Revascularization Strategies in Patients with Diabetes Mellitus and Acute Coronary Syndrome

Diabetes Mellitus in Acute Coronary Syndrome

The global prevalence of diabetes mellitus (DM) has led to a pandemic, with significant microvascular and macrovascular complications including coronary artery disease (CAD), which worsen clinical outcomes and cardiovascular prognosis. Patients with both acute coronary syndrome (ACS) and DM have worse prognosis and several pathophysiologic mechanisms have been implicated including, insulin resistance, hyperglycemia, endothelial dysfunction, platelet activation and aggregations as well as plaque characteristics and extent of coronary lesions. Therefore, regarding reperfusion strategies in the more complex anatomies coronary artery bypass surgery may be the preferred therapeutic strategy over percutaneous coronary intervention while both hyperglycemia and hypoglycemia should be avoided with closed monitoring of glycemic status during the acute phase of myocardial infraction. However, the best treatment strategy remains undefined. Non-insulin therapies, due to the low risk of hypoglycemia concurrently with the multifactorial CV protective effects, may be proved to be the best treatment option in the future. Nevertheless, evidence for the beneficial effects of glucagon like peptide-1 receptor agonists, dipeptidyl-peptidase 4 inhibitors and sodium glycose cotransporter 2 inhibitors, despite accumulating, is not robust and future randomized control trials may provide more definitive data.

Pioglitazone inhibits oxidative stress, MMP-mediated inflammation and vascular dysfunction in high glucose-induced human saphenous vein grafts

AIMS

The aim of this study was to investigate the effects of pioglitazone on reactive oxygen species (ROS), expressions/activities of MMPs and TIMP-2, and VSMC proliferation and vascular reactivity in high glucose (HG)-induced human saphenous vein (HSV) grafts.

METHODS

HSV grafts (n = 10) obtained from patients undergoing CABG were incubated with 30 mM glucose and/or 10 μM pioglitazone or 0.1 % DMSO for 24 h after endothelium removal. ROS levels were examined by chemiluminescence assay, MMP-2,-9,-14, TIMP-2, and α-SMA expression/activity was determined by gelatine zymography/immunohistochemistry. Vascular reactivity to potassium chloride, noradrenaline, serotonin, prostaglandin F_2α and papaverine was assessed in HSVs.

RESULTS

HG induced superoxide anion (SA) (123 %) and other ROS levels (159 %), up-regulated MMP-2 expression (180 %)/activity (79 %), MMP-14 expression (24 %) and MMP-9 activity while down-regulating TIMP-2 expression (27 %). HG elevated total MMP-2/TIMP-2 ratio (483 %) and MMP-14/TIMP-2 ratio (78 %). However, HG plus pioglitazone inhibited SA (30 %) and other ROS levels (29 %), down-regulated MMP-2 expression (76 %)/activity (83 %), MMP-14 expression (38 %) and MMP-9 activity, while reversing TIMP-2 expression (44 %). HG plus pioglitazone decreased total MMP-2/TIMP-2 ratio (91 %) and MMP-14/TIMP-2 ratio (59 %). HG impaired contractions to all agents but pioglitazone improved them.

CONCLUSIONS

Pioglitazone may contribute to the prevention of restenosis and maintaining vascular function in HSV grafts of DM patients undergoing CABG.

Relationship between lipoprotein(a) and revascularization after percutaneous coronary intervention in type 2 diabetes mellitus patients with acute coronary syndrome

BACKGROUND

As a residual risk factor for coronary heart disease, lipoprotein(a) [Lp(a)] is associated with the occurrence of cardiovascular events after percutaneous coronary intervention (PCI). The revascularization rate after PCI is high among diabetic patients. However, the relationship between Lp(a) and revascularization after PCI in type 2 diabetes mellitus (T2DM) patients with acute coronary syndrome (ACS) remains unclear.

METHODS

The investigation was a single-center, observational, retrospective cohort study. Patients with T2DM who were first diagnosed with ACS and underwent PCI were included in the study. As a result, 362 patients were enrolled and divided into three groups according to tertiles on basis of Lp(a) levels (11.48 mg/dL and 21.70 mg/dL). The incidence of major adverse cardiac events (MACEs), including cardiac death, revascularization due to myocardial ischemia, readmission due to angina, and nonfatal stroke, was evaluated. Subgroups were established according to the low-density lipoprotein cholesterol (LDL-C) level (70 mg/dL).

