Changes in endothelial, leucocyte and platelet markers following contrast medium injection during angiography in patients with peripheral artery disease

Soluble Platelet Release Factors as Biomarkers for Cardiovascular Disease

Platelets are the main players in thrombotic diseases, where activated platelets not only mediate thrombus formation but also are involved in multiple interactions with vascular cells, inflammatory components, and the coagulation system. Although in vitro reactivity of platelets provides information on the function of circulating platelets, it is not a full reflection of the in vivo activation state, which may be relevant for thrombotic risk assessment in various disease conditions. Therefore, studying release markers of activated platelets in plasma is of interest. While this type of study has been done for decades, there are several new discoveries that highlight the need for a critical assessment of the available tests and indications for platelet release products. First, new insights have shown that platelets are not only prominent players in arterial vascular disease, but also in venous thromboembolism and atrial fibrillation. Second, knowledge of the platelet proteome has dramatically expanded over the past years, which contributed to an increasing array of tests for proteins released and shed from platelets upon activation. Identification of changes in the level of plasma biomarkers associated with upcoming thromboembolic events allows timely and individualized adjustment of the treatment strategy to prevent disease aggravation. Therefore, biomarkers of platelet activation may become a valuable instrument for acute event prognosis. In this narrative review based on a systematic search of the literature, we summarize the process of platelet activation and release products, discuss the clinical context in which platelet release products have been measured as well as the potential clinical relevance.

Iodinated Contrast Agents Reduce the Efficacy of Intravenous Recombinant Tissue-Type Plasminogen Activator in Acute Ischemic Stroke Patients: a Multicenter Cohort Study

This study aimed to investigate whether the application of iodinated contrast agents before intravenous (IV) recombinant tissue plasminogen activator (rt-PA) reduces the efficacy in acute ischemic stroke (AIS) patients. To determine whether the application of iodinated contrast agents before intravenous rt-PA reduces the efficacy in AIS patients. We analyzed our prospectively collected data of consecutive AIS patients receiving IV rt-PA treatment in the MISSION CHINA study. Clinical outcome at 3 months was assessed with modified Rankin Scale (mRS) score and dichotomized into good outcome (0-2) and poor outcome (3-6). Symptomatic intracerebral hemorrhage (sICH) was defined as cerebral hemorrhagic transformation in combination with clinical deterioration of National Institutes of Health Stroke Scale (NIHSS) score ≥ 4 points at 24-h. We performed logistic regression analysis and propensity score matching analysis to investigate the impact of iodinated contrast agents before IV rt-PA on poor outcome and sICH, respectively. A total of 3593 patients were finally included, and iodinated contrast agents were used before IV rt-PA among 859 (23.9%) patients. Patients in the iodinated contrast group were more likely to result in poor outcome (39.9% vs 33.4%, P = 0.001) and sICH (3.4% vs 1.5%, P < 0.001), compared with non-contrast group. Binary logistic regression analysis revealed that the application of iodinated contrast agents was independently associated with poor outcome (OR 1.342; 95% CI 1.103-1.631; P = 0.003) and sICH (OR 1.929; 95% CI 1.153-3.230; P = 0.012), respectively. After propensity score matching, the application of iodinated contrast agents was still independently associated with poor outcome (OR 1.246; 95% CI 1.016-1.531; P = 0.034) and sICH (OR 1.965; 95% CI 1.118-3.456; P = 0.019). Applying iodinated contrast agents before IV rt-PA may reduce the thrombolytic efficacy in AIS patients. Further benefit-risk analysis might be needed when iodinated contrast-used imaging is considered before intravenous thrombolysis.

Inflammatory biomarkers, vascular procedures of lower limbs, and wound healing

Abnormal, persistent inflammation after bypass surgery could prevent healing of an ischaemic foot lesion. In 37 patients with peripheral arterial disease (PAD) (Rutherford Grade III Category 5) who underwent infrapopliteal vein graft and midfoot amputation, plasma levels of fibrinogen, C-reactive protein (CRP), interleukin-1 (IL-1), interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), and matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) were determined preoperatively and during the follow up. Nine patients without clinical and Doppler evidence of arterial disease, who underwent post-traumatic midfoot primary amputation, were included in the experiment group, and 15 age-matched healthy volunteers served as control. In patients who had midfoot amputation for trauma, all wounds healed. Seven (19%) wounds in patients with an occluded graft healed, and five (13%) required major amputation because of a non-healing wound. Time required for complete healing of the lesion was similar between trauma and PAD patients (8 ± 2 months vs 11 ± 6, respectively, P = NS). Univariate analysis demonstrated that, in PAD patients, the postoperative high levels of TNF-α, IL-6, and MMP-2 and -9 were predictive for wound healing failure at 3, 6, and 9 months (P < 0.05), respectively. Furthermore, the subgroup of patients who experienced occlusion of the vein graft during follow up had a significant increase of MMP-2, -9, IL-6, and TNF-α at 3, 6, and 9 months (P < 0.05), respectively. Monitoring inflammatory markers allows the determination of patients at risk of healing failure of midfoot amputation after distal revascularisation and might predict the fate of the vein graft.

