Diabetic endovascular disease: role of coronary artery revascularization

Long-term outcomes of peripheral arterial disease patients with significant coronary artery disease undergoing percutaneous coronary intervention

Background

Patients with peripheral arterial disease (PAD) have known to a high risk of cardiac mortality. However, the effectiveness of the routine evaluation of coronary arteries such as routine coronary angiography (CAG) in PAD patients receiving percutaneous transluminal angioplasty (PTA) is unclear.

Methods

A total of 765 consecutive PAD patients underwent successful PTA and 674 patients (88.1%) underwent routine CAG. Coronary artery disease (CAD) was defined as angiographic stenosis ≥70%. Patients were divided into three groups; 1) routine CAG and a presence of CAD (n = 413 patients), 2) routine CAG and no CAD group (n = 261 patients), and 3) no CAG group (n = 91 patients). To adjust for any potential confounders that could cause bias, multivariable Cox-proportional hazards regression and propensity score matching (PSM) analysis was performed. Clinical outcomes were evaluated by Kaplan-Meier curved analysis at 5-year follow-up.

Results

In this study, the 5-year survival rate of patients with PAD who underwent PTA was 88.5%. Survival rates were similar among the CAD group, the no CAD group, and the no CAG group, respectively (87.7% vs. 90.4% vs. 86.8% P = 0.241). After PSM analysis between the CAD group and the no CAD group, during the 5-year clinical follow-up, there were no differences in the incidence of death, myocardial infarction, strokes, peripheral revascularization, or target extremity surgeries between the two groups except for repeat PCI, which was higher in the CAD group than the non-CAD group (9.3% vs. 0.8%, P<0.001).

Conclusion

PAD patients with CAD were expected to have very poor long-term survival, but they are shown no different long-term prognosis such as mortality compared to PAD patients without CAD. These PAD patients with CAD had received PCI and/or optimal medication treatment after the CAG. Therefore a strategy of routine CAG and subsequent PCI, if required, appears to be a reasonable strategy for mortality risk reduction of PAD patients. Our results highlight the importance for evaluation for CAD in patients with PAD.

MicroRNA-24 regulates vascular remodeling via inhibiting PDGF-BB pathway in diabetic rat model

PURPOSE

Hyperglycemia is the high risk factor of vascular remodeling induced by angioplasty, and neointimal hyperplasia is strongly implicated in the pathogenesis of vascular remodeling caused by carotid artery balloon injury. Studies have shown that MicroRNA 24 (miR-24) plays an important role in angiocardiopathy, However, the role of miR-24 is far from thorough research. In this study, we investigate whether up-regulation of miR-24 by using miR-24 recombinant adenovirus (Ad-miR-24-GFP) can inhibit PDGF-BB signaling pathway and attenuate vascular remodeling in the diabetic rat model.

METHODS

Male Sprague-Dawley rats (n = 60) were randomly divided into 5 groups and fed with high sugar and high fat diet (Sham, Saline, Scramble, Ad-miR-24 groups), or ordinary diet (Control group). The front four groups were treated with streptozotocin (STZ) four weeks later and the blood glucose level was closely monitored. After the successful establishment of diabetic rats, the external carotid artery was injured by pressuring balloon 1.5 after internal carotid artery ligation, then the blood vessels were harvested 14 days later and indexes were detected including the following: HE staining for the level of vascular intima thickness, immunohistochemical detection for PCNA and P27 to test the proliferative degree of vascular smooth muscle cells (VSMCs), qRT-PCR for the level of miR-24, RAS,PDGF-R, western blot for the protein levels of JNK1/2, p- JNK1/2, ERK1/2, p-ERK1/2, RAS, PDGF-R, AP-1,P27 and PCNA. Serological detection was conducted for TNF-α, IL-6, IL-8.

RESULTS

The delivery of Ad-miR-24 into balloon injury site has significantly increased the level of miR-24. Up-regulation of miR-24 could regulate vascular remodeling effectively, lower the level of inflammatory factors, inhibit the expression of mRNA and protein levels of JNK1/2, ERK1/2, RAS, PDGF-R, AP-1, P27, PCNA.

CONCLUSION

miR-24 can inhibit the expression of AP-1 via the inhibition of PDGF-BB signaling pathway, thus inhibit VSMCs proliferation and vascular remodeling.

