Contributions of frequency distribution analysis to the understanding of coronary restenosis. A reappraisal of the gaussian curve

Targeted anti-inflammatory systemic therapy for restenosis: the Biorest Liposomal Alendronate with Stenting sTudy (BLAST)-a double blind, randomized clinical trial

BACKGROUND

Activation of systemic innate immunity is critical in the chain of events leading to restenosis. LABR-312 is a novel compound that transiently modulates circulating monocytes, reducing accumulation of these cells at vascular injury sites and around stent struts. The purpose of the study was to examine the safety and efficacy of a single intravenous bolus of LABR-312 in reducing restenosis in patients treated for coronary narrowing. Patient response was examined in light of differential inflammatory states as evidenced by baseline circulating monocyte levels, diabetes mellitus, and acute coronary syndrome.

METHODS

BLAST is a Phase II prospective, randomized, multicenter, double-blind, placebo-controlled trial that assessed the safety and efficacy of LABR-312. Patients were randomized to receive LABR-312 at 2 dose levels or placebo as an intravenous infusion during percutaneous coronary intervention and bare metal stent implantation. The primary end point was mean angiographic in-stent late loss at 6 months.

RESULTS

Patients (N = 225) were enrolled at 12 centers. There were no safety concerns associated with the study drug. For the overall cohort, there were no differences between the groups in the primary efficacy end point (in-stent late loss of 0.86 ± 0.60 mm, 0.83 ± 0.57 mm, and 0.81 ± 0.68 mm for the placebo, low-dose, and high-dose group, respectively; P = not significant for all comparisons). In the prespecified subgroups of patients with a baseline proinflammatory state, patients with diabetes mellitus, and patients with high baseline monocyte count, there was a significant treatment effect.

CONCLUSIONS

Intravenous administration of LABR-312 to patients undergoing percutaneous coronary intervention is safe and effectively modulates monocyte behavior. The average late loss did not differ between the treatment and placebo groups. However, in the inflammatory patient group with baseline monocyte count higher than the median value, there was a significant reduction in late loss with LABR-312.

Influence of metal alloy and the profile of coronary stents in patients with multivessel coronary disease

BACKGROUND

In Brazil, despite the recommendations of the Brazilian Society of Hemodynamics and Interventional Cardiology, the National Health System has not yet approved the use of drug-eluting stents. In percutaneous coronary interventions performed in the public and part of the private health care system, bare metal stents are used as the only option. Therefore, new information on bare metal stents is of great importance. The primary endpoint was to evaluate the influence of the alloy and the profile of coronary stents on late loss and restenosis rates 6 months after implantation in patients with multivessel coronary disease.

METHODS

Single center, randomized and prospective study comparison of cobalt-chromium versus stainless steel stent implantation in 187 patients with multivessel coronary disease. At least one cobalt-chromium and one stainless steel stent were implanted per patient.

RESULTS

Mean age of patients was 59.5 + 10.1 years with a prevalence of males (66.3%) and patients with acute coronary syndrome (56%). Baseline clinical characteristics were similar with hypertension in 146 (78%), dyslipidemia in 85 (45.5%) and diabetes in 68 (36.4%). Two hundred and twenty-nine cobalt-chromium and 284 stainless steel stents were implanted. Angiographic variables showed no statistically significant difference. Angiographic follow-up to 6 months after implantation showed similar late loss and restenosis rates.

CONCLUSION

The use of two different alloys, stainless steel and cobalt-chrome stents, in the same patient and in the same vessel produced similar 6-month restenosis and late loss rates.

