Influence of diabetes mellitus on early and late outcome after percutaneous transluminal coronary angioplasty

Percutaneous coronary intervention versus coronary artery bypass grafting in diabetic patients

Revascularization with CABG or angioplasty in diabetic patients is associated with a less favor-able outcome. The value of early intervention will be assessed in the ongoing BARI 2D trial. It remains to be determined whether the widespread use of GP IIb/IIIa drugs and prolonged dual antiplatelet therapy in diabetic patients who receive stents, and possibly drug-eluting stents, will alter results significantly so that outcomes become comparable or even better than CABG (Fig. 3). It seems prudent to consider CABG with LIMA grafting in diabetic patients who have severe multi-vessel disease and to consider angioplasty in selected patients who have more discrete and less severe disease.

Role of insulin secretagogues and insulin sensitizing agents in the prevention of cardiovascular disease in patients who have diabetes

In the absence of clinical trial evidence to compare the secretagogues with sensitizers, it is difficult to make recommendations about which class of drug is more important to prescribe for the prevention of cardiovascular disease in diabetes mellitus. Epidemiologic data supports insulin resistance as a major factor in cardiovascular disease through a variety of mechanisms. Because sensitizers improve insulin sensitivity and correct many of the vascular abnormalities that are associated with insulin resistance, it is tempting to suggest that they may be superior for this purpose. Conversely, meeting the goals that are recommended for glycemia also are important and achieving them may not be always possible with sensitizers, particularly in the later stages of the disease when insulin levels are not high,despite insulin resistance. In such situations,combination therapy may be needed with both types of drugs. No data are available on the cardiovascular effects of such combinations;some retrospective data suggest a possibility of increased events with the combination of sulfonylureas and metformin. Thus, further prospective studies in this area are necessary.

Outcomes with the polymer-based paclitaxel-eluting TAXUS stent in patients with diabetes mellitus

OBJECTIVES

We sought to determine the safety and efficacy of polymer-regulated site-specific delivery of paclitaxel in patients with diabetes mellitus undergoing stent implantation.

BACKGROUND

Percutaneous coronary intervention in patients with diabetes is associated with high rates of restenosis and repeat revascularization due to excessive neointimal proliferation, a process that may be blunted with the site-specific delivery of paclitaxel.

METHODS

In the TAXUS-IV trial, 1,314 patients were prospectively randomized to the slow rate-release polymer-based paclitaxel-eluting TAXUS stent or the bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). Medically treated diabetes was present in 318 patients (24%), 105 of whom required insulin.

RESULTS

Among patients with diabetes, the TAXUS stent, compared to the bare-metal stent, reduced the rate of 9-month binary angiographic restenosis by 81% (6.4% vs. 34.5%, p < 0.0001), and reduced the 12-month rates of target lesion revascularization by 65% (7.4% vs. 20.9%, p = 0.0008), target vessel revascularization by 53% (11.3% vs. 24%, p < 0.004), and composite major adverse cardiac events by 44% (15.6% vs. 27.7%, p = 0.01). The one-year rates of cardiac death (1.9% vs. 2.5%), myocardial infarction (3.2% vs. 6.4%), and subacute thrombosis (0.6% vs. 1.2%) were comparable between the paclitaxel-eluting and control stents, respectively. In the insulin-requiring subgroup, the TAXUS stent reduced angiographic restenosis by 82% (7.7% vs. 42.9%, p = 0.0065), and reduced the one-year rate of target lesion revascularization by 68% (6.2% vs. 19.4%, p = 0.07), a relative reduction similar to patients without diabetes.

CONCLUSIONS

The site-specific delivery of paclitaxel after coronary stent implantation is highly effective in reducing clinical and angiographic restenosis in patients with diabetes mellitus.

Requirement of aldose reductase for the hyperglycemic activation of protein kinase C and formation of diacylglycerol in vascular smooth muscle cells

Activation of protein kinase C (PKC) has been linked to the development of secondary diabetes complications. However, the underlying molecular mechanisms remain unclear. We examined the contribution of aldose reductase, which catalyzes the first, and the rate-limiting, step of the polyol pathway of glucose metabolism, to PKC activation in vascular smooth muscle cells (VSMCs) isolated from rat aorta and exposed to high glucose in culture. Exposure of VSMCs to high glucose (25 mmol/l), but not iso-osmotic mannitol, led to an increase in total membrane-associated PKC activity, which was prevented by the aldose reductase inhibitors tolrestat or sorbinil or by the ablation of aldose reductase by small interfering RNA (siRNA). The VSMCs were found to express low levels of sorbitol dehydrogenase, and treatment with the sorbitol dehydrogenase inhibitor CP-166572 did not prevent high-glucose-induced PKC activation. Stimulation with high glucose caused membrane translocation of conventional (alpha, beta1, beta2, and gamma) and novel (delta and epsilon) isoforms of PKC. Inhibition of aldose reductase prevented membrane translocation of PKC-beta2 and -delta and delayed the activation of PKC-beta1 and -epsilon, whereas membrane translocation of PKC-alpha and -gamma was not affected. Treatment with tolrestat prevented phosphorylation of PKC-beta2 and -delta. High glucose increased the formation of diacylglycerol (DAG) and enhanced phosphorylation of phospholipase C-gamma1 (PLC-gamma1). Inhibition of aldose reductase prevented high glucose-induced DAG formation and phosphorylation of PLC-gamma1 and PLC-beta2 and -delta. Inhibition of phospholipid hydrolysis by D609, but not by the synthetic alkyl-1-lysophospholipid 1-O-octadecyl-2-O-methyl-rac-glycerophosphocholine, or edelfosine, prevented DAG formation. Treatment with sorbinil decreased the levels of reactive oxygen species in high-glucose-stimulated VSMCs. Hence, inhibition of aldose reductase, independent of sorbitol dehydrogenase, appears to be effective in diminishing oxidative stress and hyperglycemic changes in signaling events upstream to the activation of multiple PKC isoforms and PLC-gamma1 and may represent a useful approach for preventing the development of secondary vascular complications of diabetes.

Pathobiology and cell interactions of platelets in diabetes

Diabetes is a well-recognised risk factor for atherosclerotic cardiovascular disease and in fact most diabetic patients die from vascular complications. The Diabetes Control and Complications Trial (DCCT) and the U.K. Prospective Diabetes Study (UKPDS) indicate a consistent relationship between hyperglycaemia and the incidence of chronic vascular complications in patients with diabetes. Platelets are essential for haemostasis, and abnormalities of platelet function may cause vascular disease in diabetes. Diabetic patients have hyperreactive platelets with exaggerated adhesion, aggregation and thrombin generation. In summary, the entire coagulation cascade is dysfunctional in diabetes. This review provides a comprehensive overview of the physiological role of platelets in maintaining haemostasis and of the pathophysiological processes that contribute to platelet dysfunction in diabetes and associated cardiovascular diseases, with special emphasis on proteomic approaches and leukocyte-platelet cross-talk.

Fluvastatin reduces the impact of diabetes on long-term outcome after coronary intervention--a Lescol Intervention Prevention Study (LIPS) substudy

BACKGROUND

Diabetes increases the risk of developing cardiovascular disease. Patients with diabetes undergoing percutaneous coronary intervention (PCI) show poorer outcomes compared with nondiabetic patients. The aim of this study was to determine the clinical benefit of long-term fluvastatin in patients with diabetes who had undergone a successful PCI.

METHODS

This subanalysis of a prospective, multicenter, randomized, double-blind, placebo-controlled trial of patients who had undergone PCI and were treated with fluvastatin determined the impact of fluvastatin on the survival-free period of major adverse cardiac events (MACE) (defined as cardiac death, nonfatal myocardial infarction, and reintervention procedure [coronary artery bypass grafting, repeat PCI, PCI for a new lesion]). Patients with baseline total cholesterol levels of 135 to 270 mg/dL (3.5-7.0 mmol/L) and triglyceride levels of 400 mg/dL (4.5 mmol/L) were randomized at discharge either to fluvastatin (n = 844) or to placebo (n = 833); follow-up was 3 to 4 years. Among these patients, there were 202 with diabetes (120 on fluvastatin, 82 placebo) and 1475 without diabetes (724 on fluvastatin, 751 on placebo). The primary clinical outcome was survival time free of MACE and MACE excluding restenosis.

