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 >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.

Promoter polymorphism in the CD14 gene and concentration of soluble CD14 in patients with in-stent restenosis after elective coronary stenting

BACKGROUND

Activated monocytes/macrophages, neutrophils, endothelial cells and smooth muscle cells participate in the restenosis processes. Monocytes/macrophages and neutrophils are activated by lipopolysaccharide (LPS) via CD14. Endothelial cells and smooth muscle cells are also stimulated by soluble CD14 (sCD14)-LPS complexes.

METHODS

We tested the hypothesis that C(-260)-->T polymorphism of the CD14 gene and sCD14 might be predictors for in-stent restenosis. We analyzed 129 consecutive patients who underwent elective coronary stenting. The restenosis was defined as > or =50% diameter stenosis at follow-up angiography.

RESULTS

The prevalence of the T/T genotype and the concentration of sCD14 were significantly higher in the restenosis group than in the no-restenosis group. This CD14 polymorphism also affected the levels of sCD14, therefore, we divided the patients into four groups. The loss index was 24.8% in C/C or C/T and < or =50th percentile of sCD14, 35.9% in T/T and < or =50th percentile of sCD14, 44.2% in C/C or C/T and >50th percentile of sCD14, and 49.1% in T/T and >50th percentile of sCD14 (P=0.02). The restenosis rate was 10.0%, 26.7%, 26.2% and 50.0% in each group, respectively (P=0.003). In the multivariate analysis, T/T and >50th percentile of sCD14 was the independent predictor for in-stent restenosis.

CONCLUSIONS

This study showed that the T/T genotype with a high level of sCD14 is an independent predictor of in-stent restenosis. The activation of monocytes/macrophages, endothelial cells and smooth muscle cells mediated by CD14 and/or sCD14 may play an important role in the restenosis processes.

Randomized, double-blind, placebo-controlled trial of oral sirolimus for restenosis prevention in patients with in-stent restenosis: the Oral Sirolimus to Inhibit Recurrent In-stent Stenosis (OSIRIS) trial

BACKGROUND

Despite recent advances in interventional cardiology, including the introduction of drug-eluting stents for de novo coronary lesions, the treatment of in-stent restenosis (ISR) remains a challenging clinical issue. Given the efficacy of systemic sirolimus administration to prevent neointimal hyperplasia in animal models and to halt and even reverse the progression of allograft vasculopathy, the aim of the present double-blind, placebo-controlled study was to evaluate the efficacy of a 10-day oral sirolimus treatment with 2 different loading regimens for the prevention of recurrent restenosis in patients with ISR.

METHODS AND RESULTS

Three hundred symptomatic patients with ISR were randomly assigned to 1 of 3 treatment arms: placebo or usual-dose or high-dose sirolimus. Patients received a cumulative loading dose of 0, 8, or 24 mg of sirolimus 2 days before and the day of repeat intervention followed by maintenance therapy of 2 mg/d for 7 days. Angiographic restenosis at 6-month angiography was the primary end point of the study. Restenosis was significantly reduced from 42.2% to 38.6% and to 22.1% in the placebo, usual-dose, and high-dose sirolimus groups, respectively (P=0.005). Similarly, the need for target vessel revascularization was reduced from 25.5% to 24.2% and to 15.2% in the placebo, usual-dose, and high-dose groups, respectively (P=0.08). The sirolimus blood concentration on the day of the procedure correlated significantly with the late lumen loss at follow-up (P<0.001).

CONCLUSIONS

In patients with ISR, an oral adjunctive sirolimus treatment with an intensified loading regimen before coronary intervention resulted in a significant improvement in the angiographic parameters of restenosis.

The relationship between preprocedural platelet size and subsequent in-stent restenosis

OBJECTIVE

Elevated mean platelet volume predicts restenosis after percutaneous transluminal coronary angioplasty but its effect on the development of in-stent restenosis is not known. We assessed the effect of mean platelet volume measured before coronary stent implantation for stable angina pectoris on subsequent development of in-stent restenosis.

METHODS AND RESULTS

We retrospectively analysed the data of 60 patients who had stent implantation on one native coronary artery for stable angina pectoris and control angiographies for clinically suspected restenosis within 6 months. Mean platelet volume was measured by auto analyzer one day before stent implantation. Clinical and demographic data and laboratory results were obtained from the hospital charts of the patients. In-stent restenosis was evaluated visually from control angiograms. Angiographic in-stent restenosis was present in 35 (58%) of 60 patients and 25 (42%) patients had no restenosis. Mean platelet volume in the in-stent restenosis group was 8.28 +/- 0.71 fl compared to 7.63 +/- 0.74 fl in the no-restenosis group (p = 0.001). There was a positive correlation between preprocedural mean platelet volume and development of in-stent restenosis (r = 0.44; p < 0.001). A mean platelet volume value of > or = 8.4 fl was associated with an odds ratio of 16.0 for development of in-stent restenosis, with high specificity and positive predictivity but poor sensitivity and negative predictivity (96%, 93%, 40% and 53%, respectively).

CONCLUSIONS

Mean platelet volume measured before stent implantation is correlated with subsequent development of in-stent restenosis. If preprocedural mean platelet volume is greater than 8.4 fl, in-stent restenosis is more probable to occur.

Relation of C-reactive protein to restenosis after coronary stent implantation and to restenosis after coronary atherectomy

To determine whether the inflammatory response is equally involved in the pathogenesis of restenosis after coronary stenting and directional coronary atherectomy, we assessed restenotic lesions with immunohistochemical methods. Levels of C-reactive protein and macrophages were greater in patients with in-stent restenosis than in those with restenosis after directional coronary atherectomy. This suggests that the inflammatory response is more involved in the pathogenesis of in-stent restenosis than in restenosis after directional coronary atherectomy.

Distinct yet complementary mechanisms of heparin and glycoprotein IIb/IIIa inhibitors on platelet activation and aggregation: implications for restenosis during percutaneous coronary intervention

OBJECTIVE

To study the effect of unfractionated heparin (UFH) versus low molecular weight heparin (LMWH) in combination with glycoprotein (Gp) IIb/IIIa blockers on platelet activation and aggregation.

METHODS

Washed platelets were stimulated with thrombin in the presence or absence of UFH (monoparin), LMWH (enoxaparin), and a Gp IIb/IIIa blocker (abciximab, eptifibatide, or tirofiban).

RESULTS

Although Gp IIb/IIIa antagonists blocked the final common pathway of thrombin induced platelet aggregation, UFH and LMWH were better at blocking upstream platelet activation. UFH was significantly more effective than LMWH at inhibiting P selectin expression (p = 0.001) and platelet derived growth factor release from thrombin activated platelets (p = 0.012).

