one day after index ACS: 10.1 (7.5-13.6) versus 17.0 (10.8-26.6) cells/ml. Similar results were observed for CEC subsets co-expressing CD133 and CD309 (VEGFR-2) or CD106 (VCAM-1).ConclusionDespite their close relation to vascular damage, no increase in cell concentrations were found prior to the occurrence of a secondary adverse cardiac event.

Atherosclerotic-Derived Endothelial Cell Response Conducted by Titanium Oxide Nanotubes

Atherosclerosis lesions are described as the formation of an occlusive wall-vessel plaque that can exacerbate infarctions, strokes, and even death. Furthermore, atherosclerosis damages the endothelium integrity, avoiding proper regeneration after stent implantation. Therefore, we investigate the beneficial effects of TiO₂ nanotubes (NTs) in promoting the initial response of detrimental human atherosclerotic-derived endothelial cells (AThEC). We synthesized and characterized NTs on Ti6Al4V by anodization. We isolated AThEC and tested the adhesion long-lasting proliferation activity, and the modulation of focal adhesions conducted on the materials. Moreover, ultrastructural cell-surface contact at the nanoscale and membrane roughness were evaluated to explain the results. Our findings depicted improved filopodia and focal adhesions stimulated by the NTs. Similarly, the NTs harbored long-lasting proliferative metabolism after 5 days, explained by overcoming cell-contact interactions at the nanoscale. Furthermore, the senescent activity detected in the AThEC could be mitigated by the modified membrane roughness and cellular stretch orchestrated by the NTs. Importantly, the NTs stimulate the initial endothelial anchorage and metabolic recovery required to regenerate the endothelial monolayer. Despite the dysfunctional status of the AThEC, our study brings new evidence for the potential application of nano-configured biomaterials for innovation in stent technologies.

Effect of invasive therapeutic coronary interventions on endothelial cell activation and thrombin generation in patients with chronic total coronary occlusion

BACKGROUND

Percutaneous coronary intervention (PCI) is commonly used treatment for chronic total occlusion (CTO). PCI can be performed in two different ways using wire escalation (WE) or subintimal dissection and reentry (DR) technique. During both procedures patients are treated with anticoagulants, however a substantial activation of coagulation cascade is expected, which may affect clinical outcome.

OBJECTIVES

Our aim was to compare the impact of WE and DR techniques regarding endothelial cell activation and thrombin formation.

METHODS

Fifty patients after CTO-PCI were enrolled into this study. Blood samples were obtained before PCI, at 48 h and 3-6 months after the intervention to measure soluble endothelium-specific markers and to investigate thrombin generation.

RESULTS

Twenty-nine patients were treated with WE, 21 received DR. In the DR group, soluble VCAM-1 (vascular cell adhesion molecule-1) and ICAM-1 (intercellular cell adhesion molecule-1) concentrations were gradually elevated and remained significantly increased at 3-6 months (p = 0.006 and p = 0.037, respectively) compared to pre-PCI. Furthermore, significant decrease in lagtime (p = 0.004) and time to peak (p = 0.002) with a substantial increment in peak thrombin (p = 0.001) were observed in these patients. In contrast, no significant alteration was found in the WE cohort. Clinical complications (myocardial infarction, stroke, thrombosis, revascularization) did not occur in the first 9 months of follow-up period in either group.

CONCLUSION

Although DR intervention induces more thrombin generation with a larger degree of endothelium activation compared to WE, this technique does not cause more clinical complications.

Persistent circulating platelet and endothelial derived microparticle signature may explain on-going pro-thrombogenicity after acute coronary syndrome

AIMS

Microparticles (MPs) are submicron vesicles, released from activated, and apoptotic cells. MPs are elevated in the circulation of patients with coronary artery disease (CAD) and have pro-thrombotic potential. However, limited data exists on MP signature over time following an acute coronary event.