RESULTS

The presence of diabetes increased the risk of MACE by almost 2-fold in placebo-treated patients (RR 1.78, 95% CI 1.20-2,64, P = .0045). In contrast, in diabetic patients treated with fluvastatin, the risk of MACE was not significantly different from that in patients without diabetes. Fluvastatin reduced the risk of MACE in diabetic patients by 51% (P = .0088).

CONCLUSIONS

Diabetes is a consistent clinical predictor of cardiovascular complications and fluvastatin reduces the increased incidence of long-term adverse complications associated with the presence of diabetes.

Diabetic cardiomyopathy: mechanisms, diagnosis and treatment

Independent of the severity of coronary artery disease, diabetic patients have an increased risk of developing heart failure. This clinical entity has been considered to be a distinct disease process referred to as 'diabetic cardiomyopathy'. Experimental studies suggest that extensive metabolic perturbations may underlie both functional and structural alterations of the diabetic myocardium. Translational studies are, however, limited and only partly explain why diabetic patients are at increased risk of cardiomyopathy and heart failure. Although a range of diagnostic methods may help to characterize alterations in cardiac function in general, none are specific for the alterations in diabetes. Treatment paradigms are very much limited to interpretation and translation from the results of interventions in non-diabetic patients with heart failure. This suggests that there is an urgent need to conduct pathogenetic, diagnostic and therapeutic studies specifically in diabetic patients with cardiomyopathy to better understand the factors which initiate and progress diabetic cardiomyopathy and to develop more effective treatments.

The impact of antidiabetic therapies on cardiovascular disease

Cardiovascular disease disproportionately affects people with diabetes and is a leading cause of death. Glycemic control has so far not been conclusively shown to decrease cardiovascular events. The therapeutic agents used in treating glycemia have different effects on cardiovascular risks and, therefore, may have different effects on outcome. Insulin sensitizers impact cardiovascular risk factors, including dyslipidemia and fibrinolysis. Metformin is the only oral antidiabetic medication shown to decrease cardiovascular events independent of glycemic control. Thiazolidinediones improve insulin resistance and lower insulin concentrations, which is beneficial because hyperinsulinemia is an independent predictor of cardiovascular disease. Insulin therapy acutely reduces cardiovascular mortality and morbidity in patients with diabetes and known coronary artery disease and also in patients with hyperglycemia when critically ill, but the long-term effects are unclear. In contrast, insulin secretagogues have very little effect on both cardiovascular risk factors and outcomes.

Insulin, C-Peptide, and Restenosis after Femoral Artery Balloon Angioplasty in Type II Diabetic and Nondiabetic Patients

PURPOSE

Endogenous and exogenous insulin is suggested to stimulate hypertrophic wound-healing responses and therefore may promote neointimal hyperplasia and restenosis after balloon angioplasty. The ratio of C-peptide to insulin reflects endogenous insulin secretion. In diabetic patients with insulin substitution, lower ratios display a higher proportion of exogenous insulin. The association and interaction of insulin and C-peptide with restenosis after percutaneous transluminal angioplasty (PTA) was investigated in type II diabetic and nondiabetic patients.

MATERIALS AND METHODS

The study group included 76 patients (median age, 68 years; interquartile range [IQR], 58-74 years; 55 men [72%]; 31 patients [41%] with type II diabetes) with intermittent claudication (n = 49; 64%) or critical limb ischemia (n = 27; 36%) who underwent primary successful femoral PTA. C-peptide and insulin levels were measured at baseline, and patients were followed to determine restenosis (> or =50%) at 12 months by color-coded duplex sonography.

RESULTS

Restenosis was found in 34 patients (45%) at 12 months. Patients with restenosis had higher insulin levels (median, 21.3 microU/mL IQR, 11.3-35.5 microU/mL) and a lower C-peptide/insulin ratio (median, 16; IQR, 10-21) compared with patients without restenosis (median insulin level, 11.6 microU/mL; IQR, 9.1-22.0 microU/mL [P = .008]; median ratio, 19 [IQR, 17-25], P = .039). In nondiabetic patients, insulin levels were significantly associated with restenosis (P = .046), whereas the ratio of C-peptide to insulin showed no association with restenosis. In patients with type II diabetes (n = 31; 41%), in contrast, the C-peptide/insulin ratio was associated with restenosis (P = .047), whereas insulin levels showed no significant association with restenosis (P = .14).

CONCLUSIONS

Insulin levels and the C-peptide/insulin ratio were associated with restenosis after femoral PTA. Exogenous and endogenous insulin may play a role in the pathogenesis of recurrent lumen loss after balloon angioplasty.

Impact of stenting and abciximab in patients with diabetes mellitus undergoing primary angioplasty in acute myocardial infarction (the CADILLAC trial)

We sought to determine the benefits of stent implantation and abciximab in patients with diabetes mellitus and acute myocardial infarction (AMI) who underwent primary angioplasty. In a 2-by-2 factorial design, 2,082 patients with AMI were randomly assigned to balloon angioplasty versus stenting, with or without abciximab. Diabetes was present in 346 patients (16.6%). The primary end point was the composite incidence of death, disabling stroke, reinfarction, and ischemic target vessel revascularization (TVR). The primary end point at 1 year occurred significantly more frequently in diabetic than nondiabetic patients (21.9% vs 16.8%, p <0.02), driven by increased rates of death (6.1% vs 3.9%, p = 0.04) and TVR (16.4% vs 12.7%, p = 0.07). Among patients with diabetes, TVR at 1 year was significantly reduced with routine stenting compared with balloon angioplasty (10.3% vs 22.4%, p = 0.004), with no differences in death, reinfarction, or stroke. Angiographic restenosis was also greatly reduced in diabetics randomized to stenting (21.1% vs 47.6%, p = 0.009). No beneficial effects were apparent with abciximab in diabetic patients at 1 year. Despite the improved outcomes with stenting in patients with diabetes, 1-year mortality remained increased in diabetic patients who received stents compared with nondiabetics (8.2% vs 3.6%, p = 0.005). Thus, routine stent implantation in diabetic patients with AMI significantly reduces restenosis and enhances survival free from TVR, independent of abciximab use, although survival remains reduced compared with survival in nondiabetic patients regardless of reperfusion modality.

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.

Impact of diabetes mellitus type 2 on in-hospital outcome after cardiac catheterizations in a large cohort of octogenarians

AIM

To assess the impact of diabetes mellitus type 2 (DM) in 1085 octogenarians on in-hospital outcome after cardiac catheterization (CATH) and/or percutaneous coronary intervention (PCI).

METHODS AND RESULTS

We studied 1085 consecutive octogenarians [82.6+/-2.6 years; 401 DM, 684 without DM (non-DM)]. Age, acute myocardial infarctions (DM: 26%, non-DM: 21%) and extent of disease (three-vessel disease, DM: 34%, non-DM: 31%) were similar in both groups. There was a similar percentage of interventions (PCI: DM: 30% vs. non-DM: 29%; bypass surgery: DM: 30% vs. non-DM: 25%) performed in both groups. Thirty-one patients (2.9%) died during hospital stay (DM: 2.2%; non-DM: 3.2%; p=0.46) of whom 16 died (DM: 1.0%; non-DM: 1.9%) during (n=4) or after (n=12) interventions in patients who were already admitted in cardiogenic shock. At the puncture site, 87 complications occurred (DM 6.5% vs. non-DM 6.4%, p=0.87). Stepwise logistic regression analyses identified DM as an independent predictor of adverse events during CATH, but not PCI. Furthermore, DM was not a predictor for vascular complications.

CONCLUSIONS

Catheterization-related complication rates are different in diabetic as compared to nondiabetic patients during CATH, but not PCI. Octogenarians should be granted access to an invasive treatment strategy even in the presence of DM.

