Anatomy of coronary disease in diabetic patients: an explanation for poorer outcomes after percutaneous coronary intervention and potential target for intervention

Drug-Coated Balloons in the Management of Coronary Artery Disease

Drug-coated balloons (DCBs) are specialized coronary devices comprised of a semicompliant balloon catheter with an engineered coating that allows the delivery of antiproliferative agents locally to the vessel wall during percutaneous coronary intervention. Although DCBs were initially developed more than a decade ago, their potential in coronary interventions has recently sparked renewed interest, especially in the United States. Originally designed to overcome the limitations of conventional balloon angioplasty and stenting, they aim to match or even improve upon the outcomes of drug-eluting stents without leaving a permanent implant. Presently, in-stent restenosis is the condition with the most robust evidence supporting the use of DCBs. DCBs provide improved long-term vessel patency compared with conventional balloon angioplasty and may be comparable to drug-eluting stents without the need for an additional stent layer, supporting their use as a first-line therapy for in-stent restenosis. Beyond the treatment of in-stent restenosis, DCBs provide an additional tool for de novo lesions for a strategy that avoids a permanent metal scaffold, which may be especially useful for the management of technically challenging anatomies such as small vessels and bifurcations. DCBs might also be advantageous for patients with high bleeding risk due to the decreased necessity for extended antiplatelet therapy, and in patients with diabetes and patients with diffuse disease to minimize long-stented segments. Further studies are crucial to confirm these broader applications for DCBs and to further validate safety and efficacy.

Prognostic Impact of Drug-Coated Balloons in Patients With Diabetes Mellitus: A Propensity-Matched Study

Patients with diabetes mellitus (DM) are at higher risk of restenosis and stent thrombosis after percutaneous coronary intervention (PCI) and drug-eluting stent (DES) positioning. Whether drug-coated balloons (DCB) can offer any benefit in this subset of patients has been seldom cleared out and was the aim of the present propensity-matched cohort study, that compared the prognostic impact of DCB versus DES in patients with DM who underwent PCI. Patients with DM enrolled in the NOvara-BIella-TREnto (NOBITRE) Registry were identified and matched according to propensity score, to a control population of patients with DM treated with DES. The primary study end point was the occurrence of major adverse cardiovascular events (MACEs). A total of 150 patients were identified in the DCB group and matched with 150 DES-treated patients. Patients treated with DCB displayed more often a previous cardiovascular history and received a more complete pharmacological therapy. Target vessel diameter and the percentage of stenosis were lower in patients with DCB, whereas binary in-stent restenosis was more common (p <0.001, p = 0.003, and p <0.001, respectively). Paclitaxel-eluting balloon represented the most common strategy in the DCB group, whereas Zotarolimus-eluting stents were used in half of the DES population. At a median follow-up of 545.5 days, MACE occurred in 54 (19.4%) of patients, with no difference according to the PCI strategy (21.6% vs 17.3%, adjusted hazard ratio [95% confidence interval] 1.51 [0.46 to 4.93], p = 0.50). Major ischemic end points were slightly increased in patients treated with DCB, whereas overall death was significantly reduced (3.6% vs 10.9%; adjusted hazard ratio [95% confidence interval] 0.27 [0.08 to 0.91], p = 0.03). In conclusion, the present propensity-matched study shows that, in patients with DM who underwent PCI for in-stent restenosis or de novo lesions, the use of DCB is associated with a similar rate of MACE and a modest increase in target lesion failure, but a significantly improved survival as compared with DES.

Association of Diabetes Mellitus and Its Types with In-Hospital Management and Outcomes of Patients with Acute Myocardial Infarction

BACKGROUND

Diabetes mellitus (DM) is an important risk factor for adverse outcomes following acute myocardial infarction (AMI), but large-scale studies investigating the differential impact of Type 1 DM (T1DM) and Type 2 DM (T2DM) on AMI outcomes are lacking.

METHODS

All adult discharges for AMI in the National Inpatient Sample (October 2015 to December 2018) were included and stratified into T1DM, T2DM and non-DM (NDM) groups. Outcomes of interests were all-cause mortality, major adverse cardiovascular and cerebrovascular events (MACCE), major bleeding and acute ischemic stroke, as well as invasive management. Binomial hierarchical multilevel multivariable logistic regression with adjusted odds ratios (aOR) and 95 % confidence intervals (95 % CI) was used to investigate the association between DM and its subtypes with the AMI outcomes.

RESULTS

Out of 2,587,615 patients, there were 29,250 (1.1 %) T1DM and 1,032,925 (39.9 %) T2DM patients. After multivariable adjustment, patients with T1DM had increased odds of MACCE (aOR 1.20, 95 % CI 1.09-1.31), all-cause mortality (aOR 1.20, 95 % CI 1.08-1.33) and major bleeding (aOR 1.28, 95 % CI 1.13-1.44), whilst T2DM patients had increased odds of MACCE (aOR 1.03, 95 % CI 1.01-1.05) and ischemic stroke (aOR 1.09, 95 % CI 1.05-1.13), compared to NDM patients. The adjusted odds of receiving percutaneous coronary intervention were lower in both T1DM and T2DM patients (aOR 0.70, 95 % CI 0.66-0.75 and aOR 0.95, 95 % CI 0.94-0.96, respectively), but T2DM patients showed higher utilization of composite percutaneous and surgical revascularization (aOR 1.03, 95 % CI 1.03-1.04) compared to NDM patients.

CONCLUSIONS

DM patients presenting with AMI have worse in-hospital clinical outcomes compared to NDM patients. There are important DM type-related differences with T1DM patients having overall worse outcomes and receiving less overall revascularization.

Type 2 diabetes mellitus and coronary artery stenosis: a risk pattern association study

Aim: Cardiovascular diseases (CVD) are the leading cause of death globally. In the condition of type 2 diabetes mellitus (T2DM), the prevalence of CVD increase parallel with the rise of metabolic complication and higher incidence of coronary artery stenosis. The aim of this study was to compare the level of percent stenosis in coronary arteries in patients with coronary artery disease (CAD) with and without T2DM, and to measure the severity of CVD using Gensini score (GS) through angiographic data. Methods: The current study was conducted in tertiary care specialized hospital in Delhi, India. The level of percent stenosis in coronary arteries was compared in patients with CAD with and without T2DM. The patients were divided into two groups: group I included 100 patients with T2DM, and group II included 100 non-diabetic CAD patients who underwent coronary angiography by Judkin’s technique. The severity of CVD was measured by GS through angiographic data. The serum levels of glycated haemoglobin (HbA1c) ≥ 6.5% were considered diabetic. Results: Significant difference was observed in serum HbA1c, and random blood sugar levels between group I and group II were also observed (P ≤ 0.001). Serum HbA1c shows a significant positive association with GS (r = 0.36, P = 0.007). Conclusions: The study shows a significant level of stenosis in coronary arteries of CAD diabetic patients. However, further prospective analysis of a larger population size will be needed to strengthen the findings and the significant association.

Drug Coated Balloon in the Treatment of De Novo Coronary Artery Disease: A Narrative Review

Drug coated balloons (DCBs) are currently indicated in guidelines as a first choice option in the management of instant restenosis, whereas their use in de novo lesions is still debated. The concerns raised after the contrasting results of the initial trials with DCBs in de novo lesions have been more recently overcome by a larger amount of data confirming their safety and effectiveness as compared to drug-eluting stents (DES), with potentially greater benefits being achieved, especially in particular anatomical settings, as in very small or large vessels and bifurcations, but also in selected subsets of higher-risk patients, where a 'leave nothing behind' strategy could offer a reduction of the inflammatory stimulus and thrombotic risk. The present review aims at providing an overview of current available DCB devices and their indications of use based on the results of data achieved so far.

