Predictive value of C-reactive protein after successful coronary-artery stenting in patients with stable angina

Soluble CD40 ligand is an early initiator of inflammation after coronary intervention

BACKGROUND

This prospective study evaluated the early increase in markers of inflammation after coronary stenting, and the predictors of early rise. Elevation of markers of inflammation after percutaneous coronary intervention correlates with an increased risk of adverse events. The role of soluble CD40 ligand (sCD40L) as a potential initiator of inflammation after stenting has not been described.

METHODS

Seventy-five patients were treated with heparin alone (n=25), or randomized to adjuvant treatment with eptifibatide (n=26) or abciximab (n=24) during stenting. Systemic blood was obtained before coronary stenting and at 10 min after stenting. C-reactive protein (CRP), interleukin (IL)-6, IL-1 receptor antagonist and sCD40L were determined by enzyme liberated immunosorbent assay.

RESULTS

sCD40L exhibited the greatest relative rise (35%, P=0.01 compared to concentrations before intervention) in the first 10 min after stenting. In a logistic regression model, an early increase in the concentration of sCD40L was predicted by baseline laboratory values (white blood count and sCD40L level before stenting) and procedural characteristics (number of stents and glycoprotein IIb-IIIa inhibitor assignment).

CONCLUSIONS

In conclusion, a systemic inflammatory response is detectable 10 min after coronary stent placement. The early increase in sCD40L suggests a possible role for this marker in the initiation of inflammation after coronary stenting.

Endothelial dysfunction and inflammation after percutaneous coronary intervention

We studied 30 consecutive patients who underwent coronary stenting with respect to postprocedure endothelial dysfunction and levels of pre- and postprocedure cytokines. Patients with severe impairment of flow-mediated dependent dilation, but not flow- mediated independent dilation, had higher concentrations of C-reactive protein before percutaneous coronary intervention (12.9 +/- 20.2 vs 5.6 +/- 13.0 microg/ml, p = 0.04) and 24 hours after stenting (18.8 +/- 20.8 vs 11.8 +/- 20.0 microg/ml, p = 0.05) than patients without severe abnormities of systemic endothelial function. Thus, endothelium-dependent dilation abnormalities were related to the systemic inflammatory state, whereas endothelium-independent dilation abnormalities were not related to the inflammatory status of the patient.

Effects of tirofiban on acute systemic inflammatory response in elective percutaneous coronary interventions

OBJECTIVE

In this study the effect of a specific glycoprotein IIb/IIIa inhibitor, tirofiban [which also has antiplatelet activity on acute systemic inflammatory responses (IR) during elective percutaneous coronary intervention (PCI)] was evaluated.

PATIENTS AND METHODS

Patients with stable angina pectoris and similar baseline characteristics who angiographically had a single lesion in their coronary arteries with a PCI performed on that lesion were enrolled in the study. One group of patients (control group, n = 52) received 0.9% NaCl (15 mL/h for 24 h) and the other group (tirofiban group, n = 55) had tirofiban (10 microg/kg bolus infusion in 3 min and 0.15 microg/kg/min for 24 h) in addition to stenting without pre-dilatation. The effect of interventional procedure on levels of cardiac troponin T (cTnT) and several parameters of acute IR (leukocytes, fibrinogen, C-reactive protein, interleukin-1, interleukin-6, interleukin-8 and tumor necrotizing factor-alpha) was assessed on blood samples obtained from all patients before PCI and at pre-specified time points after PCI.

RESULTS

During the follow-up after PCI, the number of patients becoming cTnT-positive (> 0.1 ng/mL) was greater in the control group [12 (23%) patients vs. 3 (5%) patients, p = 0.01]. However, both groups had changes (generally observed as elevations) in their levels of all inflammatory parameters during the study and C-reactive protein, interleukin-6 and tumor necrotizing factor-alpha levels were elevated significantly. Yet, no significant difference occurred between groups due to these changes in any phase of the study (p > 0.05).

CONCLUSIONS

Based on the findings of this study, it was concluded that although tirofiban limits development of myocardial necrosis during elective PCI, it does not directly affect the acute systemic inflammatory responses.

C-reactive protein plasma levels but not factor VII activity predict clinical outcome in patients undergoing elective coronary intervention

BACKGROUND

Both vascular inflammation as determined by C-reactive protein (CRP) and extrinsic coagulation as measured by factor VII activity (F VII) may predict clinical restenosis rate in patients with stable angina pectoris undergoing elective percutaneous coronary intervention (PCI).

HYPOTHESIS

The primary objective of this study was to investigate the associations between baseline CRP levels, F VII activity, and restenosis rate after elective PCI in a 6-month follow-up period.

METHODS

This prospective study included 81 patients aged > or = 19 years undergoing PCI for angiographically significant (> or = 70%) stenosis, with or without stenting, and 49 controls. Factor VII activity and CRP were measured in samples collected at angiography and 16-24 h post procedure after overnight fast. Successful PCI was defined as final diameter of < 50% with TIMI 3 flow and no complication within 1 h. After 6 months all patients who had undergone PCI were evaluated via a standardized questionnaire. Clinical restenosis was defined as the occurrence of a major adverse coronary events (MACE), within the follow-up period.

RESULTS

Diagnostic angiography led to a significant increase in CRP levels after 16-20 h in patients with discrete CAD (n = 22) but not in patients without any signs of coronary atherosclerosis (n = 27). During a 6-month follow-up after PCI, 17 of 81 (21%) patients developed MACE. Tertiles of CRP levels independently predicted clinical restenosis, as it developed in 33.3% of patients with the highest CRP levels (0.7-4.8 mg/dl), in 16.6% of patients with second tertile CRP levels (0.23-0.69 mg/dl), and in 7.4% of patients with lowest tertile CRP levels (0.0-0.22 mg/dl). There was a significant difference in the restenosis rate between patients from the first and the third tertiles (p = 0.018). Successful PCI was associated with a significant decrease of mean CRP levels after 6 months, whereas PCI in patients suffering from MACE led to no change in CRP levels. There was no association between factor VII activity and clinical outcome after PCI, and F VII activity did not change over a 6-month period.

CONCLUSIONS

In patients with stable angina pectoris undergoing elective PCI, increased preprocedural and 6-month follow-up CRP plasma levels are associated with clinical restenosis. Factor VII plasma activity lacks such correlations.

Preprocedural C-Reactive Protein Is Not Associated with Angiographic Restenosis or Target Lesion Revascularization after Coronary Artery Stent Placement

Background: We assessed the predictive value of preprocedural plasma C-reactive protein (CRP) concentrations and statin therapy on 6 months angiographic and 1-year clinical outcome after nonurgent coronary stent placement.