Determination of vessel size: a putative framework to assess clinical outcome

BACKGROUND

Unknown is the predictive value of the coronary artery diameter without the administration of vasomotor stimuli. A small reference diameter of the target vessel has been demonstrated to be an adverse prognostic factor in patients undergoing revascularisation. The present study investigated the prognostic value of the proximal non-stenotic left anterior descending coronary artery (LAD) diameter in patients referred for a first diagnostic angiogram without a previous revascularisation.

METHODS

A total of 277 patients (mean age 57 year, 61% male) were eligible for analysis. The proximal non-stenotic diameter of the LAD was measured by quantitative coronary angiography without prior nitrate infusion. We defined a small LAD as a diameter < or =2.5 mm. Cardiovascular events were defined as cardiac death, myocardial infarction, and hospitalizations for unstable angina.

RESULTS

During a median follow-up of 47 months, 24 major cardiac events occurred. The cumulative survival for patients with a small LAD was significantly lower, than for patients with a large LAD (hazard ratio 2.51; 95% confidence interval 1.11-5.66, p=0.03). In the multivariate analysis, a LAD diameter < or =2.5 mm remained a significant predictor of cardiovascular events after adjustment for age, gender, and the presence of significant coronary artery disease (hazard ratio 2.32; 95% confidence interval 1.01-5.34, p=0.048).

CONCLUSION

In patients referred for a first diagnostic angiogram without a previous revascularisation, the diameter of the proximal non-stenotic LAD is an independent predictor of cardiovascular events.

Inhibition of apoptosis and caspase-3 in vascular smooth muscle cells by plasminogen activator inhibitor type-1

Increased expression of plasminogen activator inhibitor type 1 (PAI-1) is associated with decreased apoptosis of neoplastic cells. We sought to determine whether PAI-1 alters apoptosis in vascular smooth muscle cells (VSMC) and, if so, by what mechanisms. A twofold increase in the expression of PAI-1 was induced in VSMC from transgenic mice with the use of the SM-22alpha gene promoter (SM22-PAI+). Cultured VSMC from SM22-PAI+ mice were more resistant to apoptosis induced by tumor necrosis factor plus phorbol myristate acetate or palmitic acid compared with VSMC from negative control littermates. Both wild type (WT) and a stable active mutant form of PAI-1 (Active) inhibited caspase-3 amidolytic activity in cell lysates while a serpin-defective mutant (Mut) PAI-1 did not. Similarly, both WT and Active PAI-1 decreased amidolytic activity of purified caspase-3, whereas Mut PAI-1 did not. WT but not Mut PAI-1 decreased the cleavage of poly-[ADP-ribose]-polymerase (PARP), the physiological substrate of caspase-3. Noncovalent physical interaction between caspase-3 and PAI-1 was demonstrable with the use of both qualitative and quantitative in vitro binding assays. High affinity binding was eliminated by mutations that block PAI-1 serpin activity. Accordingly, attenuated apoptosis resulting from elevated expression of PAI-1 by VSMC may be attributable, at least in part, to reversible inhibition of caspase-3 by active PAI-1.

Sex-associated differences in clinical outcomes after coronary stenting in patients with diabetes mellitus

PURPOSE

It has been suggested that the influence of diabetes on cardiovascular mortality is sex dependent. We undertook this study to determine whether there were sex-related differences in 1-year clinical outcomes following coronary artery stenting in diabetic patients.

METHODS

The study included 4460 consecutive patients (1084 women) who underwent coronary artery stenting for stable or unstable angina, of whom 970 (22%) had diabetes. Six-month follow-up angiography was performed in 3452 patients (77.4%). The primary endpoint was the combined incidence of major adverse cardiac events (death, myocardial infarction, and target vessel revascularization).

RESULTS

Diabetes was associated with a significant increase in the combined incidence of death, myocardial infarction, and target vessel revascularization at 1 year in women; this incidence was greater in diabetic women than in nondiabetic women (26.9% [84/312] vs. 18.9% [146/772]; odds ratio [OR] = 1.5; 95% confidence interval [CI]: 1.2 to 2.0; P = 0.002). The primary endpoint appeared to be similar in men regardless of diabetes status (24.6% [162/658] with diabetes vs. 23.3% [634/2718] without diabetes; OR = 1.07; 95% CI: 0.90 to 1.27; P = 0.43). There was a significant interaction between diabetes and sex in both unadjusted (P = 0.03) and adjusted (P = 0.04) analyses, with diabetes having a greater negative effect in women than in men for major adverse cardiac events after coronary stenting.

CONCLUSION

In patients who underwent coronary artery stenting, the increased risk of adverse cardiac events associated with diabetes was more pronounced in women than in men.

Direct stenting compared to conventional stenting in Diabetic Patients Undergoing Elective Angioplasty for Coronary Artery Disease (DECIDE): a multicenter, open label, randomized, controlled efficacy study

BACKGROUND

Direct stenting (DS) has been shown to be associated with reduced radiation exposure and procedural costs but has a restenosis rate and clinical outcomes similar to conventional stenting (CS) with balloon predilatation. Whether DS confers benefit in diabetic patients, who have been shown to have high restenosis risk after stent implantation, remains unknown.

METHODS

In a multicenter randomized trial, diabetic patients undergoing elective coronary stent implantation for a de novo lesion in a native coronary artery between April 2001 and October 2002 were randomized into DS or CS treatment groups. All patients received NirElite stents (SciMed, Boston Scientific, Maple Grove, Minn). They were scheduled to undergo a 6-month angiographic follow-up with quantitative coronary analysis evaluation. The primary end point was a 6-month binary restenosis rate and the secondary end point involved 6-month all-cause mortality, nonfatal acute myocardial infarction, or target vessel revascularization rates.

RESULTS

A total of 128 diabetic patients were randomized into DS or CS treatment groups (n = 64, both groups). The 2 groups were well matched in baseline and lesion characteristics. The procedural success rate was similar (DC vs CS; 98.4% vs 96.9%). Nineteen patients (29.7%) crossed over from DS to CS. Six-month angiographic follow-up showed similar restenosis rates, minimum luminal diameter and late lumen loss. The binary restenosis rate was 43% in DS and 52% in CS groups (P = NS). The 6-month all-cause mortality, nonfatal acute myocardial infarction, or target vessel revascularization rates were also similar in both groups.

CONCLUSIONS

Among diabetic patients undergoing elective coronary stent implantation, DS is safe and feasible. However, it is not associated with reduction in restenosis rate or improvement in clinical outcomes when compared with CS.

Genetic risk for restenosis after coronary balloon angioplasty

Plain old balloon angioplasty (POBA) is a useful therapeutic strategy especially for angioplasty of small coronary arteries. An association study was performed to identify genes that confer susceptibility to restenosis after POBA. The study population comprised 730 individuals (424 men, 306 women) who underwent successful POBA in at least one major coronary artery and were examined angiographically 6 months after the procedure. A total of 469 subjects (273 men, 196 women) exhibited no restenosis after POBA for any of the coronary lesions, whereas 261 subjects (151 men, 110 women) manifested restenosis for all lesions. The genotypes for 40 polymorphisms of 34 genes were determined with a fluorescence- or colorimetry-based allele-specific DNA primer-probe assay. Multivariate logistic regression analysis with adjustment for age, body mass index, and the prevalence of smoking, hypertension, diabetes mellitus, hypercholesterolemia, and hyperuricemia revealed that two polymorphisms (242C --> T in the NADH/NADPH oxidase p22 phox (p22-PHOX) gene and 2136C --> T in the thrombomodulin (THBD) gene) in men and two polymorphisms (584G --> A in the paraoxonase 1 (PON1) gene and 2445G --> A in the fatty acid-binding protein 2 (FABP2) gene) in women were significantly associated with restenosis after POBA. A stepwise forward selection procedure revealed that the effects of these polymorphisms on restenosis were statistically independent of conventional risk factors for coronary artery disease. Genotyping of these polymorphisms may prove informative for assessment of genetic risk for restenosis after POBA.

Prevention of restenosis after coronary angioplasty

PURPOSE OF REVIEW

Despite numerous advances in coronary interventional techniques, the frequent occurrence of restenosis continues to plague interventional cardiology. With the widespread use of drug-eluting stents, there is a need to reexamine critically the roles of the various interventional techniques currently available.

