Increased expression of monocyte chemoattractant protein-1 in atherectomy specimens from patients with restenosis after percutaneous transluminal coronary angioplasty

The plasma concentration of monocyte chemoattractant protein-1 (MCP-1) antigen is higher in patients with restenosis after coronary angioplasty than in those who do not restenose. In this study the MCP-1 expression of coronary atherectomy specimens was investigated by immunohistochemistry. Samples were obtained from 12 patients with restenosis and 15 with de novo lesions by directional coronary atherectomy. MCP-1 immunoreactivity was found in all patients in the restenosis group and in 8 of the de novo group. The frequency of macrophage expression was higher in the restenosis group than in de novo group. These results indicate that local expression of MCP-1 may be associated with the mechanisms of vascular remodeling after coronary angioplasty.

D-dimer increase after percutaneous transluminal angioplasty and clinical recurrence after primary revascularization in acute myocardial infarction? A pilot study

It has been reported that the increase of plasminogen activator inhibitor-1 activity immediately after elective coronary angioplasty is related to subsequent clinical recurrence in patients with chronic coronary artery disease. The aims of our study were to evaluate the behavior of plasminogen activator inhibitor-1 and D-Dimer after revascularization in acute myocardial infarction patients treated with angioplasty and stenting and if this behavior is predictive of subsequent clinical recurrence. D-Dimer and plasminogen activator inhibitor-1 activity were evaluated in two groups of patients. Group 1 consisted of 54 consecutive patients undergoing primary angioplasty for acute myocardial infarction and Group 2 consisted of 48 patients undergoing elective angioplasty. Patients underwent control coronary angiography only in the case of clinical recurrence and/or positivity of provocative tests. D-Dimer and plasminogen activator inhibitor-1 baseline levels were significantly higher in group 1 than in group 2 (P<0.0005 and P<0.05, respectively). The percentage of group 1 patients with a post-procedural increase in D-Dimer was significantly higher among those with subsequent clinical recurrence with restenosis (61%) than among those with no recurrence (25%, P<0.05). No difference was observed in group 2. The percentage of group 2 patients in whom no decrease of plasminogen activator inhibitor-1 was observed after angioplasty was significantly higher (83%) among those with subsequent recurrence than among those with no recurrence (38%, P<0.05). This pattern was not observed in group 1. In conclusion, the role of early changes in plasminogen activator inhibitor-1 in predicting clinical recurrence after primary angioplasty in acute myocardial infarction patients is less clear than that observed after elective angioplasty. A significant role seems to be played by a more-marked clotting activation with increased fibrin formation.

Homocysteine and restenosis after percutaneous coronary intervention

Numerous clinical studies in Western and Asian countries suggest that individuals with elevated blood levels of homocysteine have an increased risk of atherosclerosis, myocardial infarction, cerebral infarction, and deep vein thrombosis. Homocysteine is also known to induce both atherogenic and thrombogenic mediators in cultured vascular cells so that homocysteine may influence the damage of endothelial cells, promote smooth muscle cell growth, induce atherogenic mediators and thrombus formation after coronary angioplasty. The association between homocysteine and restenosis after percutaneous coronary intervention (PCI) has been discussed. In this study, the relationship between plasma homocysteine levels and restenosis after PCI to investigate whether plasma homocysteine levels may be a predictor of restenosis after PCI was examined. One hundred consecutive patients who underwent successful PCI were enrolled and plasma homocysteine level was measured in all patients prior to PCI. Plasma for homocysteine level was obtained in 99 of 100 patients who had angioplasty. The mean plasma homocysteine concentration in the enrolled patients was 13.61 +/- 6.04 micromol/L. The minimum and maximum of plasma homocysteine were 4.40 micromol/L and 50.00 micromol/L, respectively. In healthy subjects, the normal reference range of homocysteine level is 5-15 micromol/L However, recent data suggest that some patients may be at increased cardiovascular and cerebrovascular risk at levels as low as 12 micromol/L. For this reason, both cut off points of homocysteine level > or = 15 micromol/L or > or = 12 micromol/L to identify the high homocysteine level group were used. Of 99 patients, high homocysteine level (> or = 15 micromol/L) was established in 9 patients with restenosis versus 20 patients without restenosis. If the cut off point of homocysteine level > or = 12 micromol/L was used, high homocysteine level was established in 14 patients with restenosis versus 39 patients without restenosis. From both cut off points of homocysteine level, there was no correlation between plasma homocysteine level and the restenosis group. (p>0.05).