Angiographic analysis of pattern of late luminal loss in sirolimus- and paclitaxel-eluting stents

Late loss is becoming an important end point to compare drug-eluting stents; however, little is known about its pattern of distribution. We analyzed the pattern of late loss distribution in sirolimus-eluting stents (SESs) and paclitaxel-eluting stents (PESs) in a consecutive cohort of patients. From a cohort of 529 patients treated with drug-eluting stents in 1 year, we selected all patients who underwent angiographic follow-up. Three hundred fifty-nine patients with 592 de novo lesions received SESs (286 lesions) or PESs (306 lesions). Late loss and binary angiographic restenosis were analyzed. Binary restenosis occurred in 56 lesions (19.6%) treated with SESs compared with 53 (17.3%) treated with PESs (p = 0.48). The 2 late loss distributions were skewed to the right and were not normally distributed (p <0.001 for SES, p = 0.003 for PES). Late loss was significantly lower in the SES group (p = 0.03), with a median value of 0.29 mm (interquartile range -0.09 to 0.66) versus 0.41 mm (-0.02 to 0.85) in the PES group. When analyzing only restenotic lesions, late loss had a normal distribution in the SES and PES groups (p = 0.96 and 0.44, respectively) and was similar in the 2 groups (1.75 +/- 0.51 vs 1.82 +/- 0.62, p = 0.48). When evaluating nonrestenotic lesions, late loss was also normally distributed in the 2 groups (p = 0.75 for SES, p = 0.73 for PES) but was significantly lower (p = 0.002) after SES implantation (0.14 +/- 0.39) than after PES implantation (0.27 +/- 0.44). In conclusion, SESs and PESs have a bimodal pattern of late loss distribution. The observed difference in late loss between SES and PES seems to be partly explained by the decrease in late loss after SES implantation in nonrestenotic lesions (where SES approaches "zero late loss"). Thus, late loss may not be a reliable marker of the true efficacy of these devices due to its complex and nongaussian distribution.

Sirolimus-eluting coronary stents in small vessels

BACKGROUND

This prospective multicenter study compared angiographic in-lesion late lumen loss in de novo native coronary artery lesions (vessel diameter range 2.25-2.75 mm, length range > or = 15 to < or = 30 mm) 8 months after the implantation of a sirolimus-eluting stent with that of similar vessels with the same drug-eluting stent or a bare stent of the SIRIUS study (historical controls).

METHODS AND RESULTS

One hundred one patients (study group) were matched and compared with 323 patients receiving the bare stent (bare control group) and with 350 receiving the Cypher stent (Cypher control group) in the SIRIUS trial. Mean in-lesion late loss in the study group was lower than that in the bare control group (0.20 versus 0.76 mm, P < .0001) and not inferior to that in the Cypher control group (0.27 mm, P = .3). Adverse event rates (death and myocardial infarction) were similar between groups. At 8 months, target lesion revascularization rates were 0% in the study group, 13.2% in the bare control group (P < .001), and 4.6% in the Cypher control group (P = .03).

CONCLUSIONS

The Cypher Bx Velocity stent was confirmed to be superior to the bare Bx Velocity stent in small coronary vessels in terms of in-lesion late loss 8 months after implantation.

Is late luminal loss an accurate predictor of the clinical effectiveness of drug-eluting stents in the coronary arteries?

Late luminal loss after percutaneous coronary intervention, although not normally distributed, has been shown to be monotonically correlated with the probability of binary angiographic restenosis after drug-eluting stent implantation. A recently proposed method has been shown to predict the restenosis rate after sirolimus-eluting stent and paclitaxel-eluting stent implantation using a power transformation of the value of late loss obtained after implantation of the 2 stent types. We used the same method to compute and compare restenosis rates from late loss values observed in the "head-to-head" randomized sirolimus-eluting stent versus paclitaxel-eluting stent comparisons available thus far. Our results showed that the model proposed has a poor overall ability to predict the real incidence and relative risk of restenosis because the use of late loss as an end point tended to overestimate the difference in restenosis, and the derived effect estimate of 1 stent compared with that of the other seemed to be overemphasized with respect to the real risk. We thus believe that further investigations are needed to appraise the real clinical effect of late loss and its reliability as an end point in direct comparative drug-eluting stent trials before its use can be recommended as a clinical surrogate.