CONCLUSIONS

UFH and LMWH exert complementary effects to Gp IIb/IIIa blockers by inhibiting afferent pathways of platelet activation. Coadministration of heparin with Gp IIb/IIIa blockers provides improved protection against persistent platelet activation, thereby improving outcome after percutaneous coronary intervention. Judging from these data, UFH may be more effective in this regard than LMWH, at least in vitro. The use of LMWH in preference to UFH during percutaneous coronary intervention, although initially attractive, may inadequately protect against platelet activation despite the presence of Gp IIb/IIIa blockers.

Effect of short-term administration of high dose L-arginine on restenosis after percutaneous transluminal coronary angioplasty

BACKGROUND

A single and local administration of L-arginine after balloon angioplasty enhances nitric oxide (NO) generation and inhibits lesion formation in animals.

OBJECTIVES

The present study assessed the effect of increasing NO to inhibit restenosis after percutaneous transluminal coronary angioplasty (PTCA) in humans by local and systemic administration of L-arginine, a precursor of NO in humans.

METHODS

L-arginine was administered to 34 consecutive patients with angina pectoris or old myocardial infarction via a cardiac catheter (500 mg/4 min) before PTCA, and via a peripheral vein (30 g/4 hr, for 5 days) after PTCA. Patients were treated between December 1998 and December 2000. Plasma concentrations of L-arginine, NO (as nitrite + nitrate) and cyclic guanosine monophosphate (cGMP) were measured before and after L-arginine administration. The control group consisted of 90 patients who underwent PTCA successfully without L-arginine administration in the period between July 1996 and November 1998. Baseline clinical and angiographic characteristics were compared between the two groups. All patients were followed by coronary angiography for 3 months after PTCA. Quantitative coronary angiography and restenosis rate were studied.

RESULTS

Baseline clinical and angiographic characteristics were not different between the two study groups. Despite a significant elevation in plasma L-arginine concentration after L-arginine administration, NO and cGMP did not increase significantly. After PTCA, the difference in restenosis rates between L-arginine and control subjects (34% vs 44%) was not significantly different.

CONCLUSIONS

Short-term administration of high dose L-arginine did not significantly change the restenosis rate after PTCA.

Influence of haematological parameters before coronary angioplasty on subsequent restenosis

OBJECTIVES

Restenosis is the major limitation of coronary interventions occurring in nearly a third of the patients undergoing percutaneous transluminal coronary angioplasty (PTCA) with no single, definite predictor demonstrated in an individual patient. Platelets are known to play an important role in the pathogenesis of subsequent restenosis.

METHODS AND RESULTS

In a prospective study, follow-up coronary angiographies were performed in 102 consecutive patients with stable angina who underwent a successful PTCA for single-vessel coronary artery disease. Demographics, baseline lipid profiles (total cholesterol, HDL- and LDL-cholesterol, triglycerides) and haematological parameters (red cell, white cell and platelet counts, haemoglobin concentration, haematocrite %, mean platelet volume, platelet mass and fibrinogen levels) were compared between patients with and without restenosis. In the restenosis group, mean platelet volume (8.82 +/- 0.78 fl vs. 8.13 +/- 0.64 fl, p < 0.001), white cell count (8673 +/- 322 x 10(3)/microl vs. 7513 +/- 232 x 10(3)/microl, p < 0.01) and fibrinogen level (4.2 +/- 1.4 g/l vs 3.6 +/- 1.1 g/l) were significantly higher. The relative odds for developing angiographically defined restenosis were 2.49 times greater in diabetics (p = 0.11) and 2.54 times greater in men (p = 0.13). It is 1.43 times greater in patients with higher fibrinogen levels (p = 0.16). But, the relative odds for developing restenosis were 10.43 times greater in patients with larger pre-procedural mean platelet volumes (p < 0.01).

CONCLUSIONS

There was a positive correlation between mean platelets volume and loss in luminal diameter between post-angioplasty and follow-up angiographies (r = +2.345, p = 0.01). There was no association between restenosis and haemoglobin, haematocrit, red cell count, white cell count, platelet count, platelet mass and plasma fibrinogen level. The development of restenosis after successful coronary angioplasty may be mainly influenced by the platelet size.

CXCR3 chemokine receptor-plasma IP10 interaction in patients with coronary artery disease

In rat models of transplant vasculopathy, the strongest staining of CXCR3 is observed in the innermost layer of the neointima and because neointimal hyperplasia is seen after coronary angioplasty, the CXC chemokines may be targets for preventing stenosis. The expression of leukocyte surface chemokine receptors (CCR2/CCR5/CXCR2/CXCR3), as determined by flow cytometry, and plasma concentrations of monocyte chemoattractant protein (MCP)-1 and interferon-inducible protein (IP)10, as determined by enzyme immunoassays, were investigated in 55 patients with coronary artery disease (CAD) who underwent percutaneous transluminal coronary angioplasty (PTCA) and 20 patients without significant coronary stenosis based on the results of coronary catheterization during the same period (C group). The patients with CAD were divided into 3 groups: 20 with de novo stenosis (D group), 15 with restenosis (R group) and 20 without restenosis (N group) after PTCA. CXCR3 expression on lymphocytes, but not monocytes, in the R group was significantly lower than that in the C group. Although the plasma concentrations of IP10 in the D and N groups did not differ from that in the C group, the concentration in the R group was significantly higher. Increased plasma concentrations of IP10 were accompanied by a compensatory decrease in the CXCR3 expression on lymphocytes, but not monocytes, suggesting that a high plasma concentration of IP10 strongly induces monocytes signaling. The CXCR3 - plasma IP10 chemokine receptor - chemokine interaction on monocytes may affect the development of coronary restenosis, but not de novo stenosis, in patients with CAD.

Effect of rosiglitazone on restenosis after coronary stenting in patients with type 2 diabetes

BACKGROUND

Thiazolidinediones have been shown to have an antiproliferative vascular effect in experimental models. We sought to study the effect of rosiglitazone on in-stent restenosis in patients with established type 2 diabetes.

METHODS

Patients with treated type 2 diabetes (mean duration 5.5 +/- 7.5 years) referred for coronary stenting were randomized in a double-blind fashion to receive oral rosiglitazone or placebo for 6 months. Quantitative coronary angiography and intravascular ultrasound data were obtained at baseline and follow-up. Plasma plasminogen activator inhibitor-1 levels were prospectively measured.

RESULTS

Sixteen patients were enrolled. There were no significant differences in follow-up in-stent luminal diameter stenosis measured by quantitative coronary angiography or in-stent luminal area stenosis and neointimal volume index obtained by intravascular ultrasound, nor were there any differences in plasma plasminogen activator inhibitor-1 levels after long-term use despite improvement in diabetes control and insulin sensitivity.

CONCLUSIONS

Rosiglitazone, given at the time of stent implantation in treated diabetics, did not reduce in-stent restenosis in this small series. The vascular biological effects of this agent await further clarification in humans and evaluation in larger clinical trials.

