Diabetes mellitus: a prothrombotic state implications for outcomes after coronary revascularization

Diabetes Mellitus and Clinical Outcomes in Carotid Artery Revascularization Using Second-Generation, MicroNet-Covered Stents: Analysis from the PARADIGM Study

INTRODUCTION

Carotid artery stenting (CAS) using conventional (single-layer) stents is associated with worse clinical outcomes in diabetes mellitus (DM) vs. non-DM patients: an effect driven largely by lesion-related adverse events. CAS outcomes with MicroNet-covered stents (MCS) in diabetic patients have not been evaluated.

AIM

To compare short- and long-term clinical outcomes and restenosis rate in DM vs. non-DM patients with carotid stenosis treated using MCS.

MATERIALS AND METHODS

In a prospective study in all-comer symptomatic and increased-stroke-risk asymptomatic carotid stenosis, 101 consecutive patients (age 51-86 years, 41% diabetics) underwent 106 MCS-CAS. Clinical outcomes and duplex ultrasound velocities were assessed periprocedurally and at 30 days/12 months.

RESULTS

Baseline characteristics of DM vs. non-DM patients were similar except for a higher prevalence of recent cerebral symptoms in DM. Type 1 and type 1+2 plaques were more prevalent in DM patients (26.7% vs. 9.8%, p = 0.02; 62.2% vs. 37.7%, p = 0.01). Proximal embolic protection was more prevalent in DM (60% vs. 36%; p = 0.015). 30-day clinical complications were limited to a single periprocedural minor stroke in DM (2.4% vs. 0%, p = 0.22). 12-month in-stent velocities and clinical outcomes were not different (death rate 4.8% vs. 3.3%; p = 0.69; no new strokes). Restenosis rate was not different (0% vs. 1.7%, p = 0.22).

CONCLUSIONS

MCS may offset the adverse impact of DM on periprocedural, 30-day, and 12-month clinical complications of CAS and minimize the risk of in-stent restenosis. In this increased-stroke-risk cohort, adverse event rate was low both in DM and non-DM. Further larger-scale clinical datasets including extended follow-ups are warranted.

Diabetes and atherothrombosis: The circadian rhythm and role of melatonin in vascular protection

Obesity-related euglycaemic insulin resistance clusters with cardiometabolic risk factors, contributing to the development of both type 2 diabetes and cardiovascular disease. An increased thrombotic tendency in diabetes stems from platelet hyperactivity, enhanced activity of prothrombotic coagulation factors and impaired fibrinolysis. Furthermore, a low-grade inflammatory response and increased oxidative stress accelerate the atherosclerotic process and, together with an enhanced thrombotic environment, result in premature and more severe cardiovascular disease. The disruption of circadian cycles in man secondary to chronic obesity and loss of circadian cues is implicated in the increased risk of developing diabetes and cardiovascular disease. Levels of melatonin, the endogenous synchronizer of circadian rhythm, are reduced in individuals with vascular disease and those with deranged glucose metabolism. The anti-inflammatory, antihypertensive, antioxidative and antithrombotic activities of melatonin make it a potential therapeutic agent to reduce the risk of vascular occlusive disease in diabetes. The mechanisms behind melatonin-associated reduction in procoagulant response are not fully known. Current evidence suggests that melatonin inhibits platelet aggregation and might affect the coagulation cascade, altering fibrin clot structure and/or resistance to fibrinolysis. Large-scale clinical trials are warranted to investigate the effects of modulating the circadian clock on insulin resistance, glycaemia and cardiovascular outcome.

Type-2 diabetes mellitus and cardiovascular disease

The global prevalence of diabetes has risen in adults from 4.7% in 1980 to 8.5% in 2014. 90–95% of adults with diabetes have Type 2 diabetes (T2D). This paper focuses on the diagnosis and treatment of T2D patients who have or are at risk for cardiovascular disease. Hyperglycemia, insulin resistance and excess fatty acids increase oxidative stress, disrupt protein kinase C signaling and increase advanced glycation end-products that result in vascular inflammation, vasoconstriction, thrombosis and atherogenesis. Intensive T2D treatment produces a ≥10% risk reduction in major macrovascular and microvascular events. Glucose-lowering therapies must be individualized. Metformin is an optimal drug for monotherapy. If hemoglobin A1c is not at goal, a sodium-glucose cotransporter-2 inhibitor or a dipeptidyl peptidase-4 inhibitor should be considered for therapy with metformin. Coronary angioplasty/stenting is recommended for diabetic patients with acute myocardial infarctions. Coronary artery bypass grafting is recommended for symptomatic diabetic patients with multivessel disease.

Comparison of clinical outcomes after drug-eluting stent implantation in diabetic versus nondiabetic patients in China: A retrospective study