Identifying Biologically Active Compound Classes Using Phenotypic Screening Data and Sampling Statistics

Scoring the activity of compounds in phenotypic high-throughput assays presents a unique challenge because of the limited resolution and inherent measurement error of these assays. Techniques that leverage the structural similarity of compounds within an assay can be used to improve the hit-recovery rate from screening data. A technique is presented that uses clustering and sampling statistics to predict likely compound activity by scoring entire structural classes. A set of phenotypic assays performed against a commercially available compound library was used as a test set. Using the class-scoring technique, the resultant activity prediction scores were more reproducible than individual assay measurements, and class scoring recovered known active compounds more efficiently than individual assay measurements because class scoring had fewer false positives. Known biologically active compounds were recovered 87% of the time using class scores, suggesting a low false-negative rate that compared well to individual assay measurements. In addition, many weak and potentially novel classes of active compounds, overlooked by individual assay measurements, were suggested.

Rationale and study design of the CardioGene Study: genomics of in-stent restenosis

BACKGROUND AND AIMS

in-stent restenosis is a major limitation of stent therapy for atherosclerosis coronary artery disease. The CardioGene Study is an ongoing study of restenosis in bare mental stents (BMS) for the treatment of coronary artery disease. The overall goal is to understand the genetic determinants of the responses to vascular injury that result in the development of restenosis in some patients but not in others. Gene expression profiling at transcriptional and translational levels provides global assessment of gene activity after vascular injury and mechanistic insight. Furthermore, the delineation of genetic biomarkers would be of value in the clinical setting of risk-stratify patients prior to stent therapy. Prospective risk stratification would allow for the rational selection of specialized treatments against the development of in-stent restenosis (ISR), such as drug-eluting stents.

SETTING

Patients are enrolled at two sites in the US with high-volume cardiac catheterization facilities: the William Beaumont Hospital in Royal Oak, MI, USA, and the Mayo Clinic in Rochester, MN, USA.

STUDY DESIGN

Two complementary study designs are used to understand the molecular mechanisms of restenosis and the genetic biomarkers predictive of restenosis. First, 350 patients are enrolled prospectively at the time of stent implantation. Blood is sampled prior to stent placement and afterwards at 2 weeks and 6 months. The clinical outcome of restenosis is determined 6 and 12 months after stent placement. The primary outcome is clinical restenosis at 6 months. The major secondary outcome is clinical restenosis at 12 months. Second, a corollary case-control analysis will be carried out with the enrollment of an additional 250 cases with a history of recurrent restenosis after treatment with BMS. Controls for this analysis are derived from the prospective cohort.

PATIENTS AND METHODS

Consecutive patients presenting to the cardiac catheterization laboratory are screened, informed about the study and enrolled after signing the consent form. Enrollment has been completed for the prospective cohort, and enrollment of the additional group is ongoing. A standardized questionnaire is used to collect clinical data primarily through direct patient interview to assess medical history, medication use, functional status, family history, environmental factors, and social history. Further data are abstracted from the medical charts and catheterization reports. A total of 276 clinical variables are collected per individual at baseline, and 49 variables are collected at each of the 6- and 12-month follow-up visits. A Clinical Events Committee adjudicates clinical outcomes. Blood samples are processed at each clinical enrollment site using standardized operating procedures. From each blood sample, several aliquots are prepared and stored of peripheral blood mononuclear cells, granulocytes, platelets, serum, and plasma. Additionally, a portion of each patient's leukocytes is cryopreserved for future cell-line creation. Samples are frozen and shipped to the National Heart, Lung and Blood Institute (NHLBI). Additional materials generated in the analysis of the samples at the NHLBI are frozen and stored, including isolated genomic DNA, total RNA, reverse transcribed cDNA libraries and labeled RNA hybridization mixtures used in microarray analysis. Per individual in the prospective cohort, high-quality transcript profiles of peripheral blood mononuclear cells at each time of blood sampling are obtained using Affymetrix U133A microarrays (Affymetrix, Santa Clara, CA, USA). Per chip, this yields 495,930 features per individual per time of sampling. This represents expression levels for 22,283 genes per patients oer time of blood sampling, including 14,500 well-characterized human genes. Proteomics of plasma is performed with multidimensional liquid chromatography and tandem mass spectrometry. Protein expression is examined similarly to mRNA expression as a measure of gene expression. Genotyping is performed in two manners. First, those genes showing differential expression at the levels of mRNA and protein are investigated using a candidate gene approach. Specific variants in known gene regulatory regions, such as promoters, are sought initially, as those variants may explain differences in expression level. Second, a genome-wide scan is used to identify genetic loci that are associated with ISR. Those regions identified are further examined for genes that show differential expression in the mRNA microarray profiling or proteomics investigations. These genes are finely investigated for candidate SNPs and other gene variants. Complementary genomic and proteomic approaches are expected to be robust. Integration of data sets is accomplished using a variety of informatics tools, organization of gene expression into functional pathways, and investigation of physical maps of up- and downregulated sets of genes.