RESULTS

During follow-up (median: 2.0 years), 69 MACEs occurred, and 76.81% of these patients underwent revascularization. The Lp(a) level in the MACE group was significantly higher than that in the non-MACE group (22.90 mg/dL vs. 14.10 mg/dL, p < .001). Kaplan-Meier analysis revealed that the incidence of adverse cardiovascular events was significantly higher in the high Lp(a) groups than in the low Lp(a) groups (p = .001), mainly because of the increased occurrence of revascularization irrespective of LDL-C level (<70 mg/dL; ≥70 mg/dL, both p < .05) rather than death, nonfatal stroke, or hospital readmission due to angina (both p > .05). The receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) for Lp(a) in predicting the occurrence of MACE and revascularization were 0.664 and 0.668 respectively, both p < .05. Furthermore, multivariate Cox regression models indicated that Lp(a) was independently associated with revascularization [medium Lp(a) category: HR (95% CI): 2.988 (1.164-7.671), p = .023; high Lp(a) category: HR (95% CI): 4.937 (2.023-12.052), p < .001].

CONCLUSION

Lp(a) was an independent predictor of revascularization in patients with ACS complicated with T2DM, regardless of LDL-C levels. This suggests that Lp(a) measurement may help identify high-risk diabetic patients with ACS.

Coronary Revascularization for Patients with Diabetes Mellitus: A Contemporary Systematic Review and Meta-Analysis

OBJECTIVE

This systematic review and meta-analysis aims to review the contemporary literature comparing CABG and PCI in diabetic patients providing an up-to-date perspective on the differences between the interventions.

BACKGROUND

Diabetes is common and diabetic patients are at a 2-to-4-fold increased risk of developing coronary artery disease. Approximately 75% of diabetic patients die of cardiovascular disease. Previous literature has identified CABG as superior to PCI for revascularization in diabetic patients with complex coronary artery diseas.

METHODS

PubMed and Medline were systematically searched for articles published from January 1, 2015 to April 15, 2021. This systematic review included all retrospective, prospective, and randomized trial studies comparing CABG and PCI in diabetic patients. 1552 abstracts were reviewed and 25 studies were included in this review. The data was analyzed using the RevMan 5.4 software.

RESULTS

Diabetic patients undergoing CABG experienced significantly reduced rates of 5-year mortality, major adverse cardiovascular and cerebrovascular events, myocardial infarction, and required repeat revascularization. Patients who underwent PCI experienced improved rates of stroke that trended toward significance.

CONCLUSIONS

Previous literature regarding coronary revascularization in diabetic patients has consistently demonstrated superior outcomes for patients undergoing CABG over PCI. The development of 1st and 2nd generation DES have narrowed the gap between CABG and PCI, but CABG continues to be superior. Continued investigation with large randomized trials and retrospective studies including long term follow-up comparing CABG and 2nd generation DES is necessary to confirm the optimal intervention for diabetic patients.

Expression and regulation of tumor necrosis factor-α-induced protein-8-like 2 is associated with acute lung injury induced by myocardial ischemia reperfusion in diabetic rats

AIMS

The purpose of the present study was to investigate the possible role of TIPE2 on acute lung injury (ALI) induced by myocardial ischemia/reperfusion (MIR) in diabetic rats.

METHODS

Sprague-Dawley (SD) rats were randomly separated into four groups: control+sham (C + sham); control+MIR (C + MIR); diabetes+sham (D + sham); diabetes+MIR (D + MIR). Diabetes was induced using streptozotocin. Eight weeks after diabetes induction, MIR was conducted. At 2 h after MIR, myocardial injury indices were assessed; arterial blood, bronchoalveolar lavage fluid (BALF) and lung tissues were collected for corresponding detection.

RESULTS

Rats subjected to MIR showed serious ALI (estimated via pathological changes, lung injury score and Wet/Dry weight ratio), lung inflammation and pulmonary cell apoptosis compared with sham groups, especially in D + MIR group. Evaluation of protein expression in lung tissues showed that p-JNK and nuclear NF-κB p65 protein levels were higher in D + MIR group as compared with C + MIR group. Besides, either hyperglycemia or MIR can significantly upregulate TIPE2 protein levels.

CONCLUSIONS

In conclusion, diabetic lungs are more susceptible to MIR. TIPE2 may involve in this pathological process, possibly through regulation of inflammation, oxidative stress and apoptosis.

Prognostic value of hyperglycemia on-admission in diabetic versus non-diabetic patients presenting with ST-elevation myocardial infarction in Tunisia

BACKGROUND

Hyperglycemia on-admission is a powerful predictor of adverse events in patients presenting for ST-elevation myocardial infarction (STEMI).

AIM

In this study, we sought to determine the prognostic value of hyperglycemia on-admission in Tunisian patients presenting with STEMI according to their diabetic status.

METHODS

Patients presenting to our center between January 1998 and September 2014 were enrolled. Hyperglycemia was defined as a glucose level ≥11mmol/L. In-hospital prognosis was studied in diabetic and non-diabetic patients. The predictive value for mortality of glycemia level on-admission was assessed by mean of the area under receiver operating characteristic (ROC) curve calculation.