RECENT FINDINGS

Drug-eluting stents have dramatically reduced the rates of restenosis and target vessel revascularization in a wide spectrum of patients with varying lesion morphologies. However, when restenosis does occur, it still tends to be dependent on the same factors that predict restenosis with bare metal stenting. The routine use of drug-eluting stents entails high initial costs to the health care system. Debulking as a means to improve outcomes after angioplasty has not lived up to expectations. Gene therapy is rapidly evolving into a viable means to reduce neointimal proliferation after angioplasty.

SUMMARY

Careful patient selection and attention to the procedure of stent deployment optimize the results of angioplasty with drug-eluting stents. Because of cost considerations, drug-eluting stents should be used in patients who are expected to have the greatest absolute benefit. In this context, when judiciously used, conventional balloon angioplasty and bare metal stenting still have a definite role in the management of patients with obstructive coronary artery disease.

Intracoronary Brachytherapy After Stenting De Novo Lesions in Diabetic Patients

OBJECTIVES

We studied the efficacy of intracoronary brachytherapy (ICB) after successful coronary stenting in diabetic patients with de novo lesions.

BACKGROUND

Intracoronary brachytherapy has proven effective in preventing recurrences in patients with in-stent restenosis. However, the role of ICB for the treatment of de novo coronary stenoses remains controversial.

METHODS

Ninety-two patients were randomized to either ICB or no radiation after stenting. Primary end points were in-stent mean neointimal area (primary end point of efficacy) and minimal luminal area of the entire vessel segment (primary end point of effectiveness), as assessed by intravascular ultrasound at six-month follow-up. Quantitative coronary angiography analysis was performed at the target, injured, irradiated, and entire vessel segments.

RESULTS

At follow-up, the in-stent mean neointimal area was 52% smaller in the ICB group (p < 0.0001). However, there was no difference in the minimal luminal area of the vessel segment (4.5 +/- 2.4 mm2 vs. 4.4 +/- 2.1 mm2). Restenosis rates increased progressively by the analyzed segment in the ICB group: target (7.1% vs. 20.9%, p = 0.07), injured (9.5% vs. 20.9%, p = NS), irradiated (14.3% vs. 20.9%, p = NS), and vessel segment (23.8% vs. 25.6%, p = NS). At one year, 1 cardiac death, 6 myocardial infarctions (MIs) (3 due to late stent thrombosis), and 10 target vessel revascularizations (TVRs) (6 due to the edge effect) occurred in the ICB group, whereas in the nonradiation group, there were 11 TVRs and no deaths or MIs.

CONCLUSIONS

Intracoronary brachytherapy significantly inhibited in-stent neointimal hyperplasia after stenting in diabetic patients. However, clinically this was counteracted by the occurrence of the edge effect and late stent thrombosis.

Ischemic heart disease and congestive heart failure in diabetic patients

Ischemic heart disease and heart failure are major contributors to the morbidity and mortality associated with diabetes mellitus. With growing knowledge of how the metabolic derangements of diabetes contribute to the pathogenesis of cardiovascular disease, we must continuously refine our understanding of optimal screening and strategies for prevention and treatment for these interlinked disorders. This article summarizes our current understanding of ischemic heart disease and heart failure in patients with diabetes mellitus, highlighting gaps in our knowledge about the relationship between diabetes and cardiovascular disease. Special consideration is given to new strategies for treating the adverse effects of abnormal glucose metabolism on the cardiovascular system.

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.

Effect of diabetes on long-term mortality following contemporary percutaneous coronary intervention: analysis of 4,284 cases

OBJECTIVE

Diabetic patients are known to have reduced long-term survival following percutaneous transluminal coronary angioplasty compared with nondiabetic patients. However, it is unknown whether this survival disadvantage has persisted in the era of contemporary percutaneous coronary intervention (PCI) techniques, which include the widespread use of stents and the availability of platelet glycoprotein (GP) IIb/IIIa inhibitors.

RESEARCH DESIGN AND METHODS

Three hospitals in New York City contributed prospectively defined data on 4,284 patients undergoing PCI. The primary end point was all-cause mortality following hospital discharge for PCI.

RESULTS

Hypertension, renal insufficiency, and renal failure requiring dialysis were all more common in diabetic patients, whereas active smoking was less frequent. Congestive heart failure on admission was more common in diabetic than nondiabetic patients (7.7 vs. 4.0%, P < 0.001). Stents were placed in 78% of nondiabetic patients and 75% of diabetic patients (P = 0.045). Platelet GP IIb/IIIa antagonists were administered to 23% of nondiabetic and 24% of diabetic patients (P = NS). At a mean follow-up of 3 years, mortality was 8% among nondiabetic patients and 13% for diabetic patients (P < 0.001). After adjustment for differences in baseline characteristics between nondiabetic and diabetic patients, diabetes remained a significant independent hazard for late mortality (hazard ratio 1.462, 95% CI 1.169-1.828; P = 0.001).

CONCLUSIONS

Following contemporary PCI, diabetic patients continue to have worse survival than nondiabetic patients.

Diabetes mellitus: the major risk factor in unstable coronary artery disease even after consideration of the extent of coronary artery disease and benefits of revascularization

OBJECTIVES

This study was designed to study the influence of diabetes on the outcome of unstable coronary artery disease (CAD).

BACKGROUND

Diabetes mellitus is a major contributor to CAD. Despite improvement in the management of patients with unstable coronary syndromes, this condition is still linked to a substantially increased mortality and morbidity among diabetic patients. Recent evidence advocates early revascularization in unstable coronary syndromes. Diabetic patients subjected to coronary interventions under stable conditions have a higher risk for complications and a more dismal prognosis than nondiabetic subjects. Accordingly, it is of considerable interest to obtain further information regarding the best possible management of diabetic patients with unstable CAD.

METHODS

A total of 2158 patients without and 299 with diabetes mellitus were randomized to an early invasive or a noninvasive strategy. The severity of CAD was expressed as the number and extent of vessel involvement.

RESULTS

Three-vessel disease was diagnosed in 42% of diabetic and 31% of nondiabetic patients (p = 0.006). The percentages of patients with ST-depression and troponin-T >0.03 microg/l at admission were comparable among diabetic and nondiabetic patients. Mortality and reinfarction after 12 months were more frequent among diabetic than nondiabetic patients in both treatment groups. Diabetes remained a strong independent predictor for death and myocardial infarction in multivariable analysis. The invasive strategy reduced event rate in nondiabetic patients from 12.0% to 8.9% (odds ratio [OR] = 0.72; confidence interval [CI] 0.54 to 0.95; p = 0.019) and in diabetic patients from 29.9% to 20.6% (OR 0.61; CI 0.36 to 1.04; p = 0.066). In a multivariate analysis including the extent of CAD, diabetes remained a strong independent predictor of the combined end point (relative risk [RR] 2.40; CI 1.47 to 3.91; p = 0.0001) and of mortality (RR 5.43; CI 2.09 to 14.12; p = 0.001).

CONCLUSIONS

An invasive strategy improved outcome for both diabetic and nondiabetic patients with unstable CAD. However, diabetes mellitus remained an independent and important risk factor for death and myocardial infarction in the invasive group. Thus, factors beyond the extent of flow-limiting coronary lesions are of considerable importance for outcome in diabetic subjects with unstable coronary syndromes.