Diabetes mellitus (DM) has been proved to be a predictor of adverse outcomes after percutaneous coronary intervention (PCI). Drug-eluting stents (DESs) could reduce the adverse events in DM patients. In this study, we aimed to analyze the clinical outcome after DES implantation in diabetic versus nondiabetic patients in China. Totally, 200 Chinese DM patients and 400 Chinese non-DM patients were enrolled in this retrospective study. Compared with non-DM patients, DM patients were more likely to have a higher incidence of cardiac death (3.5% vs. 1.0%, P = .048), stent thrombosis (2.5% vs. 0.5%, P = .044), target lesion revascularization (6.0% vs. 1.8%, P = .005), target vessel failure (15.5% vs. 8.0%, P < .001), target lesion failure (14.0% vs. 4.3%, P < .001), myocardial infarction (4.5% vs. 1.5%, P = .030), and major adverse cardiac events (12.5% vs. 5.0%, P = .001) at 2-year follow-up. However, the incidence of target vessel revascularization (7.5% vs. 5.5%, P = .340) was similar between DB and non-DB patients. Patients with DB (hazard ratio [HR] = 2.54, P = .001), older than 80 years (HR = 1.33, P = .027) with hypercholesterolemia (HR = 1.03, P < .001), serum creatinine >177 μmol/L (HR = 3.04, P = .011), a history of cerebral vascular accident (HR = 4.29, P = .010), or a history of myocardial infarction (HR = 31.4, P < .001) were more likely to experience adverse events. In China, DM could also be served as an independent predictor of adverse outcomes after DES implantation. These patients should be reexamined more frequently.

A case report of very late stent thrombosis observed simultaneously in all three vessels 5 years after sirolimus-eluting stent implantation

A 67-year-old man with recent myocardial infarction underwent a total of five sirolimus-eluting stents (SES) implantation for three vessels stage by stage. A follow-up angiography showed no significant restenosis except one in the side branch. Thereafter, he had remained asymptomatic. Sixty-six months later, he had an acute myocardial infarction with cardiogenic shock due to simultaneous 3-vessel very late stent thrombosis (VLST). After successful percutaneous coronary intervention, final angiography revealed serious peri-stent contrast staining along with positive remodeling and grade V stent fracture. This rare case illustrates simultaneous 3-vessel VLST, associating with multiple SES-related problems, under continuation of aspirin and cilostazol.

Increased atherothrombotic burden in patients with diabetes mellitus and acute coronary syndrome: a review of antiplatelet therapy

Patients with diabetes mellitus presenting with acute coronary syndrome have a higher risk of cardiovascular complications and recurrent ischemic events when compared to nondiabetic counterparts. Different mechanisms including endothelial dysfunction, platelet hyperactivity, and abnormalities in coagulation and fibrinolysis have been implicated for this increased atherothrombotic risk. Platelets play an important role in atherogenesis and its thrombotic complications in diabetic patients with acute coronary syndrome. Hence, potent platelet inhibition is of paramount importance in order to optimise outcomes of diabetic patients with acute coronary syndrome. The aim of this paper is to provide an overview of the increased thrombotic burden in diabetes and acute coronary syndrome, the underlying pathophysiology focussing on endothelial and platelet abnormalities, currently available antiplatelet therapies, their benefits and limitations in diabetic patients, and to describe potential future therapeutic strategies to overcome these limitations.

Addressing cardiovascular risk in patients with type 2 diabetes: focus on primary care

Type 2 diabetes is a disorder of glucose and lipid metabolism associated with increased risk of macrovascular and microvascular complications. The primary focus of treating type 2 diabetes is glycemic control; simultaneous management of cardiometabolic risk factors, including blood pressure, lipid profile and overweight/obesity, has been shown to improve outcomes. All patients with diabetes require individualized combination therapy including diet and exercise intervention to help prevent microvascular and macrovascular complications. Because primary care physicians in the United States provide the majority of care for patients with type 2 diabetes, this article discusses the management of cardiovascular risk with a specific focus on primary care. In addition, mechanisms by which existing and novel antidiabetes therapies may modulate the metabolic pathways and a review of the benefits of cardiovascular risk reduction using multifactorial, primary care-focused intervention strategies will be discussed. Finally, early- and late-stage disease management strategies are discussed.

The Management of Antiplatelet Therapy in Patients With Coronary Stents Undergoing Noncardiac Surgery

Whereas the development of coronary stents has been a major breakthrough in the treatment of coronary artery disease, stent thrombosis, associated with myocardial infarction and death, has introduced a new challenge in the care of patients with coronary stents undergoing noncardiac surgery. This review presents the authors’ recommendations regarding the optimal management of such patients. Elective surgery should be postponed for at least 6 weeks and optimally 3 months for a bare-metal stent and at least 1 year for a drug-eluting stent. On the other hand, managing a patient undergoing non-elective surgery is more difficult and necessitates a case-by-case assessment of bleeding risk versus thrombotic risk based on patient comorbidities, type of stents present, details of the coronary intervention, and type of surgical procedure. Patients with a risk of bleeding that outweighs the risk of stent thrombosis should discontinue at least clopidogrel, whereas all other patients should continue dual antiplatelet therapy throughout the perioperative period.

Clinical importance of aspirin and clopidogrel resistance

Aspirin and clopidogrel are important components of medical therapy for patients with acute coronary syndromes, for those who received coronary artery stents and in the secondary prevention of ischaemic stroke. Despite their use, a significant number of patients experience recurrent adverse ischaemic events. Interindividual variability of platelet aggregation in response to these antiplatelet agents may be an explanation for some of these recurrent events, and small trials have linked "aspirin and/or clopidogrel resistance", as measured by platelet function tests, to adverse events. We systematically reviewed all available evidence on the prevalence of aspirin/clopidogrel resistance, their possible risk factors and their association with clinical outcomes. We also identified articles showing possible treatments. After analyzing the data on different laboratory methods, we found that aspirin/clopidogrel resistance seems to be associated with poor clinical outcomes and there is currently no standardized or widely accepted definition of clopidogrel resistance. Therefore, we conclude that specific treatment recommendations are not established for patients who exhibit high platelet reactivity during aspirin/clopidogrel therapy or who have poor platelet inhibition by clopidogrel.