Methods and Results: Baseline plasma high-sensitivity CRP concentrations were prospectively measured in 345 patients undergoing elective stent placement in a native coronary artery. The binary angiographic in-stent restenosis (ISR; stenosis ≥50% of vessel diameter) rate was 19% in patients with CRP values within the reference interval (≤3 mg/L) and 22% in patients with CRP &gt;3 mg/L [odds ratio (OR) = 1.2; 95% confidence interval (CI), 0.73–2.09]. Statin therapy in a univariate analysis significantly reduced both angiographic and clinical ISR rates. Multivariate logistic regression analysis identified unstable angina, smoking, and stent length, but neither CRP concentration nor statin therapy as independent predictors for angiographic ISR. Patients with an abnormal CRP value showed a trend toward a higher risk of nonfatal myocardial infarction (3.8% vs 0.5%; OR = 7.43; 95% CI, 0.87–61.65). Target lesion revascularization rates did not differ between the two groups (9.6% vs 10.6%; OR = 1.13; 95% CI, 0.56–2.28). In multivariate analysis, male sex (OR = 0.44, 95% CI, 0.19–0.97) and statin therapy (OR = 0.26; 95% CI, 0.09–0.68) were independent predictors for the occurrence of target lesion revascularization.

Conclusions: This study demonstrated a lack of association between preprocedural plasma CRP concentrations and angiographic coronary ISR or clinically driven target lesion revascularization. Patients with an abnormal CRP concentration showed a trend toward higher risk of nonfatal myocardial infarction during 1 year of follow-up. Statin therapy was independently associated with decreased clinically driven target lesion revascularization, underlining the beneficial effects of statins on clinical outcome.

Increase in interleukin-6 in the first hour after coronary stenting: an early marker of the inflammatory response

BACKGROUND

Inflammation after coronary stenting presages adverse outcomes after percutaneous coronary intervention (PCI). While changes in inflammatory markers have been defined 24-72 hours after PCI, potential changes during the first few hours have not. This study was designed to determine if a systemic inflammatory response could be measured within the first hour after stenting.

METHODS

Patients (n = 25) undergoing coronary stenting, with predominantly (n = 23) acute coronary syndromes were enrolled prospectively in this registry. Blood samples were collected before PCI, and 10 minutes, 1 hour and 18-24 hours later. No patient received a glycoprotein IIb-IIIa inhibitor. Concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), and interleukin-1 receptor antagonist (IL-1Ra) and soluble CD40 ligand (sCD40L) were measured using ELISA.

RESULTS

CRP and sCD40L did not change in the first hour after stenting. By contrast, IL-6 increased in the first hour (before = 7.6 +/- 7.7 pg/ml, 1 hour = 12 +/- 12 pg/ml; p < 0.001). The concentration of IL-1Ra tended to be greater after 1 hour (before = 426 +/- 261 pg/ml, 1 hour = 511 +/- 406 pg/ml; p = 0.11). Increase in IL-1Ra was apparent only in female subjects (p = 0.004 for the difference in trend between the two genders). A correlation was not observed between the increase in IL-6 at 1 hour and the increase in CRP at 24 hours (r = -0.21).

CONCLUSIONS

In patients undergoing coronary stenting, increase in IL-6 can be detected 1 hour after PCI, and thus IL-6 may be an early initiator of the systemic inflammatory response to stenting.

Preprocedural inflammatory markers do not predict restenosis after successful coronary stenting

BACKGROUND

Levels of C-reactive protein (CRP), serum amyloid A protein (SAA), and interleukin-6 (IL-6) can predict coronary restenosis following angioplasty and stent deployment in patients with unstable angina. We investigated whether measurement of periprocedural inflammatory markers predicted the angiographic outcome at 6 months in stable angina patients undergoing coronary stenting.

METHODS

We prospectively studied 182 patients; 152 patients underwent elective and successful stenting procedure for de novo lesions in native and nongrafted coronary arteries and 30 individuals in the control group underwent diagnostic angiography alone. CRP, SAA, and IL-6 were determined by high-sensitivity immunoassays.

RESULTS

At 6 months, quantitative computer-assisted angiographic analysis in 133 patients with stents showed a binary restenosis rate of 33.8%. Statins were being taken by 80% of the patients. There were no significant differences between the pre- or postprocedure values of CRP, SAA, or IL-6 in patients with or without in-stent restenosis.

CONCLUSIONS

Preprocedural inflammatory markers in stable angina subjects undergoing coronary artery stent deployment did not correlate with the development of in-stent restenosis. Differences in pathobiology between stable and unstable coronary syndromes, the widespread use of statins with anti-inflammatory activity in our cohort of patients, along with different mechanisms underlying the early angiographic appearances of restenosis as compared to clinical end points, most likely explain our findings.

The relation between preprocedural C-reactive protein levels and early and late complications in patients with acute myocardial infarction undergoing interventional coronary angioplasty

BACKGROUND

Inflammation is an important feature of arteriosclerotic disease, and the vulnerability of coronary plaques in acute myocardial infarction (AMI) may be related to the levels of serum C-reactive proteins (CRP). While some risk factors for early and late complications have been suggested, an accurate and definitive preprocedural risk stratification of patients undergoing percutaneous transluminal coronary angioplasty (PTCA) is still lacking.

HYPOTHESIS

The study was undertaken to investigate whether early and late complications after PTCA could be predicted by evaluation of baseline serum CRP levels in patients with AMI.

METHODS

Levels of serum CRP were measured in a total of 230 patients with AMI undergoing PTCA and provisional stent. They were divided into two groups: Group 1 (n = 48) with elevated CRP levels (> or = 5 mg/l) and Group 2 (n = 182) with normal CRP levels (< 5 mg/l).

RESULTS

There were no significant differences in baseline clinical, angiographic, and procedural characteristics between the two groups. However, the incidence of in-hospital adverse coronary events (reinfarction, coronary reocclusion, target vessel revascularization, and death) and severe left ventricular dysfunction was significantly higher in Group 1 (18.3 vs. 6.1%, p < 0.05 and 20.9 vs. 6.1%, p < 0.05, respectively). In addition, bailout stenting was performed more frequently in Group 1 than in Group 2 (60.4 vs. 36.3%, p < 0.005). No significant late complications were noted. The serum levels of CRP were the only independent predictors of early adverse events.

CONCLUSIONS

Preprocedural serum CRP level might be considered a powerful predictor of early but not late complications in patients undergoing PTCA/stent procedures.

[Restenosis and vascular response after angioplasty: physiopathological data]

Our purpose is to review the different mechanisms involved in the vascular response following percutaneous coronary revascularization, and their role in thrombotic complications and in restenosis. Specificities related to the various techniques of percutaneous coronary revascularization (balloon angioplasty, coronary stents, brachytherapy, drug eluting stents) are discussed.