Comparison of survival after successful percutaneous coronary intervention of patients with diabetes mellitus receiving insulin versus those receiving only diet and/or oral hypoglycemic agents

The influence of diabetic treatment status on long-term outcome after percutaneous coronary intervention (PCI) is unclear. Previous reports have suggested that patients who receive insulin treatment have worse long-term outcome compared with patients who do not need insulin. To determine the influence of diabetes treatment status on outcome after PCI, patients with diabetes mellitus who underwent successful PCI from January 1, 1996, to June 30, 2001, were divided into 2 groups based on whether or not they required insulin; patients with shock or recent (< or =7 days) myocardial infarction were excluded. Cox proportional hazards models were utilized to estimate the association between diabetes treatment status and long-term survival. One thousand one hundred four eligible diabetic patients were identified and divided into those treated with insulin (418 patients; median follow-up 35.5 months) and those treated with either an oral agent or diet alone (686 patients; median follow-up 27.9 months). Insulin-treated patients were less likely to be men, and had more previous coronary revascularizations, prior myocardial infarctions, and congestive heart failure on presentation. Angiographic and procedural characteristics were comparable. Unadjusted survival curves were constructed, demonstrating that insulin treatment was associated with worse survival than noninsulin treatment (p = 0.001). After adjusting for differences in baseline characteristics, insulin treatment did not adversely effect survival (odds ratio 1.10, 95% confidence intervals 0.77 to 1.58). Thus, among diabetic patients who underwent successful PCI, patients treated with insulin had worse survival. After adjusting for differences in baseline characteristics, insulin treatment was not independently associated with worse survival.

[Diabetic cardiopathy: pathogenesis, diagnosis and therapy]

Diabetes mellitus is one of the most widespread metabolic diseases in Western industrial countries with increasing prevalence due to a progressively aging population that is also characterized by increasing obesity and a sedentary life style. Cardiovascular conditions are the major prognostic complications of diabetes. Cardiologically, diabetic cardiopathy may become manifest on different structural and functional levels of the heart. Disorders may involve the micro- and macrocirculation (angiopathy), ventricular function (cardiomyopathy) and the intracardial nervous system (autonomous neuropathy). The following survey summarizes the cardiovascular risk with particular attention to the pathogenesis, diagnostics and therapy of diabetes mellitus related coronary disease and diabetic cardiomyopathy.

Predictors of repeat revascularization after nonemergent, first percutaneous coronary intervention in the community

BACKGROUND

We sought to determine the incidence of and risk factors for repeat revascularization after nonemergent, first percutaneous coronary intervention (PCI) performed in contemporary community practice.

METHODS

We analyzed a prospective registry of consecutive patients undergoing isolated PCI in the state of Washington. Multivariate Cox regression analysis was used to determine predictors of repeat revascularization (by PCI or bypass surgery) within 1 year after first PCI.

RESULTS

Between January 1, 1999, and December 31, 1999, there were 3571 nonemergent first PCIs, 87.7% of which involved stent placement. Repeat revascularization occurred in 577 (16.2%) patients. Repeat revascularization was predicted by multivessel disease (hazard ratio [HR] 1.36, 95% CI 1.12-1.66), stable versus no angina (HR 1.27, 95% CI 1.03-1.57), and maximum stent length used (per 1 mm longer: HR 1.01, 95% CI 1.002-1.02), while prior myocardial infarction (HR 0.77, 95% CI 0.62-0.96) and creatinine >1.2 mg/dL (HR 0.74, 95% CI 0.56-0.98) were associated with lower risk of repeat revascularization. Diabetes was a significant predictor only when the outcome was limited to revascularization by coronary artery bypass surgery (HR 1.52, 95% CI 1.03-2.23). Although glycoprotein IIb/IIIa inhibitor use was a significant univariate predictor of freedom from early repeat revascularization (within 60 days after first PCI), after controlling for potential confounders, it was no longer significant.

CONCLUSIONS

In this contemporary, community-based registry of patients undergoing nonemergent first PCI, clinical practice and outcomes are consistent with evidence from clinical trials and previous controlled studies. Results from controlled studies may reasonably be extrapolated to such a community setting.

Impact of Increasing Diabetes on Coronary Artery Disease in the Past Decade

We studied the coronary risk factors of hospitalized patients with coronary artery disease (CAD) in the Department of Cardiovascular Internal Medicine of Kobe University Hospital in 1993, 1996, 1999 and 2003, and examined trends in the factors over the past decade. The prevalences of diabetes mellitus (DM) (24.7%, 33.6%, 41.1% and 44.7%, respectively) and impaired glucose tolerance (IGT) (5.9%, 8.0%, 9.3% and 11.0%, respectively) steadily increased, whereas dyslipidemia (high total cholesterolemia, high triglyceridemia, or low high-density lipoproteinemia) and hypertension remained unchanged. We also revealed an increase in hemoglobin A1c levels (5.8%, 5.9%, 6.2% and 6.4%, respectively), in contrast to modest improvements in lipid levels and blood pressure levels. Additionally, patients with multi-vessel disease (MVD, stenosis in more than two major coronary vessels) significantly increased from 44.7% in 1993 to 58.8% in 2003 (p < 0.01). In 1993, DM and dyslipidemia were significant predictors for MVD (Odds Ratio: 2.72 and 2.68, respectively). On the other hand, in 2003, the significant predictor for MVD shifted to DM alone (Odds Ratio: 2.38). In conclusion, the prevalence rate of DM among CAD patients significantly increased in this decade, and the consequent increase in the prevalence of MVD should be recognized as the most important problem clinically.

The neointimal response to endovascular injury is increased in obese Zucker rats

BACKGROUND

Restenosis after revascularization procedures is accelerated in persons with type 2 diabetes.

AIM

The current study tested the hypothesis that the neointimal response to endovascular injury is enhanced in female obese Zucker (OZ) rats, a model of type 2 diabetes.

METHODS

Animals were randomized to receive either a standard diet (SD) or a diabetogenic diet (DD) for 6 weeks. Four weeks later, balloon injury of the right common carotid artery was induced. All rats were euthanized 2 weeks after injury. Lean Zucker (LZ) rats served as controls.

RESULTS

At the time of death, plasma glucose was elevated in OZ rats fed a SD (208 +/- 13 mg/dl) and a DD (288 +/- 21 mg/dl) compared to corresponding LZ rats (SD: 153 +/- 8; DD: 132 +/- 7 mg/dl). The ratio of high-density lipoprotein cholesterol (HDLc) to total cholesterol (Totc), an index of atherogenicity, was reduced in OZ rats on both diets (SD: 0.77 +/- 0.06; DD: 0.80 +/- 0.09) compared to LZ controls (SD: 1.11 +/- 0.02; DD: 1.20 +/- 0.05). Histomorphometric analysis of injured arteries showed that the intima to media (I : M) ratio was significantly increased in OZ (1.37 +/- 0.07) compared to LZ (0.79 +/- 0.08) rats. Elevations in plasma glucose and triglycerides (Tg) correlated positively and decreases in HDLc negatively with an increased I : M ratio. Administration of the DD did not further enhance the I : M ratio in LZ (0.87 +/- 0.06) or OZ (1.29 +/- 0.09) rats.

CONCLUSIONS

These results suggest that neointima formation following endoluminal injury of the carotid artery is enhanced at an early stage in the development of diabetes mellitus.

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

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

Angiographically silent left main disease detected by intravascular ultrasound: a marker for future adverse cardiac events

BACKGROUND

Concomitant moderate obstructive left main (LM) disease is associated with future cardiac events and poor prognosis in patients undergoing percutaneous intervention (PCI). Whether prognosis is similarly effected by LM disease not detected by angiography, but evident on intravascular ultrasound (IVUS) imaging, is not known. The purpose of this study was to evaluate the long-term prognosis of patients with angiographically insignificant LM coronary artery disease undergoing PCI.

METHODS AND RESULTS

One hundred and seven consecutive patients undergoing PCI with angiographically normal or mild LM disease had 2- and 3-dimensional IVUS imaging. IVUS images were digitized, and 3-dimensional reconstruction was performed. Percent diameter and area stenosis by angiography were 4.8% +/- 3.5% and 18.2% +/- 9.8%, respectively. IVUS mean luminal area and area stenosis were 17.9 +/- 5.6 mm2 and 30.2% +/- 14.7%, respectively. Long-term follow-up was available in 102 (95%) patients at a median of 29 (range 8-52) months. Major adverse cardiac events, defined as death (6), myocardial infarction (4), repeat PCI (13), or CABG (16), were associated with female sex (P =.04), diabetes (P =.02), angiographic minimum lumen diameter (P =.04), and IVUS minimum (P =.01) and mean (P =.01) lumen area. Multivariate predictors of late cardiac events were diabetes (hazard ratio 2.69, P =.014) and minimum lumen area by IVUS (hazard ratio 0.59, P =.015).

