Effect of clopidogrel added to aspirin before percutaneous coronary intervention on the risk associated with C-reactive protein

The role of P2Y12 receptor in ischemic stroke of atherosclerotic origin

Atherosclerosis is a chronic and progressive disease of the arterial walls and a leading cause of non-cardioembolic ischemic stroke. P2Y12 is a well-recognized receptor that is expressed on platelets and is a target of thienopyridine-type antiplatelet drugs. In the last few decades, P2Y12 receptor inhibitors, such as clopidogrel, have been applied for the secondary prevention of non-cardioembolic ischemic stroke. Recent clinical studies have suggested that these P2Y12 receptor inhibitors may be more effective than other antiplatelet drugs in patients with ischemic stroke/transient ischemic attack of atherosclerotic origin. Moreover, animal studies have also shown that the P2Y12 receptor may participate in atherogenesis by promoting the proliferation and migration of vascular smooth muscle cells (VSMCs) and endothelial dysfunction, and affecting inflammatory cell activities in addition to amplifying and maintaining ADP-induced platelet activation and platelet aggregation. P2Y12 receptor inhibitors may also exert neuroprotective effects after ischemic stroke. Thus, P2Y12 receptor inhibitors may be a better choice for secondary prevention in patients with atherosclerotic ischemic stroke subtypes because of their triple functions (i.e., their anti-atherosclerotic, anti-platelet aggregation, and neuroprotective activities), and the P2Y12 receptor may also serve as a noval therapeutic target for atherosclerosis. In this review, we summarize the current knowledge on the P2Y12 receptor and its key roles in atherosclerosis and ischemic stroke of atherosclerotic origin.

High-sensitive C-reactive protein and dual antiplatelet in intracranial arterial stenosis

Objective

To determine the relationship of high-sensitive C-reactive protein (hsCRP) and the efficacy and safety of dual antiplatelet therapy in patients with and without intracranial arterial stenosis (ICAS) in the Clopidogrel in High-Risk Patients with Acute Non-disabling Cerebrovascular Events (CHANCE) trial.

Methods

A subgroup of 807 patients with both magnetic resonance angiography images and hsCRP measurement was analyzed. Cox proportional hazards models were used to assess the interaction of hsCRP levels with the effects of dual and single antiplatelet therapy.

Results

A total of 358 (44.4%) patients had ICAS and 449 (55.6%) did not. The proportion of patients with elevated hsCRP levels was higher in the ICAS group than in the non-ICAS group (40.2% vs 30.1%, p = 0.003). There was significant interaction between hsCRP and the 2 antiplatelet therapy groups in their effects on recurrent stroke after adjustment for confounding factors in the patients with ICAS (p = 0.012), but not in those without (p = 0.256). Compared with aspirin alone, clopidogrel plus aspirin significantly reduced the risk of recurrent stroke only in the patients with ICAS and nonelevated hsCRP levels (adjusted hazard ratio 0.27; 95% confidence interval 0.11 to 0.69; p = 0.006). Similar results were observed for composite vascular events. No significant difference in bleeding was found.

Conclusions

Presence of both ICAS and nonelevated hsCRP levels may predict better response to dual antiplatelet therapy in reducing new stroke and composite vascular events in minor stroke or high-risk TIA patients. Further large-scale randomized and controlled clinical trials are needed to confirm this finding.

Platelets, inflammation and anti-inflammatory effects of antiplatelet drugs in ACS and CAD

Platelets play a pivotal role in chronic inflammation leading to progression of atherosclerosis and acute coronary events. Recent discoveries on novel mechanisms and platelet-dependent inflammatory targets underpin the role of platelets to maintain a chronic inflammatory condition in cardiovascular disease. There is strong and clinically relevant crosslink between chronic inflammation and platelet activation. Antiplatelet therapy is a cornerstone in the prevention and treatment of acute cardiovascular events. The benefit of antiplatelet agents has mainly been attributed to their direct anti-aggregatory impact. Some anti-inflammatory off-target effects have also been described. However, it is unclear whether these effects are secondary due to inhibition of platelet activation or are caused by direct distinct mechanisms interfering with inflammatory pathways. This article will highlight novel platelet associated targets that contribute to inflammation in cardiovascular disease and elucidate mechanisms by which currently available antiplatelet agents evolve anti-inflammatory capacities, in particular by carving out the differential mechanisms directly or indirectly affecting platelet mediated inflammation. It will further illustrate the prognostic impact of antiplatelet therapies by reducing inflammatory marker release in recent cardiovascular trials.

Effects of clopidogrel therapy on oxidative stress, inflammation, vascular function, and progenitor cells in stable coronary artery disease

BACKGROUND

Traditional cardiovascular risk factors lead to endothelial injury and activation of leukocytes and platelets that initiate and propagate atherosclerosis. We proposed that clopidogrel therapy in patients with stable coronary artery disease imparts a pleiotropic effect that extends beyond antiplatelet aggregation to other atheroprotective processes.

METHODS

Forty-one subjects were randomized in a double-blind, placebo-controlled, crossover study to receive either clopidogrel 75 mg daily or placebo for 6 weeks and then transitioned immediately to the other treatment for an additional 6 weeks. We assessed (1) endothelial function as flow-mediated dilation of the brachial artery, (2) arterial stiffness and central augmentation index using applanation tonometry, (3) vascular function as fingertip reactive hyperemia index, (4) inflammation by measuring plasma CD40 ligand and serum high-sensitivity c-reactive protein levels, (5) oxidative stress by measuring plasma aminothiols, and (6) circulating progenitor cells, at baseline and at the end of each 6-week treatment period.

RESULTS

Clopidogrel therapy resulted in a significant reduction in soluble CD40 ligand (P = 0.03), a prothrombotic and proinflammatory molecule derived mainly from activated platelets. However, clopidogrel therapy had no effect on endothelial function, arterial stiffness, inflammatory and oxidative stress markers, or progenitor cells.

CONCLUSIONS

Our findings suggest a solitary antiplatelet effect of clopidogrel therapy in patients with stable coronary artery disease, with no effect on other subclinical markers of cardiovascular disease risk.

Effects of weight loss and pharmacotherapy on inflammatory markers of cardiovascular disease

Obesity is currently an epidemic, and the prevalence of cardiovascular risk factors is increasing dramatically as a result. Visceral adiposity is correlated with a proinflammatory and prothrombotic state that is believed to promote atherosclerosis and acute coronary syndromes. This article will review clinical trials on the effects of weight loss and pharmacotherapy on obesity associated inflammatory and thrombotic markers linked with cardiovascular disease.