METHODS & RESULTS

Circulating total annexin v + (Anv+) MPs of endothelial (EMP), platelet (PMP), monocyte (MMP), neutrophil (NMP) and smooth muscle cell (SMMP) origin were quantified by flow cytometry. 13 patients with acute coronary syndrome (ACS) were prospectively enrolled and 12 patients with stable angina (SA) were included as a comparator group. A panel of MP was measured at baseline, after percutaneous coronary intervention (PCI) and at days 1, 7, 30 and 6 months. Intra & inter group comparison was made between various time points. MP mediated thrombin generation was measured by recording lag phase, velocity index, peak thrombin and endogenous thrombin potential at these time points and compared with healthy controls. The total AnV+ MP levels were similar in ACS and SA groups at baseline, peaked immediately after PCI and were at their lowest on day 1. PMP & EMP levels remained significantly elevated in ACS patients at 6 months when compared to SA. No such difference was noted with NMP, MMP and SMMP. Patients with coronary artery disease showed abnormal thrombograms when compared to controls. Peak thrombin (nano moles) was significantly higher in CAD when compared to controls (254 IQR [226, 239] in ACS, 255 IQR [219, 328] in SA and 132 IQR [57, 252] in controls; p = 0.006). Differences in thrombin generation between ACS and SA were not significant (p = 1). Furthermore, thrombin parameters remained abnormal in ACS & SA patients at 6 months.

CONCLUSIONS

Total MP and individual MP phenotypes were significantly elevated after PCI reflecting endothelial injury. Elevated PMP and EMP levels at 6 months in ACS patients is suggestive of on-going inflammation, endothelial injury and may explain on-going pro-thrombogenicity seen up to 6 months after ACS despite dual antiplatelet therapy.

Inflammation during Percutaneous Coronary Intervention-Prognostic Value, Mechanisms and Therapeutic Targets

Periprocedural myocardial injury and myocardial infarction (MI) are not infrequent complications of percutaneous coronary intervention (PCI) and are associated with greater short- and long-term mortality. There is an abundance of preclinical and observational data demonstrating that high levels of pre-, intra- and post-procedural inflammation are associated with a higher incidence of periprocedural myonecrosis as well as future ischaemic events, heart failure hospitalisations and cardiac-related mortality. Beyond inflammation associated with the underlying coronary pathology, PCI itself elicits an acute inflammatory response. PCI-induced inflammation is driven by a combination of direct endothelial damage, liberation of intra-plaque proinflammatory debris and reperfusion injury. Therefore, anti-inflammatory medications, such as colchicine, may provide a novel means of improving PCI outcomes in both the short- and long-term. This review summarises periprocedural MI epidemiology and pathophysiology, evaluates the prognostic value of pre-, intra- and post-procedural inflammation, dissects the mechanisms involved in the acute inflammatory response to PCI and discusses the potential for periprocedural anti-inflammatory treatment.

Prognostic value of plasma von Willebrand factor levels in major adverse cardiovascular events: a systematic review and meta-analysis

BACKGROUND

Prediction of major adverse cardiovascular events (MACEs) may offer great benefits for patients with coronary artery disease (CAD). Von Willebrand factor (vWF) is stored in endothelial cells and released into blood plasma upon vascular dysfunction. This meta-analysis was performed to evaluate the prognostic value of plasma vWF levels in CAD patients with MACEs.

METHODS

A total of 15 studies were included in this meta-analysis through the search in PubMed, Embase and CNKI. Data were collected from 960 patients who had MACEs after CAD and 3224 controls nested without the adverse events. The standard mean difference (SMD) and 95% confidence intervals (95% CI) were calculated using random-effects model.

RESULTS

The plasma vWF levels examined at 24 h and 48 h after admission were significantly higher in CAD patients with MACEs than those without. The pooled SMD among the MACEs group and the non-MACEs group was 0.55 (95% CI = 0.30-0.80, P < 0.0001) and 0.70 (95% CI = 0.27-1.13, P = 0.001), respectively. However, no significant difference was found in plasma vWF levels on admission between the two groups.

CONCLUSION

Plasma vWF level in CAD patients examined at 24 h and 48 h after admission might be an independent prognostic factor for MACE.