A persistent increase in C-reactive protein is a risk factor for restenosis in patients with stable angina who are not receiving statins

Inflammation has been postulated to be a major contributor to restenosis after angioplasty. We examined the correlation between inflammatory and coagulatory reactions and the occurrence of restenosis, and how treatment with statins influences this correlation. A total of 243 patients with stable angina who were scheduled for a percutaneous coronary intervention (PCI) and follow-up coronary angiography were enrolled in the study. Eighty-one of these patients were treated with statins for at least 1 month before their PCI and throughout the study period. Blood was withdrawn on the day of the PCI and on the day of the follow-up catheterization. Patients with the highest hs-CRP at the time of the initial PCI maintained elevated hs-CRP levels over time and showed significantly higher rates of restenosis or TLR after 6 +/- 1 months than subjects with low initial hs-CRP. Statin treatment abolished this difference. Fibrinogen levels were also increased in subjects with high initial hs-CRP, both at the time of the initial PCI and at follow-up. In an univariate analysis, both initial and follow-up levels of hs-CRP and fibrinogen correlated with restenosis. However, both the initial and follow-up levels of hs-CRP only were independent predictors of increased restenosis in a multivariate analysis, except in the statin-treated subgroup. In conclusions, the persistent increase in CRP is a risk factor for restenosis in patients with stable angina who have not been treated with statins.

Role of C-reactive protein in cardiovascular disease

OBJECTIVE

To discuss the role of C-reactive protein (CRP) in cardiovascular disease as a predictor of vascular events and identify key factors that increase or decrease this inflammatory marker.

DATA SOURCES

Articles were identified through searches of MEDLINE (1966-July 2003), International Pharmaceutical Abstracts (1970-June 2003), and bibliographies of selected articles. Search terms included C-reactive protein, HMG-CoA reductase inhibitors, fenofibrate, niacin, aspirin, estrogen, thiazolidinediones, and raloxifene. data selection and data extraction: All studies relevant to CRP and cardiovascular disease or the effects of pharmacologic and nonpharmacologic interventions on CRP levels were evaluated. All information deemed relevant to this review was included.

DATA SYNTHESIS

Numerous studies have shown a strong association between CRP levels and future vascular events (i.e., coronary, cerebrovascular, peripheral vascular disease), with minimal correlation to low-density-lipoprotein cholesterol. Clinical guidelines have recently been published indicating that CRP levels of <1, 1-3, and >3 mg/L correspond to low, moderate, and high risk, respectively, for future vascular events. Drugs including statins, fibrates, niacin, thiazolidinediones, and antiplatelet agents, as well as weight loss and exercise, have demonstrated efficacy in lowering CRP levels.

CONCLUSIONS

CRP appears to be a valuable tool for predicting future vascular events in patients striving for primary or secondary prevention of cardiovascular disease. While several pharmacologic and nonpharmacologic interventions have been shown to lower CRP levels, the impact on clinical outcomes requires further study.

Therapeutic Potential of Oral Antiproliferative Agents in the Prevention of Coronary Restenosis

The treatment of coronary artery disease has reached many milestones - from balloon angioplasty to drug-eluting stents. The last decade witnessed the revolution of bare metal stents with new designs, alloys and strut thicknesses. Yet restenosis, the aphorismic 'Achilles heel', remains to be conquered. The restenosis rates with balloon angioplasty alone are 30-40% and are reduced to 20-30% with stents. Although intravascular brachytherapy proved to be a durable and safely used technique to treat in-stent restenosis, clinical event rates were not reduced to single digits.Drug-eluting stents are showing positive results in this direction, but it is too early to predict their efficacy in various subsets of lesions. With the increased usage of these stents, there are reports of problems such as late stent malapposition, subacute and late thromboses, and aneurysm formations due to the vessel toxicity associated with this method of treatment. Furthermore, when multivessel stenting is considered, the cost of drug-eluting stents is a significant problem given the fact that these are no longer 'zero restenosis' devices. There is a definite need for a simple, safe and durable solution to restenosis. Oral agents are an alternative delivery strategy that can target multiple coronary lesions, which are targets for catheter-based revascularisation with any approved metal stent and with potentially lower cost. Although oral agents have been an interesting option to treat restenosis and several agents have been tested in trials since the 1980s, the results were disappointing. The development of devices such as intravascular ultrasound has led to a greater understanding of restenosis mechanisms, and the focus on pathophysiological mechanisms, which centred mainly on platelets, growth factors and lipids, has changed to inflammation, endothelium and smooth muscle cell proliferation.Accordingly, the targets of pharmaceutical agents have shifted from platelets to cell cycle inhibition, smooth muscle cell proliferation and migration, synthesis of extra cellular matrix, and inflammatory mediators. Initial encouraging results with oral drugs such as cilostazol, sirolimus (rapamycin) and thiazolidinediones indicate a definite place for this strategy to reduce restenosis. A desirable oral agent would be anti-inflammatory, inhibit smooth muscle cell migration and proliferation, promote endothelial growth, and be well tolerated and free from significant adverse effects. It may be useful to start with a high loading dose before stent implantation and then follow with a short-term lower maintenance dose. Future trials should be aimed at finding an ideal agent, effective loading dose, maintenance dose and optimum duration of therapy.

Patient care before and after percutaneous coronary artery interventions

Care of the patient before and after percutaneous coronary interventions has changed largely because of the increased use of stents. Important patient management issues include the evaluation of chest pain after the procedure, recognition of acute vessel closure during the periprocedural period, management of the vascular access site, and prevention of contrast-induced renal dysfunction. Risk factor modification and drug therapies are important interventions for the secondary prevention of coronary events. Functional testing has a meaningful role in the evaluation of some patients after coronary intervention. It is important for the specialist in internal medicine to have a firm working knowledge of the various aspects of patient care before and after these procedures because their role in the management of these patients is increasing.

C-reactive protein and immunoglobulin-E response to coronary artery stenting in patients with stable angina

Recent reports indicate that inflammatory mechanisms play a crucial role in the pathogenesis of atherosclerosis and neointimal proliferation as well as coronary restenosis. To provide baseline data for further studies regarding stenting, restenosis and inflammatory response. we prospectively conducted a clinical study to investigate the time related response of plasma levels of immunoglobulin-E (IgE) and C-reactive protein (CRP) which are two different inflammatory markers mediated by different cytokines in stable patients who underwent elective coronary artery stenting. Thirteen consecutive stable patients who underwent coronary artery stenting were included in the study. Levels of IgE and CRP were determined pre- and poststent implantation on four consecutive days and at the end of the first as well as third month. Levels of these two markers were gradually elevated on postprocedure days while reaching peak values on the second and third days for IgE (initial 278 +/- 335 IU/mL vs peak 350 +/- 489 IU/mL, P = 0.01) and CRP (initial 0.5 +/- 0 mg/dL vs peak 2.7 +/- 3 mg/dL, P = 0.002), respectively. High levels gradually returned to baseline values determined at the end of the first and even third months after stent implantation implying an acute inflammatory reaction. Stent implantation seems not to cause any persistent and ongoing inflammatory response in the long-term.

Diagnostic coronary angiography induces a systemic inflammatory response in patients with stable angina

BACKGROUND

Systemic markers of inflammation increase after percutaneous coronary intervention (PCI). The rise in inflammatory markers after PCI is frequently attributed to the inflammatory stimulus associated with coronary artery injury during balloon inflation and coronary stent implantation. The aim of this study was the determine whether diagnostic coronary angiography performed in patients with stable angina triggers a systemic inflammatory response.

METHODS

We prospectively studied patients with chronic stable angina undergoing either coronary angiography (n = 13) or coronary angiography followed by PCI (n = 13). Peripheral blood samples were obtained before and 24 hours, 48 hours, and 4 weeks after the procedure and analyzed for C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha). Patients with periprocedural myocardial necrosis were excluded.