C-reactive protein, cardiovascular disease and stroke: new roles for an old biomarker

Stroke is a leading cause of death and disability worldwide. A new and exciting development in cardiovascular disease is the recognition of the role of inflammation in atherosclerosis. C-reactive protein, an acute phase reactant, appears to be a promising biomarker for cardiovascular disease, possibly more predictive than cholesterol and also may play an etiological role. C-reactive protein also appears to be predictive of stroke risk, although less so in the elderly. Although the number of studies on stroke (apart from cardiovascular disease) is limited, there is a significant graded increase in stroke risk within the low-to-high normal range of C-reactive protein. C-reactive protein is readily amenable to treatment with anti-inflammatory drugs, such as aspirin and statins. New and increasingly available high-sensitivity assays may make C-reactive protein a standard screening tool for cardiovascular disease.

Association of baseline C-reactive protein levels with periprocedural myocardial injury in patients undergoing percutaneous bifurcation intervention: a CACTUS study subanalysis

OBJECTIVES

To assess the predictive value of C-reactive protein (CRP) on periprocedural myocardial injury (PMI), evaluated by creatine kinase-myocardial band isoform (CK-MB) elevation in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation for the treatment of coronary bifurcation lesions is actually unknown.

BACKGROUND

Systemic inflammation as assessed by CRP has been associated with averse events after DES implantation. After PCI, the occurrence of PMI is common and has also been associated with worse outcomes. Finally, bifurcations are frequently encountered anatomically complex lesions which the treatment is associated with higher complication rate compared with simple lesions.

METHODS

A total of 96 patients (66 ± 10 years, 70 men) from the Coronary bifurcations: Application of the Crushing Technique Using Sirolimus-eluting stents (CACTUS) trial who had baseline CRP dosage and both baseline and postprocedural CK-MB measurement were included.

RESULTS

A complex bifurcation strategy was implemented in 53 (55%) patients, and angiographic success was achieved in all but two (2%) patients. Periprocedural myocardial necrosis (increase of CK-MB between one and three times the upper limit of normal [ULN]) was observed in 12 (13%) patients, and four (4%) patients had PCI-related myocardial infarction (increase of CK-MB more than three times ULN). Notably, progressively higher CRP levels were observed in patients with different increase in CK-MB (P = 0.041). Moreover, CRP >1 mg/L significantly predicted CK-MB rise (odds ratio 5.6, 95% confidence interval 1.5-4.3, P = 0.011).

CONCLUSION

In the setting of true coronary bifurcations treated by DES, baseline CRP levels were significantly associated with both the incidence and the extent of PMI.

Aspirin and platelet adenosine diphosphate receptor antagonists in acute coronary syndromes and percutaneous coronary intervention: role in therapy and strategies to overcome resistance

Platelet activation and aggregation are key components in the cascade of events causing thrombosis following plaque rupture. Antiplatelet therapy is essential in the treatment of patients with acute coronary syndromes (ACS) and for those requiring percutaneous coronary intervention (PCI). Aspirin (acetylsalicylic acid) is a well established antiplatelet therapy and is mandated for secondary prevention of cardiovascular events following ACS. In patients with ACS, the addition of clopidogrel to aspirin is more effective than aspirin alone. For patients undergoing PCI, dual antiplatelet therapy with aspirin and clopidogrel is warranted. Aspirin should be continued indefinitely after PCI. Pretreatment of patients with clopidogrel prior to PCI lowers the incidence of cardiovascular events, yet the optimum timing of drug administration and dose are still being investigated, as is the duration of therapy following PCI. Late-stent thrombosis with drug-eluting stents has pushed the recommendation for duration of clopidogrel therapy up to 1 year and perhaps beyond, in patients without risks for bleeding. The concepts of aspirin and clopidogrel resistance are important clinical questions. No uniform definition exists for aspirin or clopidogrel resistance. Measurements of resistance are often highly variable and do not necessarily correlate with clinical resistance. Noncompliance remains the most prominent mode of resistance. Screening of selected patient populations for resistance or pharmacologic intervention of those patients termed 'resistant' warrants further study.

Roles of purinergic receptor P2Y, G protein-coupled 12 in the development of atherosclerosis in apolipoprotein E-deficient mice

OBJECTIVE

The aim of the study was to evaluate the role of purinergic receptor P2Y, G protein-coupled 12 (P2Y12), an ADP receptor, in the development of atherosclerotic lesions.

METHODS AND RESULTS

Apolipoprotein E-null mice were crossed with P2y12(-/-) mice to generate double knockout mice. The double knockout mice and the control apolipoprotein E-null mice were fed a high-fat diet for 20 weeks. Assessment of the atherosclerotic lesions in the control and double knockout mice demonstrated that P2Y12 deficiency caused a diminished lesion area, an increased fibrous content at the plaque site, and decreased monocyte/macrophage infiltration of the lesions. Polymerase chain reaction studies revealed that white blood cells do not express significant levels of P2Y12. Bone marrow transplantation experiments confirmed that P2Y12 expressed on platelets is a key factor responsible for atherosclerosis, but do not exclude a role of smooth muscle cell P2Y12. Supernatant fluid from activated P2y12(+/+) but not P2y12(-/-) platelets was capable of causing monocyte migration. In vitro studies showed that platelet P2Y12 deficiency suppressed platelet factor 4 secretion and P-selectin expression. Further work demonstrated that platelet P2Y12, through inhibition of the cAMP/protein kinase A pathway, critically regulates the release of platelet factor 4, and thereby affects monocyte recruitment and infiltration.

CONCLUSIONS

These results demonstrate that P2Y12 modulates atherogenesis, at least in part by augmenting inflammatory cell recruitment via regulation of platelet α-granule release.

Inflammation as a marker for the prediction of internal carotid artery restenosis following eversion endarterectomy--evidence from clinical studies

The role of inflammation is well established in the pathogenesis of atherosclerosis and an increased level of circulating inflammatory markers may predict the future risk of atherosclerosis progression and plaque rupture. C-reactive protein (CRP) identification by hypersensitive methods (high-sensitivity CRP [hsCRP]) has become a clinical and laboratory inflammation marker. Carotid endarterectomy (CEA) is a well-established procedure for carotid stenosis treatment which can reduce stroke rate. Internal carotid artery (ICA) restenosis reduction may be prevented by the anti-inflammatory effect of statins. This review considers the recent findings on the presence of hsCRP and C3 complement concentration and inflammatory plaque composition as well as their effects on ICA restenosis rate, following eversion CEA with emphasis on human studies.