Danhong injection mobilizes endothelial progenitor cells to repair vascular endothelium injury via upregulating the expression of Akt, eNOS and MMP-9

BACKGROUD

Endothelial progenitor cells (EPCs) have been characterized as one of the key effectors of endothelial healing. The effect of Danhong injection (DHI), the most widely prescribed Chinese medicine for coronary heart disease (CHD), on EPCs mobilization remains unclear.

PURPOSE

We aimed to assess the effect of DHI on EPCs mobilization to repair percutaneous coronary intervention (PCI) induced vascular injury, and to investigate the characteristics and potential mechanism of DHI on EPCs mobilization.

METHOD

Forty-two patients with CHD underwent PCI and received stent implantation were enrolled in a Phase II clinical trials. All patients received routine western medical treatment after PCI, patients of DHI group received DHI in addition. The levels of CECs, cytokines (vWF, IL-6, CRP) and EPCs were analyzed at baseline, post-PCI and after treatment. To investigate the characteristics of DHI on EPCs mobilization, 12 healthy volunteers received intravenous infusion of DHI once and the other 12 received for 7 days. EPCs enumeration were done at a series of time points. At last we tested the effect of DHI and three chemical constituents of DHI (danshensu; lithospermic acid, LA; salvianolic acid D, SaD) on EPCs level and expression of Akt, eNOS and MMP-9 in bone marrow cells of myocardial infarction (MI) mice.

RESULTS

In the DHI group the angina symptoms were improved, the levels of cytokines and CECs were reduced; while EPCs population was increased after treatment. In the phase I clinical trials, EPCs counts reached a plateau phase in 9 h and maintained for more than 10 h after a single dose. After continuous administration, EPCs levels plateaued on the 3rd or 4th day, and maintain till 1 day after the withdrawal, then its levels gradually declined. DHI treatment induced a timely dependent mobilization of EPCs. DHI promoted EPCs mobilization via upregulating the expression of Akt, eNOS and MMP-9 in BM. LA and SaD have played a valuable role in EPCs mobilization.

CONCLUSION

These initial results demonstrated that DHI is effective in alleviating endothelial injury and promoting endothelial repair through enhancing EPCs mobilization and revealed the effect feature and possible mechanisms of DHI in mobilizing EPCs.

Endothelial cell activation is attenuated by everolimus via transcriptional and post-transcriptional regulatory mechanisms after drug-eluting coronary stenting

We previously found higher level of endothelial cell (EC) activation in patients who suffered from in-stent restenosis after bare-metal stenting compared to subjects who underwent drug-eluting stenting (DES) showing no complications. Here we investigated the potential transcriptional and post-transcriptional regulatory mechanisms by which everolimus attenuated EC activation after DES. We studied the effect of everolimus on E-selectin (SELE) and VCAM1 mRNA levels when human coronary artery (HCAECs) and human umbilical vein ECs were challenged with recombinant TNF-α (100 ng/mL) for 1–24 hours in the presence or absence of everolimus using 0.5 μM concentration locally maintained by DES. EC activation was evaluated via the levels of IL-1β and IL-6 mRNAs with miR-155 expression by RT-qPCR as well as the nuclear translocation of nuclear factor kappa beta (NF-κB) detected by fluorescence microscopy. To investigate the transcriptional regulation of E-selectin and VCAM-1, TNF-α-induced enhancer RNA (eRNA) expression at p65-bound enhancers in the neighboring genomic regions of SELE and VCAM1 genes, including SELE_-11Kb and VCAM1_-10Kb, were measured in HCAECs. Mature and precursor levels of E-selectin and VCAM-1 repressor miR-181b were quantified to analyze the post-transcriptional regulation of these genes in HCAECs. Circulating miR-181b was analyzed in plasma samples of stented subjects by stem-loop RT-qPCR. TNF-α highly elevated E-selectin and VCAM-1 expression at transcriptional level in ECs. Levels of mature, pre- and pri-miR-181b were repressed in ECs by TNF-α, while everolimus acted as a negative regulator of EC activation via inhibited translocation of NF-κB p65 subunit into cell nuclei, lowered eRNA expression at SELE and VCAM1 genes-associated enhancers and modulated expression of their post-transcriptional repressor miR-181b. Significant negative correlation was observed between plasma miR-181b and soluble E-selectin and VCAM-1 in patients. In conclusion, everolimus attenuates EC activation via reduced NF-κB p65 translocation causing decreased E-selectin and VCAM-1 expression at transcriptional and post-transcriptional level after DES.