CONCLUSIONS

The CardioGene Study is designed to understand ISR. Global gene and protein expression profiling define molecular phenotypes of patients. Well-defined clinical phenotypes will be paired with genomic data to define analyses aimed to achieve several goals. These include determining blood gene and protein expression in patients with ISR, investigating the genetic basis of ISR, developing predictive gene and protein biomarkers, and the identification of new targets for treatment.

Short- and long-term clinical outcome after various stent implantation: Overview of the results of uni- and multicenter stent registries

The present study reports the results of the short- and long-term outcomes of prospective uni- and multicenter stent registries: Palmaz-Schatz (n = 140 patients), Ave-Micro and GFX (n = 280), Multilink Duet (n = 340), Multilink Tetra (n = 192), and Carbo (n = 140) Stent Registries, as well as the predictors and angiographic cutoff points predicting major adverse cardiac events (MACE) after different stent implantations. Significant decrease in subacute stent thrombosis (from 2.9% to 0) and MACE (from 35% to 8.3%) occurred as the improved stents, optimized stent implantation technique, and new postintervention drug therapy were introduced. The changes of angiographic cutoff values (postintervention minimal lumen diameter and preintervention reference diameter: from 2.9 and 3.1 mm for Palmaz-Schatz to 2.5 and 2.8 mm for Multilink Duet, Multilink Tetra, and Carbo stents) and clinical and angiographic factors predicting MACE indicated the change of traditional restenosis paradigm and that progress in clinical practice might be able to counterbalance unfavorable lesion and intervention-related characteristics.

Coronary stenting after rotational atherectomy in diffuse lesions of the small coronary artery: comparison with balloon angioplasty before stenting

The purpose of this randomized trial was to evaluate the role of debulking and balloon predilation on acute and long-term results of stent implantation in diffuse stenosis of small vessels. Patients with symptomatic diffuse stenosis of the native left anterior descending coronary artery between 2 and 2.9 mm in size were randomly assigned to rotational atherectomy (group I, n = 21) or balloon dilation (group II, n = 20) before stenting. The primary end point of the study was the incidence of angiographic restenosis at follow-up; adverse clinical events, such as death, myocardial infarction, stroke, or target vessel revascularization, were assessed as secondary end points. Acute gain was significantly greater in group I than in group II (p = 0.038), but net gain at follow-up was similar in both groups (p = 0.24). There was no significant difference in angiographic restenosis rate (33.3% vs 31.3%, p = 0.80), target vessel revascularization (23.8% vs 15%, p = 0.21) or 1-year event-free survival rate (72.8% vs 84.6%, p = 0.28). In conclusion, rotational atherectomy before stenting showed no additional benefit over balloon dilation with stenting in the management of diffuse lesions in small coronary vessels.

Correlates of coronary blood flow before and after percutaneous coronary intervention and their relationship to angiographic and clinical outcomes in the RESTORE trial. Randomized Efficacy Study of Tirofiban for Outcomes and REstenosis

BACKGROUND AND OBJECTIVES

Slower blood flow in the setting of acute myocardial infarction (MI) has been related to adverse outcomes, but the relationship of coronary blood flow after percutaneous transluminal coronary angioplasty (PTCA) in the setting of acute coronary syndromes to adverse outcomes and restenosis has not been well described. We sought to evaluate the correlates of pre- and post-PTCA coronary blood flow to shed light on potential modifiable determinants.