Relationship Between Plasma Inflammatory Markers and Platelet Aggregation in Patients With Clopidogrel Resistance After Angioplasty

We evaluated the relationship between plasma inflammation markers and clopidogrel resistance in patients after stent implantation. The plasma levels of C-reactive protein (CRP), P-selectin, platelet soluble CD40 ligand (sCD40L), interleukin 6 (IL-6) and platelet aggregation were measured in 352 patients undergoing percutaneous coronary intervention (PCI) at baseline and after 6 months. The plasma levels of CRP, P-selectin, sCD40L, IL-6 was higher in 65 (18.5%) patients with clopidogrel resistance than in those with normal responsiveness at 6 months after PCI. There was a significant positive correlation between soluble CD40L levels and platelet aggregation ( r = .28, P < .05). Diabetes (DM) and sCD40L level were independent predictors for unresponsiveness after stent implantation according to stepwise multivariate analyses. The hazard ratio (HR) for sCD40L level was 3.02 (95% CI = 1.28 to 3.25; P = .036) and for DM 2.53 (95% CI = 1.28 to 6.55, P = .03). We conclude that sCD40L and DM may influence clopidogrel resistance.

Beyond thrombosis: the versatile platelet in critical illness

Sepsis, acute lung injury, and ARDS contribute substantially to the expanding burden of critical illness within our ICUs. Each of these processes is characterized by a myriad of injurious events, including apoptosis, microvascular dysfunction, abnormal coagulation, and dysregulated host immunity. Only recently have platelets--long considered merely effectors of thrombosis--been implicated in inflammatory conditions and the pathobiology of these disease processes. A growing body of evidence suggests a prominent role for maladaptive platelet activation and aggregation during sepsis and ARDS and has begun to underscore the pluripotential influence of platelets on outcomes in critical illness. Not only do platelets enhance vascular injury through thrombotic mechanisms but also appear to help orchestrate pathologic immune responses and are pivotal players in facilitating leukocyte recruitment to vulnerable tissue. These events contribute to the organ damage and poor patient outcomes that still plague the care of these high-risk individuals. An understanding of the role of platelets in critical illness also highlights the potential for both the development of risk stratification schema and the use of novel, targeted therapies that might alter the natural history of sepsis, acute lung injury, and ARDS. Future studies of adenosine, platelet polyphosphates, and the platelet transcriptome/proteome also should add considerably to our ability to unravel the mysteries of the versatile platelet.

Role of the P2Y12 receptor in the modulation of murine dendritic cell function by ADP

The effects of ADP on the biology of dendritic cells have been studied much less than those of ATP or adenosine. In this study, we showed that adenosine-5'-O-(2-thiodiphosphate) (ADPβS) induced intracellular Ca(2+) transients in murine dendritic cells (DCs). This effect was abolished by AR-C69931MX, a dual P2Y(12) and P2Y(13) receptor antagonist. RT-PCR experiments revealed the expression of both P2Y(12) and P2Y(13) mRNA in DCs. The Ca(2+) response to ADPβS was maintained in P2Y(13)-deficient DCs, whereas it was abolished completely in P2Y(12)(-/-) DCs. ADPβS stimulated FITC-dextran and OVA capture in murine DCs through macropinocytosis, and this effect was abolished in P2Y(12)(-/-) DCs. ADPβS had a similar effect on FITC-dextran uptake by human monocyte-derived DCs. OVA loading in the presence of ADPβS increased the capacity of DCs to stimulate OVA-specific T cells, whereas ADPβS had no effect on the ability of DCs to stimulate allogeneic T cells. Moreover, after immunization against OVA, the serum level of anti-OVA IgG1 was significantly lower in P2Y(12)(-/-) mice than that in wild-type controls. In conclusion, we have shown that the P2Y(12) receptor is expressed in murine DCs and that its activation increased Ag endocytosis by DCs with subsequent enhancement of specific T cell activation.

Predictive value of C-reactive protein after drug-eluting stent implantation

During the last few decades, with the evolution of techniques and materials and the increasing experience of operators, percutaneous coronary interventions (PCI) have become an equally efficient alternative to coronary artery bypass grafts for the treatment of most coronary stenoses. Bare-metal stent implantation represented a major step forward, compared with plain old balloon angioplasty (POBA), by improving the immediate angiographic success. However, the incidence of in-stent restenosis (ISR) remained unacceptably high. Development of the drug-eluting stent (DES) significantly improved the outcome of PCI by dramatically abating the rate of ISR and reducing the incidence of target lesion revascularization. However, ISR has not been eliminated and the persistence of metal vessel scaffolding also raises concern regarding the occurrence of late or very late stent thrombosis. POBA and stent implantation have been shown to induce a local and systemic inflammatory response, whose magnitude is associated with worse clinical outcome, and they increase the risk of ISR. C-reactive protein, a marker of systemic inflammation, has been demonstrated to predict clinical and angiographic outcome after POBA or bare-metal stent implantation. However, conflicting data regarding the prognostic value of C-reactive protein following DES implantation are available. In this paper, we review the literature regarding the clinical and pathophysiological association between inflammation and prognosis after DES implantation and suggest some possible therapeutic approaches to reduce inflammatory burden with the aim to improve clinical and angiographic outcome after PCI.

Relationship between baseline inflammatory markers, antiplatelet therapy, and adverse cardiac events after percutaneous coronary intervention: an analysis from the clopidogrel for the reduction of events during observation trial

BACKGROUND

We evaluated patients undergoing percutaneous coronary intervention to assess the predictive value of high-sensitivity C-reactive protein (hs-CRP) and pregnancy-associated plasma protein-A (PAPP-A) on adverse cardiac outcomes and the effect of antiplatelet therapy on these outcomes.

METHODS AND RESULTS

Baseline blood samples were available on 1468 CREDO (Clopidogrel for the Reduction of Events During Observation) patients for hs-CRP testing and 1096 patients for PAPP-A testing. The 1-year primary end point was the composite incidence of death, myocardial infarction, or stroke. Patients in the highest 2 tertiles of hs-CRP had more events compared with the lowest tertile (11.4% versus 6.4%, P=0.003). Treatment with clopidogrel reduced the 1-year composite end point for patients in the highest 2 tertiles of hs-CRP (9.1% clopidogrel versus 13.5% placebo, P=0.04) but not in the lowest tertile. Elevated PAPP-A levels were associated with a trend toward more events at 1 year that did not reach statistical significance. Patients in the highest 2 tertiles of PAPP-A randomized to clopidogrel had fewer events (7.3% clopidogrel versus 13.1% placebo, P=0.01), but no benefit was seen in the lowest tertile. A 46% risk reduction with randomization to clopidogrel was seen in patients in the highest 2 tertiles of both biomarkers (8.7% versus 16.2%, P=0.02).