Serum lipoprotein (a) level and restenosis after percutaneous coronary intervention

Restenosis is regarded as the result of a combination of various pathological events. The mechanisms are complex and not completely understood. In this study, the authors focused on the lipoprotein (a) (Lp (a)). It is one of the novel risk factors in atherosclerotic vascular disease. Numerous clinical studies suggest that individuals with elevated blood levels of Lp (a) have been shown to be associated with atherosclerotic vascular disease. However, whether a high serum concentration of Lp (a) affects restenosis after PCI remains controversial. In this study, the relationship between serum Lp (a) levels and restenosis after PCI was examined to investigate whether serum Lp (a) levels may be a predictor of restenosis after PCI. Of the 100 patients studied, 31 patients (31%) were classified as the restenosis group and 69 patients (69%) the non-restenosis group. Both groups did not significantly differ in serum concentration of total cholesterol, triglyceride, HDL-C, and LDL-C. The mean serum Lp (a) concentration in patients with restenosis was 41.50 +/- 34.99 mg/dL compared with a mean serum Lp (a) concentration of 29.87 +/- 25.47 mg/dL in those without restenosis. There was no statistical significance of Lp (a) level between the restenosis and non-restenosis groups (p=0.06). In healthy subjects, the normal reference range of serum Lp (a) concentration is below 30 mg/dL. From this reference, if a cut off point of serum Lp (a) concentration equal to 30 mg/dL or above to identify high Lp (a) level group was used. High serum Lp (a) level was established in 15 patients with restenosis versus 21 patients without restenosis. From this cut off point of serum Lp (a) level, the authors did not find a correlation between serum Lp (a) level and the restenosis group. (p=0.08).

[Systemic markers of inflammation after coronary angioplasty]

THE RISK OF RESTENOSIS: Coronary angioplasty is an effective treatment of stable and instable coronary disease and its principle limitation, despite technical progress, remains restenosis. In instable angina, the physiopathologic and prognostic role of inflammation proteins is well documented. THE ROLE OF THE C-REACTIVE PROTEIN (CRP): Is a validated risk factor for patients presenting with heart failure, whether instable or stable angina and in the general population. This risk factor is distinct from tobacco abuse, hypercholesterolemia or diabetes. In all the series studied to date, the frequency of restenosis following coronary angioplasty increases when CRP values are high prior to surgery and continue to rise up to the 48th or 72nd hour.

PERSPECTIVES

New therapeutic measures widen the possibilities of mechanical strategies (angioplasty with or without stent) and treatment of inflammatory mechanisms in the atheromatous plaques (statines, brachytherapy or "covered" stents).

Postprocedural PAI-1 activity is a risk marker of subsequent clinical restenosis in patients both with and without stent implantation after elective balloon PTCA

Stent implantation after balloon dilation of coronary arteries has improved clinical prognosis in patients undergoing transluminal coronary angioplasty (PTCA), but late restenosis remains a relevant problem. A previous study has indicated that PAI-1 activity changes immediately after PTCA without stent implantation are predictive of clinical restenosis. The present study was aimed to investigate the early PAI-1 changes and fibrin formation in patients undergoing elective PTCA with stent implantation. PAI-1 activity and D-dimer plasma levels were evaluated in two groups of patients (G1 underwent only elective balloon PTCA and G2 underwent elective PTCA with stent implantation) before and after the procedure. At the end of the procedure, PAI-1 activity significantly decreased, while D-dimer levels significantly increased in both groups. Post-PTCA D-dimer levels in the group with stent implantation were significantly higher than in the other group (P<.05). In both groups of patients, the post-PTCA PAI-1 activity was higher in patients with subsequent clinical recurrence with restenosis (P<.005 in G1 and P<.0005 in G2) than in those without, whereas no differences were found in D-dimer levels. In conclusion, our results demonstrate that fibrin formation assessed by D-dimer levels is enhanced by stent implantation. However, this behaviour is not related, differently from PAI-1 changes, to subsequent occurrence of clinical restenosis.

Ischemic heart disease associated with protein C deficiency

Three patients of ischemic heart disease associated with protein C deficiency are reported. Although delayed diagnosis of protein C deficiency resulted in the failure of repeated interventions, coronary artery bypass grafting performed after making the correct diagnosis has led to satisfactory mid-term results under strict anticoagulation therapy. The level of protein C should be measured more frequently in the field of ischemic heart disease and earlier diagnosis of its deficiency should be made, because measurement of protein C does not cost much.