CONCLUSIONS

Despite being angiographically silent, LM disease detected by IVUS is an independent predictor of cardiac events and may serve as a marker for such events. These data extend the spectrum of LM disease severity and its relationship to cardiac prognosis in patients undergoing PCI.

Haptoglobin genotype is predictive of major adverse cardiac events in the 1-year period after percutaneous transluminal coronary angioplasty in individuals with diabetes

OBJECTIVE

The goal of this study was to determine whether the haptoglobin (Hp) genotype was predictive of restenosis and major adverse cardiac events (MACEs) after percutaneous transluminal coronary angioplasty (PTCA) in individuals with diabetes.

RESEARCH DESIGN AND METHODS

A consecutive series of 935 diabetic patients treated with oral agents and/or insulin were followed for 1 year after PTCA. The primary study end point was angiographic restenosis, MACEs and secondary study end points were defined as target vessel revascularization, myocardial infarction, and death. Two alleles exist at the Hp gene locus, denoted 1 and 2. The Hp genotype (Hp 1-1, Hp 2-1, or Hp 2-2) was determined by PCR.

RESULTS

In multivariate analysis controlling for all known determinants of outcome after PTCA, we found that the Hp genotype was a highly significant independent predictor of MACEs in the 1-year period after PTCA in individuals with diabetes. This was predominantly due to differences in the risk of myocardial infarction during that period: Hp 1-1, 0 of 129 (0%); Hp 2-1, 20 of 424 (4.7%); and Hp 2-2, 32 of 382 (8.4%); P < 0.0001.

CONCLUSIONS

The Hp genotype seems to be highly predictive of adverse cardiac events, particularly myocardial infarction, in the 1-year period after PTCA. Determination of the Hp genotype may be useful in the evaluation of new therapies to reduce cardiovascular risk after PTCA.

Long-term clinical benefits of a platelet glycoprotein IIb/IIIa receptor blocker, abciximab (ReoPro), in high-risk diabetic patients undergoing percutaneous coronary intervention

BACKGROUND

High-risk percutaneous coronary interventions (PCIs) are associated with a high complication rate, a low procedural success rate and a high restenosis rate, especially in diabetics. We sought to determine whether abciximab (ReoPro) therapy affects long-term clinical outcomes of Korean patients with diabetes undergoing high-risk PCI.

METHODS

One hundred and nineteen patients with 152 lesion sites were administered ReoPro among 2,231 patients who underwent PCI at Chonnam National University Hospital from March 1999 to Feb 2001. These 119 patients were divided into two groups, 30 were allocated to a diabetic group (Group 1, 57.7 +/- 8.2 years, 22 male), and 89 to a non-diabetic group (Group II, 59.6 +/- 10.8 years, 68 male). Early and long-term clinical outcomes after PCI were analyzed.

RESULTS

In terms of clinical diagnosis, the number of acute myocardial infarctions in Group I was 25 (83.3%) and 76 in Group II (85.4%). As for risk factors, target artery lesions, and ACC/AHA types, no differences were found between the two groups. The number of patients with total occlusion was 21 (55.3%) and 62 (53.9%), and the number with a thrombus-containing lesion was 28 (93.3%) and 88 (98.9%) in Groups I and II, respectively. The procedure was successful in 27 (90.0%) in Group I, and in 80 (89.9%) in Group II, and no differences were evident between the two groups in terms of bleeding complications. No major adverse cardiac events (MACE), including myocardial infarction, repeat revascularization or cardiac death, were observed in Group I, but 8 cases of MACE occurred in Group II during hospitalization. Clinical follow-up was performed in 116 patients (97.5%) over 18.5 +/- 6.7 (5-28) months. The number of overall MACEs was 10 (3.3%) in Group I and 14 (15.7%) in Group II (p = 0.038).

CONCLUSION

ReoPro used in high-risk PCI in diabetics was effective in terms of early clinical outcomes, but its long-term clinical benefits were not proven.

Predictive value of myocardial tomoscintigraphy in asymptomatic diabetic patients after percutaneous coronary intervention

OBJECTIVE

This study was designed to assess the prognostic value of myocardial tomoscintigraphy perfusion imaging after percutaneous coronary intervention (PCI) in asymptomatic diabetic patients.

METHODS

One hundred and fourteen diabetic patients were followed up during 27+/-16 (mean+/-SD) months after the myocardial tomoscintigraphy. PCI-related events were studied after myocardial tomoscintigraphy stress testing and included major cardiac events (MACE) (cardiovascular death, myocardial infarction) and revascularization (bypass surgery or new PCI). Stress myocardial tomoscintigraphy imaging was performed 5+/-5 months after PCI and ischemia was considered as present if at least 2 contiguous segments were showing reversible defects.

RESULTS

Persistent silent ischemia was found in 49/114 (43%) patients. No difference was observed between the two groups for MACE: four among the 65 (6%) non ischemic patients versus 2 among the 49 (4%) ischemic patients (NS). In contrast, 15 (31%) among the ischemic patients and 4 (6%) among the non ischemic patients underwent iterative revascularization (p<0.01). The relative risk of revascularization for patients with significant ischemia was 5.5 versus non ischemic patients (p<0.001).

CONCLUSION

After PCI, in asymptomatic diabetic patients followed by myocardial tomoscintigraphy a high frequency of persistent silent ischemia was found and associated with a high risk for repeat interventional procedure, although no increase in major cardiac events was observed.

Underuse of evidence-based treatment modalities in diabetic patients with non-ST elevation acute coronary syndrome. A prospective nation wide study on acute coronary syndrome (FINACS)

This study was designed to evaluate how new treatment guidelines of acute coronary syndrome (ACS) without ST elevation have been implemented in clinical practice especially in diabetic patients. A prospective follow-up was performed on 501 consecutive patients with suspected ACS without ST elevation admitted to nine hospitals in Finland between 15 January and 11 March 2001. The study group included 143 (29%) diabetic patients. Their risk profile was more severe than in non-diabetic patients; ST-depression on admission electrocardiography 57 versus 38%; P<0.0001, elevated troponin levels 66 versus 56%; P<0.05. Six months composite incidence of death, new myocardial infarction (MI), refractory angina or readmission for unstable angina was 39% in diabetic patients and 20% in non-diabetic patients (P<0.0001). In spite of this more severe risk profile, glycoprotein (GP) IIb/IIIa receptor antagonists and statins were used with similar frequency in non-diabetic and diabetic patients (15 vs. 19 and 48 vs. 54%, respectively; P=NS for both). In diabetic patients mean delay for in hospital coronary angiography was longer (6.4 vs. 4.2 days, P<0.05) and it was performed less often (32 vs. 45% P<0.05). Our results show that diabetic patients with ACS have higher risk profile and worse outcome than non-diabetic patients. Despite their indisputable benefits in diabetic patients, statins, GP IIb/IIIa receptor antagonists and invasive strategy were underused or often neglected. Further education is needed to change attitudes and to better implement new guidelines into clinical practice.

The platelet in diabetes: focus on prevention of ischemic events

Accelerated atherosclerosis and the increased risk of thrombotic vascular events in diabetes may result from dyslipidemia, endothelial dysfunction, platelet hyperreactivity, an impaired fibrinolytic balance, and abnormal blood flow. There is also a correlation between hyperglycemia and cardiovascular (CV) events. The importance of platelets in the atherothrombotic process has led to investigation of using antiplatelet agents to reduce CV risk. A meta-analysis conducted by the Antiplatelet Trialists' Collaboration demonstrated that aspirin reduced the risk of ischemic vascular events as a secondary prevention strategy in numerous high-risk groups, including patients with diabetes. Based on results from placebo-controlled randomized trials, the American Diabetes Association recommends low-dose enteric-coated aspirin as a primary prevention strategy for people with diabetes at high risk for CV events. Clopidogrel is recommended if aspirin allergy is present. There is occasionally a need for an alternative to aspirin or for additive antiplatelet therapy. Aspirin in low doses inhibits thromboxane production by platelets but has little to no effect on other sites of platelet reactivity. Agents such as ticlopidine and clopidogrel inhibit ADP-induced platelet activation, whereas the platelet glycoprotein (Gp) IIb/IIIa complex receptor antagonists block activity at the fibrinogen binding site on the platelet. These agents appear to be useful in acute coronary syndromes (ACSs) in diabetic and nondiabetic patients. A combination of clopidogrel plus aspirin was more effective than placebo plus standard therapy (including aspirin) in reducing a composite CV outcome in patients with unstable angina and non-ST segment elevation myocardial infarction. In a meta-analysis of six trials in diabetic patients with ACSs, intravenous GpIIb-IIIa inhibitors reduced 30-day mortality when compared with control subjects. Results from controlled prospective clinical trials justify the use of enteric-coated low-dose aspirin (81-325 mg) as a primary or secondary prevention strategy in adult diabetic individuals (aged >30 years) at high risk for CV events. Recent studies support the use of clopidogrel in addition to standard therapy, as well as the use of GpIIb-IIIa inhibitors in ACS patients.