Thrombin Receptor Protease-Activated Receptor 4 Is a Key Regulator of Exaggerated Intimal Thickening in Diabetes Mellitus

Background—

Diabetes mellitus predisposes to thrombotic and proliferative vascular remodeling, to which thrombin contributes via activation of protease-activated receptor (PAR) 1. However, the use of PAR-1 inhibitors to suppress remodeling may be limited by severe bleeding. We recently reported upregulation of an additional thrombin receptor, PAR-4, in human vascular smooth muscle cells exposed to high glucose and have now examined PAR-4 as a novel mediator linking hyperglycemia, hypercoagulation, and vascular remodeling in diabetes mellitus.

Methods and Results—

PAR-4 expression was increased in carotid atherectomies and saphenous vein specimens from diabetic versus nondiabetic patients and in aorta and carotid arteries from streptozotocin-diabetic versus nondiabetic C57BL/6 mice. Vascular PAR-1 mRNA was not increased in diabetic mice. Ligated carotid arteries from diabetic mice developed more extensive neointimal hyperplasia and showed greater proliferation than arteries from nondiabetic mice. The augmented remodeling response was absent in diabetic mice deficient in PAR-4. At the cellular level, PAR-4 expression was controlled via the mRNA stabilizing actions of human antigen R, which accounted for the stimulatory actions of high glucose, angiotensin II, and H 2 O 2 on PAR-4 expression, whereas cicaprost via protein kinase A activation counteracted this effect.

Conclusions—

PAR-4 appears to play a hitherto unsuspected role in diabetic vasculopathy. The development of PAR-4 inhibitors might serve to limit mainly proliferative processes in restenosis-prone diabetic patients, particularly those patients in whom severe bleeding attributed to selective PAR-1 blockade or complete thrombin inhibition must be avoided or those who do not require anticoagulation.

Randomized trial of insulin versus usual care in reducing restenosis after coronary intervention in patients with diabetes. the STent Restenosis And Metabolism (STREAM) study

BACKGROUND

Diabetes status is an independent marker of restenosis after percutaneous coronary intervention (PCI). Previous studies suggest that metabolic abnormalities associated with diabetes increase stent restenosis by promoting intimal hyperplasia. Preclinical studies have indicated that insulin therapy reduces intimal hyperplasia. The objective of this study was to determine whether insulin-mediated glucose lowering reduces in-stent restenosis in patients with diabetes undergoing PCIs.

METHODS

We conducted a prospective, randomized, multicenter, open-labeled study with blinded outcomes. Patients were randomized 1:1 to daily bedtime subcutaneous NPH insulin (Novo Nordisk) versus usual therapy with oral hypoglycemic agents. The main outcomes were change in volume of intimal hyperplasia within the stent measured by intravascular ultrasound and late lumen loss by quantitative coronary angiography at 6 months post-PCI.

RESULTS

Seventy-eight patients (36 insulin, 42 usual care) were randomized. Eight patients in each group received drug-eluting stents. The insulin group achieved greater reductions in both glycosylated hemoglobin A1c (mean±S.D.) (insulin: 8.0%±1.2% to 6.7%±0.7% vs. control: 7.5%±1.2% to 7.1%±1.0 %, P=.0038) and fasting glucose (insulin: 9.3±3.8 to 5.8±1.7 vs. usual care: 8.4±2.4 to 7.7±2.0 mmol/l, P<.0001). There were no hypoglycemic events. At 6 months, there were no significant differences in either intravascular-ultrasound-determined neointimal volume (insulin: 41.2±38.9 vs. usual care: 48.4±40.2 mm(3), P=.33) or late lumen loss by angiography (insulin: 1.29±0.74 mm vs. usual care: 1.02±0.71 mm, P=.17).

CONCLUSIONS

Addition of a single bedtime dose of insulin in patients with diabetes does not influence in-stent restenosis.

Choosing a revascularization strategy in patients with diabetes and stable coronary artery disease: a complex decision

Diabetes mellitus is associated with well-known increases in cardiovascular morbidity and mortality. In diabetics with stable coronary artery disease, the best therapeutic option is widely discussed. Current studies comparing surgical to percutaneous revascularization have been unable to definitely demonstrate any significant advantage of one strategy over the other regarding the prevention of cardiac death or acute myocardial infarction. Therefore, even taking into account clinical and angiographic information as well as the risks determined by each type of treatment, the decision regarding the best therapeutic strategy in diabetics with stable coronary artery disease is still complex.

Hypotheses, rationale, design, and methods for prognostic evaluation in type 2 diabetic patients with angiographically normal coronary arteries. The MASS IV-DM Trial

Background

The MASS IV-DM Trial is a large project from a single institution, the Heart Institute (InCor), University of São Paulo Medical School, Brazil to study ventricular function and coronary arteries in patients with type 2 diabetes mellitus.