Aktuelle Indikationsstellung und Sicherheit beim Einsatz des koronaren Sirolimus-Stents im klinischen Alltag in Deutschland

BACKGROUND

Although randomized, controlled clinical trials (RCTs) showed a reduced target vessel revascularization rate and a good safety profile for the sirolimus-eluting coronary Cypher stent, at least the safety data need to be confirmed by larger data in clinical practice. Under the circumstances of frozen medical budgets in Germany, there may also be a shift toward implantation of a drug-eluting stent (DES) for indications not yet evaluated by RCTs.

METHODS

The authors analyzed the data of the German Cypher Registry a nationwide registry which was initiated in parallel to the launch of the first DES, the Cypher stent, in April 2002.

RESULTS

From April 2002 until December 2003, 3,579 interventions using a Cypher stent at 102 centers were included in the German Cypher Registry. This reflects a proportion of this DES compared to all stents implanted at the participating centers of < 10%. Patients' median age was 63.4 years (quartiles: 55-70 years) with 75% men. Renal insufficiency was seen in 10.1%, previous myocardial infarction in 37%, prior percutaneous coronary intervention (PCI) in 54.6%, and prior coronary artery bypass grafting (CABG) in 18.7%. In a large proportion of interventions, Cypher stents were implanted in lesions or in clinical situations not yet evaluated by RCTs: 10.1% ST elevation myocardial infarction, 1.8% cardiogenic shock, 2.1% left main stenoses, 5.5% CABG lesions, 23.2% in-stent stenosis, and 6% chronic total occlusions. PCI before DES implantation was performed in 65.5% of cases, a mean of 1.02 +/- 0.43 Cypher stents per lesion were implanted with a median sum length of all Cypher stents per lesion of 18 mm (quartiles: 13-21 mm). Maximum median balloon diameter during stent implantation was 3.00 mm (quartiles: 2.75-3.00 mm). Acute complication rate was low, with 0.2% deaths, 0.3% subacute stent thromboses, 1.3% myocardial infarctions, 2.1% urgent PCIs, and 0.2% CABGs.

CONCLUSION

In about one half of the patients included into the German Cypher Registry, the DES were implanted in lesions that were excluded from RCTs. The use of this sirolimus-eluting coronary stent in "real life" conditions was found to be safe concerning acute complications.

Rapamycin Analogs for Stent-Based Local Drug Delivery

The inhibitory action of the sirolimus-like agent everolimus on smooth muscle cell proliferation, evidenced in animal models, has triggered the interest in everolimus as stent coating for local inhibition of in-stent restenosis. For preclinical and clinical evaluation of safety and efficacy of an everolimus-eluting stent design, a new stent has recently been introduced by Biosensors International Inc, covered by a resorbable "composite" coating, that contains the immunosuppressive drug within a polyhydroxyacid biodegradable polymer matrix with roughly equal resorption rates. FUTURE I, the feasibility trial of this new stent concept, revealed a 30-day MACE (major adverse cardiac events) rate of 0% as well as a restenosis rate of 0% at 6-month follow-up in a total of 32 patients included. The more sensitive QCA (quantitative computerized analysis) and IVUS (intravascular ultrasound) parameters showed an 88% reduction of in-stent late loss and an 87% reduction of the neointimal volume. Adding a second feasibility trial including diabetics, the multicenter trial FUTURE II confirmed the initial beneficial findings of FUTURE I in a total of 64 patients in a 1 : 2 randomization to a bare metal control stent. Based on these results, the FUTURE program has now been expanded by Guidant with two large-scale multicenter studies, FUTURE III and IV, which evaluate this stent design in a larger patient population. Furthermore, FUTURE IV is addressed to demonstrate the non-inferiority of this stent concept in a head-to-head comparison to an approved drug-eluting stent (DES) concept. In contrast to everolimus, tacrolimus is a well-known potent antiproliferative agent, already used in various therapeutic areas. Preclinical studies on tacrolimus-eluting stents for treatment of native coronary artery lesions demonstrated safety and efficacy of this stent concept with significant reduction of neointimal proliferation within the implanted study stents. However, the clinical trial program of the first tacrolimus-eluting stent system in the treatment of native coronary lesions (PRESENT I, II) and saphenous vein graft lesions (EVIDENT) failed to prove the clinical benefit of the stent systems tested and demonstrated the impact of specific stent designs, especially the drug carrier characteristics, on the patient outcome. The progressive PRESET study, evaluating a directly coated tacrolimus-eluting stent, will provide important insights, that will clarify the potential of tacrolimus for prevention of neointimal proliferation in clinical practice without being affected by any additional artificial surface compounds.

Direct Stenting with TAXUS Stents Seems to be as Safe and Effective as with Predilatation

BACKGROUND AND METHOD

Although direct coronary stenting does not improve angiographic outcome, it makes sense by reducing procedure times, radiation exposure and costs. Other potential advantages of direct stenting may be a reduction of myocardial ischemia time, which could be clinically relevant in high-risk patients. With the introduction of drug-eluting stents, however, concern arose that direct stenting would possibly damage the polymer coating and change or diminish the efficacy of the programmed drug release. Also, concerns about safety by preventing optimal apposition of single stent struts developed. It is the purpose of this paper to retrospectively analyze the data from the TAXUS-II Trial (536 patients) regarding patients with and without direct stenting. While predilatation was recommended per protocol, direct stenting was not forbidden: thus, direct stenting was performed in 49 patients (TAXUS n = 23, control n = 26).

RESULTS

In the TAXUS groups, there was no significant difference regarding major adverse cardiac events (MACE; 7.5% vs. 4.3%), angiographic restenosis in the analysis segment (4.8% vs. 4.3%), late loss (0.28 +/- 0.36 vs. 0.33 +/- 0.30 mm) or intravascular ultrasound-(IVUS-)measured volume obstruction (7.95 +/- 9.84% vs. 5.61 +/- 7.91%) at six months between the predilated and directly stented patients. The same was true for the patients receiving the control stent. Compared with the directly stented control group, the statistically significant positive effects of TAXUS direct stenting were maintained, regarding angiographic restenosis in the analysis segment (4.3% vs. 30.8%), late loss (0.33 +/- 0.30 vs. 0.80 +/- 0.62 mm) or IVUS-measured volume obstruction (5.61 +/- 7.91% vs. 22.50 +/- 21.62%) at six months. MACE was reduced from 19.2% to 4.3%; due to the small number of patients this trend did not reach statistical significance. After predilatation, all parameters were significantly improved by the TAXUS stent.

CONCLUSION

Comparison of patients receiving TAXUS stents with or without predilatation revealed no differences in clinical, angiographic or IVUS parameters at six months. This suggests that direct stenting with the polymer-based paclitaxel-eluting TAXUS stent is feasible, safe and equally effective. Randomized trials comparing stenting after predilatation versus direct stenting with drug-eluting stents are warranted.