Treatment of Danhong Injection Combined with Naoxintong Capsule in Acute Coronary Syndrome Patients Undergoing PCI Operation: Study for a Randomized Controlled and Double-Blind Trial

Objective

This double-blind and randomized placebo-controlled trial evaluated the safety and efficacy of Danhong injection combined with Naoxintong capsule in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI).

Methods

ACS patients scheduled to undergo PCI (n = 130) were equally and randomly apportioned to either a treatment or control group. After PCI, the treatment group received Danhong injection combined with Naoxintong capsule for 12 weeks, while the control group was given placebo. Both groups were otherwise treated with conventional secondary prevention of coronary artery disease. The groups were primarily evaluated for clinical efficacy and cardiovascular events. Evaluative indicators of safety included adverse events, platelet count, and liver, renal, and blood coagulation functions.

Result

No cardiovascular events or adverse reactions were observed in either group. The treatment group demonstrated better signs of clinical efficacy, including left ventricular ejection fraction, higher nitric oxide levels, and lower levels of endothelin-1 (ET-1) and von Willebrand factor (VWF).

Conclusion

ACS patients treated with Danhong injection combined with Naoxintong capsule after PCI demonstrated better improvement with regard to markers associated with atherosclerosis and adverse cardiovascular events, without apparent adverse effects. Thus, Danhong injection combined with Naoxintong capsule was safe and effective for treating ACS patients after PCI.

Coagulation, Fibrinolysis, and Platelet Activation Following Open Surgical or Percutaneous Angioplasty Revascularization for Symptomatic Lower Limb Chronic Ischemia

Introduction:

Critical limb ischemia (CLI) is associated with a prothrombotic diathesis that involves a complex balance between the coagulation and fibrinolytic systems. Knowledge of this is essential when considering revascularization procedures but is often overlooked. The aim of this review is to summarize the available literature and provide an overview of the effects of lower limb angioplasty and open surgical revascularization on coagulation, fibrinolysis, and platelet activation.

Methods:

A MEDLINE and EMBASE search was conducted between 1973 and 2014 for articles relating to the effects of revascularization for patients with CLI on the fibrinolytic and coagulation pathways. Studies with a small cohort of patients (<5) were rejected.

Results:

Many of the studies included in this analysis had small cohorts. Multiple markers were assessed across the published literature including von Willebrand factor, tissue factor, prothrombin fragments 1 and 2, platelets, soluble platelet selectin, plasminogen activator inhibitor 1, tissue plasminogen activator, and thrombin–antithrombin complex. Percutaneous intervention causes an exaggerated prothrombotic and a disturbed fibrinolytic effect. Surgery seems to cause a similar prothrombotic derangement with reduced fibrinolysis and platelet hyperactivity, but this appears to be maintained for a considerable amount of time postoperatively.

Conclusion:

There is a sparse amount published on the effects of the coagulation and fibrinolytic systems in patients undergoing intervention for CLI. Much of these studies are small, historical, and completely heterogeneous, making it difficult to draw meaningful conclusions. The literature does identify a prothrombotic state in patients with CLI, which appears to be exacerbated by any form of intervention and prolonged in those having surgery. Understanding this may allow us to tailor the intervention offered to patients and prevent limb loss.