RESULTS

A total of 1289 patients were included. Mean age was 60.39±12.8years and 977 (77.3%) patients were male. Prevalence of diabetes mellitus was 70.2% and 15.2% in patients presenting with and without hyperglycemia, respectively (p<0.001). In univariate analysis, hyperglycemia was associated to in-hospital death in diabetic (OR: 8.85, 95% CI: 2.11-37.12, p<0.001) and non-diabetic patients (OR: 2.57, 95% CI: 1.39-4.74, p=0.002). In multivariate analysis, hyperglycemia was independently predictive of in-hospital death in diabetic patients (OR: 9.6, 95% CI: 2.18-42.22, p=0.003) but not in non-diabetic patients (OR: 1.93, 95% CI: 0.97-3.86, p=0.06). Area under ROC curve of glycemia as a predictor of in-hospital death was 0.792 in diabetic and 0.676 in non-diabetic patients.

CONCLUSION

In patients presenting with STEMI, hyperglycemia was associated to hospital death in diabetic and non-diabetic patients in univariate analysis. In multivariate analysis, hyperglycemia was independently associated to in-hospital death in diabetic but not in non-diabetic patients.

[Poly(ADP-ribose) polymerases-1 inhibitor MRL-45696 alleviates DNA damage after myocardial ischemia-reperfusion in diabetic rats]

OBJECTIVE

To study the protective effect of MRL-45696, an inhibitor of poly(ADP-ribose) polymerase-1 (PARP-1), against DNA damage after myocardial ischemia/reperfusion (I/R) in diabetic rats.

METHODS

Rat models of type 2 diabetes mellitus were established by high-fat feeding and a single peritoneal dose of streptozotocin. Forty diabetic rats were randomized equally into diabetic group, sham-operated group, sham-operated group with MRL-45696 treatment, I/R injury model group and I/R injury group with MRL-45696 treatment. The rats in MRL-45696-treated groups were subjected to daily intragastric administration of MRL-45696 (50 mg/kg) for 7 consecutive days, after which sham operation was performed or myocardial I/R injury was induced by ligation of the left anterior descending coronary artery for 30 min followed by reperfusion for 120 min. The range of myocardial infarction, plasma cardiac troponin I (cTnI), serum creatine kinase (CK), lactate dehydrogenase (LDH) activity, malondialdehyde (MDA), superoxide dismutase (SOD) activity, and cardiac myocyte apoptosis were detected. The levels of γ-H2AX, cleaved caspase-3, PARP-1, and PAR were detected with Western blotting, and the level of NAD was detected using colorimetry.

RESULTS

The infarct size was significantly smaller in MRL-45696 treatment group than in I/R injury group (P < 0.05). In I/R model group, the levels of cTnI, CK, and LDH in the plasma or serum and MDA, γ-H2AX, cleaved caspase-3 and apoptotic rate in the cardiac myocytes were significantly higher than those in the other groups (P < 0.05), and SOD activity was significantly decreased (P < 0.05). Compared with I/R model group, the rats with MRL- 45696 treatment showed significantly decreased levels of cTnI, CK, LDH, MDA, γ-H2AX, cleaved caspase-3, PARP- 1, PAR expression and cell apoptosis with significantly increased levels of SOD and NAD (P < 0.05).

CONCLUSIONS

MRL-45696 can inhibit excessive activation of PARP-1, increase intracellular level of NAD and inhibit cardiac myocyte apoptosis to alleviate myocardial I/R-induced DNA damage and reduce myocardial infarct size in diabetic rats.

Revascularization for patients with diabetes mellitus and stable ischemic heart disease: an update

PURPOSE OF REVIEW

To provide an update on the management of patients with diabetes mellitus and requiring coronary revascularization.

RECENT FINDINGS

Evidence continues to show that patients with diabetes mellitus and ischemic heart disease represent a very high-risk group of patients. Choice of stent appears important for minimizing target lesion and target vessel adverse events with everolimus eluting stents having the best performance, particularly in patients being treated with insulin. The higher risk of adverse angioplasty results in patients with diabetes appears most related to the disease state per se and not necessarily to anatomical complexities. Interestingly, physiologic documentation of nonischemia producing lesions with use of fractional flow reserve appears less reassuring in this setting of aggressive and rapid atherosclerosis progression, particularly if myocardial infarction has occurred previously, than in patients without diabetes. Coronary artery bypass surgery in patients with appropriate anatomy and diabetes continues to emerge in many analyzes as the optimal, long-term therapy.

IMPLICATIONS

The treatment of diabetes per se, advances in stent technology and optimization of coronary artery bypass techniques are all occurring in parallel making it very critical for the design of modern era trials that keep pace with these advances. Currently, in patients with appropriate anatomy who are willing candidates, bypass surgery remains the optimal, long-term therapeutic option.