Polymer-Sirolimus-Eluting Stents in de Novo Lesions

Sirolimus has been shown to inhibit vascular smooth muscle cell proliferation and migration. Stents coated with a mixture of polymer and active drug achieved near total inhibition of neointimal hyperplasia in patients with de novo coronary lesions. Larger, randomized trials confirmed these initial results to a large extent; late luminal loss was not only reduced by > 70% in patients with type A lesions, but also in complex situations such as diabetic patients, long lesions, and small vessels < 2.5 mm. Registries containing several thousand patients, however, indicate that under realistic conditions the flawless results of the initial studies could not be reproduced in all patient groups.

Circulating monocytes and in-stent neointima after coronary stent implantation

OBJECTIVES

The aim of this study was to investigate the relationship between circulating monocytes and in-stent neointimal volume at six-month follow-up.

BACKGROUND

In-stent neointimal hyperplasia is the main contributing factor to in-stent restenosis. There is increasing evidence that white blood cells (WBCs), especially monocytes, play a central role in restenosis after stent implantation.

METHODS

We performed coronary stent implantation in 107 patients (107 lesions). Peripheral blood was obtained from all patients immediately before coronary angiography and every day for seven days after the intervention, and each WBC fraction count was analyzed. At scheduled six-month follow-up, all patients received angiographic and volumetric intravascular ultrasound analysis.

RESULTS

The circulating monocyte count increased and reached its peak two days after stent implantation (from 350 +/- 167 to 515 +/- 149/mm3, p < 0.01). The maximum monocyte count after stent implantation showed a significant positive correlation with in-stent neointimal volume at six-month follow-up (r = 0.44, p < 0.0001). Other fractions showed neither significant serial changes nor a correlation with in-stent neointimal volume. Multiple regression analysis revealed that in-stent neointimal volume was independently correlated with stent volume immediately after implantation (r = 0.45, p < 0.0001) and maximum monocyte count (r = 0.35, p < 0.001). Angiographic restenosis, defined as percent diameter stenosis >50%, was observed in 22 patients (21%), and these patients showed a significantly larger maximum monocyte count than patients without restenosis (642 +/- 110 vs. 529 +/- 77/mm3, p < 0.01).

CONCLUSIONS

Circulating monocytes increased after coronary stent implantation, and the peak monocyte count related to in-stent neointimal volume. Our results suggest that circulating monocytes play a role in the process of in-stent neointimal hyperplasia.

Increased Expression of Monocyte CD11a and Intracellular Adhesion Molecule-1 in Patients With Initial Atherosclerotic Coronary Stenosis

BACKGROUND

Cell adhesion molecules have been implicated in the adhesion of leukocytes to endothelial cells and therefore play a role in atherosclerosis, which is a frequent cause of morbidity and mortality in patients with coronary artery disease (CAD) or undergoing hemodialysis (HD). The levels of expression of leukocyte adhesion molecules were evaluated in patients with CAD or HD.

METHODS AND RESULTS

The expression of leukocyte (ie, neutrophil, monocyte and lymphocyte) surface CD11a, CD18, intracellular adhesion molecule-1 (ICAM-1), very late antigen-4 alpha (VLA-4 alpha) and L-selectin was investigated by flow cytometry in 20 patients who were initially diagnosed with CAD (CAD group), 15 patients with coronary re-stenosed vessels (RESTE group), 20 undergoing HD (HD group) and 20 without CAD (CONT group). Monocyte surface expression of both CD11a and ICAM-1 in the CAD group was significantly higher than in the CONT group. Interestingly, when 15 patients with RESTE were analyzed, they showed monocyte CD11a and ICAM-1 expression levels comparable to those in the CONT group. On the other hand, there were no significant differences in the expression of CD11a, CD18, L-selectin or VLA-4 alpha between the HD group and CONT group, but monocyte L-selectin was increased in the CAD group compared with the CONT group.

CONCLUSIONS

Because CD11a and CD18 are expressed on the cell surface as a heterodimer and ICAM-1 is a ligand for CD11a/CD18, this increased expression of CD11a and ICAM-1 may affect the development of initial atherosclerotic coronary stenosis, but not re-stenosis.

Homocysteine Status and Polymorphisms of Methylenetetrahydrofolate Reductase Are Not Associated With Restenosis After Stenting in Coronary Arteries

Objective— We investigated the influence of elevated homocysteine plasma levels and 2 polymorphisms, 677C/T and 1298A/C, of the methylenetetrahydrofolate reductase (MTHFR) gene on the risk of restenosis after stenting in patients with symptomatic coronary artery disease.

Methods and Results— Homocysteine levels and MTHFR genotypes were determined in 800 consecutive patients treated with coronary artery stenting. Angiographic restenosis (≥50% diameter stenosis at 6-month follow-up) was present in 25.8% of the patients with low homocysteine levels (at or below the median of 11.6 μmol/L; n=400) and 24.1% of the patients with high homocysteine levels (>11.6 μmol/L; n=400; P =0.62). Rates of angiographic restenosis were 26.0%, 23.5%, and 26.9% in carriers of the 677CC, 677CT, and 677TT genotypes ( P =0.75), respectively, and 24.4%, 25.9%, and 24.0% in patients with the 1298AA, 1298AC, and 1298CC genotypes ( P =0.90), respectively. The need for restenosis-driven reintervention (clinical restenosis) was 18.8% in subjects with low homocysteine concentrations and 19.0% in subjects with high homocysteine concentrations during the first year after the intervention ( P =0.93). Rates of clinical restenosis were 19.5%, 17.1%, and 23.3% in carriers of the 677CC, 677CT, and 677TT genotypes ( P =0.37), respectively, and 17.6%, 18.6%, and 24.7% in patients with the 1298AA, 1298AC, and 1298CC genotypes ( P =0.27), respectively.

Conclusions— Elevated levels of homocysteine and 2 polymorphisms of the MTHFR gene are not associated with restenosis after stenting in coronary arteries.

Homocysteine and post-angioplasty restenosis

AIM

To review the effect of moderate hyperhomocysteinemia on restenosis after coronary angioplasty.

DATA SUMMARY

Hyperhomocysteinemia is associated with arterial neointimal proliferation in subjects with homocystinuria, atherosclerosis and coronary graft disease. In the rat model, it exacerbates neointimal proliferation after carotid injury. In humans, restenosis after coronary angioplasty is inconsistently associated with hyperhomocysteinemia. A large clinical trial has shown that the administration of folic acid lowers homocysteinemia and the risk of restenosis after coronary angioplasty.

CONCLUSION

Hyperhomocysteinemia is probably a weak risk factor for coronary restenosis after angioplasty, although it is still difficult to ascertain whether homocysteine plays a causative role in restenosis. Further studies of restenosis prevention after coronary stenting are necessary before the routine post-angioplasty administration of folic acid can be recommended.