Glycaemic control in people with diabetes following acute myocardial infarction

Diabetes is a highly prevalent disease associated with considerable cardiovascular end organ damage and mortality. Despite significant changes to the management of acute myocardial infarction over the last two decades, people with diabetes remain at risk of complications and mortality following a myocardial infarct for a multitude of reasons, including increased coronary atherosclerosis, associated coronary microvascular dysfunction, and diabetic cardiomyopathy. Dysglycaemia causes significant endothelial dysfunction and upregulation of inflammation within the vasculature and epigenetic changes mean that these deleterious effects may persist despite subsequent efforts to tighten glycaemic control. Whilst clinical guidelines advocate for the avoidance of both hyper- and hypoglcyaemia in the peri-infarct period, the evidence base is lacking, and currently there is no consensus on the benefits of glycaemic control beyond this period. Glycaemic variability contributes to the glycaemic milieu and may have prognostic importance following myocardial infarct. The use of continuous glucose monitoring means that glucose trends and parameters can now be captured and interrogated, and its use, along with newer medicines, may provide novel opportunities for intervention after myocardial infarction in people with diabetes.

Impact of Diabetes on 10-Year Outcomes Following ST-Segment-Elevation Myocardial Infarction: Insights From the EXAMINATION-EXTEND Trial

Background Long-term outcomes of ST-segment-elevation myocardial infarction in patients with diabetes have been barely investigated. The objective of this analysis from the EXAMINATION-EXTEND (10-Years Follow-Up of the EXAMINATION trial) trial was to compare 10-year outcomes of patients with ST-segment-elevation myocardial infarction with and without diabetes. Methods and Results Of the study population, 258 patients had diabetes and 1240 did not. The primary end point was patient-oriented composite end point of all-cause death, any myocardial infarction, or any revascularization. Secondary end points were the individual components of the primary combined end point, cardiac death, target vessel myocardial infarction, target lesion revascularization, and stent thrombosis. All end points were adjusted for potential confounders. At 10 years, patients with diabetes showed a higher incidence of patient-oriented composite end point compared with those without (46.5% versus 33.0%; adjusted hazard ratio [HR], 1.31 [95% CI, 1.05-1.61]; P=0.016) mainly driven by a higher incidence of any revascularization (24.4% versus 16.6%; adjusted HR, 1.61 [95% CI, 1.19-2.17]; P=0.002). Specifically, patients with diabetes had a higher incidence of any revascularization during the first 5 years of follow-up (20.2% versus 12.8%; adjusted HR, 1.57 [95% CI, 1.13-2.19]; P=0.007) compared with those without diabetes. No statistically significant differences were found with respect to the other end points. Conclusions Patients with ST-segment-elevation myocardial infarction who had diabetes had worse clinical outcome at 10 years compared with those without diabetes, mainly driven by a higher incidence of any revascularizations in the first 5 years. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04462315.

Impact of diabetes mellitus on periprocedural and 18-month clinical outcomes in Korean patients requiring rotational atherectomy: results from the ROCK Registry

BACKGROUND

Diabetes mellitus (diabetes) increases the risk of severe coronary artery calcification, which increases the complexity of percutaneous coronary intervention requiring rotational atherectomy (RA) by interfering with lesion preparation, and limiting final stent expansion.

OBJECTIVE

Investigate 30-day and 18-month clinical outcomes in patients with and without diabetes treated with percutaneous coronary intervention requiring RA.

DESIGN

Medical record review SETTING: Multicenter registry in South Korea PATIENTS AND METHODS: The ROtational atherectomy in Calcified lesions in Korea (ROCK) registry was a large, retrospective, multicenter study to assess RA treatment of severe coronary artery calcification.

MAIN OUTCOME MEASURES

The primary endpoint was target-vessel failure including cardiac death, target-vessel myocardial infarction, and target-vessel revascularization.

SAMPLE SIZE

540 patients followed for a median of 16.1 months.

RESULTS

Of the 540 patients, 305 had diabetes (56.5%). The diabetes group had a significantly higher frequency of multivessel disease; comorbidities such as hypertension, dyslipidemia, and chronic kidney disease; and lower ejection fraction of the left ventricle compared to the non-diabetes group (n=235). There were no significant differences in procedure success and complications observed between the two groups. Target vessel failure at 30 days between the diabetes and non-diabetes groups was not statistically significant in a multivariate Cox regression analysis (1.6% vs. 2.6%, adjusted hazard ratio [HR] 0.595, 95% confidence interval [CI] 0.154-2.300, P=.451). During an 18-month follow-up, the risk of target vessel failure was higher (12.5% vs. 8.9%) but the difference was not statistically significant (adjusted HR 1.393, 95% CI 0.782-2.482, P=.260).

CONCLUSIONS

Patients with diabetes have a risk of complications comparable to patients without diabetes, and 30-day and 18-month clinical outcomes are similar in severe coronary artery calcification requiring RA, despite having more comorbidities.

LIMITATIONS

Retrospective design. Sample size not based on power calculation.

CONFLICT OF INTEREST

None.

Impact of Different Measures of Body Size on the Radiation Dose During Coronary Angiography and Percutaneous Coronary Intervention: Results from a Large Single Center Cohort

Efforts to reduce and optimize the radiation exposure during coronary angiography and intervention have pointed at patients' body size as a major determinant of irradiation for the patients and operators. We aimed at comparing body weight and body mass index (BMI) among consecutive patients undergoing angiographic procedures (coronary angiography and/or interventions) in a single center. Patients were divided in normal weight (NW, BMI <25 Kg/m²) and overweight (OW, BMI ≥25 Kg/m²). Patients' dose exposure was evaluated as dose area product (DAP), time of exposure (fluoroscopy duration), and relative DAP (DAP/minutes of exposure). We included 748 patients, 61.6% undergoing percutaneous coronary interventions and 56.8% classified as OW. OW patients were more often men (P < .001), with history of hypertension (P < .001) and diabetes (P = .001). Mean DAP and relative DAP were significantly higher among OW compared with NW patients (P < .001). DAP and relative DAP were directly related with body weight (both r = .22, P < .001); a similar linear association was also described for BMI (r = .18, P < .001 and r = .19, P < .001, respectively). At multivariate analysis, however, body weight, but not BMI, independently predicted the DAP. Therefore, body weight should be considered as the preferred indicator of body size in the setting and optimization of radiation exposure during coronary diagnostic and intervention procedures.

Greater plaque burden and cholesterol content may explain an increased incidence of non-culprit events in diabetic patients: a Lipid-Rich Plaque substudy

AIMS 

Diabetes mellitus (DM) is associated with increased cardiovascular morbidity and mortality. The multicentre, prospective Lipid-Rich Plaque trial (LRP) examined non-culprit (NC) non-obstructive coronary segments with a combined near-infrared spectroscopy (NIRS)-intravascular ultrasound (IVUS) catheter. This study assessed the differences in NC plaque characteristics and their influence on major adverse cardiac events (MACE) in diabetic and non-diabetic patients.