METHODS

The RESTORE trial (Randomized Efficacy Study of Tirofiban for Outcomes and REstenosis) was a randomized, double-blind, placebo-controlled trial of tirofiban in patients undergoing balloon angioplasty or directional atherectomy within 72 hours of occurrence of either unstable angina pectoris or acute MI. Coronary blood flow was assessed with the corrected TIMI frame count (CTFC), and clinical outcomes were assessed at 30 days.

RESULTS

In addition to tighter and longer minimum lumen diameters (MLDs), the multivariate correlates of slower flow before PTCA also included the presence of thrombus, collaterals, left coronary artery lesion location, acute MI, and >8F catheter size. As well as the above variables, type C and D dissection grades were related to slower post-PTCA CTFC. Death, or the composite of death/MI/coronary artery bypass graft at 30 days, was more frequent among patients with slower post-PTCA CTFCs and those with post-PTCA thrombus. In a multivariate model correcting for reference segment diameter and MLD, the post-PTCA CTFC was an independent predictor of late lumen loss and the follow-up MLD at 6 months. As a single index that integrates functional and anatomical aspects of the post-PTCA results, the ratio of CTFC/MLD was associated with death/MI by 30 days.

CONCLUSIONS

In addition to MLD, variables such as the presence of thrombus, left coronary artery lesion location, and dissection grade also are associated with slower coronary blood flow after PTCA. In turn, post-PTCA CTFCs were an independent predictor of late lumen loss and follow-up MLDs. Furthermore, patients who die or who sustain other adverse cardiac events have slower coronary blood flow and greater thrombus burden after PTCA.

Interleukin 1 receptor antagonist gene polymorphism and restenosis after coronary angioplasty

BACKGROUND

Percutaneous transluminal coronary angioplasty (PTCA) is limited by the recurrence of luminal stenosis, which occurs in up to 50% of procedures. It has been shown that patient specific factors, perhaps genes, contribute to this process.

OBJECTIVE

To determine whether completion of healing after PTCA is part of an acute self limiting inflammatory process and whether polymorphism at important inflammatory gene loci might determine susceptibility to restenosis after PTCA.

DESIGN

DNA samples were collected from 171 patients attending for elective PTCA in Sheffield (S) and Leicester (L), who were scheduled to undergo follow up angiography (at four months (L) or six months (S)) as part of other restenosis studies. At follow up angiography, the patients were separated into restenosers (> 50% luminal narrowing) and non-restenosers (< 50% luminal narrowing). Four DNA polymorphisms within interleukin 1 (IL-1) related loci (IL-1A (-889), IL-1B (-511), IL-1B (+3954), and IL-1RN intron 2 VNTR (variable number tandem repeat)) were genotyped using methods based on polymerase chain reaction. Significance was assessed by chi(2) analysis of the relevant contingency table, and the magnitude of effect was estimated by calculating odds ratios. The Mantel-Haenszel (MH) test was applied to summarise data across the two populations.

RESULTS

Allele 2 at IL-1RN (IL-1RN*2) was significantly over represented in the non-restenoser group (L+S, 34% v 23% in restenosers). Furthermore, IL-1RN*2 homozygosity was increased in the non-restenoser population compared with the restenosers (MH test: p = 0.0196 (L+S); p = 0.031 (L+S, single vessel disease only), and the effect seemed to be restricted to the single vessel disease subpopulation. For other polymorphism within IL-1 related loci no significant associations were found with either restenosis or non-restenosis.

CONCLUSIONS

IL-1RN*2 may be associated with protection from restenosis after PTCA for individuals with single vessel disease. As this polymorphism has functional significance, this finding suggests that alteration in an individual's inflammatory predisposition may modulate the blood vessel response to injury.