Leukocyte CD15 Expression and Platelet Activation in the Coronary Sinus after Coronary Intervention

Markers associated with coronary restenosis must be identified to develop therapeutic strategies for improving the clinical outcome. We studied whether adhesion proteins on leukocytes and platelets from coronary sinus blood were associated with restenosis after coronary intervention in patients with stable coronary artery disease. Adhesion proteins on platelets and leukocytes were measured by flow cytometry. Pre- and postinterventional leukocyte CD15 expression was significantly higher in patients with restenosis than in those without it. Increased leukocyte CD15 expression during the intervention may contribute to coronary restenosis. Inhibition of leukocyte adhesion may be useful for the prevention of restenosis.

Preprocedural level of soluble CD40L is predictive of enhanced inflammatory response and restenosis after coronary angioplasty

BACKGROUND

Inflammation plays a pathogenic role in the development of restenosis after percutaneous transluminal coronary angioplasty (PTCA). CD40-CD40L interaction is involved in the pathogenesis of atherosclerosis; however, its role in the pathophysiology of restenosis is still unclear. We tested the hypothesis that soluble CD40L (sCD40L) may be involved in the process of restenosis and that it exerts its effect by triggering a complex group of inflammatory reactions on endothelial and mononuclear cells.

METHODS AND RESULTS

We studied 70 patients who underwent PTCA and who had repeated angiograms at 6-month follow-up. Plasma sCD40L was measured before and 1, 5, 15, and 180 days after PTCA, whereas plasma soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, E-selectin, and monocyte chemoattractant protein (MCP)-1 were measured before and 24 hours after PTCA. Furthermore, the release of adhesion molecules and MCP-1 and the ability to repair an injury in endothelial cells, as well as the generation of O2- in monocytes, were analyzed in vitro after stimulation with serum from patients or healthy control subjects. Restenosis occurred in 18 patients (26%). Restenotic patients had preprocedural sCD40L significantly higher than patients with favorable outcomes (2.13+/-0.3 versus 0.87+/-0.12 ng/mL, P<0.0001). Elevated sCD40L at baseline was significantly correlated with adhesion molecules and MCP-1 generation after PTCA and with lumen loss at 6-month follow-up. Furthermore, high sCD40L was directly associated in vitro with adhesion molecules and MCP-1 generation and impaired migration in endothelial cells and with enhanced O2- generation in monocytes.

CONCLUSIONS

We conclude that increased sCD40L is associated with late restenosis after PTCA. This may provide an important biochemical link between restenosis and aspirin-insensitive platelet activation. These results provide a rationale for studies with new antiplatelet treatments in patients who underwent PTCA.

Number and adhesive properties of circulating endothelial progenitor cells in patients with in-stent restenosis

OBJECTIVE

Intact endothelialization machinery is essential to facilitate vessel healing after stent placement and to prevent restenosis. Circulating endothelial progenitor cells (EPC) have been demonstrated in the peripheral blood and shown to display endothelial functional properties, along with the ability to traffic to damaged vasculature. We reasoned that robust in-stent intimal growth could be partially related to impaired endothelialization resulting from reduced circulating EPC number or function.

METHODS AND RESULTS

Sixteen patients with angiographically-demonstrated in-stent restenosis were compared with patients with a similar clinical presentation that exhibited patent stents (n=11). Groups were similar with respect to the use of drugs that could potentially influence EPC numbers. Circulating EPC numbers were determined by the colony-forming unit assay, and their phenotype was characterized by endothelial-cell markers. Adhesiveness of EPC from both groups to extracellular matrix and to endothelial cells was also assayed. Patients with in-stent restenosis and with patent stents displayed a similar number of circulating EPC. Fibronectin-binding was compromised in patients with in-stent restenosis as compared with their controls exhibiting patent stents. Patients with diffuse in-stent restenosis exhibited reduced numbers of EPC in comparison with subjects with focal in-stent lesions.

CONCLUSIONS

Reduced numbers of circulating EPC in patients with diffuse in-stent restenosis and impaired adhesion of EPC from patients with restenosis provides a potential mechanism mediating the exuberant proliferative process. These markers, if further validated, could provide means of risk stratifying patients for likelihood of developing in-stent restenosis.

Association of insulin resistance, hyperleptinemia, and impaired nitric oxide release with in-stent restenosis in patients undergoing coronary stenting

BACKGROUND

Previously undiagnosed diabetes, impaired glucose tolerance, and insulin resistance are common in patients with acute myocardial infarction and coronary heart disease (CHD) and might be involved in early restenosis after stent implantation. To evaluate whether markers of insulin resistance syndrome, including leptin, and endothelial dysfunction are related to increased rate of early restenosis, we studied nondiabetic patients with CHD after successful coronary stenting.

METHODS AND RESULTS

Both patients with CHD undergoing coronary stenting (120 patients) and control subjects (58 patients) were submitted to an oral glucose tolerance test (OGTT). Fasting leptin levels and fasting and postglucose load insulin sensitivity were assessed. Endothelial function was measured by nitrite and nitrate release (NOx) during OGTT. More than 50% of patients treated with stent implantation presented impaired glucose tolerance or type 2 diabetes, which was previously undiagnosed. These patients also had higher glucose, insulin, and leptin levels than control subjects. Among the stented patients, insulin and leptin levels were higher in patients with restenosis than in patients without restenosis. A significant increase in NOx levels was found during OGTT both in patients without restenosis and in control subjects. On the contrary, NOx profiles were blunted in patients with restenosis. At multiple regression analysis, only DeltaAUC-NOx areas and insulin sensitivity index showed an independent correlation with the minimal lumen diameter at follow-up.

CONCLUSIONS

We demonstrated that insulin resistance and endothelial dysfunction are independent predictors of early restenosis after coronary stenting.

An elevated value of C-reactive protein is the only predictive factor of restenosis after percutaneous coronary intervention

BACKGROUND

The current techniques for percutaneous coronary interventions (PCI) remain limited by restenosis. Recent studies have provided evidence of inflammation playing a role in the pathogenesis of cardiovascular disease.

METHODS

Whether inflammatory markers are predictors of subsequent restenosis were prospectively tested in 272 consecutive patients with angiographically proven coronary artery disease. Patients having undergone PCI at Chonnam National University Hospital, between Sept. 1999 and Mar. 2001, were divided into two groups according to the occurrence of restenosis on a follow-up coronary angiogram: Group I were patients with restenosis (n = 99, 59.5 +/- 10.8 years, M:F = 77:22) and Group II were those without restenosis (n = 173, 58.8 +/- 10.2 years, M:F = 131:42). The IgG seropositivity, cytomegalovirus (CMV) titers, C. pneumoniae. H. pylori and levels of C-reactive protein (CRP) were compared between the two groups.