Hypotonic contrast media is more toxic than isotonic contrast media on endothelial cells in vivo and in vitro

The aim of the current study was to investigate the cytotoxic effects of hypotonic (iopamidol) and isotonic (iodixanol) contract media (CMs) in vitro and in vivo. A total of 60 Wistar rats were included and were randomly divided into three groups (20 rats per group). Iodixanol (4 g iodine/kg), iopamidol (4 g iodine/kg) or equal volume of normal saline was injected via tail vein. HUVEC and H5V cell viability was determined by Cell Counting Kit‑8 agents. Western blotting was performed to detect ATP‑binding cassette subfamily G member 1 (ABCG1) expression. For histological analysis, hematoxylin and eosin staining was performed. Plasma endothelin, von Willebrand factor, tissue type plasminogen activator, plasminogen activator inhibitor, D‑Dimer, fibrinogen, anti‑thrombin III, plasminogen and nitric oxide synthase (NOS) were measured by using ELISA. Both iopamidol and iodixanol treatments deceased cell viability and increased apoptosis of HUVEC and H5V cells, along with downregulated NOS and ABCG1. The injection of iopamidol or iodixanol into rats changed the endothelium‑related plasma levels of biomarkers, including endothelin, von Willebrand factor, tissue type plasminogen activator, plasminogen activator inhibitor, D‑Dimer, fibrinogen and anti‑thrombin III. However, endothelia isolated from rat abdominal aorta in the iodixanol group retained their normal structure, whereas endothelial structure in the iopamidol group was injured and disrupted. The findings in the present study suggested that both hypotonic and isotonic CMs may lead to endothelial dysfunction and thrombin and fibrinolytic system disorder. However, hypotonic CMs may be more toxic than isotonic CMs. Therefore, additional cautions should be taken when selecting hypotonic CMs and their dosages during cardioangiography.

Iohexol-Induced Neutrophil Myeloperoxidase Release and Activation upon Contact with Vascular Stent-Graft Material: A Mechanism Contributing to the Postimplantation Syndrome?

Purpose:

To investigate whether the contrast medium iohexol alone or in combination with vascular stent-graft material induces neutrophil degranulation.

Methods:

Human whole blood or isolated human neutrophils were incubated with or without iohexol and vascular stent-graft material. Samples were also drawn from 5 patients undergoing diagnostic angiography using iohexol. Myeloperoxidase and lactoferrin concentrations were determined by enzyme immunoassays.

Results:

Both in vitro and in the patients, iohexol induced neutrophil degranulation with considerable individual variation in dose sensitivity and timing. The in vitro effect was independent of the type of anticoagulant used (ethylenediamine tetra-acetic acid, heparin, lepirudin). Experiments using isolated neutrophils showed that degranulation was independent of complement activation or platelet-derived mediators. The dose for maximal response varied from 5 to 50 mg I/mL (10.7–107.6 mg/mL iohexol). In vitro, vascular stent-graft material alone did not induce neutrophil degranulation. As compared to iohexol alone, incubation with iohexol and vascular stent-graft material in combination substantially increased the release of myeloperoxidase.

Conclusions:

Iohexol induces neutrophil degranulation, which is greatly enhanced when combined with vascular stent-graft material. Thus, iohexol-induced neutrophil activation may contribute to an inflammatory response following stent-graft implantation. We speculate that neutrophil activation during other procedures combining catheters and iohexol (e.g., angiography) may induce inflammation, which might have detrimental effects.

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.

Heme oxygenase-1 counteracts contrast media-induced endothelial cell dysfunction

Endothelial cell (EC) dysfunction is involved in the pathogenesis of contrast-induced acute kidney injury, which is a major adverse event following coronary angiography. In this study, we evaluated the effect of contrast media (CM) on human EC proliferation, migration, and inflammation, and determined if heme oxygenase-1 (HO-1) influences the biological actions of CM. We found that three distinct CM, including high-osmolar (diatrizoate), low-osmolar (iopamidol), and iso-osmolar (iodixanol), stimulated the expression of HO-1 protein and mRNA. The induction of HO-1 was associated with an increase in NF-E2-related factor-2 (Nrf2) activity and reactive oxygen species (ROS). CM also stimulated HO-1 promoter activity and this was prevented by mutating the antioxidant responsive element or by overexpressing dominant-negative Nrf2. In addition, the CM-mediated induction of HO-1 and activation of Nrf2 was abolished by acetylcysteine. Finally, CM inhibited the proliferation and migration of ECs and stimulated the expression of intercellular adhesion molecule-1 and the adhesion of monocytes on ECs. Inhibition or silencing of HO-1 exacerbated the anti-proliferative and inflammatory actions of CM but had no effect on the anti-migratory effect. Thus, induction of HO-1 via the ROS-Nrf2 pathway counteracts the anti-proliferative and inflammatory actions of CM. Therapeutic approaches targeting HO-1 may provide a novel approach in preventing CM-induced endothelial and organ dysfunction.