The Roles of Autophagy in Acute Lung Injury Induced by Myocardial Ischemia Reperfusion in Diabetic Rats

Patients with diabetes are vulnerable to myocardial ischemia reperfusion (IR) injury, which may also induce acute lung injury (ALI) due to overaccumulation of reactive oxygen species (ROS) and inflammation cytokine in circulation. Despite autophagy plays a significant role in diabetes and pulmonary IR injury, the role of autophagy in ALI secondary to myocardial IR in diabetes remains largely elusive. We aimed to investigate pulmonary autophagy status and its roles in oxidative stress and inflammation reaction in lung tissues from diabetic rats subjected to myocardial IR. Control or diabetic rats were either treated with or without autophagy inducer rapamycin (Rap) or autophagy inhibitor 3-methyladenine (3-MA) before myocardial IR, which was achieved by occluding the left anterior descending coronary artery for 30 min and followed by reperfusion for 120 min. Diabetic rats subjected to myocardial IR showed more serious ALI with higher lung injury score and WET/DRY ratio and lower PaO₂ as compared with control rats, accompanied with impaired autophagy indicated by reduced LC-3II/LC-3I ratio and Beclin-1 expression, decreased superoxide dismutase (SOD) activity, and increased 15-F2t-Isoprostane formation in lung tissues, as well as increased levels of leukocyte count and proinflammatory cytokines in BAL fluid. Improving autophagy with Rap significantly attenuated all these changes, but the autophagy inhibitor 3-MA exhibited adverse or opposite effects as Rap. In conclusion, diabetic lungs are more vulnerable to myocardial IR, which are involved in impaired autophagy. Improving autophagy could attenuate ALI induced by myocardial IR in diabetic rats, possibly through inhibiting inflammatory reaction and oxidative stress.

Inhibitory effects of ASP6537, a selective cyclooxygenase-1 inhibitor, on thrombosis and neointima formation in rats

INTRODUCTION

Percutaneous coronary interventions (PCIs), such as balloon angioplasty and stent placement, are effective in the treatment of coronary artery disease. PCI has drawbacks, however, including acute thrombosis after the procedure and restenosis of the vascular lumen due to abnormal neointimal hyperplasia. ASP6537 is a selective COX-1 inhibitor that has been investigated as a possible candidate for clinical development as an antiplatelet agent. In the present study, we evaluated the in vivo antithrombotic effect of ASP6537 and its effect on neointima formation after balloon angioplasty.

MATERIAL AND METHODS

The antithrombotic effect of ASP6537 was examined using an arteriovenous shunt thrombosis model in rats while the effect of ASP6537 on neointima formation was evaluated in a rat carotid arterial balloon angioplasty model.

RESULTS

In the thrombosis study, ASP6537 dose-dependently decreased the protein content of the thrombus, while no prolongation of template bleeding time was observed. In the neointima study, ASP6537 reduced neointima formation.

CONCLUSIONS

ASP6537 may be a promising agent for the prevention of acute thrombosis and restenosis after PCI in place of aspirin.

Stent fracture is associated with a higher mortality in patients with type-2 diabetes treated by implantation of a second-generation drug-eluting stent

Type 2 diabetes correlates with clinical events after the implantation of a second-generation drug-eluting stent (DES). The rate and prognostic value of stent fracture (SF) in patients with diabetes who underwent DES implantation remain unknown. A total of 1160 patients with- and 2251 without- diabetes, who underwent surveillance angiography at 1 year after DES implantation between June 2004 and August 2014, were prospectively studied. The primary endpoints included the incidence of SF and a composite major adverse cardiac event [MACE, including myocardial infarction (MI), cardiac death, and target-vessel revascularization (TVR)] at 1-year follow-up and at the end of follow-up for overall patients, and target lesion failure [TLF, including cardiac death, target vessel myocardial infarction (TVMI) and target lesion revascularization (TLR)] at the end of study for SF patients. In general, diabetes was associated with a higher rate of MACE at 1-year (18.4 vs. 12.9%) and end of follow-up (24.0 vs. 18.6%, all p < 0.001), compared with those in patients who did not have diabetes. The 1-year SF rate was comparable among patients with diabetes (n = 153, 13.2%) and non-diabetic patients (n = 273, 12.1%, p > 0.05). Diabetic patients with SF had a 2.6-fold increase of SF-related cardiac death at the end of study and threefold increase of re-repeat TLR when compared with non-diabetic patients with SF (5.9 vs. 2.2%, p = 0.040; 6.5 vs. 2.2%, p = 0.032), respectively. Given the fact that diabetes is correlated with increased MACE rate, SF in diabetic patients translates into differences in mortality and re-repeat TLR compared with the non-diabetic group.