Methods/Design

The study will enroll 600 patients with type 2 diabetes who have angiographically normal ventricular function and coronary arteries. The goal of the MASS IV-DM Trial is to achieve a long-term evaluation of the development of coronary atherosclerosis by using angiograms and coronary-artery calcium scan by electron-beam computed tomography at baseline and after 5 years of follow-up. In addition, the incidence of major cardiovascular events, the dysfunction of various organs involved in this disease, particularly microalbuminuria and renal function, will be analyzed through clinical evaluation. In addition, an effort will be made to investigate in depth the presence of major cardiovascular risk factors, especially the biochemical profile, metabolic syndrome inflammatory activity, oxidative stress, endothelial function, prothrombotic factors, and profibrinolytic and platelet activity. An evaluation will be made of the polymorphism as a determinant of disease and its possible role in the genesis of micro- and macrovascular damage.

Discussion

The MASS IV-DM trial is designed to include diabetic patients with clinically suspected myocardial ischemia in whom conventional angiography shows angiographically normal coronary arteries. The result of extensive investigation including angiographic follow-up by several methods, vascular reactivity, pro-thrombotic mechanisms, genetic and biochemical studies may facilitate the understanding of so-called micro- and macrovascular disease of DM.

Drug-eluting stents: a comprehensive appraisal

Cardiovascular medicine has evolved over the last few decades, with the advent of percutaneous interventional treatments. In particular, balloon angioplasty and, subsequently, coronary stenting has revolutionized our current perspective of stable and unstable coronary artery disease management. However, the long-term results of stent usage have been blighted by the dual problems of in-stent restenosis and stent thrombosis. Whilst stent thrombosis became much less frequent with the introduction of dual-antiplatelet therapy, restenosis remained a significant problem. Intense work on stent development has successfully led to the introduction of drug-eluting stents (DES) in an effort to address this problem. Randomized trials have consistently proven the superior efficacy of DES over bare metal stents, in elective patients, acute coronary syndromes and patients with diabetes mellitus. Nevertheless, the routine use of DES in by-pass venous graft disease remains debatable. The initial DES used sirolimus and paclitaxel are now being joined by newer stents releasing drugs, such as everolimus, zotarolimus and tacrolimus. Ongoing developments with the stent platform and the polymer coating are also gradually improving the performance of these stents in clinical practice. More recently, the idea of antibody-coated stents that would encourage epithelialization of stent struts by endothelial progenitor cells recruitment has gained attraction among interventionists, with a possible beneficial impact on reducing the incidence of restenosis.

[Update on interventional cardiology]

Percutaneous intervention, whether coronary or noncoronary, continues to be a highly active area of medicine. This article contains an overview of the most notable developments reported in recent months. Drug-eluting stents (DESs) have provided one of the major advances in interventional cardiology as they have very effectively reduced the restenosis rate. Both randomized clinical trials and large observational studies have confirmed their safety, and their use has been extended to include highly complex conditions. Although thrombosis is one complication that can affect both conventional stents and DESs, the rate of late stent thrombosis is slightly, though significantly, higher with DESs. Primary angioplasty is the treatment of choice for patients with acute myocardial infarction if carried out under appropriate conditions, within a reasonable time period in a specialized center by experienced personnel. Use of thrombectomy devices can improve procedural outcomes and it appears that DES implantation is safe and effective, though more data are still needed. In patients with non-ST-elevation acute coronary syndrome, early treatment using an invasive approach coupled to the administration of various combinations of antiplatelet and antithrombotic drugs continues to be fundamental. Although left main coronary artery lesions are generally treated surgically, advances in percutaneous techniques and the use of DESs mean that an increasing number of patients are being treated using percutaneous coronary interventions. A number of studies have shown good results in other lesions and in high-risk patients with, for example, bifurcation lesions, chronic occlusions or diabetes. Intracoronary ultrasound is the predominant intracoronary diagnostic technique and it can be used to assist in optimizing DES implantation. In addition, measurement of the fractional flow reserve is helpful in evaluating the severity of moderate lesions whereas the high-resolution images provided by optical coherence tomography are particularly informative. Multislice computed tomography enables the presence of coronary artery disease to be ruled out and the technique is also useful as a complementary tool for interventional cardiologists. Research into regenerative techniques is promising but remains experimental at present. With regard to noncoronary interventions, new data have become available that support the use of a percutaneous approach in patients with patent foramen ovale. In addition, clinical experience with percutaneous aortic valve replacement, via either the transfemoral or transapical route, is increasing.