Non-ionic contrast media induces oxidative stress and apoptosis through Ca²⁺ influx in human neutrophils

Non-ionic contrast media (CM) can induce tissue kidney injury via activation of phagocytosis and oxidative stress, although the mechanisms of injury via neutrophils are not clear. We investigated the effects of CM on oxidative stress and Ca²⁺ concentrations in serum and neutrophils of humans. Ten migraine patients were used in the study. Serum and neutrophil samples from patients' peripheral blood were obtained before (control) and 30 min after non-ionic (iopromide) CM injection. The neutrophils were incubated with non specific transient receptor potential 2 (TRPM2) channel blocker, 2-aminoethoxydiphenyl borate (2-APB), and voltage gated Ca²⁺ channel blockers, verapamil plus diltiazem. Serum and neutrophil lipid peroxidation, apoptosis and intracellular Ca²⁺ concentrations levels were higher in the CM group than in controls. The neutrophilic reduced glutathione (GSH) and glutathione peroxidase (GSH-Px) levels as well as serum vitamin E and β-carotene concentrations were lower in the CM group than in controls. Neutrophil lipid peroxidation levels were lower in the CM+2-APB and CM+verapamil-diltiazem groups than in the CM group, although GSH, GSH-Px and intracellular Ca²⁺ values increased in the CM+2-APB and CM+verapamil-diltiazem groups. However, caspase-3, caspase-9, vitamin A and vitamin C values were unaltered by CM treatment. In conclusion, we observed that CM induced oxidative stress and Ca²⁺ influx by decreasing vitamin E, β-carotene and Ca²⁺ release levels in human serum and neutrophils. However, we observed protective effects of Ca²⁺ channel blockers on Ca²⁺ influx in neutrophils.

Improvement of microcirculation after percutaneous transluminal angioplasty in the lower limb with prostaglandin E1

OBJECTIVE

The aim of the study was to investigate prospectively the microcirculation after angioplasty and its improvement with additional Prostaglandin E1 (PGE1) therapy assessed by transcutaneous pressure of oxygen.

PATIENTS AND METHODS

45 patients with intermittent claudication eligible for angioplasty were enrolled in a prospective randomised controlled clinical trial. Patients received either intra-arterial bolus of 40 microg PGE1 in addition to angioplasty or a 40 microg PGE1 intravenous infusion. Control group received no trial medication. Additional 15 patients undergoing intra-arterial angiography were also investigated. tcpO(2) values were recorded distal to the PTA region before, during the intervention, 24h, 2 and 4 weeks after intervention. Clinical endpoint was the change of tcpO(2) values 4 weeks after intervention.

RESULTS

During the 4 week follow-up tcpO(2) values decreased in patients treated with angioplasty. At the same time tcpO(2) increased significantly in those patients additionally treated with intra-arterial PGE1 bolus injection as well as with intravenous PGE1 infusion.

CONCLUSIONS

Impaired microcirculation after angioplasty can be improved with additional intravenous as well as intra-arterial PGE1 administration.

Role of adhesion molecules in the induction of restenosis after angioplasty in the lower limb

OBJECTIVE

The adhesion molecules P selectin, E selectin, intercellular adhesion molecule, vascular cellular adhesion molecule (VCAM), and monocyte chemoattractant protein 1 play a important role in the development of arteriosclerotic lesions and are considered main contributors to restenosis after angioplasty. We expected that the serum levels of these markers would increase in the early phase of the first few weeks after angioplasty.

METHODS

We assessed prospectively the levels of soluble forms of adhesion molecules on the day before and then 24 hours and 2 and 4 weeks after angioplasty in arteries of the lower limb by using enzyme-linked immunosorbent assays. We investigated the distribution pattern of these markers in 44 patients (25 male and 19 female; age, 67.7 +/- 8.5 years [mean +/- SD]) presenting with intermittent claudication (Fontaine stage IIb). Twelve patients (27.3%) underwent diagnostic angiography, 32 (72.2%) received interventional treatment, 22 (68.8%) received balloon angioplasty, and 10 (31.2%) required stent placement.