METHODS AND RESULTS 

Patients with known DM status were divided into no diabetes, diabetes not treated with insulin (non-ITDM), and insulin-treated diabetes (ITDM). The association between presence and type of DM and NC-MACE was assessed at both the patient and coronary segment levels by Cox proportional regression modelling. Out of 1552 patients enrolled, 1266 who had their diabetes status recorded were followed through 24 months. Female sex, hypertension, chronic kidney disease, peripheral vascular disease, and high body mass index were significantly more frequent in diabetic patients. The ITDM group had more diseased vessels, at least one NC segment with a maxLCBI4 mm ≥400 in 46.2% of patients, and maxLCBI4 mm ≥400 in nearly one out of six Ware segments (15.2%, 125/824 segments). The average maxLCBI4 mm significantly increased from non-diabetic patients (NoDM) to non-insulin-treated diabetic patients (non-ITDM) to insulin-treated diabetic patients (ITDM; 137.7 ± 161.9, 154.8 ± 173.6, 182.9 ± 193.2, P < 0.001, respectively). In patients assigned to follow-up (692 ± 129 days), ITDM doubled the incidence of NC-MACE compared with the absence of diabetes (15.7% vs. 6.9%, P = 0.0008). The presence of maxLCBI4 mm>400 further increased the NC-MACE rate to 21.6% (Kaplan-Meier estimate).

CONCLUSION 

Cholesterol-rich NC plaques detected by NIRS-IVUS were significantly more frequent in diabetic patients, especially those who were insulin-treated, and were associated with an increased NC-MACE during follow-up.

Autoimmune diseases in patients undergoing percutaneous coronary intervention: A risk factor for in-stent restenosis?

BACKGROUND AND AIMS

Despite the relation between autoimmune diseases and increased atherosclerotic risk is established, the influence of autoimmune disorders on in-stent restenosis (ISR) after percutaneous coronary intervention (PCI) is only partly known. ISR is an aberrant reparative process mainly characterized by an increased number of vascular smooth muscle cells and excessive deposition of extracellular proteoglycans and type III collagen. Chronic inflammation, always present in autoimmune diseases, modulates the endothelial response to PCI. Aim of this review is to resume the current evidence on the association between ISR and autoimmune diseases, focusing on pathogenic mechanisms and therapeutic targets.

METHODS

We conducted a comprehensive review of the literature on the relationship between ISR and insulin-dependent diabetes mellitus (IDDM), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), antiphospholipid-antibodies syndrome (APS), inflammatory bowel diseases (IBD), and Hashimoto's thyroiditis (HT).

RESULTS

Patients affected with IDDM, RA, SLE, APS, IBD and HT proved to face higher rates of ISR compared to the general population. The endothelial dysfunction seems the principal common pathogenic pathway for ISR and is attributed to both the immune system disorder and the systemic inflammation. Some evidence suggested that methotrexate and anti-tumor necrosis factor treatments can be effective in reducing ISR, while antibodies against vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 showed to reduce neointimal hyperplasia in animal models.

CONCLUSIONS

Autoimmune diseases are a risk factor for ISR. The study of the potential cardiovascular benefits of the current therapies, mainly anti-inflammatory drugs, and the pursuit of innovative treatments appear of paramount interest.

Impact of diabetes mellitus on mortality rates and outcomes in myocardial infarction

BACKGROUND

Diabetes mellitus (DM) represents a major cardiovascular risk factor for increased risk of coronary artery disease and myocardial infarction (MI). DM is also associated with a poorer clinical outcome in MI.

MATERIALS AND METHODS

The nationwide German inpatient population treated between 2005 and 2016 was used for statistical analyses. Hospitalized MI patients were stratified by the presence of DM and investigated for the impact of DM on in-hospital events.

RESULTS

In total, 3,307,703 hospitalizations for acute MI (37.6% female patients, 56.8% aged ≥ 70 years) treated in Germany during 2005-2016 were included in this analysis. Of these patients, 410,737 (12.4%) died while in hospital. Overall, 1,007,326 (30.5%) MI cases were coded for DM. While the rate of MI patients with DM increased slightly over time, from 29.8% in 2005 to 30.7% in 2016 (β = 7.04, 95% CI: 4.13-9.94; P <  0.001), their in-hospital mortality decreased from 15.2% to 11.5% (β = -0.36, 95% CI: -0.38 to -0.34; P <  0.001). Rates of in-hospital death (13.2% vs 12.1%; P <  0.001) and recurrent MI (0.8% vs 0.6%; P <  0.001) were higher in MI patients with vs without DM. Also, in MI patients with DM, significantly lower use of coronary artery angiography (51.5% vs 56.8%; P <  0.001) and interventional revascularization (37.6% vs 43.9%; P <  0.001) was noted.

CONCLUSION

Although in-hospital mortality of patients with MI decreased in both diabetes and non-diabetes patients, in-hospital deaths were still higher in diabetes patients, thereby revealing the impact of this metabolic disorder on cardiovascular outcomes.

One-year clinical outcome of biodegradable polymer sirolimus-eluting stent in diabetic patients: Insight from the ULISSE registry (ULtimaster Italian multicenter all comerS Stent rEgistry)

BACKGROUND

The ULISSE registry evaluated the real-world performance of the Ultimaster® biodegradable polymer sirolimus-eluting stent (BP-SES) in a multicenter-independent cohort of patients undergoing percutaneous coronary intervention, including a large proportion of diabetes mellitus (DM) patients.

METHODS

In this subgroup analysis, 1,660 consecutive patients, 2,422 lesions, treated with BP-SES enrolled in the ULISSE registry were divided in two groups: DM (485 patients, 728 lesions) and non-DM (1,175 patients, 1,694 lesions). Primary endpoint was target lesion failure (TLF), a composite endpoint of cardiac-death, target-vessel myocardial infarction (TV-MI), and clinically driven target lesion revascularization (TLR) at 1-year. Secondary endpoint was TLR at 1-year.

RESULTS

At 1-year follow-up TLF occurred in 5% overall patients and was significantly higher in DM patients (8 vs. 3.7%; p = .001), due to more cardiac deaths (3.4 vs. 1.1%; p = .002). TLR occurred in 3.2% overall patients, and it was not significantly higher in DM compared to non-DM patients (4.4 vs. 2.8%; p = .114). The incidence of stent thrombosis was low and similar between groups (0.4 vs. 0.9%; p = .526). Insulin-treated DM (ITDM) patients showed higher rate of TLF as compared to non-ITDM patients (13 vs. 6.5%; p = .041), but similar rate of TLR (6 vs. 4%; p = .405). After adjustment for relevant comorbidities, DM was not significantly associated with TLF or cardiac death in patients undergoing BP-SES implantation.

CONCLUSIONS

This study is the first all-comers evaluation of BP-SES in DM patients. Our findings show that DM patients, mostly those with ITDM, still represent a vulnerable population and experience significantly higher rate of TLF. Overall BP-SES efficacy is considerable, although not statistically significant higher rate of TLR is still present in DM compared to non-DM patients.

Glycaemic Control and Vascular Complications in Diabetes Mellitus Type 2

Diabetes mellitus is constantly increasing worldwide. Vascular complications are the most common in the setting of long-standing disease, claiming the greatest burden in terms of morbidity and mortality. Glucotoxicity is involved in vascular damage through different metabolic pathways, such as production of advanced glycation end-products, activation of protein kinase C, polyol pathway activation and production of reactive oxygen species. Vascular complications can be classified according to the calibre of the vessels involved as microvascular (such as diabetic retinopathy, nephropathy and neuropathy) or macrovascular (such as cerebrovascular, coronary and peripheral artery disease). Previous studies showed that the severity of vascular complications depends on duration and degree of hyperglycaemia and, as consequence, early trials were designed to prove that intensive glucose control could reduce the number of vascular events. Unfortunately, results were not as satisfactory as expected. Trials showed good results in reducing incidence of microvascular complications but coronary heart diseases, strokes and peripheral artery diseases were not affected despite optimal glycemia control. In 2008, after the demonstration that rosiglitazone increases cardiovascular risk, FDA demanded stricter rules for marketing glucose-lowering drugs, marking the beginning of cardiovascular outcome trials, whose function is to demonstrate the cardiovascular safety of anti-diabetic drugs. The introduction of new molecules led to a change in diabetes treatment, as some new glucose-lowering drugs showed not only to be safe but also to ensure cardiovascular benefit to diabetic patients. Empaglifozin, a sodium-glucose cotransporter 2 inhibitor, was the first molecule to show impressing results, followed on by glucagon-like peptide 1 receptor agonists, such as liraglutide. A combination of anti-atherogenic effects and hemodynamic improvements are likely explanations of the observed reduction in cardiovascular events and mortality. These evidences have opened a completely new era in the field of glucose-lowering drugs and of diabetes treatment in particular with respect to vascular complications.