Effect of diabetes on the mortality risk of cardiogenic shock in a community-based population

OBJECTIVE

To examine the mortality of diabetic vs nondiabetic patients with anterior myocardial infarction (AMI) among the subsets of this population who did and did not develop cardiogenic shock.

PATIENTS AND METHODS

The study population consisted of a consecutive series of 1263 Olmsted County, Minnesota, patients admitted to the coronary care unit at the Mayo Clinic in Rochester, Minn, between January 1, 1988, and July 31, 2000. Of these patients, 73 met the criteria for cardiogenic shock during their hospitalization. In-hospital and postadmission mortality were compared between diabetic and nondiabetic patients within the cardiogenic shock and nonshock patient groups, respectively.

RESULTS

In patients with AMI and cardiogenic shock, diabetes was associated with a trend for increased in-hospital mortality (odds ratio, 2.82; 95% confidence interval [CI], 0.90-9.92; P = .08). In 73 patients with cardiogenic shock, estimated survival at 1, 3, and 5 years was 25%, 17%, and 17%, respectively, for diabetic patients, and 50%, 44%, and 36%, respectively, for nondiabetic patients (P = .046). The association between diabetic patients and increased long-term mortality was stronger in patients with cardiogenic shock than in patients without cardiogenic shock (adjusted relative risk, 2.08; 95% CI, 1.11-3.90; P = .02). In diabetic patients without cardiogenic shock, estimated survival at 1, 3, and 5 years was low, at 75%, 61%, and 45%, respectively, compared with 83%, 76%, and 69%, respectively, for nondiabetic patients (adjusted relative risk, 1.29; 95% CI, 1.02-1.62; P = .03).

CONCLUSION

The presence of diabetes as a comorbidity in patients with AMI appears to be associated with increased mortality compared with nondiabetic patients, and this relationship may be potentially magnified in patients who develop cardiogenic shock.

Impact of diabetes mellitus on angiographically silent coronary atherosclerosis

Constrictive remodeling occurs in significant atherosclerotic lesions of the diabetic patient, but the impact of diabetes mellitus (DM) on the angiographically normal coronary artery is still unclear. Morphometric analysis using intravascular ultrasound (IVUS) prior to intervention evaluated 54 sites in 33 DM patients and 106 in 62 non-diabetic patients. Vessel area (VA) and lumen area (LA) were measured at angiographically normal sites in the vessel. Plaque area (PA) was calculated as VA - LA. Percentage plaque area (%PA) was calculated as PA VA. Even in the angiographically normal site, mild coronary atherosclerosis was detected by IVUS in both groups. In the patients with DM, VA and LA were significantly smaller than in the non-diabetic patient (15.5 vs 17.8 mm(2), p<0.01; and 10.1 vs 12.2 mm(2), p<0.01 respectively), whereas % PA was similar (34.5 vs 31.6%). At angiographically normal sites where mild coronary atherosclerosis is detected by IVUS, the coronary artery of diabetic patients is smaller than that of the non-diabetic. These results suggest impaired compensatory enlargement or some other constrictive mechanism has already occurred in the early stages of coronary atherosclerosis in patients with DM.

Impact of restenosis and disease progression on clinical outcome after multivessel stenting in diabetic patients

Clinical outcome after percutaneous coronary intervention (PCI) is significantly worse in diabetic patients in comparison to nondiabetic patients. The subset of diabetic patients in the ARTS trial treated with multivessel stenting had the lowest 1-year event-free survival. We examined our experience of multivessel PCI in diabetics to assess clinical outcome outside clinical trials and to determine if repeat revascularizations are the result of restenosis or the progression of nontreated disease. Between January 2000 and December 2001, we performed multivessel PCI in 99 diabetic patients. Our group was well matched with those in the ARTS trial, with mean age of 69 +/- 8 years, male sex 70%, hypertension 68%, hypercholesterolemia 51%, and mean LV ejection fraction 60%. The mean number of diseased segments treated was 2.8 +/- 0.9 and 56% of the patients had three-vessel disease. There were 2.3 +/- 0.6 stents implanted per patient. Target vessels included the LAD in 90%, LCx in 77%, and the RCA in 87% of cases. The in-hospital MACE rate was 8%, which included eight nonfatal MI but no deaths or repeat revascularizations. After a mean follow-up of 14 +/- 8 months, there were 4 deaths (4%), no further MIs, and 21 (21%) repeat revascularizations (2 CABG; 19 PCI), giving a 1-year event-free survival of 67%. There were 18 repeat revascularizations (2 CABG; 16 PCI) for restenosis, but in 9 of the 18 (50%) patients treatment was also required for progression of disease. Three further patients had PCI for symptomatic disease progression without restenosis. Thus, disease progression contributed to 57% of repeat revascularization procedures. The medium- and longer-term success of multivessel PCI in diabetic patients is limited principally by the need for repeat revascularization. However, it is important to realize that these revascularizations are performed not only for restenosis but also for disease progression in more than 50% of patients. Consequently, even if drug-eluting stent technology can eliminate restenosis, disease progression will continue to impact the clinical outcome of diabetic patients after PCI.

Intravascular ultrasound observations of atherosclerotic lesion formation and restenosis in patients with diabetes mellitus

Coronary artery disease is more aggressive in diabetic patients than in nondiabetics; they have more diffuse disease, higher mortality rates and worse clinical outcomes after coronary interventions. Intravascular ultrasound (IVUS) produces transmural tomographic images of the coronary arteries in vivo. Recent IVUS studies have provided new insights into the mechanisms of stenosis formation and restenosis in both nondiabetic and diabetic patients. Arterial remodeling is defined as a change in arterial area. During atherogenesis, an increase in arterial area usually accompanies plaque accumulation to delay lumen compromise. Stenosis formation is related to: (a) the rate of plaque accumulation versus the rate of positive remodeling; and (b) the limits and ultimate failure of positive remodeling. However, there is a marked variability in remodeling. IVUS studies have suggested that remodeling may be impaired in some diabetic patients during atherogenesis. Following non-stent catheter-based interventions, serial (post-intervention and follow-up) IVUS studies have shown that the change in lumen area correlates better with the change in arterial area (remodeling) than with the change in plaque area (neointimal hyperplasia). In some patients, a positive remodeling response mitigates against the increase in plaque area to limit late lumen loss and restenosis. Neointimal hyperplasia is exaggerated in diabetic patients. Despite this, there is a reduced frequency of positive remodeling, potentially similar to the impaired positive remodeling in some diabetic patients during atherogenesis. Failed or inadequate arterial remodeling may contribute to the pathogenesis and natural history of atherosclerotic coronary artery disease in diabetic patients.

Diabetes mellitus is associated with a shift in the temporal risk profile of inhospital death after percutaneous coronary intervention: an analysis of 25,223 patients over 20 years

BACKGROUND

Numerous studies have demonstrated that patients with diabetes have higher rates of restenosis, late myocardial infarction, and late death after percutaneous coronary interventions (PCI). However, it remains unclear whether patients with diabetes mellitus also have an increased hazard for early death after either elective or urgent PCI.