RESULTS

There was a significant increase in CRP levels at 24 and 48 hours in both the coronary angiography (P <.05) and PCI (P <.01) groups. IL-6 levels peaked at 24 hours in both the coronary angiography (median, 2.5-9.5 pg/mL; P =.01) and PCI (median, 3.0-8.2 pg/mL; P <.005) groups. At 4 weeks, both CRP and IL-6 returned to baseline levels. TNF-alpha levels were unchanged with either coronary angiography or PCI. The magnitude of the rise of CRP and IL-6 levels was not significantly different between the groups. There was a fair correlation between baseline and peak postprocedural levels of CRP (r = 0.67, P =.008) and IL-6 (r = 0.48, P =.016).

CONCLUSION

Uncomplicated diagnostic coronary angiography triggers a systemic inflammatory response in patients with stable angina. The contribution of coronary angiography should be considered in interpreting the significance of the systemic inflammatory response observed after PCI.

Adjunctive Pharmacotherapy before Percutaneous Coronary Intervention in Non-ST-Elevation Acute Coronary Syndromes: The Role of Modulating Inflammation

Vascular inflammation is central to the pathogenesis of acute coronary syndromes (ACS) and the response to vascular injury after percutaneous coronary intervention (PCI). For both ACS and PCI, the magnitude of vascular inflammation is linked to adverse late clinical outcomes (e.g., death, recurrent myocardial infarction [MI] or ischemia, and restenosis). Many pharmacologic therapies with demonstrated efficacy for the treatment of ACS have anti-inflammatory properties, which are distinct from their perceived primary mechanism of action. The anti-inflammatory effects of aspirin, clopidogrel, low-molecular-weight heparin (LMWH), platelet glycoprotein (GP) IIb/IIIa receptor inhibitors, statins, and angiotensin converting enzyme (ACE) inhibitors are reviewed, and the hypothesis is generated that modulation of vascular inflammation at least in part contributes a common basis for the long-term clinical benefit ascribed to these medications. A therapeutic algorithm based on clinical risk stratification and coronary revascularization strategy is proposed for incorporating the current American College of Cardiology (ACC)/American Heart Association (AHA) guideline recommendations for treatment of patients who present with non-ST-elevation ACS.

Inflammation as a therapeutic target: a unique role for abciximab

Vascular inflammation is a central pathogenic mechanism for both acute coronary syndromes and the vascular response to injury after percutaneous coronary intervention. The magnitude of vascular inflammation has been correlated with adverse late clinical outcomes (death, myocardial infarction, recurrent ischemia, restenosis). Vascular inflammation is also increased in patients with diabetes mellitus. Many adjunctive pharmacotherapies used in the treatment of acute coronary syndromes or during percutaneous coronary intervention have anti-inflammatory effects, which are distinct from their perceived primary mechanism of action. Data in support of the anti-inflammatory effects of abciximab are presented and the role that these effects may play in modulating atherosclerotic plaque stability and late clinical outcomes is discussed. Vascular inflammation represents the "final common pathway" for many disease processes and thus represents the "ultimate therapeutic target" for pharmacologic intervention.

Comparison of inflammatory markers in patients with diabetes mellitus versus those without before and after coronary arterial stenting

Patients with diabetes are at increased risk for adverse events after coronary stenting, perhaps reflecting a pro-inflammatory state. To characterize the inflammatory response to coronary stenting in patients with and without diabetes, blood samples were obtained from 75 patients before stenting and 10 minutes, 1 hour, and 24 hours later. C-reactive protein (CRP, microg/ml), interleukin (IL)-6 (pg/ml), IL-1 receptor antagonist (pg/ml), and soluble CD40 ligand (ng/ml) were assayed in each sample by enzyme-linked immunosorbent assay. Concentration changes after stenting were identified by repeated-measures analysis of variance. Multivariate analysis was performed to delineate independent predictors of increased concentrations of inflammation markers. Overall, 88% of patients had acute coronary syndromes; 36% had elevated markers of cardiac injury. The preprocedural concentrations of CRP in those with diabetes were more than twice as high as those in patients without diabetes. Two independent predictors of elevated preprocedural CRP concentrations were diabetes (odds ratio 3.95, 95% confidence interval 1.17 to 13.4) and a cardiac marker-positive acute coronary syndrome (odds ratio 3.70, 95% confidence interval 1.22 to 11.2). Preprocedural concentrations of IL-6, IL-1 receptor antagonist, and soluble CD40 ligand tended to be greater in patients with diabetes. The increase in CRP after stenting was much greater for patients without diabetes compared with that in patients with diabetes such that the apparent intensity of inflammation after 24 hours was similar in those with and without diabetes. Thus, patients with and without diabetes exhibit different inflammatory responses to stenting, reflecting the lower preprocedural inflammation in those without diabetes versus those with diabetes.

C-reactive protein and coronary events following percutaneous coronary angioplasty

PURPOSE

We investigated the associations between baseline C-reactive protein levels in patients undergoing percutaneous coronary angioplasty and death, nonfatal myocardial infarction, and repeat revascularization during 14 months of follow-up.

METHODS

In a single-center, prospective, cohort study, plasma levels of C-reactive protein were measured in 1458 consecutive patients undergoing elective or urgent coronary angioplasty. Patients were followed at 12 to 14 months for the occurrence of death, nonfatal myocardial infarction, and repeat revascularization.

RESULTS

The incidence of death or myocardial infarction was 6.1% (44/716) in patients with an increased C-reactive protein level (>3 mg/L) and 1.5% (11/742) in patients with a normal level (relative risk [RR] = 4.4; 95% confidence interval [CI]: 2.2 to 8.5; P <0.0001). In a multivariate logistic regression model, an increased C-reactive protein level was an independent predictor of death or nonfatal myocardial infarction (RR = 3.6; 95% CI: 1.8 to 7.2; P =0.0001). The incidence of repeat revascularization was similar in patients with or without an increased C-reactive protein level (23% [168/716] vs. 22% [163/742], P = 0.54). Statin therapy at the time of the procedure was associated with a lower mean (+/- SD) C-reactive protein level (5.8 +/- 9.7 mg/L vs. 7.2 +/- 12.1 mg/L, P =0.02), but was not associated with the risk of death, nonfatal myocardial infarction, and repeat revascularization during follow-up.

CONCLUSION

An increased C-reactive protein level is an independent prognostic indicator for the occurrence of death or nonfatal myocardial infarction following coronary angioplasty, but is not associated with the need for repeat revascularization.

Comparison of effects of a thrombin-based femoral artery closure device with those of a mechanical compression device on serum C-reactive protein and amyloid A after percutaneous coronary intervention

The present study evaluates whether the closing procedure of the femoral artery after percutaneous coronary intervention influences the degree of inflammation related to the procedure as measured by C-reactive protein (CRP) and serum amyloid A (SAA). A thrombin-based device (Duett sealing device) was compared with a mechanical compression device (FemoStop).