RESULTS

Ten (31.3%) of the treated patients developed restenosis within 6 months. These patients had significantly higher levels of P selectin (P = .034), E selectin (P = .006), and VCAM (P = .050) at all time points. E selectin, VCAM, and monocyte chemoattractant protein 1 levels increased between 24 hours and 4 weeks after angiographic procedures, thus indicating that the angiographic procedure itself leads to activation and inflammation of the endothelium.

CONCLUSIONS

This study emphasizes a meaningful role of the adhesion molecules E selectin, P selectin, and VCAM as interesting contributors to restenosis formation after percutaneous transluminal angioplasty.

Effects of iodinated contrast media on blood and endothelium

The aim of the study was to assess the effects of iodinated contrast media on blood components and endothelium based on experimental and clinical studies and to produce clinically relevant guidelines for reducing thrombotic and hematologic complications following the intravascular use of contrast media. A report was drafted after review of the literature and discussions among the members of the Contrast Media Safety Committee of the European Society of Urogenital Radiology. The final report was produced following discussion at the 12th European Symposium on Urogenital Radiology in Ljubljana, Slovenia (2005). Experimental data indicate that all iodinated contrast media produce an anticoagulant effect and that this effect is greater with ionic contrast media. Several of the in vitro and experimental in vivo studies on haematological effects of contrast media have not been confirmed by clinical studies. Low- or iso-osmolar contrast media should be used for diagnostic and interventional angiographic procedures, including phlebography. Meticulous angiographic technique is the most important factor for reducing the thrombotic complications associated with angiographic procedures. Drugs and interventional devices that decrease the risk of thromboembolic complications during interventional procedures minimize the importance of the effects of contrast media.

Inflammatory markers increase following exposure to radiographic contrast media

PURPOSE

Increased levels of markers of systemic inflammation have been noted in patients following coronary angiographic procedures. The purpose of the present study was to examine the influence of the type of the angiographic procedure as well as the type of radiographic contrast media (RCM) on markers of inflammation.

MATERIAL AND METHODS

Thirty-seven patients undergoing diagnostic or interventional coronary angiographic procedures were randomly assigned to receive one of three RCM - an ionic low osmolar agent; a non-ionic, iso-osmotic agent; or a non-ionic, low osmolar agent. Sera were analyzed at baseline (prior to receiving RCM), and at 2, 6 and 24 h thereafter for interleukin (IL)-6 and soluble receptors for tumor necrosis factor alpha (TNFalpha)-1 and TNFalpha- 2.

RESULTS

Statistically significant increases over time in each RCM group were noted for IL-6 and both TNFalpha receptors. Comparable increases in inflammatory markers were observed in patients undergoing diagnostic angiography and in patients undergoing an associated coronary intervention. While these markers increased following exposure to both ionic and non-ionic RCM, there was a consistent trend towards lessened marker release with non-ionic RCM.

CONCLUSION

Both diagnostic and interventional coronary angiographic procedures are associated with an increase in serum inflammatory markers. While both ionic and non-ionic RCM are associated with increases in serum inflammatory markers, this increase may be attenuated with non-ionic RCM.

Activation of circulating platelets in patients with peripheral arterial disease during digital subtraction angiography and percutaneous transluminal angioplasty

Platelet activation plays a crucial role in the pathogenesis of coronary heart disease (CHD), peripheral arterial disease (PAD) and cerebral ischaemia, the three main clinical manifestations of atherosclerosis. Circulating-activated platelets are thought to trigger ischaemic complications after angiography, angioplasty and vascular surgery. We studied activation of circulating thrombocytes in patients with PAD and evaluated the influence on platelet activation of intraarterial digital subtraction angiography (DSA) and percutaneous transluminal angioplasty (PTA) in the area of the lower extremities. Our study included 16 control subjects with PAD (clinical stage IIb according to Fontaine), 25 healthy control subjects and 34 PAD patients (clinical stage IIb according to Fontaine), 14 of whom we examined during DSA, 10 during PTA and 10 which we studied during both interventions. To characterize platelet ex vivo activation, the expression of activation-dependent platelet antigens (CD62 and CD63) was measured using flow cytometry. Platelet sensitization was analysed by an additional in vitro activation. Our results show that angioplasty in peripheral vessels causes activation and presumably slight migration or a reduction in the life span of circulating thrombocytes immediately after the PTA procedure and up to 4 h afterwards. DSA was also found to be associated with platelet activation, sensitization and presumptive minor migration or shortened life span of circulating platelets. Immediately after the intervention, PTA seems to influence platelet migration or shortened lifetime of platelets to a greater extent than DSA. We postulate that this is mainly induced by dilatation. More activated and sensitized thrombocytes circulated in patients with PAD compared to healthy control subjects. This supports our assumption that preactivated platelets are particularly involved in activation, sensitization and migration processes or affected by a reduced life span.