Personnel exposure during gamma endovascular brachytherapy

PURPOSE

The use of 192Ir brachytherapy for the treatment of in-stent restenosis of the coronary arteries has shown promising clinical results. This paper investigates the radiation exposure of catheterization laboratory staff associated with the performance of this procedure.

METHODS AND MATERIALS

Cath lab staff were monitored using personal monitors (shielded against fluoroscopic x-rays) during the performance of eleven cases using nominal 10 GBq 192Ir sources. Staff positions in the lab were simultaneously tracked by video cameras. Direct measurements were also made using a survey meter. Treatments were administered in a conventional cardiac-catheterization-laboratory.

RESULTS

The dosimeter readings were analyzed in combination with the radiation survey and time motion survey. Brachytherapy procedural times for the cardiologist, oncologist, physicist, and angiographic assistants were, respectively, 26 +/- 24, 401 +/- 132, 486 +/- 148, and 7 +/- 13 s per case (mean +/- standard deviation). Readings of the personnel monitors were low. Credible upper limits of the respective doses are estimated to be less than 10, 10, 7, and 5 microSv per procedure. Auxiliary shields reduced the dose to individuals located outside of the catheterization laboratory to less than 0.5 microSv per procedure.

CONCLUSIONS

The average radiation dose received by laboratory personnel during a representative 192Ir endocoronary brachytherapy procedure is estimated to be less than 0.1% of the NCRP recommended annual radiation worker's Maximum Permissible Dose (1% of the general public's MPD). This level is justifiable as long as the use of 192Ir benefits patients by producing an improved clinical outcome relative to the use of a less penetrating radionuclide or the application of alternative therapies. Further optimization of the delivery procedure is expected to reduce staff dose.

Longitudinal straightening effect of stents is an additional predictor for major adverse cardiac events. Austrian Wiktor Stent Study Group and European Paragon Stent Investigators

OBJECTIVES

The aim of this study was to perform an investigation of the effects of the longitudinal straightening of coronary arteries by stents and the possible association with major adverse cardiac events (MACE) (primary end point) and angiographic restenosis (secondary end point).

BACKGROUND

Stent deployment straightens a tortuous artery, and any consequent arterial longitudinal stretch may contribute to MACE and stent restenosis severity.

METHODS

Clinical, qualitative and quantitative angiographic data on 404 patients with single stent implantation were subjected to multivariate nominal logistic regression analysis for the prediction of MACE. The predictive accuracy, sensitivity and specificity values and cut-off points of the continuous variables were determined via receiver operating characteristics curves. The longitudinal straightening effect of stents was characterized through the changes in vessel angle (defined by the tangents to the proximal and distal parts of the stenoses/stents).

RESULTS

Follow-up angiography on 354 patients revealed 73 cases of stent restenosis (> or =50% diameter stenosis). Coronary bypass surgery was performed in 4 patients and repeated percutaneous transluminal coronary angioplasty in 56 patients; acute myocardial infarction (AMI) occurred in 2 patients, and 4 patients died during the follow-up. The overall incidence of MACE (death, AMI and revascularization) was 16.3% (66 patients). The best predictive accuracies and sensitivities/specificities of factors indicative of MACE were found for the minimal lumen diameter (MLD) at follow-up (predictive accuracy: 0.9305, sensitivity/specificity: 86.6%), the post-stent MLD (0.773, 77.2%), the percent diameter stenosis (%DS) at follow-up (0.9432, 87.1%), the prestent vessel angulation (0.6797, 68.2%) and the poststent changes in vessel angulation (0.6279, 62.2%). Multivariate nominal logistic regression analysis demonstrated that a poststent MLD < or =2.63 mm (p = 0.0017, odds ratio [OR] = 17.961, 95% confidence interval [CI] = 17.45-20.428), an MLD at follow-up < or =1.7 mm (p = 0.0059, OR = 11.880, 95% CI = 11.490-14.093), a %DS at follow-up > or =42.2% (p = 0.0000, OR = 49.553, 95% CI = 48.024-53.507), a prestent vessel angulation > or =33.5 degrees (p = 0.0477, OR = 5.404, 95% CI = 5.382-7.142) and poststent changes in vessel angulation > or =9.1 degrees (p = 0.0026, OR = 19.161, 95% CI = 18.562-21.750) were significant predictors for MACE. Multiple linear regression revealed that the poststent MLD (multivariate p = 0.0001), the MLD at follow-up (p = 0.0000), the prestent vessel angulation (p = 0.0431) and the changes in vessel angulation after stent implantation (p = 0.0316) were significant independent variables predicting angiographic stent restenosis severity.