Blood pressure level associated with lowest cardiovascular event in hypertensive diabetic patients

BACKGROUND

The ACCORD BP trial failed to show the benefit of strict blood pressure (BP) control on cardiovascular events in diabetics with high cardiovascular risk. However, this result cannot be generalized to all diabetics. We investigated whether lower mean BP in diabetic people with hypertension is associated with better prognosis.

METHODS

Participants from the Korea National Health Insurance Service Health Examinee Cohort who were diagnosed with diabetes and hypertension between 2003 and 2006 were included in the analysis (N = 7926). Mortality and cardiovascular events were compared among three groups according to mean SBP (<130, 130-<140, ≥140 mmHg) and mean DBP (<80, 80-<90, ≥ 90 mmHg) recorded during follow-up health examinations for up to 11 years.

RESULTS

Significant reductions in the risk of all-cause death, nonfatal myocardial infarction (MI), nonfatal stroke, and end-stage renal disease were observed in patients with a mean SBP of 130 mmHg to less than 140 mmHg, as compared with patients with a mean SBP of at least 140 mmHg. The additional clinical benefit of a mean SBP of less than 130 mmHg was unclear. Lower risk of all-cause death, cardiovascular mortality, and nonfatal strokes was observed in patients with a mean DBP of 80 mmHg to less than 90 mmHg. A mean DBP of less than 80 mmHg was associated with further reduction in all-cause mortality, cardiovascular mortality, ischaemic stroke, and total stroke.

CONCLUSION

A mean BP of less than 140/80 mmHg was associated with further reduction in the risk of all-cause mortality, cardiovascular mortality, and nonfatal cardiovascular events in diabetic hypertensive patients.

The impact of financial crisis on coronary artery disease burden in Greece

BACKGROUND

Economic crisis poses an immense threat to public health worldwide and has been linked to cardiovascular morbidity and mortality. Greece is facing a distinctive recession over the recent years. However, the exact impact on coronary artery disease (CAD) burden has not been adequately addressed.

METHODS

Demographic, clinical, and angiographic data of 3895 hospitalized patients were retrospectively studied. Patients were classified into two groups: those before crisis (2006-2007, n = 1228) and those during crisis (2011-2015, n = 2667).

RESULTS

All data before and during crisis were compared. During crisis, patients presented with less acute coronary syndrome (ACS - 45.5% vs. 39.9%, p < 0.001). Subsequently, there were more patients without CAD (23.7% vs. 35.1%, p < 0.001) or one-vessel disease (20.5% vs. 23%, p < 0.001). The prevalence of traditional risk factors decreased significantly or remained stable except obesity (26.3% vs. 31.4%, p = 0.002). A significant increase in the examined females (23.6% vs. 26.7%, p = 0.04) was also observed.

CONCLUSIONS

The burden of CAD in Greece was partially affected during the financial crisis. Even though the incidence of ACS was decreased, more women and more patients with no- or single-vessel disease were referred for cardiac catheterization. In addition, the prevalence of traditional risk factors for CAD did not increase except obesity confirming the "obesity paradox." It seems that the impact of traditional risk factors for CAD is not an immediate process and is somewhat related to living conditions or other exogenous and social factors.

Challenges in Patients with Diabetes: Improving Clinical Outcomes After Percutaneous Coronary Intervention Through EVOlving Stent Technology

Patients with diabetes have poorer outcomes after percutaneous coronary intervention than patients without diabetes. The Cre8™ EVO drug-eluting stent (DES) has design features that aim to improve clinical outcomes in patients with diabetes. These include Abluminal Reservoir Technology - a proprietary polymer-free drug-release system consisting of reservoirs on the abluminal surface of the stent that control drug release and direct the drug exclusively towards the vessel wall - and the Amphilimus™ drug formulation, which enables enhanced drug-tissue permeation utilising fatty acid transport pathways. The latter is particularly advantageous in patients with diabetes, whose cell metabolism favours increased cellular uptake of fatty acid. Furthermore, evidence suggests that mTOR inhibitors (-limus drugs) utilised in conventional DES are less effective in diabetic cells. The new stent architecture provides high device deliverability and conformability, facilitating clinical use in complex disease patterns and high-risk lesion morphologies. Clinical evidence for the efficacy and safety of the Cre8™ DES in patients with diabetes has been demonstrated in a number of clinical trials and observational registries. These data are reviewed herein, along with an overview of on-going randomised trials.

Stress Perfusion Cardiac Magnetic Resonance Imaging Effectively Risk Stratifies Diabetic Patients With Suspected Myocardial Ischemia

BACKGROUND

Diabetics remain at high risk of cardiovascular disease and mortality despite advancements in medical therapy. Noninvasive cardiac risk profiling is often more difficult in diabetics owing to the prevalence of silent ischemia with unrecognized myocardial infarction, reduced exercise capacity, nondiagnostic electrocardiographic changes, and balanced ischemia from diffuse epicardial coronary atherosclerosis and microvascular dysfunction.

METHODS AND RESULTS

A consecutive cohort of 173 patients with diabetes mellitus (mean age, 61.7±11.9 years; 37% women) with suspected myocardial ischemia underwent stress perfusion cardiac magnetic resonance imaging. Patients were evaluated for adverse cardiac events after cardiac magnetic resonance imaging with mean follow-up time of 2.9±2.5 years. Mean hemoglobin A1c for the population was 7.9±1.8%. Primary end point was a composite of cardiac death and nonfatal myocardial infarction. Diabetics with no inducible ischemia (n=94) experienced an annualized event rate of 1.4% compared with 8.2% (P=0.0003) in those with inducible ischemia (n=79). Diabetics without late gadolinium enhancement or inducible ischemia had a low annual cardiac event rate (0.5% per year). The presence of inducible ischemia was the strongest unadjusted predictor (hazard ratio, 4.86; P<0.01) for cardiac death and nonfatal myocardial infarction. This association remained robust in adjusted stepwise multivariable Cox regression analysis (hazard ratio, 4.28; P=0.02). In addition, categorical net reclassification index using 5-year risk cutoffs of 5% and 10% resulted in reclassification of 43.4% of the diabetic cohort with net reclassification index of 0.38 (95% confidence interval, 0.20-0.56; P<0.0001).

CONCLUSIONS

Stress perfusion cardiac magnetic resonance imaging provided independent prognostic utility and effectively reclassified risk in patients with diabetes mellitus referred for ischemic assessment. Further evaluation is required to determine whether a noninvasive imaging strategy with cardiac magnetic resonance imaging can favorably affect downstream outcomes and improve cost-effectiveness of care in diabetics.