C-reactive protein: a novel marker of cardiovascular risk

Patients without traditional cardiovascular risk factors continue to suffer from cardiovascular events, which has prompted a search for novel markers to better assess cardiovascular risk. Inflammatory biomarkers have surfaced as prime candidates, given the integral role of inflammation in atherosclerosis. C-reactive protein (CRP) measurements in particular have emerged as powerful predictors of cardiovascular risk in a broad spectrum of patient populations. Newer high sensitivity CRP assays now in use are standardized and reproducible, and can detect variations in CRP below the limit of standard assays. In primary prevention populations, studies have shown up to a 2-4-fold increased risk of cardiovascular events in healthy patients with elevated CRP levels. In this population, models incorporating CRP and lipid parameters appear to predict risk significantly better than lipids alone. In patients with established cardiovascular disease and in patients undergoing percutaneous coronary interventions, CRP levels may help predict short- and long-term prognosis, identifying subgroups of patients at increased risk of recurrent events. CRP levels may also prove useful in targeting therapy for primary and secondary prevention, by identifying patients who would most benefit from medications such as statins and aspirin. This review presents an overview of the data regarding CRP measurement for cardiovascular risk assessment.

Increased C-reactive protein level after coronary stent implantation in patients with stable coronary artery disease

BACKGROUND

Elevation of C-reactive protein (CRP), among other markers of inflammation, is associated with an increased risk for cardiac events in patients with known coronary diseases and in apparently healthy individuals. Moreover, in patients with acute coronary syndromes, elevated serum levels of CRP are strongly predictive of the risk for death from cardiac causes. The purpose of this study was to investigate whether mechanical rupture of an atherosclerotic coronary plaque during elective stent implantation in patients with stable coronary artery disease (CAD) at low risk will cause a significant increase in serum levels of CRP.

METHODS AND RESULTS

We measured serum CRP levels in 40 patients. Group 1 consisted of 12 consecutive patients with stable coronary disease who were at low risk, before and after elective coronary stent implantation. We compared the results in these patients to those of patients in 2 control groups: group 2 consisted of 12 consecutive patients with non-ST-segment elevation acute coronary syndrome (NSTSE ACS) who were undergoing coronary stent implantation, and group 3 included 16 consecutive patients with stable or unstable CAD who were undergoing diagnostic coronary angiography only without PCI. Peripheral blood samples for CRP level testing were withdrawn before percutaneous coronary intervention or angiography at the completion of the procedure, and 6, 20, and 48 hours thereafter. All patients with stable CAD (group 1) had a significant and uniform increase in serum CRP levels after elective stent implantation. The low mean baseline serum CRP levels increased 4.9 +/- 4.1-fold 20 hours after coronary intervention (2.1 +/- 1.2 before, 7.9 +/- 3.4 after, P <.002). The baseline CRP level was much higher in the patients with unstable coronary syndromes (group 2). In this group, only a 2.1-fold increase in mean CRP level was observed after stent implantation (7.4 +/- 5.5 before, 14.1 +/- 9.6 after, P <.004). Also, the response in this group was less uniform when compared with that in the stable CAD group. By contrast, in patients undergoing diagnostic coronary angiography, the mean baseline CRP level was higher than in the patients in the group with stable CAD; however, the mean CRP after the procedure was not significantly elevated in this group (4.5 +/- 3.6 before, 5.5 +/- 3.7 20 hours after, P = not significant).

CONCLUSIONS

Mechanical disruption of an atherosclerotic coronary plaque during elective coronary stent implantation in patients with stable CAD who are at low risk causes a systemic inflammatory response expressed by marked elevation in CRP concentration.

The Prognostic Value of IL-8 for Cardiac Events and Restenosis in Patients with Coronary Heart Diseases After Percutaneous Coronary Intervention

The objective of the present study was to investigate the prognostic value of plasma interleukin-8 (IL-8) for adverse cardiac events and restenosis in patients with percutaneous coronary intervention (PCI). The pre- and post-procedural peak plasma levels of IL-8 and serum C-reactive protein (CRP) were examined by immunoassay, while adverse cardiae events and restenosis within one year follow-up were observed in 134 consecutive patients who underwent PCI. Angiography revealed that 23.88% (32/134) of the patients had adverse cardiac events and 29.41% (35/119) of the patients had restenosis. Preprocedural levels of IL-8 and CRP and post-procedural peak levels of IL-8 in patients with adverse cardiac events were higher than those without adverse cardiac events (all P < 0.05). The incidence of adverse cardiac events increased from 6.67% in the bottom tertile to 31.82% in the top tertile of IL-8 levels (P = 0.001): a similar trend was observed for restenosis from 10% in low tertile to 51.28% in high tertile of IL-8 levels to 51.8% (P = 0.012). The preprocedural levels of IL-8 (RR = 5.539, CI = 1.720-17.887, P = 0.001) and CRP (RR = 2.031, CI = 1.132-2.049, P = 0.003) were the only independent predictors of adverse cardiac events. The post-procedure peak level of IL-8 (RR = 3.766, CI = 2.990-5.904, P = 0.002) and stent length (RR = 1.468, CI = 1.161-2.022. P = 0.021) were the independent predictors of restenosis. The results demonstrate that the release of IL-8 after PCI is a powerful prognostic factor for cardiac events and restenosis. The higher the peak level of post-procedure IL-8, the lower the event-free survival observed.

Immunosuppressive Therapy for the Prevention of Restenosis after Coronary Artery Stent Implantation (IMPRESS Study)

OBJECTIVES

This study tested the effect of oral prednisone on clinical and angiographic restenosis rate after successful stent implantation in patients with persistent elevation of systemic markers of inflammation after the procedure.

BACKGROUND

Experimental studies have shown that corticosteroids have the potential to reduce the inflammatory response associated with stent implantation.

METHODS

Eighty-three patients undergoing successful stenting with C-reactive protein (CRP) levels >0.5 mg/dl 72 h after the procedure were randomized to receive oral prednisone or placebo for 45 days. The primary clinical end point was 12-month event-free survival rate (defined as freedom from death, from myocardial infarction, and from recurrence of symptoms requiring additional revascularization). The angiographic end points were restenosis rate and late loss at six months.

RESULTS

Twelve-month event-free survival rates were 93% and 65% in patients treated with prednisone and placebo, respectively (relative risk [RR] 0.18, 95% confidence intervals [CI], 0.05 to 0.61, p = 0.0063). Six-month restenosis rate and late loss were lower in prednisone-treated than in placebo-treated patients (7% vs. 33%, p = 0.001, and 0.39 +/- 0.6 mm vs. 0.85 +/- 0.6 mm, p = 0.001, respectively).

CONCLUSIONS

In patients with persistently high CRP levels after successful coronary artery stent implantation, oral immunosuppressive therapy with prednisone results in a striking reduction of clinical events and angiographic restenosis rate.