Effect of High Dose Statin Pretreatment on Endothelial Progenitor Cells After Percutaneous Coronary Intervention (HIPOCRATES Study)

BACKGROUND

Pretreatment with high-dose statins given before percutaneous coronary intervention (PCI) has been shown to have beneficial effects, in particular by reducing peri-procedural myocardial infarction. The mechanism of these lipid-independent beneficial statin effects is unclear. Circulating endothelial progenitor cells (EPCs) have an important role in the process of vascular repair, by promoting re-endothelization following injury. We hypothesized that statins can limit the extent of endothelial injury induced by PCI and promote re-endothelization by a positive effect on EPCs. We, therefore, aimed to examine the effect of high-dose statins given prior to PCI on EPCs profile.

METHODS

Included were patients, either statin naïve or treated chronically with low-dose statins, with stable or unstable angina who underwent PCI. Patients were randomized to receive either high-dose atorvastatin (80 mg the day before PCI and 40 mg 2-4 h before PCI) or low- dose statin. EPCs profile was examined before PCI and 24 h after it. Circulating EPCs levels were assessed by flow cytometry as the proportion of peripheral mononuclear cells co-expressing VEGFR-2+ CD133+ and VEGFR-2+ CD34+. The capacity of the cells to form colony forming units (CFUs) was quantified after 7 days of culture.

RESULTS

Twenty three patients (mean age 61.4 ± 7.4 years, 87.0% men) were included in the study, of which 12 received high-dose atorvastatin prior to PCI. The mean number of EPC-CFUs before PCI was higher in patients treated with high-dose atorvastatin vs. low-dose statins (165.8 ± 58.8 vs. 111.7 ± 38.2 CFUs/plate, respectively, p < 0.001). However, 24 h after the PCI, the number of EPC-CFUs was similar (188.0 ± 85.3 vs. 192.9 ± 66.5 CFUs/plate in patients treated with high-dose atorvastatin vs. low- dose statins, respectively, p = 0.15). There were no statistical significant differences in FACS analyses between the 2 groups.

CONCLUSIONS

The current study showed higher EPC- CFUs levels in patients treated with high-dose atorvastatin before PCI and a lower increment in EPC-CFUs after PCI. These findings could account for the beneficial effects of statins given prior to PCI, yet further investigation is required.

Integrity(®) bare-metal coronary stent-induced platelet and endothelial cell activation results in a higher risk of restenosis compared to Xience(®) everolimus-eluting stents in stable angina patients

Drug-eluting stenting (DES) has become a reliable tool for coronary stenting; however, its direct effects on platelet and endothelium function differ from those of bare-metal stenting (BMS). This study involved a periprocedural analysis of various biomarkers of cellular activation after elective DES (Xience(®), Abbott Vascular, Santa Clara, CA, USA) or BMS (Integrity(®), Medtronic, Minneapolis, MI, USA). Forty-nine stable angina patients were recruited: 28 underwent BMS, and 21 received everolimus-eluting stents. Samples were collected (i) prior to stenting, (ii) at 24 hours after procedure, and (iii) after 1 month of dual antiplatelet therapy. Platelet activation was analyzed by surface P-selectin positivity in parallel with plasma levels of soluble P-selectin, CD40L and platelet-derived growth factor (PDGF). Endothelial cell (EC) activation was detected by measuring markers of early (von Willebrand factor) and delayed response (VCAM-1, ICAM-1, E-selectin). Patients were followed for 6 months for the occurrence of restenosis or stent thrombosis. Increased platelet activation was sustained regardless of stent type or antiplatelet medication. Concentrations of most EC markers were more elevated after BMS than after DES. No stent thrombosis was seen, but six BMS subjects displayed restenosis with significantly higher sCD40L (779 [397-899] vs. 381 [229-498] pg/mL; p = 0.032) and sICAM-1 (222 [181-272] vs. 162 [153-223] ng/mL; p = 0.046) levels than in those without complication, while DES patients exhibited significantly decreased PDGF (572 [428-626] vs. 244 [228-311] pg/mL; p = 0.004) after 1 month. Nonresponsiveness to antiplatelet drugs did not influence these changes. In conclusion, the degree of platelet and EC activation suggests that Xience(®) DES may be regarded a safer coronary intervention than Integrity(®) BMS, with a lower risk of in-stent restenosis.