Coronary triglyceride deposition in contemporary advanced diabetics

It is of importance to clarify pathophysiology of diabetic heart diseases such as heart failure and coronary artery disease. We reported a novel clinical phenotype called triglyceride deposit cardiomyovasculopathy (TGCV), showing aberrant TG accumulation in both coronary arteries and myocardium, in a cardiac transplant recipient. Here, we examined autopsied diabetics for TG deposition in cardiovasculature. Consecutive series of hearts from advanced diabetes mellitus (DM) subjects (DM group: DMG, n = 20) and those from age- and sex-matched non-diabetic controls (non DM group: NDMG, n = 20) were examined. The diagnostic criteria of 'advanced DM' was made based on 2014 Clinical Practice Recommendations proposed by the American Diabetes Association. The mean duration of DM was 15.8 years. All DMG suffered from heart diseases including coronary artery diseases and 14 subjects had multi-vessel disease. Tissue TG contents were measured biochemically. Coronary arterial TG contents was significantly higher in DMG compared with NDMG. Spatial distribution of TG in transverse sections of coronary arteries showed TG deposition mainly in smooth muscle cells by Imaging Mass Spectrometry. Abundant TG deposition in coronary artery might be associated with advanced DM.

Clinical outcomes with Biolimus (A9)™ eluting stent, 'BioMatrix' in diabetic patients--interim results from multicenter post market surveillance registry in India

OBJECTIVE

The objective of this registry is to establish safety and efficacy of BioMatrix, BioMatrix™-Biolimus A9™ eluting stent in diabetic population in India.

BACKGROUND

Diabetes mellitus is a major predisposing factor for coronary artery disease. Prognosis for diabetic population patients presenting with coronary artery disease who undergo coronary revascularization is inferior to non diabetics and remains an independent risk factor of restenosis, need for revascularization, and overall mortality. Stent thrombosis is a potential complication of first generation, permanent polymer drug-eluting stents. Biodegradable polymer is a good relief in this era and its utility in diabetic patients will be a major advantage for them.

METHODS

334 patients with diabetes mellitus and requiring angioplasty, implanted with BioMatrix stent were followed at 1, 6, 12 and 24 months who entered in a multicenter registry in India. We analyzed the incidence of major adverse cardiac events (MACE) and stent thrombosis (ST) at 1, 6, 12 and 24 months.

RESULTS

The mean age was 58.71 ± 9.2 years, 81% were males, comorbidity index was 1.6 ± 1.02, and 59.1% presented with acute coronary syndrome. The incidence of adverse event rates was: MACE 1.27%. There were no incidences of myocardial infarction (MI) and target vessel revascularization (TVR). Definite stent thrombosis occurred only in 2 patients.

CONCLUSION

In this registry of diabetic population treated with BioMatrixTM-Biolimus A9TM eluting stent (BioMatrix), the reported incidence of MACE and ST were much lower than previously published results. The 1- and 2-year follow-up result supports favorable clinical outcomes of using BioMatrix stents as a suitable alternative to contemporary DES available during PCI in diabetic patients.

Percutaneous versus surgical interventions for coronary artery disease in those with diabetes mellitus

Diabetes mellitus (DM) is a metabolic disorder of multiple etiologies that causes long-term damage of various organs including the cardiovascular system. A consistent observation shows that DM amplifies the risk of cardiovascular events by 4- to 6-fold. Since coronary artery disease (CAD) in diabetic patients exhibits diffuse and accelerated lesions, invasive revascularization continues to be a challenge and has worse outcomes than patients without DM. Owing to the pathogenesis of DM and the presence of severe endothelial dysfunction, investigators have been trying to find new treatment modalities that could target the treatment of the disease rather than the treatment of the lesion. Until new treatment modalities are proven and gain acceptance, invasive revascularization remains to be the choice of treatment in such patients. The focus of this review is to compare the results of percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) for the treatment of stable CAD in patients with DM.

Predictors and incidence of stent edge dissections in patients with type 2 diabetes as determined by optical coherence tomography

Patients with type 2 diabetes are at increased risk for post-PCI complications including stent thrombosis and restenosis. Stent edge dissections (SEDs) have been associated with these complications. This study assessed incidence and predictors of SEDs in patients with type 2 diabetes using optical coherence tomography (OCT). Intravascular lesion parameters and plaque morphology were investigated pre- and post-PCI using OCT in 73 type 2 diabetic patients with 90 lesions and 166 visible stent edges. We detected 42 (25.3 %) SEDs in 166 stent edges and 37 (41.1 %) SEDs in 90 lesions. More SEDs occurred if the border of the stent had been placed within diseased vessel segments with predominantly fibrous (42.9 %) and fibrocalcific (40.5 %) plaques compared to healthy vessel wall morphology (p < 0.001). Furthermore, the lumen eccentricity of the stent at its edges (SAE) (16.00 ± 6.07 vs. 13.11 ± 5.22 %, p < 0.003) and the stent-edge-to-lumen-area-ratio (1.26 ± 0.27 vs. 0.99 ± 0.20, p < 0.001) were both significantly larger in the presence of SEDs. All of the above parameters were significant predictors for SEDs on uni- and multivariate logistic regression analysis (all p < 0.01), suggesting that the lumen eccentricity of the SAE, the stent-edge-to-lumen-area-ratio and diseased vessel wall morphology of the reference segment adjacent to the stent edge are independent risk factors for the presence of SEDs. These results suggest that diseased vessel wall morphology at the stent edges may promote the occurrence of SEDs and that avoidance of longitudinal and transverse mismatch between stent and vessel could be important to reduce SEDs in cardiovascular high-risk patients with type 2 diabetes.

Ca2+ regulatory mechanisms of exercise protection against coronary artery disease in metabolic syndrome and diabetes

Chronic exercise attenuates coronary artery disease (CAD) in humans largely independent of reductions in risk factors; thus major protective mechanisms of exercise are directly within the coronary vasculature. Further, tight control of diabetes, e.g., blood glucose, can be detrimental. Accordingly, knowledge of mechanisms by which exercise attenuates diabetic CAD could catalyze development of molecular therapies. Exercise attenuates CAD (atherosclerosis) and restenosis in miniature swine models, which enable precise control of exercise parameters (intensity, duration, and frequency) and characterization of the metabolic syndrome (MetS) and diabetic milieu. Intracellular Ca(2+) is a pivotal second messenger for coronary smooth muscle (CSM) excitation-contraction and excitation-transcription coupling that modulates CSM proliferation, migration, and calcification. CSM of diabetic dyslipidemic Yucatan swine have impaired Ca(2+) extrusion via the plasmalemma Ca(2+) ATPase (PMCA), downregulation of L-type voltage-gated Ca(2+) channels (VGCC), increased Ca(2+) sequestration by the sarcoplasmic reticulum (SR) Ca(2+) ATPase (SERCA), increased nuclear Ca(2+) localization, and greater activation of K channels by Ca(2+) release from the SR. Endurance exercise training prevents Ca(2+) transport changes with virtually no effect on the diabetic milieu (glucose, lipids). In MetS Ossabaw swine transient receptor potential canonical (TRPC) channels are upregulated and exercise training reverses expression and TRPC-mediated Ca(2+) influx with almost no change in the MetS milieu. Overall, exercise effects on Ca(2+) signaling modulate CSM phenotype. Future studies should 1) selectively target key Ca(2+) transporters to determine definitively their causal role in atherosclerosis and 2) combine mechanistic studies with clinical outcomes, e.g., reduction of myocardial infarction.

Assessment of coronary plaque characteristics by optical coherence tomography in patients with diabetes mellitus complicated with unstable angina pectoris

BACKGROUND

Diabetic patients are characterised by poorer prognosis and more cardiovascular complications compared with non-diabetic patients, which may be due to metabolic abnormalities and atherosclerotic plaque characteristics.

METHODS

Patients with unstable angina pectoris were enrolled in the study and divided into diabetes mellitus (DM) (patients, n=25; plaques, n=42) and non-DM (patients, n=53; plaques, n=65) groups according to their DM history. Optical coherence tomography (OCT) examinations were performed on all patients, and images were analysed by two independent investigators. Fibrous cap thickness was measured at the thinnest point of each plaque. The presence of plaque disruption, dissection, erosion, thrombosis and calcification were also noted.