RESULTS

There were no statistical differences in the seropositivity of the CMV IgG C. pneumoniae IgG and H. pylori IgG between the two groups (Groups I vs. II: 100 vs. 100%, 24.7 vs. 25.7% and 62.2 vs. 63.7%, respectively). Of the angiographic parameters, a low Thrombolysis in Myocardial Infarction (TIMI) flow (TIMI 0 or 1) was more common in Group I than Group II (p = 0.038). The patients with an elevated CRP (> 0.5 mg/dL) were more common in Group I than Group II (57.6 vs. 36.4%, p = 0.001), with the CRP values being higher in Group I than Group II (3.3 +/- 5.8 vs. 1.3 +/- 2.6 mg/dL, p = 0.001). According to a multiple logistic regression analysis, the CRP was the only predictor of restenosis, with an odds ratio of 2.1169 (95% C.I. 1.2062-3.7154, p = 0.009).

CONCLUSION

The CRP value is the most important predictor of restenosis after PCI.

High preprocedural non-HDL cholesterol is associated with enhanced oxidative stress and monocyte activation after coronary angioplasty: possible implications in restenosis

OBJECTIVE

To investigate whether enhanced oxidant stress in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) is associated with a higher concentration of non-high density lipoprotein (HDL) cholesterol at baseline, and whether this contributes to the inflammatory reaction and luminal renarrowing after PTCA.

DESIGN

An ex vivo and in vitro study of 46 patients who underwent PTCA and who had repeat angiograms after six months. Blood samples were collected immediately before PTCA, and at 24 hours, 48 hours, and 15 days after.

SETTING

Tertiary referral centre.

SUBJECTS

46 patients (30 male, 16 female; mean (SD) age, 62 (5) years) with stable or unstable angina who underwent elective PTCA.

MAIN OUTCOME MEASURES

Continuous variable luminal loss as defined by change in minimum lumen diameter during follow up, normalised for vessel size; lag phase of low density lipoprotein to in vitro oxidation; plasma fluorescent products of lipid peroxidation (FPLP); plasma vitamin C and E; interleukin (IL) 1beta secretion from unstimulated monocytes; plasma C reactive protein (CRP).

RESULTS

Restenosis occurred in 12 patients (26%). Oxidant stress after PTCA was greater (p < 0.0001 at 15 days) in the patients with restenosis and showed a significant correlation with the preprocedural concentration of non-HDL cholesterol (p < 0.001). Inflammatory reaction (as reflected by IL-1beta production and CRP) and late lumen loss were linearly correlated (p < 0.001) with lag phase and FPLP throughout the study, and inversely (p < 0.05) with vitamin C and E measured at two and 15 days after PTCA.

CONCLUSIONS

This study provides evidence for the critical role of cholesterol dependent oxidant stress in the pathophysiology of restenosis after PTCA. The findings raise the possibility that drugs capable of modulating oxidant status might provide a novel form of adjuvant treatment in patients with hypercholesterolaemia undergoing PTCA.

Factor Xa inhibitors: today and beyond

Serine proteases play an important role in thrombogenesis, the process that leads to blood clotting and conditions such as heart attack, stroke and other cardiovascular disorders. In the coagulation network, the activation of various serine proteases facilitates the formation of the serine protease Factor Xa, which plays a central role in the process of coagulation and platelet activation. Factor Xa is an essential component of the prothrombinase complex, from which thrombin is formed, which then directly leads to fibrin clot formation. Thus, the inhibition of Factor Xa and its generation is an important strategy in the development of new antithrombotic drugs.

Total plasma homocysteine and restenosis after percutaneous coronary angioplasty: current evidence

BACKGROUND

Restenosis after percutaneous coronary angioplasty (PTCA) remains an important limitation of this procedure.

AIM

To assess the relationship between homocysteine levels and restenosis after PTCA, and discuss the potential benefit of homocysteine-lowering therapy.

METHOD

MEDLINE-based literature review.

RESULTS

The conflicting literature on the association between homocysteine levels and restenosis after PTCA can partially be explained by differences in methodology. Depending on the type of studies considered, a pooling of data resulted in a 22%-36% risk reduction of restenosis in lesions exposed to low homocysteine levels. The strongest reduction was found in balloon-only treated lesions (42%), while only a trend (14%) was seen in stented lesions. Based on the only available trial, homocysteine-lowering therapy yielded a 54% restenosis rate reduction, 76% in balloon-only treated lesions and 31% in stented lesions. Furthermore, homocysteine-lowering therapy provided a significant clinical benefit with a 40% relative reduction in major adverse events at 6 months' follow-up.

CONCLUSIONS

This review suggests that plasma homocysteine is a modifiable risk factor for restenosis, which when lowered improves outcome after PTCA. This inexpensive treatment with virtually no side-effects could therefore be considered as adjunctive therapy for patients undergoing PTCA, while awaiting results from further studies.

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.

Predicting the risk of restenosis after angioplasty in patients with peripheral arterial disease

Restenosis is a serious therapeutic problem after percutaneous transluminal angioplasty (PTA). Strategies for the prevention of late restenosis include the use of antiaggregatory and anticoagulant drugs, aggressive lipid-lowering, intravascular radiation and others. As some of these therapeutic options are not without side effects it is important to identify patients with an increased risk to develop restenosis. Major clinically recognizable risk factors for restenosis are advanced disease stage and female gender. Elevated plasma levels of fibrinogen, Lp(a), CRP, and migration-inducing activity appear to indicate an unfavorable clinical outcome, and so does post-interventional increase of vWF and PAI-1 antigen. For peripheral arterial disease, only one study has addressed the influence of homocysteine levels upon the restenosis rate after PTA. Although homocysteine levels were elevated in >50% of patients at entry, they were not associated with a higher restenosis rate. Currently the available data allow a rough approximation of a patient's individual risk.

The impact of plasma levels of C-reactive protein, lipoprotein (a) and homocysteine on the long-term prognosis after successful coronary stenting: The Global Evaluation of New Events and Restenosis After Stent Implantation Study

OBJECTIVES

The objective of this study was to evaluate the association of high plasma levels of either C-reactive protein (CRP), lipoprotein (a) (Lp[a]) or total homocysteine (tHCY) with the long-term prognosis after successful coronary stenting (CS).

BACKGROUND

High plasma levels of either CRP, Lp(a) or tHCY may have an impact in coronary artery disease. However, long-term prospective data after coronary stenting (CS) are limited.

METHODS

Four-hundred and eighty-three consecutive patients with either stable or unstable coronary syndromes were followed for up to three years after successful CS. The composite of cardiac death, myocardial infarction or rehospitalization for rest unstable angina, whichever occurred first, was the prespecified primary end point. Moreover, the one-year incidence of clinical recurrence of symptoms, in-stent restenosis (ISR) and progression of atherosclerosis to a significant lesion (PTSL) were additionally evaluated. PTSL was defined as an increase by at least 25% in the luminal diameter stenosis of a known nonsignificant lesion (<or=50% luminal diameter stenosis) that was located in a nonintervened vessel at restudy, resulting in an angiographically significant lesion (>or=70% luminal diameter stenosis).