CONCLUSIONS

Patients undergoing nonurgent percutaneous coronary intervention who have elevated hs-CRP and PAPP-A have an increased incidence of adverse cardiovascular events. The clinical benefit of adding clopidogrel to aspirin seems greater in those with increased levels of these inflammatory biomarkers.

Impact of thienopyridine administration prior to primary stenting in acute myocardial infarction

The impact of thienopyridine administration prior to primary stenting in acute myocardial infarction (AMI) has not been well studied. We therefore examined the database from the prospective, multicenter, controlled CADILLAC trial in which 1,036 patients were randomized to bare metal stenting with or without abciximab to determine whether patients who received a thienopyridine prior to bare metal stenting in AMI had superior clinical outcomes. Per operator discretion, 659 patients (63.6%; Th+) received either a 500 mg ticlopidine loading dose (n = 623) or a 300 mg clopidogrel loading dose (n = 40), while 377 patients (36.4%; Th-) received no thienopyridine prior to stent implantation. Baseline and procedural characteristics of the two groups, including abciximab use (52.5% vs 52.8%, P = 0.93) were well matched. Th+ compared to Th- patients had lower rates of core lab assessed TIMI 0/1 flow postprocedure (0.8% vs 2.7%, P = 0.01). Th+ compared to Th- patients also had significantly reduced in-hospital and 30-day rates of ischemic target vessel revascularization (TVR) (1.1% vs 3.2%, P = 0.01 and 1.5% vs 3.8%, P = 0.02, respectively) and major adverse cardiovascular events (MACE) (2.7% vs 5.8%, P = 0.01 and 4.0% vs 6.9%, P = 0.03, respectively), results that remained significant after covariate adjustment. In conclusion, in this large prospective, controlled trial, patients receiving a thienopyridine prior to primary stenting in AMI were less likely to have TIMI 0/1 flow postprocedure and experienced reduced in-hospital and 30-day rates of ischemic TVR and MACE compared to those not administered a thienopyridine prior to stent implantation.

Efficacy of clopidrogel on reperfusion and high-sensitivity C-reactive protein in patients with acute myocardial infarction

We investigated the effects of clopidogrel on reperfusion and inflammatory process in STEMI. A total of 175 STEMI patients with similar clinical characteristics were included to this study. One was the standard pharmacological reperfusion therapy group (group 1, n : 90), who received 300 mg aspirin, 70 U/kg bolus, and 12 U/kg/hr continuous infusion of unfractioned heparin and accelerated t-PA. Clopidogrel 450 mg loading and 75 mg/d thereafter was added to standard reperfusion therapy in the other group (group 2, n : 85). The ST-segment resolution, CK-MB, and high-sensitive CRP (hs-CRP) parameters were measured. Complete ST resolution was observed in 32 patients (36.8%) in group 1 and 53 patients (63.8%) in group 2 (P < .001). Also in the first 24 hours, the CK-MB levels of patients in group 1 were significantly higher than those of group 2 (P = .001). The hs-CRP values were greater in group 1 than group 2 at 48th hour (gruop 1: 9.4 ± 0.1 mg/L, group 2: 3.7 ± 1.4 mg/L; P = .000). We concluded that adding clopidogrel to standard treatment in STEMI patients provided early reperfusion and suppression of inflammatory response.

New evidences for C-reactive protein (CRP) deposits in the arterial intima as a cardiovascular risk factor

Inflammatory processes are orchestrated by several soluble molecules, which interact with cell populations involved. Cytokines, chemokines, acute-phase reactants, and hormones are crucial in the evolution of several inflammatory disorders, such as atherosclerosis. Several evidences suggest that C-reactive protein (CRP) started to be considered as a cardiovascular risk factor, since CRP directly induces atheroslerosis development. The recent demonstration of CRP production not only by the liver, but also within atherosclerotic plaques by activated vascular cells, also suggests a possible dual role, as both a systemic and tissue agent. Although more studies are needed, some therapeutic approaches to reduce CRP levels have been performed with encouraging results. However, given the strong limitations represented by its low specificity and still accordingly with the American Heart Association, there is no need for high sensitivity CRP screening of the entire adult population as a public-health measure. The measure of serum CRP might be useful only for patients who are considered at intermediate risk.

Effect of Conventional and More Aggressive Rosuvastatin Treatment on Markers of Endothelial Activation

Treatment of hypercholesterolemia with HMG-CoA reductase inhibitors results in an earlier reduction of morbidity and mortality than expected from trials using conventional cholesterol-lowering therapies. Possible explanations for this effect include improvement of endothelial function, plaque stabilization, and inhibition of the inflammatory response associated with atherosclerosis. In this study we assessed the effects of low and moderate dose rosuvastatin treatment, on circulating markers of endothelial activation in patients admitted for acute coronary syndromes without ST segment elevation. Thirty patients with unstable angina and non ST segment elevation myocardial infarction were rando - mized into two groups, and received rosuvastatin 10 mg/day (n =16) or rosuvastatin 20 mg/day (n =14) for 12 weeks. Circulating levels of soluble vascular cell adhesion molecule (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) were measured at admission, and at the end of the study. Lipid values were significantly reduced in both treatment groups, but with significantly greater reduction in the aggressively treated group. Serum levels of sICAM-1 and sVCAM-1 were significantly decreased in both rosuvastatin-treated groups during 12 weeks of follow-up with a more pronounced decrease in the more aggressively treated group. Therefore, rosuvastatin modulates endothelial activation in patients after acute coronary syndromes.

Prolonged application of clopidogrel reduces inflammation after percutaneous coronary intervention in the porcine model

OBJECTIVE

We determined the effect of prolonged treatment with clopidogrel on C-reactive protein (CRP) concentrations and blood thrombogenicity after percutaneous transluminal coronary angioplasty followed by intracoronary brachytherapy in the porcine model. ANIMAL MODEL: All 48 pigs received antiplatelet therapy, including aspirin (325 mg, daily) and clopidogrel (300 mg, loading dose) 1 day before PCI, followed by a daily dose of clopidogrel (75 mg/day) in addition to aspirin. During PCI, one of two balloon-injured arteries was randomly assigned to receive immediate radiation treatment. Animals were sacrificed after 24 h, 1 month, and 3 months post-PCI. The pigs, which were sacrificed 3 months post-PCI, were divided into two groups. The first group received clopidogrel in addition to aspirin for 3 months, and the second group received clopidogrel in addition to aspirin for only 1 month after PCI and then aspirin alone.