RESULTS

Calcified plaques in the DM group were significantly greater than those in the non-DM group (42.9% vs. 23.1%; p=0.03). Thin-cap fibroatheroma (TCFA) were detected, and no significant difference was found in the frequencies (42.9% vs. 52.3%; p=0.34) and fibrous cap thickness (57.08 ± 6.20 μm vs. 56.11 ± 9.23 μm, p=0.74) between the DM and non-DM groups. Thrombus and plaque erosion were similar in the two groups, but the frequency of dissection in the DM group was greater than that in the non-DM group (21.4% vs. 7.7%, p=0.04). The high sensitivity C-reactive protein between the two groups was similar (0.44 ± 0.20mg/dl vs. 0.46 ± 0.15 mg/dl, p=0.83).

CONCLUSION

Higher calcification and dissection were detected in diabetic patients with unstable angina pectoris, and the difference in coronary plaque characteristics can explain the difference in clinical prognoses between DM and non-DM patients.

Metabolic syndrome and coronary artery disease in Ossabaw compared with Yucatan swine

Metabolic syndrome (MetS), a compilation of associated risk factors, increases the risk of type 2 diabetes and coronary artery disease (CAD, atherosclerosis), which can progress to the point of artery occlusion. Stents are the primary interventional treatment for occlusive CAD, and patients with MetS and hyperinsulinemia have increased restenosis. Because of its thrifty genotype, the Ossabaw pig is a model of MetS. We tested the hypothesis that, when fed high-fat diet, Ossabaw swine develop more features of MetS, greater native CAD, and greater stent-induced CAD than do Yucatan swine. Animals of each breed were divided randomly into 2 groups and fed 2 different calorie-matched diets for 40 wk: control diet (C) and high-fat, high-cholesterol atherogenic diet (H). A bare metal stent was placed in the circumflex artery, and pigs were allowed to recover for 3 wk. Characteristics of MetS, macrovascular and microvascular CAD, in-stent stenosis, and Ca(2+) signaling in coronary smooth muscle cells were evaluated. MetS characteristics including, obesity, glucose intolerance, hyperinsulinemia, and elevated arterial pressure were elevated in Ossabaw swine compared to Yucatan swine. Ossabaw swine with MetS had more extensive and diffuse native CAD and in-stent stenosis and impaired coronary blood flow regulation compared with Yucatan. In-stent atherosclerotic lesions in Ossabaw coronary arteries were less fibrous and more cellular. Coronary smooth muscle cells from Ossabaw had impaired Ca(2+) efflux and intracellular sequestration versus cells from Yucatan swine. Therefore, Ossabaw swine are a superior model of MetS, subsequent CAD, and cellular Ca(2+) signaling defects, whereas Yucatan swine are leaner and relatively resistant to MetS and CAD.

S6K1 plays a critical role in early adipocyte differentiation

Earlier, we reported that S6K1(-/-) mice have reduced body fat mass, have elevated rates of lipolysis, have severely decreased adipocyte size, and are resistant to high fat diet (HFD)-induced obesity. Here we report that adipocytes of S6K1(-/-) mice on a HFD have the capacity to increase in size to a degree comparable to that of wild-type (WT) mice, but not in number, indicating an unexpected lesion in adipogenesis. Tracing this lesion revealed that S6K1 is dispensable for terminal adipocyte differentiation, but is involved in the commitment of embryonic stem cells to early adipocyte progenitors. We further show that absence of S6K1 attenuates the upregulation of transcription factors critical for commitment to adipogenesis. These results led to the conclusion that a lack of S6K1 impairs the generation of de novo adipocytes when mice are challenged with a HFD, consistent with a reduction in early adipocyte progenitors.

Eighteen-Month Clinical Safety and Efficacy Outcomes of Sirolimus-, Paclitaxel and Zotarolimus-drug Eluting Stents in Diabetic Patients Undergoing Percutaneous Coronary Intervention for Complex Coronary Artery Stenosis

Introduction: This was a single centre registry study on clinical efficacy and safety of drug-eluting stent (DES) in diabetic patients undergoing percutaneous coronary intervention (PCI) for complex coronary lesions. Materials and Methods: A total of 288 diabetic patients who underwent elective PCI between September 2003 and June 2006 in our centre were enrolled and followed-up for 18 months. Among them, 79 (27.4%) patients received sirolimus-eluting stent (SES), 138 (47.9%) paclitaxel-eluting stent (PES) and 71 (24.7%) zotarolimus-eluting stent (ZES). The endpoints were major adverse cardiac events (MACE) and stent thrombosis rates. Results: Baseline demographics were comparable among the 3 DES groups (median age was 60 years; 69% men). Complex lesions (defined as ACC/AHA type C stenosis) accounted for 55.6% of the total lesions: SES (50.6%), PES (65.2%) and ZES (43.7%), P = 0.005. At 18 months follow-up, the composite endpoint of MACE was found in 12.7% in SES group, 8.7% in the PES group, 12.7% in ZES group and (P = 0.55). Stent thrombosis (ST) occurred in 1 patient (1.3%) in the SES group, 2 patients (1.4%) in PES group and 1 patient (1.4%) in ZES group, respectively (P = 1.00). Conclusion: The use of DES for elective PCI in diabetic patients was associated with favourable intermediate-term clinical outcomes with no significant differences in efficacy among the 3 groups. Stent thrombosis had low event occurrence rate. Key words: Drug-eluting coronary stents, Diabetes mellitus, Stent thrombosis

Exercise training decreases store-operated Ca2+entry associated with metabolic syndrome and coronary atherosclerosis

AIMS

Stenting attenuates restenosis, but accelerated coronary artery disease (CAD) adjacent to the stent (peri-stent CAD) remains a concern in metabolic syndrome (MetS). Smooth muscle cell proliferation, a major mechanism of CAD, is mediated partly by myoplasmic Ca2+ dysregulation and store-operated Ca2+ entry (SOCE) via canonical transient receptor potential 1 (TRPC1) channels is proposed to play a key role. Exercise is known to prevent Ca2+ dysregulation in CAD. We tested the hypothesis that MetS increases SOCE and peri-stent CAD and exercise attenuates these events.

METHODS AND RESULTS

Groups (n = 9 pigs each) were (i) healthy lean Ossabaw swine fed standard chow, (ii) excess calorie atherogenic diet fed (MetS), and (iii) aerobically exercise trained starting after 50 weeks of development of MetS (XMetS). Bare metal stents were placed after 54 weeks on diets, and CAD and SOCE were assessed 4 weeks later. Coronary cells were dispersed proximal to the stent (peri-stent) and from non-stent segments, and fura-2 fluorescence was used to assess SOCE, which was verified by Ni2+ blockade and insensitivity to nifedipine. XMetS pigs had increased physical work capacity and decreased LDL/HDL (P < 0.05), but no attenuation of robust insulin resistance, glucose intolerance, hypertriglyceridaemia, or hypertension. CAD was greater in peri-stented vs. non-stented artery segments. MetS had the greatest CAD, SOCE, and TRPC1 and STIM1 mRNA and protein expression, which were all attenuated in XMetS.

CONCLUSION

This is the first report of the protective effect of exercise on native CAD, peri-stent CAD, SOCE, and molecular expression of TRPC1, STIM1, and Orai1 in MetS.

A randomized comparison of sirolimus-eluting versus bare metal stents in the treatment of diabetic patients with native coronary artery lesions: the DECODE study

OBJECTIVE

To compare the effects of sirolimus-eluting (SES) versus bare metal stents (BMS) on 6-month in-stent late luminal loss (LLL) and 1-year major adverse cardiac events (MACE) in diabetics undergoing percutaneous coronary interventions.