Optimal revascularization strategy for diabetic patients with multivessel coronary artery disease: the duel between old hero and young warrior

Given the results of the BARI and ARTS I trials and a meta-analysis, coronary artery bypass surgery has been preferred to percutaneous coronary intervention in diabetics with multivessel coronary artery disease requiring hypoglycemic treatment and in whom internal mammary artery grafts can be used. This approach was strongly recommended in a 2002 ACC/AHA Task Force on the management of patients with acute coronary syndrome. But, these recommendations were made before the availability of drug-eluting stents. We strongly believe that the ongoing, multi-centre FREEDOM, CARDia and SYNTAX trials will elucidate the optimal revascularization strategy for diabetic patients with multivessel disease in the near future.

Comparison of effectiveness and safety of sirolimus-eluting stents versus bare-metal stents in patients with diabetes mellitus (from the Italian Multicenter Randomized DESSERT Study)

Few studies directly compared drug-eluting stents and bare-metal stents (BMSs) in diabetic patients. DESSERT was an Italian multicenter randomized trial to show the efficacy of sirolimus-eluting stents (SESs) compared with BMSs in de novo lesions of diabetic patients treated with insulin and/or oral antidiabetics for > or =3 months on top of glycoprotein IIb/IIIa inhibitors. The primary end point was in-stent late lumen loss, assessed using centralized quantitative coronary angiography at 8-month follow-up. Centrally adjudicated composite major adverse cardiac events (MACEs) and target-vessel failure (TVF; death, treated vessel-related acute myocardial infarction, and target-vessel revascularization) at 30 days and 9 and 12 months were secondary end points. Seventy-five patients were randomly assigned to an SES (109 lesions), and 75 (109 lesions), to a BMS. The 2 groups were well balanced for clinical, anatomic, and procedural characteristics. In-stent late lumen loss decreased from 0.96 +/- 0.61 mm for BMSs to 0.14 +/- 0.33 for SESs (p <0.001), and in-segment binary restenosis was 38.8% versus 3.6%, respectively (p <0.001). Twelve-month clinical events were significantly lower in the sirolimus group: MACEs 22.1% versus 40% (p = 0.023), target-lesion revascularization 5.9% versus 30% (p <0.001), and TVF 14.7% versus 34.3% (p = 0.008). At multivariate analysis, stent type was confirmed as an independent predictor of in-segment late loss (p <0.001), binary restenosis (p <0.001), 12-month TVF (p = 0.010), and 12-month MACEs (p = 0.037). In conclusion, the randomized DESSERT showed SESs to be safe and effective in decreasing both angiographic parameters of restenosis and incidence of MACEs compared with BMSs in diabetic patients with de novo 1- or 2-vessel coronary stenoses.

Long-Term Mortality After Percutaneous Coronary Intervention With Drug-Eluting Stent Implantation Versus Coronary Artery Bypass Surgery for the Treatment of Multivessel Coronary Artery Disease

Background— Although previous studies have compared the treatment effects of percutaneous coronary intervention and coronary artery bypass grafting (CABG), the long-term outcomes beyond 1 year among patients with multivessel coronary artery disease who underwent percutaneous coronary intervention with drug-eluting stents (DES) or CABG have not been evaluated.

Methods and Results— Between January 2003 and December 2005, 3042 patients with multivessel disease underwent coronary implantation of DES (n=1547) or CABG (n=1495). The primary end point was all-cause mortality. In a crude analysis, the rate of long-term mortality was significantly higher in patients who underwent CABG than in those who underwent DES implantation (3-year unadjusted mortality rate, 7.0% for CABG versus 4.4% for percutaneous coronary intervention; P =0.01). However, after adjustment for baseline differences, the overall risks of death were similar among all patients (hazard ratio, 0.85; 95% confidence interval [CI], 0.56 to 1.30; P =0.45), diabetic patients (hazard ratio, 1.76; 95% CI, 0.82 to 3.78; P =0.15), and patients with compromised ventricular function (hazard ratio, 1.39; 95% CI, 0.41 to 4.65; P =0.60). In the anatomic subgroups, mortality benefit with DES implantation was noted in patients with 2-vessel disease with involvement of the nonproximal left anterior descending artery (hazard ratio, 0.23; 95% CI, 0.01 to 0.78; P =0.016). The rate of revascularization was significantly higher in the DES than in the CABG group (hazard ratio, 2.81; 95% CI, 2.11 to 3.75; P <0.001).

Conclusions— For the treatment of multivessel coronary artery disease, percutaneous coronary intervention with DES implantation showed equivalent long-term mortality as CABG.