The influence of plasma lipoprotein (a) on angiographic restenosis and coronary events in patients undergoing planned coronary balloon angioplasty. Ancillary analysis of the Fluvastatin Angioplasty Restenosis (FLARE) trial

Elevated Lipoprotein (a) [Lp (a)] has been reported frequently, but not consistently, to be associated with restenosis following percutaneous transluminal coronary angioplasty (PTCA). The purpose of this study was to examine the association between Lp (a) and restenosis and clinical events in the context of a multi-centre randomised restenosis [Fluvastatin Angioplasty Restenosis (FLARE)] study of patients undergoing elective PTCA with full angiographic follow up. In the FLARE trial 40 mg fluvastatin twice daily did not influence restenosis, compared with placebo, after successful balloon angioplasty, measured as late loss in 834 patients, but did reduce the risk of death or myocardial infarction. Lp (a) was not effected by fluvastatin. Lp (a) and other biochemical details were established prior to planned PTCA. Among those undergoing successful PTCA, follow up angiography was performed at 26+/-2 weeks. Clinical follow up was complete to week 40. Included in this analysis are the 823 patients who underwent successful angioplasty and had a baseline Lp (a) performed yielding 891 lesions for quantitative coronary angiography (QCA). No association was observed between Lp (a) and either quantitative markers of restenosis or binary restenosis rates. Late loss was 0.27 (SD 0.51) in the lowest quintile (Lp (a) 0-4 g/dl) compared with 0.23 (SD 0.49) (P>0.05). Elevated Lp (a) was not associated with an increased risk of individual or combined major coronary events over 40 weeks. A major adverse cardiac event (MACE) occurred in 41 (24%) of the lowest quintile and 42 (26%) of the highest (P>0.05). In conclusion, elevated Lp (a) was not associated with restenosis or clinical events following elective coronary balloon angioplasty in this randomised clinical trial and should not be considered a risk factor for post angioplasty restenosis.

Lipid peroxidation may predict restenosis after coronary balloon angioplasty

The present study assessed whether lipid peroxidation in plasma might predict restenosis after coronary balloon angioplasty. A total of 87 patients, who had undergone successful coronary balloon angioplasty using standard techniques, were enrolled. Fasting blood samples before the intervention were measured for plasma levels of thiobarbituric acid reactive substances (TBARS, an indicator of lipid peroxidation). Angiography was carried out before and 15 min after angioplasty, and at follow-up (4 months after angioplasty), and evaluated using a quantitative approach. There were 23 patients with restenosis (group R) and 64 patients without restenosis (group N) after coronary balloon angioplasty. The plasma TBARS level (mean+/-SEM) of 4.3+/-0.1 micromol/L in group R was significantly higher than that of 3.2+/-0.1 micromol/L in group N (p<0.01). There were no significant differences in other parameters, including plasma lipid levels, between the 2 groups. The plasma level of TBARS positively correlated with lumen loss of the coronary artery at the time of follow-up angiography (r=0.57, p<0.01). Our results suggest that oxidative stress contributes to restenosis and indicate that an elevated plasma level of TBARS may be a reliable predictor of restenosis.

Relation of a common methylenetetrahydrofolate reductase mutation and plasma homocysteine with intimal hyperplasia after coronary stenting

BACKGROUND

Hyperhomocysteinemia has been identified as an independent risk factor for coronary artery disease. Recent studies have shown that a common mutation (nucleotide 677 C-->T) in the methylenetetrahydrofolate reductase (MTHFR) gene may contribute to mild hyperhomocysteinemia and, therefore, to the incidence of coronary artery disease. No information exists, however, regarding the association between the mutation of the MTHFR gene or plasma homocysteine levels and morphological analysis of coronary atherosclerosis using intravascular ultrasound.

METHODS AND RESULTS

To examine the potential influence of MTHFR genotype and homocysteine on coronaryarteries morphologically, we screened 62 patients with 65 lesions that were treated with 93 Palmaz-Schatz stents. The plasma homocysteine levels in the patients with the TT genotype were not significantly higher than those in the patients with non-TT (CC+CT) genotypes (13.1 +/- 5.5 versus 11.5 +/- 3.1 mmol/L, P=0.16). Angiographic analysis showed that the percent diameter stenosis in the patients with the TT genotype was significantly greater than that in those with non-TT genotypes (43.7 +/- 17.8% versus 29.0 +/- 22.0%, P=0.015). Intravascular ultrasound analysis showed that the TT genotype was significantly associated with greater intimal hyperplasia area (5.70 +/- 1.94 versus 3.72 +/- 1.38 mm2, P=0.001). In multiple stepwise regression analysis, the number of the T alleles was the only independent predictor of intimal hyperplasia after intervention (r2=0.21, P=0.004).

CONCLUSIONS

The homozygous mutant genotype of the MTHFR gene may increase the risk of in-stent restenosis more than does the normal homozygous or heterozygous genotype.

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.