BACKGROUND

In studies of unselected patients, coronary restenosis rates have been lower with SES than with BMS. Comparisons of SES versus BMS in diabetics with more than one stenosis or more than one vessel disease are few.

METHODS

This open-label trial randomly assigned 200 diabetics with de novo coronary artery stenoses to receive up to three SES versus BMS in a 2:1 ratio. The patients underwent repeat coronary angiography at 6 months after the index procedure and were followed-up for 1 year. The primary study endpoint was in-stent LLL at 6 months.

RESULTS

Between August 2002 and May 2004, 83 patients (mean age = 60 years) with 128 lesions (mean = 1.5 per patient) were enrolled at four U.S. and seven Asian medical centers. Enrollment was terminated early by the Safety Monitoring Board because of a statistically significant difference in rates of clinical endpoints. The mean in-stent LLL at 6 months was 0.23 mm in SES versus 1.10 mm in BMS recipients (P < 0.001). At 12 months, 8 patients (15%) assigned to SES had experienced MACE versus 12 patients (41%) assigned to BMS (P = 0.006).

CONCLUSIONS

In diabetics, the mean 6-month in-stent LLL was significantly smaller, and 12-month MACE rate significantly lower, after myocardial revascularization with SES than with BMS.

Comparison of coronary plaque characteristics between diabetic and non-diabetic subjects: An in vivo optical coherence tomography study

AIMS

Postmortem series have reported that subjects with diabetes mellitus have coronary plaques with larger necrotic cores and increased macrophage infiltration. Optical coherence tomography (OCT) is a high-resolution imaging modality that allows in vivo characterization of atherosclerotic plaques. Using OCT imaging, we compared in vivo plaque characteristics between diabetic and non-diabetic subjects.

METHODS

Sixty-three patients undergoing cardiac catheterization were enrolled. OCT imaging was performed in culprit coronary arteries. Assessment of plaque lipid content, fibrous cap thickness and frequency of thin-cap fibroatheroma were made independently. Macrophage density was determined from the optical signal within fibrous cap.

RESULTS

Eighty-two plaques in total were imaged (19 diabetic vs. 63 non-diabetic). There were no significant differences in frequency of lipid-rich plaques (68% vs. 71%; P=0.78), thin-cap fibroatheroma (29% vs. 36%; P=0.76) or minimum fibrous cap thickness (66.6microm vs. 62.9microm; P=0.87) between diabetic and non-diabetic patients. Fibrous cap macrophage density was higher in lipid-rich plaques (P=0.01) but showed no difference between diabetic and non-diabetic patients (5.94% vs. 5.94%; P=0.37).

CONCLUSIONS

There were no significant differences in culprit vessel plaque characteristics between diabetic and non-diabetic patients presenting with coronary artery disease. This represents the first study to characterize coronary plaques in diabetic patients using OCT.

[Diabetes mellitus and coronary artery disease--a high risk combination]

Patients with diabetes mellitus are often not recognized in clinical routine, but also not well characterized in clinical trials. As a diagnostic approach it is recommended to test fasting glucose and glycosylated hemoglobin (HbA1c) in every patient with coronary artery disease (CAD). HbA1c, in addition, provides important prognostic information. Patients with diabetes mellitus do have an enhanced cardiovascular risk in all stages and during all kind of interventions of CAD. However, diabetes is not equal to diabetes; risk modifying factors such as HbA1c, concomitant diseases and medication have to be considered. Absolute benefit of pharmacological therapies is also enhanced in patients with diabetes compared to non-diabetics. However, statins or anti-hypertensive treatment seem to be even more effective in reducing cardiovascular events than pure control of glucose levels alone. During percutaneous interventions (PCI) glycoprotein IIb/IIIa-inhibitors reduce mortality in diabetics, an effect which may be partially also achieved by Clopidogrel. Glitazones reduce restenosis rates; however, clinical end point studies are still ongoing. After PCI, restenosis may be a predictor of mortality in patients with diabetes. Whether drug eluting stents, besides effectively reducing restenosis, may also reduce hard clinical events in patients with diabetes remains to be demonstrated. Current available studies comparing PCI with bypass are limited due to not considered factors (stenosis morphology), randomization bias, and faster progress of technology compared to study termination. During an acute coronary syndrome/myocardial infarction, hyperglycemia is an adverse prognostic marker. However, so far studies using glucose-insulin-potassium (GIK) infusion have not been convincingly demonstrate to be beneficial.

Renal dysfunction is the most important predictor of the extent and severity of coronary artery disease in patients with diabetes mellitus

OBJECTIVES

Diabetic patients tend to have more extensive and diffuse coronary artery disease (CAD) that may contribute to the less favorable outcomes in them. The aim of this study was to elucidate the predictors of the angiographic severity and extent of CAD in patients with diabetes.

METHODS

A total of 203 diabetic patients (116 men; mean age, 61.9+/-10.8) who were referred for a first coronary angiogram were included. The extent and severity of CAD was assessed in several ways. The first was a simple classification in one-vessel, two-vessel, and three-vessel disease scoring system. The total numbers of segments with > or = 20 and > or = 50% stenosis were calculated as CASS 20 and CASS 50 scores, respectively. Hamsten and Gensini scores were also calculated.

RESULTS

Of the 203 patients included in the study, 175 (86.2%) had CAD. Multivariate ordinal logistic regression analysis showed that age (Wald 5.741, P=0.017), glomerular filtration rate (Wald 5.032, P=0.025), previous myocardial infarction (Wald 10.955, P=0.001), and family history of CAD (Wald 7.236, P=0.007) were independent predictors of the severity of CAD, as assessed by the clinical zero-vessel to three-vessel disease scoring system. On stepwise multiple linear regression analysis, glomerular filtration rate was an independent predictor of the CASS 20 (r=-0.221, P=0.004), CASS 50 (r=-0.239, P=0.005), Gensini (r=-0.328, P<0.001), and Hamsten (r=-0.320, P<0.001) scores. Previous myocardial infarction was an independent predictor of the CASS 50 (r=0.355, P<0.001), Gensini (r=0.350, P<0.001), and Hamsten (0.256, P<0.001) scores. Age and sex were independent predictors for the CASS 50 (r=0.174, P=0.039; r=0.172, P=0.016, respectively) and Hamsten (r=0.212, P=0.011; r=0.244, P=0.001, respectively) scores.

CONCLUSION

Renal function is one of the most important factors associated with the extent and severity of coronary atherosclerosis, whereas classical coronary risk factors and the degree of metabolic control were not associated with the severity of coronary atherosclerosis in diabetic patients.

Glucose, insulin, diabetes and mechanisms of arterial dysfunction

1. This commentary reviews and discusses the association between increased arterial stiffness and indices of glucose and insulin metabolism and diabetes mellitus (DM). 2. Diabetes mellitus is associated with increased cardiovascular events, is an established major independent risk factor for cardiovascular disease and is included in current risk assessment algorithms. Based on Framingham risk assessment, the incremental risk due to DM, at a given level of baseline risk in non-diabetics, is approximately equivalent to 10 years and, at any given level of other major risk factors, DM increases risk three- to fourfold. 3. Increased aortic stiffness has been shown to be an independent risk factor for both cardiovascular and overall mortality in high-risk groups and recently in the general population. Both DM1 and DM2 are associated with accelerated stiffening of the elastic arteries, over and above that associated with normal ageing, and DM can be considered as imparting added biological age and, thus, added cardiovascular risk. 4. Aortic stiffness provides a plausible mechanism relating diabetes to increase cardiovascular disease. 5. A proportion of the increased risk of cardiovascular events in DM is a sequel of stiff arteries. Direct measures of arterial stiffness, such as aortic pulse wave velocity, are likely to be better candidates than pulse wave analysis for refining interventions to improve outcomes in diabetes.