RESULTS

By the end of the follow-up, high plasma levels of either CRP or Lp(a) but not tHCY were independently associated with the primary end point. In particular, CRP >or=0.68 mg/dl (p < 0.001) or Lp(a) >or=25 mg/dl (p = 0.003) conferred a significantly increased risk. By 1 year, a CRP >or=0.68 mg/dl conferred a significantly increased risk for clinical recurrence of symptoms (p < 0.001) or PTSL (p < 0.001). None of the studied biochemical markers was related to ISR.

CONCLUSIONS

High plasma levels of either CRP or Lp(a) but not tHCY may be associated with a higher incidence of late adverse events after successful CS. PTSL in vessels not previously intervened upon may play a significant role in the underlying pathophysiology as opposed to ISR.

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.

[Acute phase proteins and recurrence of angina after effective coronary angioplasty]

AIM

Analysis of relationships between clinical characteristics of the patients, high concentration of acute phase proteins--fibrinogen, C-reactive protein (CRP), activity of the inhibitor of type 1 plasminogen activator (PAI-1)--and frequency of angina recurrence after successful coronary angioplasty (CA).

MATERIAL AND METHODS

The trial included 53 patients after successful CA for a single hemodynamically significant stenosis. Peripheral blood was examined for plasm fibrinogen, CRP, activity of PAI-1 one day before and 2 days, 3 and 6 months after CA. After 12-month follow-up the patients were divided into two groups: angina-free patients (n = 37) and with recurrent angina (n = 16).

RESULTS

Significant differences between the above groups were in PAI-1 activity 3 and 6 months after CA, in CRP initially, on day 2, after 6 months after CA (p < 0.05) but multifactor analysis has found that only CRP level both initial and on day 2 after CA is an independent predictor of recurrent angina pectoris after successful CA.

CONCLUSION

An anginal recurrence after successful CA can be predicted by the initial and postoperative day 2 levels of CRP.

[Increased expression of monocytic cell adhesion molecules and formation of monocyte-thrombocyte aggregates in coronary restenosis]

AIM

To examine expression of superficial antigens by blood monocytes and granulocytes as well as the number of leukocyte-platelet complexes forming in in vitro activation in patients subjected to coronary angioplasty; to analyse changes in these parameters in coronary restenosis.

MATERIAL AND METHODS

Membrane expression of leukocytic antigens and the number of leukocyte-platelet complexes after activation in the whole blood were measured by direct immunofluorescence and flow cytometry in 24 patients who have undergone stenting of coronary arteries. 14 of them had angiographically confirmed restenosis.

RESULTS

The tests discovered high expression of integrins Mac-1 and VLA-4 by monocytes and elevated relative number of monocyte-platelet complexes in patients with restenosis vs those free of stenosis (1425 +/- 76 and 1195 +/- 71 r.u. for Mac-1, 87 +/- 7 and 65 +/- 6 r.u. for VLA-4, 47 +/- 4 and 29 +/- 3%, respectively, for monocyte-platelet complexes; p < 0.05 for all the indices).

CONCLUSION

Coronary restenosis may result from elevated expression of adhesion molecules by monocytes manifest in activation of the cells in vitro.

Greater pathogen burden but not elevated C-reactive protein increases the risk of clinical restenosis after percutaneous coronary intervention

BACKGROUND

Restenosis after percutaneous coronary intervention (PCI) constitutes a serious complication in the treatment of cardiovascular disease, but known risk factors do not fully account for the observed restenosis risk. Preliminary studies of infection or inflammation in restenosis report varied results. We tested whether C-reactive protein (CRP) or pathogen burden (seropositivity to 0, 1, 2, or 3 pathogens, of Chlamydia pneumoniae [Cpn], cytomegalovirus [CMV], or Helicobacter pylori [Hpy]) predict clinical restenosis after percutaneous coronary intervention (PCI).

METHODS

Blood samples were collected from 415 patients undergoing PCI, and levels of plasma CRP and antibodies to Cpn, CMV, and Hpy were measured. The patient's medical history, demographics, and procedural data were recorded. Patient end points were determined for as long as 6 months as a means of evaluating the incidence of clinical restenosis and major adverse cardiac events.

RESULTS

The average patient age was 62 years, and 80% of patients were male. Fifty-eight patients (14%) experienced clinical restenosis, whereas 17 patients (4%) died or had an acute myocardial infarction. After adjusting for 19 possible predictors, we found the pathogen burden (P-trend =.04, adjusted odds ratio [OR] 1.5 per number of pathogens) and minimum luminal diameter (P =.003, OR 1.8 per mm decrease) to be significant predictors of clinical restenosis. Male sex was a nonsignificant predictor of restenosis (P =.06, OR 2.2), but CRP was not significant after adjustment (P-trend =.10, OR 0.73 per tertile).

CONCLUSION

Pathogen burden was associated with clinical coronary restenosis, an association that deserves further exploration and evaluation. CRP, a marker of inflammation, was not associated with an increased risk of restenosis.

Morphological predictors of restenosis after coronary stenting in humans

BACKGROUND

Experimental studies suggest that arterial injury and inflammation lead to increased neointimal growth after stenting. Despite the increased use of coronary stents in humans, there are only limited pathological data on the morphological features of in-stent restenosis.

METHODS AND RESULTS

Detailed histology was performed on 116 stents, implanted > or =90 days in 87 coronary arteries, from 56 patients (mean age, 59+/-13 years). The mean duration of stent implant was 10 months. In-stent restenosis was defined as a stent area stenosis of >75%. Lumen area increased as stent area increased (r2=0.27, P=0.0001), but there was a much stronger correlation between stent area and neointimal area (r2=0.70, P<0.0001). Arterial medial fracture was associated with a 29% increase (P<0.01) in neointimal thickness compared with arteries with an intact media. Neointimal thickness (P=0.0001), inflammatory cell density (P<0.0001), and neointimal vascular channel density (P<0.0001) were greater when struts were in contact with a ruptured arterial media compared with fibrous plaque or an intact fibrous cap. Stent strut penetration into a lipid core was associated with increased neointimal thickness (P=0.04) and inflammatory cell density (P=0.03). Neointimal inflammatory cell content was 2.4-fold greater in stents with restenosis versus no restenosis, and inflammation was associated with increased neoangiogenesis.

CONCLUSIONS

Coronary stenting that is accompanied by medial damage or penetration of the stent into a lipid core induces increased arterial inflammation, which is associated with increased neointimal growth. These data suggest the use of stenting strategies that reduce inflammation and neoangiogenesis to reduce the incidence of restenosis.

Five-year clinical follow-up after intracoronary radiation: results of a randomized clinical trial

BACKGROUND

Several clinical trials indicate that intracoronary radiation is safe and effective for treatment of restenotic coronary arteries. We previously reported 6-month and 3-year clinical and angiographic follow-up demonstrating significant decreases in target lesion revascularization (TLR) and angiographic restenosis after gamma radiation of restenotic lesions. The objective of this study was to document the clinical outcome 5 years after treatment of restenotic coronary arteries with catheter-based iridium-192 (192Ir).