METHODS

Blood was taken from all pigs before intervention, immediately after intervention, and before sacrifice. Serum CRP was measured by enzyme-linked immunosorbent assay. To analyze the procoagulant effects of PCI on blood thrombogenicity, a one-stage clotting assay was performed.

RESULTS

Clopidogrel treatment for 3 months reduced CRP levels more than did clopidogrel therapy for 1 month only at 3 months post-PCI (27.9+/-3.9 vs. 56.6+/-11.3 microg/ml; P=.019). Baseline CRP levels were found to be 50.4+/-4.8 microg/ml. Plasma clotting was not affected by prolonged clopidogrel therapy (322.8+/-59.3 s vs. 295.2+/-52.5 s; P=ns).

CONCLUSIONS

Prolonged treatment with clopidogrel reduced CRP levels post-PCI.

Progress in clinical neurosciences: The 'antiplatelet' agents and the role of the endothelium

The antiplatelet drugs, commonly used in the prevention and treatment of cerebrovascular disease, possess a number of effects that are independent of direct antiplatelet actions. Beneficial and detrimental effects both occur. The endothelium is an important mediator of these non-antiplatelet effects. We performed a literature search to locate articles related to acetylsalicylic acid (aspirin), clopidogrel, ticlopidine, and dipyridamole and the interactions of these medications with the endothelium. The role of each of the above medications is explored in relation to vasodilation, inflammation, oxidation, platelet-leukocyte interactions, and thrombogenic tendency via platelet-vessel wall interactions.

Clinical evidence for anti-inflammatory effects of antiplatelet therapy in patients with atherothrombotic disease

Recent advances in our understanding of cardiovascular disease have revealed that atherothrombotic events, such as myocardial infarction and ischemic stroke, are the end result of a complex inflammatory response to multifaceted vascular pathology. As well as initiating thrombus formation at the site of a ruptured atherosclerotic plaque, platelets play a key role in vascular inflammation, through release of their own pro-inflammatory mediators and interactions with other relevant cell types (endothelial cells, leukocytes, and smooth muscle cells). An increasing body of literature shows that inflammatory biomarkers can be used to predict atherothrombotic risk and that antiplatelet therapy may reduce the levels of these markers. Acetylsalicylic acid (ASA) has been attributed with reducing levels of the transcription factor nuclear factor kappaB (NF-kappaB), C-reactive protein, and soluble CD40 ligand, although the evidence relating to the latter two markers is conflicting. There is also substantial evidence that therapy with clopidogrel, a specific antagonist of the platelet P2Y12 ADP-receptor, also leads to reductions in serum levels of CD40 ligand, C-reactive protein, P-selectin, and platelet-leukocyte aggregate formation. Beneficial effects of clopidogrel on inflammatory markers have been demonstrated across the spectrum of atherothrombotic disease (acute coronary syndrome patients, patients undergoing percutaneous coronary intervention (PCI), acute ischemic stroke patients, and those with peripheral arterial disease). Oral glycoprotein (GP) IIb/IIIa receptor antagonists, at doses that achieve moderate levels of receptor blockade, may paradoxically be associated with platelet-mediated pro-inflammatory effects. A similar phenomenon has been observed with intravenous GP IIb/IIIa antagonists in vitro, but most often at low doses, and data from clinical studies suggest that these agents may actually attenuate release of inflammatory mediators when administered at doses producing more complete receptor blockade.

Does pravastatin therapy affect cardiac enzyme levels after percutaneous coronary intervention?

Serum cardiac enzyme elevation after percutaneous coronary intervention (PCI), a relatively common complication, is a prognostic determinant of long-term outcome in patients who undergo these procedures. Statins are postulated to reduce such complications. This study investigated the short-term effects of pravastatin on serum creatine kinase myocardial isoform (CK-MB) and serum cardiac troponin I (cTpI) levels after elective PCI. Of 93 patients studied, 72 (77.4%) were men, and 21 (22.6%) were women (mean age, 58.9+/-11.0 y). Patients were randomly divided into 3 groups before they underwent elective PCI. Preoperatively, group 1 patients (n=30) received pravastatin 10 mg/d, and group 2 patients (n=29) received pravastatin 40 mg/d. Control group patients (n=34) received no lipid-lowering medication. Serum CK-MB and serum cTpI levels were measured preoperatively and then again at 6, 24, and 36 h postoperatively. Demographic features of patients and characteristics of the PCI procedure, including number of vessels/lesions and duration and number of inflations, did not differ among groups (P>.05). Mean serum CK-MB and serum cTpI levels were significantly increased after PCI in all patients (P<.001). When compared with control group patients, those given pravastatin did not experience significantly lowered postprocedural serum CK-MB or serum cTpI levels (P>.05). Preprocedural pravastatin therapy at dosages of 10 mg/d and 40 mg/d seems inadequate for preventing serum cardiac enzyme elevations during short-term follow-up after PCI. Additional research on this topic is recommended.

Relation between impaired antiplatelet response to clopidogrel and possible pleiotropic effects

BACKGROUND

The study was designed to determine whether impaired antiplatelet response to clopidogrel but not to aspirin may be responsible for loss of pleiotropic effects of the drug.

METHODS

Study included 34 consecutive patients with STEMI undergoing primary percutaneous coronary intervention (PCI) with stent implantation treated with aspirin (loading dose 300 mg followed by 75 mg/day) and clopidogrel (loading dose 600 mg followed by 75 mg/day). On the basis of Platelet Function Analyzer (PFA)-100 test which measured closure times (CT) in test with collagen/epinephrine (CEPI-CT) or collagen/adenosine diphosphate (CADP-CT) patients were stratified after 7 days from admission as full aspirin or clopidogrel responders (CEPI-CT or CADP-CT = 300 sec., respectively) and non-full aspirin or clopidogrel responders (CEPI-CT or CADP-CT < 300 sec., respectively). High sensitivity C-reactive protein (hs-CRP) was measured at baseline and after 7 days of treatment.