Lipid-modifying therapy in diabetic patients with high plasma non-high-density lipoprotein cholesterol after percutaneous coronary intervention

OBJECTIVE

To investigate the effects of atorvastatin on long-term prognosis in diabetic patients with high plasma levels of non-high-density lipoprotein cholesterol (non-HDL-C) after percutaneous coronary intervention (PCI).

METHODS

A total of 648 diabetic patients with high plasma levels of non-HDL-C who had undergone successful PCI were randomly assigned to therapy group (n=327, atorvastatin, 20 mg/day) or control group (n=321, without any lipid-modifying therapy). Study end points included all-cause death, fatal or nonfatal myocardial infarction (MI), and revascularization.

RESULTS

The median follow-up was 21+/-2.9 months. Rates of MI (6.4% versus 12.3%, P=0.013), revascularization (19.2% versus 26.6%, P=0.029) and composite end points (26.9% versus 41.5%, P<0.001) were significantly lower in the atorvastatin group compared with those of the control group, although mortality rate (5.1% versus 7.9%, P=0.196) was not. Patients treated with atorvastatin had significantly improved adjusted event-free survival rate than controls (hazard ratio 0.52, 95% CI 0.30 to 0.91, P=0.022).

CONCLUSION

Diabetic patients with high plasma levels of non-HDL-C should receive long-term lipid-modifying drugs after PCI to reduce MI and revascularization rates.

Nutrient overload, insulin resistance, and ribosomal protein S6 kinase 1, S6K1

Nutrient overload leads to obesity, insulin resistance, and often type 2 diabetes. Whereas increased fat intake is commonly cited as the major factor in diet-induced dysmetabolic states, increased protein consumption also contributes, through elevated circulating amino acids. Recent studies have revealed that ribosomal protein S6 kinase 1, S6K1, an effector of mTOR, is sensitive to both insulin and nutrients, including amino acids. Although S6K1 is an effector of growth, recent reports show that amino acids also negatively affect insulin signaling through mTOR/S6K1 phosphorylation of IRS1. Moreover, rather than signaling through the class 1 PI3K pathway, amino acids appear to mediate mTOR activation through class 3 PI3K, or hVps34. Consistent with this, infusion of amino acids into humans leads to S6K1 activation, inhibition of insulin-induced class 1 PI3K activation, and insulin resistance. Thus, S6K1 may mediate deleterious effects, like insulin resistance, and potentially type 2 diabetes in the face of nutrient excess.

Heterogeneity of neointimal distribution of in-stent restenosis in patients with diabetes mellitus

Diabetes mellitus is an independent predictor of restenosis after percutaneous coronary intervention. The pattern of restenosis after bare metal stent implantation in diabetic patients was examined with 3-dimensional intravascular ultrasound analysis. Lumen and stent were manually traced at every 0.5-mm interval in stented segments. Using Simpson's method, stent, luminal, and neointimal (stent minus lumen) volumes were calculated and average area was calculated as volume data divided by length. To measure the cross-sectional and longitudinal severities of luminal encroachment by the neointima, percent neointimal area (neointimal area divided by stent area) and neointimal hyperplasia 50 (IH50) (defined as percent stent length with percent neointimal area >50%) were calculated. In 278 patients (68 with diabetes and 210 without diabetes), there was a significantly higher percentage of maximal percent neointimal area with significantly longer percent stent length that was severely encroached by the neointima in diabetic patients. Diabetic patients showed a more heterogenous pattern of the neointima after bare metal stenting, resulting in longer high-grade obstruction segments. This may have important implications for stent design and pharmacokinetic properties of next-generation drug-eluting technology for this complex patient subset.

High Mortality Associated With Precluded Coronary Artery Bypass Surgery Caused by Severe Distal Coronary Artery Disease

Background— Patients with extensive coronary artery disease (CAD) have better prognosis when treated with coronary artery bypass grafting surgery (CABG), especially when left ventricular dysfunction (LVD) is present. However, there are scanty data about the clinical course of patients not referred to CABG because of extensive and severe atherosclerotic involvement of distal coronary arteries (ENDCAD). The aim of this study was to evaluate patients with multivessel (MV) or left main CAD (LM) who had CABG precluded because of ENDCAD.

Methods and Results— Between August 1999 and July 2001, 51 patients who had clinical indication but were not eligible for CABG because of ENDCAD were followed for at least 12 months or until death. There were 32 men and 19 women (age 61±9 years). Previous acute myocardial infarction (AMI) was present in 31 (60.8%), diabetes mellitus (DM) in 28 (54.9%), systemic arterial hypertension in 37 (72.5%), LVD (left ventricular ejection fraction <40%) in 26 (51%), 3 vessel CAD in 31 (60.8%), and LM in 4 (7.8%). During follow-up there were 20 cardiac (39.2%) deaths, 19 (37.2%) AMI, and 3 (5.8%) patients developed congestive heart failure. There were 2 (3.9%) noncardiac deaths. Patients with DM (60.7% versus 13%; P =0.001; odds ratio [OR], 10.30; 95% confidence interval [CI], 2.46 to 43.09), LVD (76.9% versus 0%; P <0.0001; OR, 4.33; 95% CI, 2.14 to 8.74), 3-vessel CAD (51.6% versus 20%; P =0.039; OR, 4.26; 95% CI, 1.16 to 15.69), and LM (100% versus 34%; P =0.019; OR, 1.25; 95% CI, 1.004 to 1.556) were more likely to die. There was no deaths in patients with 2-vessel CAD but they had more nonfatal AMI (43.8% versus 14.3%; OR, 4.667; 95% CI, 1.188 to 18.332).

Conclusions— Patients in whom CABG could not be performed because of ENDCAD had high mortality, especially in the presence of LVD. DM (particularly insulin-dependent), LM CAD, and 3-vessel CAD were independent markers of increased risk.

Role of aldose reductase and oxidative damage in diabetes and the consequent potential for therapeutic options

Aldose reductase (AR) is widely expressed aldehyde-metabolizing enzyme. The reduction of glucose by the AR-catalyzed polyol pathway has been linked to the development of secondary diabetic complications. Although treatment with AR inhibitors has been shown to prevent tissue injury in animal models of diabetes, the clinical efficacy of these drugs remains to be established. Recent studies suggest that glucose may be an incidental substrate of AR, which appears to be more adept in catalyzing the reduction of a wide range of aldehydes generated from lipid peroxidation. Moreover, inhibition of the enzyme has been shown to increase inflammation-induced vascular oxidative stress and prevent myocardial protection associated with the late phase of ischemic preconditioning. On the basis of these studies, several investigators have ascribed an important antioxidant role to the enzyme. Additionally, ongoing work indicates that AR is a critical component of intracellular signaling, and inhibition of the enzyme prevents high glucose-, cytokine-, or growth factor-induced activation of protein kinase C and nuclear factor-kappa-binding protein. Thus, treatment with AR inhibitors prevents vascular smooth muscle cell growth and endothelial cell apoptosis in culture and inflammation and restenosis in vivo. Additional studies indicate that the antioxidant and signaling roles of AR are interlinked and that AR regulates protein kinase C and nuclear factor-kappaB via redox-sensitive mechanisms. These data underscore the need for reevaluating anti-AR interventions for the treatment of diabetic complications. Potentially, the development of newer drugs that selectively inhibit AR-mediated glucose metabolism and signaling, without affecting aldehyde detoxification, may be useful in preventing inflammation associated with the development of diabetic complications, particularly micro- and macrovascular diseases.