Inflammation and restenosis in the stent era

The pathophysiology of restenosis involves early elements of direct injury to smooth muscle cells, deendothelialization, and thrombus deposition. Over time, this leads to smooth muscle cell proliferation/migration and extracellular matrix deposition. There is an increasing body of evidence to suggest that inflammation plays a pivotal role linking early vascular injury to the eventual consequence of neointimal growth and lumen compromise. The widespread use of coronary stents has fundamentally altered the vascular response to injury by causing a more intense and prolonged inflammatory state. Many of the cellular and molecular elements responsible for leukocyte recruitment have been elucidated, providing potential therapeutic targets for restenosis. This review seeks to provide an integrated view of the pathophysiology of restenosis that explains the central role of inflammation.

Treatment with cerivastatin in primary mixed hyperlipidemia induces changes in platelet aggregation and coagulation system components

Platelet activation, impairment of fibrinolysis, activation of the coagulation pathway, and dyslipidemia are important factors in the pathogenesis and progression of ischemic heart disease, and patients generally need to use an antiplatelet agent. Lipid-lowering cerivastatin, a novel 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, was administered to 20 patients with primary mixed hyperlipidemia for the assessment of the effect of cerivastatin on lipid levels, plasma fibrinogen concentration, factor VII, VIII, and X levels, plasminogen and antiplasmin concentrations, platelet count, and aggregation (adenosine diphosphate [ADP], collagen, and epinephrine induced). Assessments were made immediately after 2 months of a standard lipid-lowering diet, 4 weeks of placebo administration, and 4 weeks of cerivastatin treatment. Cerivastatin achieved significant reductions in triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels. The significant improvement of the lipid profile was associated with platelet aggregation reduction in vitro stimulated by ADP, collagen, and epinephrine (P < .05, P = .05, P < .005, respectively). Significantly lower levels of factor VII and fibrinogen were observed (P = .001, P < .0001) immediately after cerivastatin treatment. No significant differences were detected in factor VIII level, plasminogen and antiplasmin concentrations, and platelet count after cerivastatin treatment. It was concluded that cerivastatin in mixed hyperlipidemia can exert beneficial changes on specific hemostatic variables and platelet aggregation in addition to its positive effects on plasma lipid values.

Predictive value of preprocedural fibrinogen concerning coronary stenting

Elevated fibrinogen levels after coronary balloon angioplasty have been reported to be useful in predicting restenosis. Therefore, we sought to evaluate the relationship between preprocedural fibrinogen levels and the 6-12-month outcomes of patients undergoing coronary stenting. Plasma levels of fibrinogen were measured in 390 consecutive patients prior to coronary stenting. The primary end point was binary restenosis (percent diameter stenosis of >/=50%). The secondary combined end point was death due to cardiac causes, myocardial infarction related to the target vessel and target lesion revascularization. Patients were grouped into tertiles according to fibrinogen levels. Both at baseline and immediately after procedure, clinical and angiographic characteristics were almost identical in the fibrinogen tertiles. An increase in restenosis rate was observed across the tertiles (18.6, 23.9, 38.1%, P<0.001, respectively). In addition, the frequency of the secondary end point increased in the highest tertile (14.9, 21.5, 37.2%, P<0.001, respectively). Multivariate analysis revealed that high levels of fibrinogen (per 100 mg/dl, OR 1.82, P<0.001) and stent length (P=0.034) were independent predictors for restenosis. An elevated preprocedural fibrinogen level should be considered as a stronger predictor for restenosis after coronary stenting, which might be associated with coagulation and inflammation.

Prognostic value of interleukin-1 receptor antagonist in patients undergoing percutaneous coronary intervention

Elevated plasma levels of inflammatory markers, such as C-reactive protein (CRP), have been associated with adverse outcome in selected patients with coronary artery disease (CAD) treated with coronary angioplasty or stenting. The aim of this study was to evaluate the predictive value of preprocedural interleukin-1 receptor antagonist (IL-1Ra) plasma levels for long-term major adverse cardiac events (MACE) in a series of unselected patients with symptomatic CAD treated with percutaneous coronary intervention (PCI). Seventy-three consecutive patients (62 men, aged 62 +/- 9 years) undergoing PCI were enrolled in a prospective follow-up study. IL-1Ra and CRP plasma levels were measured before the procedure; 36 patients (49%) had unstable angina pectoris on admission, 37 (51%) had chronic stable angina pectoris, and 30 (41%) had multivessel CAD, 15 of whom underwent multivessel PCI. Success was achieved in all 73 patients, with coronary stenting performed in 63 (86%). Follow-up clinical assessment included occurrence of MACE at 3, 6, 12, and 18 months. Logistic regression analysis, performed to determine independent predictors of MACE, identified IL-1Ra levels in the upper quartile as the only independent predictive factor of MACE at 18 months (19% in the fourth quartile vs 0% in the first quartile; p = 0.032). Patients with high preprocedural CRP levels (fourth quartile) had a nonsignificant increased risk of MACE (p = 0.09). Thus, preprocedural IL-1Ra plasma levels appear to be a valuable independent predictive factor of MACE in unselected patients undergoing PCI.

Early and sustained survival benefit associated with statin therapy at the time of percutaneous coronary intervention

BACKGROUND

Long-term administration of statin therapy has been shown to reduce major coronary events and cardiac mortality within randomized clinical trials. In addition to lowering lipids, statins favorably affect platelet adhesion, thrombosis, endothelial function, inflammation, and plaque stability, which may potentially improve outcome after percutaneous coronary intervention (PCI). Therefore, we hypothesized that statin therapy has an early beneficial effect among patients undergoing PCI.

METHODS AND RESULTS

Each year from 1993 to 1999, we prospectively collected data among the first 1000 patients undergoing PCI. Patients who presented with acute or recent myocardial infarction or cardiogenic shock were excluded from the analysis. Baseline, procedural, and 6-month data of statin-treated and non-statin-treated patients were compared. Propensity score and multivariate survival analysis were used to adjust for heterogeneity between the two groups. Of 5052 patients who completed follow-up, 26.5% were treated with statin at the time of the procedure. Statin therapy was associated with a mortality reduction at 30 days (0.8% versus 1.5%; hazard ratio, 0.53; P=0.048) and at 6 months (2.4% versus 3.6%; hazard ratio, 0.67; P=0.046). After adjusting for the propensity to receive statin therapy before the procedure and other confounders, statin therapy remained an independent predictor for survival at 6 months after coronary intervention (hazard ratio, 0.65; 95% CI, 0.42 to 0.99; P=0.045).

CONCLUSIONS

In this large study cohort, statin therapy among PCI patients seems to be associated with a significant mortality advantage at early and intermediate-term follow-up.