RESULTS

All patients received comparable statin treatment. Median and interquartile ranges (IQR) of hs-CRP increased significantly from 2.5 mg/L (0.4-44.8) at baseline to 8.05 mg/L (1.4-33.9) at day 7 (P = .002) in non-full clopidogrel responders subgroup and only slightly in the full clopidogrel responders subgroup (2.45 mg/L, IQR 0.4-48.3 vs. 4.2 mg/L, IQR 1.9-17.5) (P = .3) remaining within reference intervals. On the contrary median and IQR of hs-CRP increased significantly in both non-full aspirin responders (2.4 mg/L, IQR 1.3-3.3 vs. 5.8 mg/L, IQR 3.2-14.8, P = .01) and full aspirin responders (2.9 mg/L, IQR 2.0-3.7 vs. 5.6 mg/L, IQR 4.3-12.9, P = .04).

CONCLUSIONS

Impaired antiplatelet response to clopidogrel but not to aspirin may contribute to smaller anti-inflammatory response in patients with ST-elevation myocardial infarction.

Critical appraisal of C-reactive protein throughout the spectrum of cardiovascular disease

Clinicians involved in the care of patients with cardiovascular conditions have recently been confronted with an important body of literature linking inflammation and cardiovascular disease. Indeed, the level of systemic inflammation as measured by circulating levels of C-reactive protein (CRP) has been linked to prognosis in patients with atherosclerotic disease, congestive heart failure, atrial fibrillation, myocarditis, aortic valve disease and heart transplantation. In addition, a number of basic science reports suggest an active role for CRP in the pathophysiology of cardiovascular diseases. This article explores the potential role of CRP in disease initiation, progression, and clinical manifestations and reviews its role in the prediction of future events in clinical practice. Therapeutic interventions to decrease circulating levels of CRP are also reviewed.

Platelets as Mediators of Inflammation

An expanding body of evidence continues to build on the central role of inflammation in the progression and clinical manifestations of atherosclerosis. Platelets, long thought to play only a reactionary role at the time of endothelial disruption, are now recognized as important mediators of the inflammatory process. Platelet activation, which is modulated by both inflammatory and hemostatic factors, can lead to the release of hundreds of proteins--many with known proinflammatory functions. Although compelling evidence is lacking that antiplatelet therapies directly lower markers of inflammation, there are intriguing, although preliminary, data suggesting that markers of inflammation predict the clinical benefit of antiplatelet therapies.

Safety and efficacy of low-dose unfractionated heparin during percutaneous coronary revascularisation and the relationship between activated clotting time and haemorrhagic or ischaemic complications: our results

OBJECTIVE

An inverse relation between the degree of heparin anticoagulation and the subsequent risk of postprocedural thrombotic complications was observed in the era of conventional balloon angioplasty, but the optimal dose of heparin during percutaneous coronary intervention (PCI) using newer interventional equipment and glycoprotein IIb/IIIa receptor inhibition has not been clearly defined. Previous studies did not assess the increased risk of adverse cardiac events with an activated clotting time of <200 s using strategies of routine stent placement and glycoprotein IIb/IIIa receptor inhibition. We hypothesised that the efficacy and safety of PCI would be maintained, if not improved, especially when performed in conjunction with glycoprotein IIb/IIIa receptor inhibitors (abciximab, tirofiban or eptifibatide as a bolus plus infusion for 12-18 h) and oral antiplatelet therapy (clopidogrel 75 mg plus aspirin 325 mg/day) associated with low doses (5000-10 000 U) of unfractionated heparin using a target activated clotting time of </=200 s during PCI. In this way, the sheath could be immediately removed at the end of the procedure.

METHODS

We evaluated the outcome at 30 days and at one year of 2552 consecutive patients who underwent PCI and stenting; most of them were treated with PCI and selective administration of glycoprotein IIb/IIIa inhibitors in high-risk cases (61%).

RESULTS

By design, the activated clotting time was 184 +/- 39 s. The incidence of access site complications and of in-hospital major adverse cardiac events during the first 48 h following PCI was 3.7% and 3.3%, respectively. The incidence of major adverse cardiac events was 4.5% at 30 days and 7.6% at one year.

CONCLUSIONS

This study shows the safety and efficacy of this therapeutic strategy in the era of frequent stent implantation and aggressive intravenous and oral platelet inhibition. Additional research is warranted to determine whether these results can be extrapolated routinely to patients with acute myocardial infarction or undergoing PCI without stent implantation.

Clopidogrel

Clopidogrel (Plavix), Iscover) selectively and irreversibly inhibits adenosine diphosphate (ADP)-induced platelet aggregation. Long-term administration of clopidogrel was associated with a modest but statistically significant advantage over aspirin in reducing adverse cardiovascular outcomes in patients with established cardiovascular disease in the CAPRIE trial. In other large well designed multicentre trials, such as CURE, COMMIT and CLARITY-TIMI 28, the addition of clopidogrel to aspirin therapy improved outcomes in patients with acute coronary syndromes. However, some issues regarding the use of clopidogrel remain unresolved, such as the optimal loading dose in patients undergoing percutaneous coronary interventions (PCI) and the optimal treatment duration following drug-eluting intracoronary stent placement. Results of several large randomised trials, therefore, have established clopidogrel as an effective and well tolerated antiplatelet agent for the secondary prevention of ischaemic events in patients with various cardiovascular conditions, including those with ischaemic stroke or acute coronary syndromes. In addition, treatment guidelines from the US and Europe acknowledge the importance of clopidogrel in contemporary cardiovascular medicine.

Naproxen treatment prevents periprocedural inflammatory response but not myocardial injury after percutaneous coronary intervention

BACKGROUND AND AIM

Recent studies have documented that elevation of C-reactive protein (CRP) levels after percutaneous coronary intervention (PCI) have been predictive of adverse outcome. This study was performed to test the hypothesis that preprocedural use of naproxen sodium is associated with a reduction in the extent of inflammatory response and myocardial injury after PCI.

METHODS

Ninety-seven patients who were scheduled for elective PCI were randomized either for naproxen sodium (500 mg bid) (n:39, 75% male, 59+/-10 years) or control (n:58, 76% male, 60+/-10 years). All patients were troponin negative before the procedure. Blood samples for CRP, Troponin I and CK-MB were collected at baseline and after the procedure.