METHODS

Patients undergoing PCI at the Mid American Heart Institute between 1980 and 1999 were identified. The main end point was inhospital death. Patients were stratified both by diabetes status and whether they underwent elective or urgent PCI.

RESULTS

There were 17,341 nondiabetic patients and 4308 patients with diabetes who underwent elective PCI. There were 2946 nondiabetic patients and 628 patients with diabetes who underwent urgent PCI. Multivariate analysis demonstrated that diabetes was associated with increased inhospital mortality rate after any PCI (odds ratio 1.4, 95% CI 1.1-1.8, P =.003). The unadjusted inhospital mortality rates for the nondiabetic patients and patients with diabetes were 0.8% and 1.4%, respectively (P <.001), after elective PCI. The mortality rate was 6.9% for the nondiabetic patients and 12.7% for the patients with diabetes (P <.001) after urgent PCI. The inhospital mortality rates among diabetic patients appear to be decreasing over time among the elective cohort (elective PCI diabetes-time interaction, P =.007) but not in the urgent cohort (urgent PCI-diabetes-time interaction, P =.68).

CONCLUSIONS

There has been an improvement in the inhospital survival rate among patients with diabetes in the elective PCI cohort. This improved hospital survival has yet to be realized among patients with diabetes undergoing urgent PCI.

Impairment of myocardial protection in type 2 diabetic patients

Diabetic patients are more prone to develop postinfarction complications. It remained unclear whether diabetes mellitus- or sulfonylureas-associated changes of ATP-sensitive potassium (K(ATP)) channels, an integral player in ischemic preconditioning, are responsible for the increased mortality. The purpose of this study was to determine the impact of diabetes mellitus per se and different sulfonylurea administration on cardioprotective effects in diabetic patients undergoing coronary angioplasty. Myocardial ischemia after coronary angioplasty was evaluated in 20 nondiabetic and 23 diabetic patients chronically taking either glibenclamide or glimepiride. Nondiabetic patients treated with glimepiride significantly lowered the ischemic burden assessed by an ST-segment shift, chest pain score, and myocardial lactate extraction ratios compared with the glibenclamide-treated patients, implying that acute administration of glimepiride did not abolish cardioprotection. In the diabetic glibenclamide-treated group, the reduction in the ST-segment shift afforded by nicorandil in the first inflation (-58% vs. the first inflation in the glibenclamide group alone) was similar to that afforded by preconditioning (-59% during the second vs. the first inflation). In glimepiride-treated groups, the magnitude of attenuated lactate production was less in diabetes than that in nondiabetes at the second inflation, suggesting that diabetes mellitus per se plays a role in determining lactate production. Our results show that both diabetes mellitus and sulfonylureas can act in synergism to inhibit activation of K(ATP) channels in patients undergoing coronary angioplasty. The degree of inhibition assessed by metabolic and electrocardiographic parameters is less severe during treatment with glimepiride than with glibenclamide. Restitution of a preconditioning response in glimepiride-treated patients may be the potential beneficial mechanism.

Five-year angiographic outcome in patients without restenosis following coronary balloon angioplasty: a comparison between non diabetic and diabetic lesions

Few studies have investigated the long-term angiographic outcome of successful coronary balloon angioplasty (CBA) among diabetic and nondiabetic dilated lesions. The purpose of this study was to evaluate and compare the long-term (>5 years) outcomes of diabetic and nondiabetic CBA lesions which had remained patent 3-12 months after intervention. Twenty-five patients (45 lesions) with diabetes mellitus and 79 patients (138 lesions) without diabetes mellitus were enrolled as subjects. All patients who underwent CBA without restenosis within 3-12 months of the initial CBA based on follow-up angiographic evaluation were included. Quantitative coronary angiograms performed before, immediately after CBA, during the 3-12-month period (mean 4.1 +/- 1.0 months), and at or after 5 years (mean 6.4 +/- 2.0 years) were compared. There was no significant difference in the reference diameter between nondiabetic and diabetic lesions at any of the four time points studied. The minimum lumen diameter before and immediately after the procedure and at the 3-12-month follow-up did not differ significantly between the two groups. At >5-year follow-up. the minimum lumen diameter was significantly (P = 0.005) decreased in diabetic lesions. Total occlusion occurred in 9% (4/45) of the diabetic lesions compared to only 1%, (1/138) in the nondiabetic lesions (P = 0.007). Diabetic lesions showed significant (P = 0.049) narrowing between the 3-12 month period and >5-year follow-up. Fifty-one percent (18/35) of the nondiseased vessels in the diabetic patients at the time of enrollment had new stenosis during the follow-up periods. In conclusion, compared to nondiabetic lesions, patients with diabetic lesions who underwent CBA were more predisposed to have stenotic progression and total occlusion.

[Recanalization of chronic coronary occlusions]

Recanalization of occluded coronary arteries is the aim of percutaneous interventions with acute myocardial infarction. Moreover, chronic coronary occlusion is a common finding during diagnostic coronary angiography and is often a contributing factor in the choice of revascularisation by surgery rather than by percutaneous coronary interventions (PCI). An occluded coronary artery with some degree of collateral supply is functionally comparable to a severe coronary stenosis. Therefore, recanalization of chronic occluded coronary arteries results in less angina and often in improvement of left ventricular function. Success is limited in particular in longer lasting occlusions. Characterization of lesions, where recanalization can performed successfully is warranted. We correlated primary success rates of attempted coronary recanalizations with localisation of lesions and procedural characteristics. We analyzed records of 124 consecutive patients, who underwent attempted coronary recanalization of chronically occluded coronary arteries at our institution in 1998. Revascularisation was successful in 84 (64 male, 20 female) of 124 (92 male, 32 female) patients. Therefore, success rate was 67.7% (69.9% in men, 62.5% in women, p = 0.42). Target vessel was the left anterior descending artery (LAD) in 49 cases. Success rate in the LAD did not differ significantly from that in "non-LAD"-vessels (65.3% versus 69.3%; p = 0.35). Successful recanalizations were performed using only one guide-wire in 77.3%. More than one guide-wires were used during procedures without success in 44.5% and exceeded use in successful interventions (p < 0.05). Procedures, failing to be successful after an attempt with a first guide-wire, could be performed successfully using at least a second wire in 50%. Coronary stenting after recanalization has been performed in 84.4% in the LAD and in 59.7% in non-LAD vessels (p < 0.01). Success rate of attempted recanalizations of chronic occluded coronary arteries in unselected patients is high. Most procedures can be performed successfully using only one guidewire. Additional use of other wires can increase success rates in procedures with primary failure to pass the occlusion. Stenting has been performed in three out of four patients with successful recanalization of chronically occluded coronary arteries.

Comparison of in-hospital and one-year outcomes in patients with and without diabetes mellitus undergoing percutaneous catheter intervention (from the National Heart, Lung, and Blood Institute Dynamic Registry)

Extrapolation of improvements in percutaneous coronary intervention (PCI) and outcomes to patients with diabetes has not been systematically examined in clinical practice. Two waves of consecutive patients (n = 4,629) who underwent PCI from July 1997 to June 1999 enrolled in the National Heart, Lung, and Blood Institute Dynamic Registry comprise the study population. There were 1,058 patients with treated diabetes and 3,571 patients without clinically evident diabetes. As a group, patients with diabetes tended to have more clinical, angiographic, and procedural risk factors. Although crude in-hospital mortality rates were higher in patients with diabetes (diabetics 2.3%, nondiabetics 1.3%; p = 0.02), the adjusted risk of in-hospital death (odds ratio 1.46, 95% confidence interval [CI] 0.80 to 2.66) was not significantly different. At 1 year, patients with diabetes had a significantly higher adjusted risk of mortality (risk ratio [RR] 1.80, 95% CI 1.35 to 2.41) and need for repeat revascularization (RR 1.40, 95% CI 1.13 to 1.74). There was a significant interaction between stent use and diabetic status with the need for repeat revascularization (adjusted RR in nondiabetics 0.73, 95% CI 0.61 to 0.88; adjusted RR in patients with diabetes 1.20, 95% CI 0.88 to 1.65). Beta blockers at the time of hospital discharge were significantly associated with reduced mortality rates at 1 year in both groups.