Distribution of C-reactive protein and its relation to risk factors and coronary heart disease risk estimation in the National Health and Nutrition Examination Survey (NHANES) III

The authors examined the distribution of, and risk factors associated with, the inflammatory marker C-reactive protein (CRP) among a large sample of non-institutionalized American adults aged 30-74 years of age, and its relation to estimated 10-year coronary heart disease risk. The population studied comprised 4472 men and 5212 women aged 30-74 years, without coronary heart disease, who had CRP measurements in the Third National Health and Nutrition Examination Survey (NHANES III). The 10-year risk of coronary heart disease was estimated from Framingham risk factor algorithms among those with CRP levels of less-than-or-equal0.21 mg/dL, >0.21 to <0.5mg/dL, 0.5 to <1.0 mg/dL, and greater-than-or-equal1.0 mg/dL. Mean (SD) levels of CRP were 0.41 (0.64) mg/dL in men and 0.55 (0.91) mg/dL in women. Levels of at least 1 mg/dL were measured in 6.4% of men and 12.9% of women. CRP levels were highest among non-Hispanic black men and Mexican-American women. According to multiple logistic regression analysis, cigarette smoking and increased age, body mass index, and systolic blood pressure in men, and body mass index and diabetes in women, were strongly associated with a greater likelihood of CRP levels of greater-than-or-equal1.0 mg/dL (p<0.001). Among persons with CRP levels of less-than-or-equal0.21 mg/dL, >0.21 to <0.5 mg/dL, 0.5 to <1.0 mg/dL and greater-than-or-equal1.0 mg/dL, the 10-year estimated risk of coronary heart disease were 13.4%, 17.6%, 19.6%, and 21.1% among men, respectively, and 2.7%, 3.6%, 4.1% and 4.3% among women, respectively (both p<0.001 across CRP categories); higher risks across CRP groups were also found among ethnic/gender subgroups. CRP remained a significant predictor of coronary heart disease risk in unadjusted and age-adjusted analyses. Conclusion. Elevation of CRP is associated with several major coronary heart disease risk factors and with unadjusted and age-adjusted projections of 10-year coronary heart disease risk in both men and women. (c)2001 CHF, Inc. Presented at the Fifth International Conference on Preventive Cardiology, Osaka, Japan, May, 2001.

Gender differences in C-reactive protein concentrations-confirmation with two sensitive methods

Two new automated, highly sensitive methods for the measurement of C-reactive protein (CRP) were compared using blood samples from active and retired health care workers (116 males, 114 females). The regression equation was y=1.115x-0.0267 forthe Kamiya K assay immunoturbidimetric method (x) vs. the Behring BNII nephelometric method (y) with medians (IQR) of 0.156 (0.081 to 0.276) and 0.150 (0.060 to 0.240) mg/dl, respectively. Significant differences in hsCRP values between males and females were observed (p=0.013 and p=0.0018 for Behring and Kamiya methods, respectively). This gender difference in CRP levels was confirmed by analysis of serum samples from 1,114 individuals (639 males and 475 females) obtained through Mayo Medical Laboratories reference services, which represents participants from across the United States. The gender difference, which was confirmed (p<0.0001), was independent of age differences as assessed by multiple regression analysis. The observed gender differences have important implications for the establishment of cut-off points for cardiovascular risk stratification.

Statin therapy, inflammation and recurrent coronary events in patients following coronary stent implantation

OBJECTIVES

We sought to investigate whether statin therapy affects the association between preprocedural C-reactive protein (CRP) levels and the risk for recurrent coronary events in patients undergoing coronary stent implantation.

BACKGROUND

Low-grade inflammation as detected by elevated CRP levels predicts the risk of recurrent coronary events. The effect of inflammation on coronary risk may be attenuated by statin therapy.

METHODS

We investigated a potential interrelation among statin therapy, serum evidence of inflammation, and the risk for recurrent coronary events in 388 consecutive patients undergoing coronary stent implantation. Patients were grouped according to the median CRP level (0.6 mg/dl) and to the presence of statin therapy.

RESULTS

A primary combined end point event occurred significantly more frequently in patients with elevated CRP levels without statin therapy (RR [relative risk] 2.37, 95% CI [confidence interval] [1.3 to 4.2]). Importantly, in the presence of statin therapy, the RR for recurrent events was significantly reduced in the patients with elevated CRP levels (RR 1.27 [0.7 to 2.1]) to about the same degree as in patients with CRP levels below 0.6 mg/dl and who did not receive statin therapy (RR 1.1 [0.8 to 1.3]).

CONCLUSIONS

Statin therapy significantly attenuates the increased risk for major adverse cardiac events in patients with elevated CRP levels undergoing coronary stent implantation, suggesting that statin therapy interferes with the detrimental effects of inflammation on accelerated atherosclerotic disease progression following coronary stenting.

Markers of the acute phase response in cardiovascular disease: an update

There is now widespread agreement that inflammation is a key component in the progression of atheromatous lesions. Inflammatory cells are present at all stages in the development of the atheromatous plaque, and gene knockout experiments in mice show that atheroma is largely prevented in the absence of the normal inflammatory mediators. In humans reduction of inflammation accompanies successful treatment strategies for atheroma. An increasing number of studies suggest that the acute phase protein, C-reactive protein, provides increased prognostic information over and above existing markers of atheroma severity or progression in healthy individuals and in the acute coronary syndromes. Recent advances in our knowledge of the normal variability of C-reactive protein levels and in precise and sensitive measurements strengthen the arguments for adding this marker to the repertoire of the routine laboratory assessment of cardiovascular disease.

Incremental prognostic value of elevated baseline C-reactive protein among established markers of risk in percutaneous coronary intervention

BACKGROUND

Established methods of risk assessment in percutaneous coronary intervention have focused on clinical and anatomical lesion characteristics. Emerging evidence indicates the substantial contribution of inflammatory processes to short-term and long-term outcomes in coronary artery disease.

METHODS AND RESULTS

Within a single-center registry of contemporary percutaneous coronary revascularization strategies with postprocedural creatine kinase and clinical events routinely recorded, we assessed the association of baseline C-reactive protein with death or myocardial infarction within the first 30 days. Predictive usefulness of baseline C-reactive protein within the context of established clinical and angiographic predictors of risk was also examined. Among 727 consecutive patients, elevated baseline C-reactive protein before percutaneous coronary intervention was associated with progressive increase in death or myocardial infarction at 30 days (lowest quartile, 3.9%, versus highest quartile, 14.2%; P=0.002). Among clinical and procedural characteristics, baseline C-reactive protein remained independently predictive of adverse events, with the highest quartile of C-reactive protein associated with an odds ratio for excess 30-day death or myocardial infarction of 3.68 (95% CI, 1.51 to 8.99; P=0.004). A predictive model that included baseline C-reactive protein quartiles, American College of Cardiology/American Heart Association lesion score, acute coronary syndrome presentation, and coronary stenting appears strongly predictive of 30-day death or myocardial infarction within this population (C-statistic, 0.735) and among individual patients (Brier score, 0.006).

CONCLUSIONS

Elevated baseline C-reactive protein portends heightened risk of 30-day death or myocardial infarction after coronary intervention. Coupled anatomic, clinical, and inflammatory risk stratification demonstrates strong predictive utility among patients undergoing percutaneous coronary intervention and may be useful for guiding future strategies.