RESULTS

The characteristics were similar between the two groups. After coronary stenting, the rise in CRP levels was significantly higher in controls than those treated with naproxen (DeltaCRP=6.4 mg/L in the controls and 0.43 mg/L in the naproxen group, p<0.0001). The incidence of any troponin I elevation or CK-MB elevation above upper limit of normal was not statistically different between groups. During follow up (12+/-2 months), major cardiac adverse events (death, myocardial infarction, and revascularization of target lesion) was similar between groups.

CONCLUSION

Our data show that naproxen pretreatment leads to significant suppression in PCI related CRP elevation. However this improvement in CRP levels was not associated with any significant reduction in post-PCI myonecrosis.

The potential role of antiplatelet agents in modulating inflammatory markers in atherothrombosis

Atherothrombosis is the process that links atherosclerotic lesion development with unpredictable and life-threatening ischemic vascular events such as angina, myocardial infarction, transient ischemic attack, and stroke. Atherothrombosis is triggered when an unstable atherosclerotic lesion is ruptured, leading to platelet activation and thrombus formation. Inflammatory mediators are responsible for lesion instability leading to rupture, and in recent years atherothrombosis and its underlying condition of atherosclerosis have come to be recognized as manifestations of inflammatory disease. Inflammatory mediators may therefore serve as early markers of atherothrombosis. Measurement of early markers may be used to predict future ischemic events and improve risk stratification in patients following diagnosis of atherothrombotic disease. In addition, detection of such markers may help to optimize the use of current therapies to manage atherothrombosis. Molecules that may serve as early markers of atherothrombotic disease include C-reactive protein, CD40 ligand, myeloperoxidase, pregnancy-associated plasma protein and plasminogen activator inhibitor-1. Early indications are that levels of these markers are influenced by therapies currently in use in the treatment of atherothrombotic conditions, including antiplatelet agents. Ongoing studies will provide further insight into routine assessment of inflammatory markers as a guide to the management of patients with atherothrombosis.

Relation between soluble intercellular adhesion molecule-1, statin therapy, and long-term risk of clinical cardiovascular events in patients with previous acute coronary syndrome (from PROVE IT-TIMI 22)

High levels of adhesion molecules, such as soluble intercellular adhesion molecule-1 (sICAM-1), are associated with long-term risk of cardiac events in patients with and without stable coronary artery disease. The relation between sICAM-1 and long-term risk after acute coronary syndromes (ACSs) and the influence of statin treatment has not been explored. Using a nested case-control design, patients with ACS who were enrolled in the PROVE IT-TIMI 22 trial were matched for age, gender, smoking, diabetes, type of ACS presentation, and revascularization for index event (583 patients with recurrent events vs 581 controls). Patients with recurrent events were identified as such by death, myocardial infarction, or hospitalization for recurrent ACS. Soluble ICAM-1 was measured at study entry (approximately 7 days after ACS). After adjusting for statin regimen and other risk factors, patients in quartiles 2 to 4 were at a higher risk of clinical events compared with those in quartile 1 (odds ratio 1.6 for quartile 4 vs 1, 95% confidence interval 1.1 to 2.3, p = 0.02). The risk of adverse events in patients with sICAM-1 levels in quartiles 2 to 4 was most marked in subjects who were allocated to standard dose statin therapy, even after adjusting for low-density lipoprotein cholesterol and C-reactive protein at day 30. The risk in quartiles 2 to 4 was somewhat attenuated in the intensive therapy group. In conclusion, in this large study of patients with ACS, we provide evidence that increased endothelial activation after ACS is independently associated with increased long-term risk of death, myocardial infarction, or recurrent ACS.

Divergent effects of rofecoxib on endothelial function and inflammation in acute coronary syndromes

BACKGROUND

The safe use of selective inhibitors of cyclooxygenase-2 in patients with cardiovascular disease has been questioned because of studies showing an increased risk of cardiac events. We examined the short-term effect of rofecoxib, a selective cyclooxygenase-2 inhibitor, on endothelial function, oxidative damage and inflammation in patients with acute coronary syndromes without ST-segment elevation.

METHODS

Forty-three patients with acute coronary syndromes without ST-segment elevation participated in the study. Flow-mediated dilatation (FMD), nitrate-mediated dilatation (NMD) of the brachial artery, malondialdehyde, a marker of lipid peroxidation, C-reactive protein, an acute phase marker of inflammation, and interleukin-6, a proinflammatory cytokine, were measured within 24 h of admission and a week later. Patients were randomized to receive for a week 100 mg aspirin daily with either 25 mg of rofecoxib (n=21) or placebo (n=22) orally once daily.

RESULTS

Malondialdehyde, C-reactive protein and interleukin-6 levels were reduced in the rofecoxib group (p=0.04, p=0.003 and p=0.02 respectively) while they remained unchanged in the placebo group after 1 week of treatment. FMD and NMD changes in both groups were not statistically different.

CONCLUSIONS

Co-administration of rofecoxib with low-dose aspirin decreases inflammatory and oxidative indices but does not improve endothelial function. The lack of improvement in FMD despite the improvement in inflammation and oxidative stress could be viewed in association to the recent observations on the adverse effects of COX-2 inhibition on the cardiovascular system.

A randomized comparison of high clopidogrel loading doses in patients with non-ST-segment elevation acute coronary syndromes: the ALBION (Assessment of the Best Loading Dose of Clopidogrel to Blunt Platelet Activation, Inflammation and Ongoing Necrosis) trial

OBJECTIVES

We sought to compare the antiplatelet effects of three clopidogrel loading doses (LDs).

BACKGROUND

Administration of a 300-mg clopidogrel LD is beneficial in situations requiring rapid platelet inhibition. Whether higher LDs can provide further benefits remains unknown.

METHODS

Patients (n = 103) with non-ST-segment elevation acute coronary syndromes were randomized to receive a 300-mg, 600-mg, or 900-mg clopidogrel LD, given on top of other standard therapy (including acetylsalicylic acid). The main outcome measure was inhibition of adenosine diphosphate-induced inhibition of platelet aggregation (IPA); inhibition of platelet activation, inflammatory markers, troponin I release, and major adverse cardiac events also were evaluated; all measures were blindly evaluated.

RESULTS

Compared with the 300-mg LD, greater doses were associated with significantly greater platelet inhibition, with dose-effect relationships observed for onset of action, maximal plateau, 24-h areas under the curves of IPA, and rates of low IPA (<10% at 6 h), using 20 micromol/l major adverse cardiac events. A significant dose-response was also observed for the vasodilator-stimulated phosphoprotein index, a measure of P2Y(12) receptor inhibition. Similar but nonsignificant trends were observed for troponin release and major adverse cardiac events. Bleeding rates were similar in each group.