CONCLUSIONS

The longitudinal straightening effect of coronary artery stents contributes significantly to the occurrence of MACE and angiographic restenosis, and this finding may have an impact on future stent design.

Genetic risk factors and restenosis after percutaneous coronary interventions

Restenosis is the major limitation of percutaneous coronary interventions. Depending on the form of intervention and patients' characteristics, 20 to 50% of the treated patients incur significant restenosis. Restenosis is caused by a complex and only partially understood cascade of events. Thrombus formation at the injury site, formation of the neointima as a result of the migration and proliferation of smooth muscle cells (SMC) and extracellular matrix production, as well as constrictive remodeling of the vessel wall contribute by a variable degree to restenosis. Restenosis is not a random event but it affects selectively a certain subset of patients. These patients have some peculiar characteristics that help to identify the presence of a higher risk for restenosis. Conventional patient-related factors account only for a relatively small portion of the predictive power, much more contribution comes from lesion and procedural characteristics. There is increasing evidence that inherited factors may explain at least part of the excessive risk for restenosis observed in certain patients. Evidence exists that gene polymorphisms may lead to quantitative or functional alterations of the respective gene products. Recent studies have also found significant associations between several polymorphic alleles encoding for proteins with a relevant role in the process of lumen renarrowing and restenosis after percutaneous coronary interventions. The best studied polymorphisms in this regard are those of the genes encoding for angiotensin-converting enzyme and platelet glycoprotein-IIIa. Completed or ongoing studies have focused on polymorphisms of genes encoding for proteins interfering with lipid metabolism, hemostasis, nitric oxide production, inflammatory mechanisms, SMC proliferation and matrix production. The results of this research will have considerable pathophysiological and therapeutical implications for the battle against restenosis.

Preprocedural serum levels of C-reactive protein predict early complications and late restenosis after coronary angioplasty

OBJECTIVES

We sought to investigate whether early and late outcome after percutaneous transluminal coronary angioplasty (PTCA) could be predicted by baseline levels of acute-phase reactants.

BACKGROUND

Although some risk factors for acute complications and restenosis have been identified, an accurate preprocedural risk stratification of patients undergoing PTCA is still lacking.

METHODS

Levels of C-reactive protein (CRP), serum amyloid A protein (SAA) and fibrinogen were measured in 52 stable angina and 69 unstable angina patients undergoing single vessel PTCA.

RESULTS

Tertiles of CRP levels (relative risk [RR] = 12.2, p < 0.001), systemic hypertension (RR = 4.3, p = 0.046) and female gender (RR = 4.1, p = 0.033) were the only independent predictors of early adverse events. Intraprocedural and in-hospital complications were observed in 22% of 69 patients with high serum levels (>0.3 mg/dl) of CRP and in none of 52 patients with normal CRP levels (p < 0.001). Tertiles of CRP levels (RR = 6.2, p = 0.001), SAA levels (RR = 6.0, p = 0.011), residual stenosis (RR = 3.2, p = 0.007) and acute gain (RR = 0.3, p = 0.01) were the only independent predictors of clinical restenosis. At one-year follow-up, clinical restenosis developed in 63% of patients with high CRP levels and in 27% of those with normal CRP levels (p < 0.001).

CONCLUSIONS

Preprocedural CRP level, an easily measurable marker of acute phase response, is a powerful predictor of both early and late outcome in patients undergoing single vessel PTCA, suggesting that early complications and clinical restenosis are markedly influenced by the preprocedural degree of inflammatory cell activation.