METHODS AND RESULTS

A double-blind, randomized trail compared 192Ir to placebo sources in patients with restenosis after coronary angioplasty. Over a 9-month period, 55 patients were enrolled; 26 were randomized to 192Ir and 29 to placebo. At 5-year follow-up, TLR was significantly lower in the 192Ir group (23.1% versus 48.3%; P=0.05). There were 2 TLRs between years 3 and 5 in patients in the 192Ir group and none in patients in the placebo group. The 5-year event-free survival rate (freedom from death, myocardial infarction, or TLR) was greater in 192Ir-treated patients (61.5% versus 34.5%; P=0.02).

CONCLUSIONS

Despite apparent mitigation of efficacy over time, there remains a significant reduction in TLR at 5 years and an improvement in event-free survival in patients treated with intracoronary 192Ir. The early clinical benefits after intracoronary gamma radiation with 192Ir seem durable at 5-year clinical follow-up.

Association of plasma homocysteine with restenosis after percutaneous coronary angioplasty

AIMS

Restenosis after percutaneous coronary angioplasty remains an important limitation of this procedure. This study evaluates whether elevated total plasma homocysteine levels contribute to the development of restenosis after coronary angioplasty.

METHODS AND RESULTS

Two hundred and five patients were recruited after successful angioplasty of at least one coronary stenosis (> or =50%). End-points were restenosis (> or =50%) and a composite of major adverse cardiac events. Of the 205 patients, 183 (89.3%) underwent 6 months angiographic follow-up. Patients with restenosis had significantly higher homocysteine levels than those without (10.9+/- 3.9 micromol x l(-1) vs 9.3+/-3.8 micromol x l(-1), P<0.01). Homocysteine levels were significantly correlated to follow-up diameter stenosis (r=0.24, P=0.0001), especially in small vessels (<3 mm) treated with balloon angioplasty only (r=0.40, P<0.0005). Late lumen loss at follow-up was significantly smaller with homocysteine levels below 9 micromol x l(-1) (0.62+/-0.82 mm vs 0.90+/-0.77 mm, P<0.01). Restenosis rate (25.3% vs 50.0%, P<0.001) and major adverse cardiac events (15.7% vs 28.4%, P<0.05) were also significantly lower in patients with homocysteine levels below 9 micromol x l(-1). Multivariate analysis did not weaken these findings.

CONCLUSION

Total plasma homocysteine is a strong predictor of restenosis and major adverse cardiac events after coronary angioplasty. Thus, plasma homocysteine appears to be an important cardiovascular risk factor influencing outcome after successful coronary angioplasty.

Angiotensin-converting enzyme insertion/deletion polymorphism does not influence the restenosis rate after coronary stent implantation

BACKGROUND

Experimental studies have shown an activation of the angiotensin-converting enzyme (ACE) system as a response to endothelial injury. Recent publications have elucidated the hypothesis that the ACE gene polymorphism may influence the level of late luminal loss after coronary stent implantation. It is still unclear whether the polymorphism of the angiotensin gene is a major predictor of the extent of neointimal hyperplasia. In this multicenter study, we therefore tested the relationship between the ACE gene polymorphism and the restenosis rate after coronary stent implantation.

METHODS

As a substudy of the optimization with intracoronary ultrasound (ICUS) to reduce stent restenosis (OPTICUS) study, we analyzed ACE serum levels and the ACE gene polymorphism in 154 patients at 9 different centers. All patients underwent elective coronary stent implantation in a stenosis of a major coronary vessel. Balloon inflations were repeated until a satisfactory result was achieved in on-line quantitative coronary angiography or ICUS fulfilling the OPTICUS study criteria. After follow-up of 6 months, all patients underwent reangiography under identical projections as the baseline procedure. A blinded quantitative analysis of the initial procedure as well as the follow-up examinations were performed by an independent core laboratory. ACE gene polymorphism and ACE serum activity were measured at the 6-month follow-up in a double-blinded setting.

RESULTS

With respect to the ACE gene polymorphism, there were three subgroups: DD genotype (48 patients), ID (83 patients) and II (23 patients). The subgroups did not differ in regard to age, gender, extent of coronary artery disease, stenosis length, initial degree of stenosis or degree of stenosis after stent implantation. In all, 39 patients (25.3%) had significant restenosis: 12 DD patients (25.0%), 18 ID patients (21.7%) and 9 II patients (39.1%) (odds ratio 2.164, 95% confidence interval 0.853-5.493). We obtained the following results for ACE serum levels: 0.53 micromol/l/s in the DD subgroup, 0.29 micromol/l/s in the ID subgroup and 0.09 micromol/l/s in the II subgroup (p < 0.001). Multivariate logistic regression analysis of the influence of ACE gene polymorphism on the restenosis rate after coronary stent implantation adjusted for lesion length (>12 mm), ACE inhibitor or hydroxymethylglutaryl coenzyme A reductase (CSE) inhibitor treatment, age, male gender, diabetes mellitus, hypertension, high cholesterol, family history, smoking and three-vessel disease did not uncover any statistic significance.

CONCLUSIONS

In contrast to other study groups, we were unable to disclose that the DD polymorphism of the ACE gene was associated with a higher rate of restenosis after coronary stent implantation in this multicenter study. In addition, patients with higher ACE serum levels did not show a higher restenosis rate in this trial. We conclude that the pathogenesis of restenosis is a multifactorial process involving various genetic and nongenetic factors.

Relation of homocysteine, vitamin B(12), and folate to coronary in-stent restenosis

Coronary in-stent restenosis represents a clinical problem. Because homocysteine is being discussed as a new risk factor for atherosclerosis and thrombosis, this study investigated the relations of homocysteine, folate, and vitamin B(12) to the rate of in-stent restenosis. Patients undergoing successful percutaneous transluminal coronary angioplasty of native coronary lesions with stent implantation were investigated for fasting total serum homocysteine, folic acid, and vitamin B(12). The rate of in-stent restenosis was determined angiographically after 6 months, or earlier if clinically indicated. Of 292 enrolled patients, 262 (90%) (189 men and 73 women) underwent control angiography on an average of 6.3 +/- 1.0 (SD) months after intervention. The rate of in-stent restenosis was 36%. Univariate and multivariate analyses revealed no significant differences between patients with or without restenosis with regard to total homocysteine (median [interquartile range]: 12.9 [11.2 to 14.8] and 12.4 [10.3 to 15.4] micromol/L, respectively), folate (16.1 [12.4 to 20.5] and 15.4 [12.5 to 19.5] nmol/L, respectively), or vitamin B(12) (239.0 [182.5 to 322.1] and 258.4 [205.8 to 330.5] pmol/L, respectively). These results suggest that homocysteine, folate, and vitamin B(12) are not related to the angiographically determined rate of coronary in-stent restenosis after 6 months.