CONCLUSIONS

In low-to-moderate risk patients with non-ST-elevation acute coronary syndromes, clopidogrel LDs >300 mg provide a faster onset of action, a higher IPA plateau, and greater reductions in platelet activation during the first 24 h. A 900-mg LD may induce a greater antiplatelet effect than 600 mg, when compared with the standard 300-mg regimen. These findings require further clinical confirmation.

Preprocedural C-reactive protein levels predict myocardial necrosis after successful coronary stenting in patients with stable angina

BACKGROUND

Myocardial necrosis as assessed by cardiac troponin elevation occurs frequently after coronary stenting and is associated with adverse clinical outcome. Mechanical factors have been implicated in this complication and the role of systemic inflammation is not known.

METHODS

We prospectively studied 208 patients with chronic stable angina who underwent elective coronary stenting. All patients had normal troponin levels before the procedure. Blood samples for high-sensitivity C-reactive protein (CRP) were obtained before the procedure and analyzed using a high-sensitivity kit. Cardiac troponin T (cTnT) was obtained 24 hours after the procedure.

RESULTS

Postprocedural cTnT elevations were observed in 46 (22%) patients. There were 11 (16%), 14 (20%), and 21 (30%) patients with elevated postprocedural cTnT in the first, second, and third CRP tertile, respectively (P for trend = .045). In a multivariate logistic regression model, adjusting for all the significant univariate predictors and for statin therapy, CRP remained a significant independent predictor of postprocedural cTnT elevation with an odds ratio of 2.6 in patients in the third CRP tertile compared with patients in the first CRP tertile (95% CI 1.1-6.0, P = .02). Patients in the third CRP tertile also had higher cTnT elevations compared with patients in the first and second CRP tertile (P = .03).

CONCLUSIONS

Elevated baseline CRP levels are associated with higher risk of postprocedural troponin elevations in patients with stable angina undergoing uncomplicated coronary stenting. These results underscore the role of systemic inflammation in the pathogenesis of periprocedural myocardial injury.

Inflammation, Atherosclerosis, and Stroke

BACKGROUND

Inflammation has received increasing attention in recent years as a cause of atherosclerosis, coronary artery disease, and stroke. Basic and animal research has implicated inflammatory mechanisms in the pathogenesis and progression of atherosclerosis, as well as in clinical events related to plaque rupture and other atherothrombotic events.

REVIEW SUMMARY

The literature on the association of inflammatory markers with risk of stroke was reviewed and a clinical example provided. Several inflammatory biomarkers, and particularly high-sensitivity C-reactive protein (hsCRP), have been identified as likely predictors of the risk of a future stroke. Medications, particularly hydroxymethylglutaryl coenzyme A reductase inhibitors, or statins, have been demonstrated to reduce levels of inflammatory markers independently of effects on cholesterol. Most recently, the ability of these agents to reduce risk of myocardial infarction and other coronary events in patients with acute coronary artery disease has been demonstrated to correlate with their ability to lower levels of hsCRP. Whether reduction of hsCRP would have similar benefits in stroke patients remains unsettled, as does whether other drugs may be similarly used to lower hsCRP levels.

CONCLUSION

Inflammatory biomarkers, especially hsCRP, may allow improved prediction of the risk of stroke in primary and secondary stroke prevention. Modalities to reduce inflammation are becoming available that may help to modify this risk. Further studies, however, are needed before inflammatory markers become a routine part of the evaluation of stroke patients.

Oral antiplatelet therapy and percutaneous coronary intervention

The benefit of oral antiplatelet therapy following percutaneous coronary intervention (PCI) with intracoronary stent implantation is well established. Combined aspirin with clopidogrel or ticlopidine therapy is superior to aspirin alone in reducing thrombotic events after stent placement. Clopidogrel is the drug of choice, given that its efficacy is comparable to ticlopidine and it has a superior safety profile. Despite dual antiplatelet therapy, patients remain at risk of recurrent vascular events. Optimal timing, duration and dosage of antiplatelet therapy remain controversial. Recent evidence suggests additional benefit with clopidogrel pretreatment, high clopidogrel loading dose and long-term dual antiplatelet therapy post-PCI in high-risk patients.

Antiplatelet Therapy after Percutaneous Coronary Intervention

There is intense interest in the relationship between inflammation, thrombosis, platelet aggregation, and hyperlipidemia in patients with coronary artery disease. The specific role of inflammation with its linkage to the coagulation cascade has been well studied. A number of inflammatory markers have been identified which can be used for risk stratification in patients with acute coronary syndromes. Patients with acute coronary syndromes at the time of presentation often have an underlying inflammatory state which needs therapy with antiplatelet regimens including now increasingly frequently clopidogrel in addition to the standard of aspirin. In those patients who are treated medically for their acute coronary syndromes, long-term treatment with dual antiplatelet therapy has been documented to be associated with improved outcome. In patients who undergo an invasive approach with placement of intracoronary stents, the importance of dual antiplatelet therapy is increased. Drug-eluting stents are now used in approximately 90% of all interventional procedures. There is evidence to suggest that while these patients have improved outcome in terms of a decreased need for subsequent procedures to treat restenosis, there is the potential for late subacute stent thrombosis. When late subacute stent thrombosis occurs, it results in mortality or infarction in 40-60% of patients. Dual antiplatelet therapy is therefore recommended for an increasingly longer time in this patient group. At the present time, protocols indicate 3 months for one of the drug-eluting stents and 6 months for the other. However, increasingly longer antiplatelet therapy is being used clinically. Assessment of platelet function during follow-up is as yet early. There are issues about which specific test to use and the definition of platelet hyperreactivity. In the future, more individually targeted therapy may be possible if we can more adequately assess the degree of hyperreactivity and underlying inflammation.

Coronary stenting and inflammation

Restenosis after stent implantation is mainly caused by neointimal proliferation through the stent struts. Experimental studies performed in the last decade indicate that inflammatory mechanisms play a key role in the process of neointimal proliferation and restenosis. Coronary stenting is a strong inflammatory stimulus, and the acute local and systemic inflammatory responses to local inflammation produced by coronary stenting are highly individual and predictive of restenosis and event-free survival. The benefit of anti-inflammatory periprocedural therapy, such as with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and steroids, and long-term follow-up is dependent on the individual's inflammatory status. Measurement of acute-phase reactants, such as C-reactive protein plasma concentration, appears to be important for the identification of subjects at high risk and the development of specific treatment tailored to individual patients.