Abciximab suppresses the rise in levels of circulating inflammatory markers after percutaneous coronary revascularization

BACKGROUND

Previous investigators have shown that systemic markers of inflammation may be increased in patients with acute ischemic syndromes or after percutaneous coronary revascularization and that persistent elevation in these markers is predictive of excess risk of subsequent adverse cardiac events. By virtue of its cross-reactivity with the glycoprotein IIb/IIIa, avbeta3, and alphaMbeta2 receptors, abciximab may reduce inflammatory processes. Methods and Results-- Assays for the inflammatory markers C-reactive protein, interleukin-6, and tumor necrosis factor-alpha were performed on serum samples obtained from 160 patients in a placebo-controlled, randomized trial of abciximab during angioplasty. Eighty patients each had received a placebo or abciximab bolus plus a 12-hour infusion. Serum samples were drawn at baseline (before revascularization), 24 to 48 hours after study drug administration, and 4 weeks after study drug administration. Between baseline and 24 to 48 hours, the increase in C-reactive protein was 32% less in patients receiving abciximab than placebo (P=0.025); the rise in interleukin-6 levels was 76% less in the abciximab group (P<0.001); and the rise in tumor necrosis factor-alpha levels was 100% less with abciximab therapy (P=0.112). By 4 weeks, most marker levels had returned to baseline, with no significant differences between placebo and abciximab groups.

CONCLUSIONS

Systemic markers of inflammation increase in the first 24 to 48 hours after angioplasty, but the magnitude of that rise is diminished by periprocedural abciximab. Some of the long-term clinical benefit derived from this agent may be related to an anti-inflammatory effect.

Role of cytokines in the pathogenesis of restenosis after percutaneous transluminal coronary angioplasty

BACKGROUND

Inflammatory cytokines play an important role in mediating inflammatory/proliferative responses including atherosclerosis. However, their role in the pathogenesis of restenosis after percutaneous transluminal coronary angioplasty (PTCA) remains to be clarified.

OBJECTIVE

To determine plasma levels of inflammatory cytokines as well as cytokine-generation capacities of monocytes before PTCA and after the follow-up period.

METHODS

Plasma levels of cytokines in 34 consecutive patients before and 3-6 months after PTCA were measured by enzyme-linked immunosorbent assay. We measured the plasma levels of macrophage-colony-stimulating factor (MCSF) and transforming growth factor-beta. Cytokine-generation capacities of monocytes were also measured by a whole-blood induction method with lipopolysaccharide. The levels of cytokines measured for assessment of the capacities included those of interleukin-1alpha, interleukin-1beta, interleukin-6, granulocyte-colony-stimulating factor, tumor necrosis factor-alpha and interferon-gamma.

RESULTS

Plasma levels of MCSF in patients without restenosis (n = 20) decreased significantly (from 1460+/-138 microg/ml before PTCA to 1039+/-125 microg/ml after the follow-up period, P < 0.01), whereas those in patients with restenosis (n = 14) increased significantly (from 1107+/-105 microg/ml before PTCA to 1039+/-125 microg/ml after the follow-up period, P < 0.05). We noted a positive correlation between the increase in plasma levels of MCSF and the extent of loss of lumen by restenosis. Cytokine-generation capacities of monocytes for interleukin-1alpha and interleukin-1beta of patients with restenosis significantly increased but those of patients without restenosis did not. Furthermore, plasma levels of C-reactive protein decreased significantly only in patients without restenosis after the follow-up period.

CONCLUSIONS

These results suggest that inflammatory changes mediated by cytokines may be involved in the pathogenesis of restenosis after PTCA.

Preprocedural C-reactive protein levels and cardiovascular events after coronary stent implantation

OBJECTIVES

This study assessed the predictive value of preprocedural C-reactive protein (CRP) levels on six-month clinical and angiographic outcome in patients undergoing coronary stent implantation.

BACKGROUND

Recent data indicate that low-grade inflammation as detected by elevated CRP serum levels predicts the risk of recurrent coronary events.

METHODS

We prospectively investigated the predictive value of preprocedural CRP-levels on restenosis and six-month clinical outcome in 276 patients after coronary stent implantation. The primary combined end point was death due to cardiac causes, myocardial infarction related to the target vessel and repeat intervention of the stented vessel.

RESULTS

Grouping patients into tertiles according to preprocedural CRP-levels revealed that, despite identical angiographic and clinical characteristics at baseline and after stent implantation, a primary end point event occurred in 24 (26%) patients of the lowest tertile, in 42 (45.6%) of the middle tertile and in 38 (41.3%) of the highest CRP tertile, p = 0.01. On multivariate analysis, tertiles of CRP levels were independently associated with a higher risk of adverse coronary events (relative risk = 2.0 [1.1 to 3.5], tertile I vs. II and III, p = 0.01) in addition to the minimal lumen diameter after stent (p = 0.04). In addition, restenosis rates were significantly higher in the two upper tertiles compared with CRP levels in the lowest tertile (45.5% vs. 38.3% vs. 18.5%, respectively, p = 0.002).

CONCLUSIONS

Low-grade inflammation as evidenced by elevated preprocedural serum CRP-levels is an independent predictor of adverse outcome after coronary stent implantation, suggesting that a systemically detectable inflammatory activity is associated with proliferative responses within successfully implanted stents.

Importance of microembolization and inflammation in atherosclerotic heart disease

Considerable evidence now exists that inflammation is a central component of events that initiate and propagate an acute coronary syndrome. This process evokes the potential for embolization, which occurs more often than previously suspected, and imparts poor cardiovascular prognosis. Recent development of techniques to detect inflammation and embolization represents an important advance. In addition, therapies that diminish occurrence of these phenomena such as aspirin, statins, angiotensin converting enzyme (ACE) inhibitors, and IIb/IIIa receptor antagonists have been shown to improve outlook.

Evaluation of Four Automated High-Sensitivity C-Reactive Protein Methods: Implications for Clinical and Epidemiological Applications

Background: C-reactive protein (CRP) can provide prognostic information about the risk of developing atherosclerotic complications in apparently healthy patients. This new clinical application requires quantification of CRP concentrations below those traditionally measured in the clinical laboratory.

Methods: The Dade Behring BN II, the Abbott IMx, the Diagnostic Products Corporation IMMULITE, and the Beckman Coulter IMMAGE are four automated analyzers with high-sensitivity CRP (hs-CRP) methods. We evaluated these assays for precision, linearity, and comparability with samples from 322 apparently healthy blood donors.

Results: The imprecision (CV) of the BN II, IMx, IMMULITE, and IMMAGE methods was ≤7.6%, ≤12%, ≤9.8%, and ≤9.7% at 3.5 mg/L, respectively. The BN II, IMx, IMMULITE, and IMMAGE methods were linear down to ≤0.30, ≤0.32, ≤0.85, and 2.26 mg/L, respectively. CRP concentrations demarcating each quartile in a healthy population were method dependent. The IMx method gave results comparable to the BN II method for values in the reference interval. The IMMULITE method had a positive intercept compared with the BN II method. The IMMAGE method demonstrated more scatter and a positive intercept compared with the BN II method, which may reflect the fact that it is a less sensitive assay.

Conclusions: The four hs-CRP methods exhibited differences in results for a healthy population. Additional standardization efforts are required to ensure that hs-CRP results can be related to large-scale epidemiologic studies.