Comparative outcomes of percutaneous coronary interventions in diabetics vs non-diabetics with prior coronary artery bypass grafting

Diabetes mellitus associated with an increased risk of percutaneous coronary intervention long-term adverse outcomes in Taiwan: A nationwide population-based cohort study

AIMS

This study compared the incidence rates of patients with diabetes mellitus (DM) and patients without DM with percutaneous coronary intervention (PCI) in a national population-based cohort to determine if the patients with DM have an increased risk of adverse outcomes.

METHODS

We performed a retrospective cohort study among 92,624 patients with and without DM, who underwent PCI for the first time in 2000-2008. The patients were identified from National Health Insurance Program Database through propensity score matching. Endpoints were the occurrence of PCI adverse outcomes, including myocardial infarction (MI), need for target vessel revascularization by either bypass surgery or repeat PCI, all-cause mortality or 2011/12/31. Incidence rate was calculated and hazard ratios of PCI adverse events were estimated using Cox's proportional hazard regression model.

RESULTS

During the mean six-year follow up, the rates of MI (incidence rate 20.96 vs. 15.59 per 1000 person-years), bypass surgery (incidence rate 8.15 vs. 5.15 per 1000 person-years), all-cause mortality (incidence rate 6.20 vs. 4.72 per 1000 person-years), and the composite measure of MI, repeat PCI, bypass surgery, all-cause mortality (incidence rate 37.31 vs. 28.14 per 1000 person-years) were higher in patients with DM. The corresponding hazard ratios (HRs) and their 95% confidence intervals (CIs) were 1.34 (95% CI: 1.29, 1.39), 1.46 (1.38, 1.56), 1.34 (1.25, 1.44), and 1.31 (1.27, 1.35). However, the repeat PCI rate (incidence rate 2.65 vs. 2.70 per 1000 person-years); with an adjusted HR of 0.97 (0.88, 1.07) was not statistically different.

CONCLUSIONS

This nationwide retrospective cohort study determined a positive correlation between PCI adverse events and DM. As the prevalence of DM and PCI continues to increase, novel treatments and intensified surveillance coronary angiography for high risk patients are needed.

Non-haemodynamic anti-anginal agents in the management of patients with stable coronary artery disease and diabetes: A review of the evidence

Patients with coronary artery disease and concomitant diabetes mellitus tend to have more extensive vessel disease than non-diabetes mellitus coronary artery disease patients, are at high risk of adverse cardiovascular events and suffer from a great anginal burden. Very few trials have specifically addressed the issue of optimal anti-anginal therapy in coronary artery disease patients who also have diabetes mellitus. Among 'classical' anti-anginal agents, recent guidelines do not specifically recommend any molecule over others; however, European Society of Cardiology guidelines acknowledge that favourable data in patients with concomitant diabetes mellitus and coronary artery disease are available for trimetazidine and ranolazine, two anti-anginal agents with a non-haemodynamic mechanism of action. The aim of this article is to review available evidence supporting the anti-anginal efficacy of these two drugs in the difficult-to-treat population of diabetes mellitus patients, including their effects on glycated haemoglobin (HbA1c), a measure of medium-term glycaemic control. Although direct head-to-head comparisons have not been performed, available evidence favours ranolazine as an effective anti-anginal agent over trimetazidine in this population. In addition, ranolazine lowers HbA1c, indicating that it may improve glycaemic control in patients with diabetes mellitus. Conversely, scanty data are available on the metabolic effects of trimetazidine in this cohort of patients. Thus, ranolazine may represent a valuable therapeutic option in stable coronary artery disease patients with diabetes mellitus.

Outcomes in diabetic versus nondiabetic patients who present with acute myocardial infarction and are treated with drug-eluting stents

Patients with diabetes mellitus (DM) are at a greater risk of mortality and cardiovascular events after percutaneous coronary intervention than those without DM. We aimed to determine whether differences exist in the long-term mortality of patients with versus without DM who present with acute myocardial infarction and receive drug-eluting stents. Data were collected on 161 patients with and 395 without DM referred for primary percutaneous coronary intervention for acute myocardial infarction and treated with drug-eluting stents. The patients with cardiac arrest or cardiogenic shock were excluded. The 1-year major cardiac event (MACE) rates, defined as death, Q-wave myocardial infarction, or target lesion revascularization, were compared between the 2 groups. The patients with DM were sicker at baseline. The MACE rates at 1 year were significantly increased in those with DM compared to those without DM. This was primarily driven by all-cause mortality. No differences in Q-wave myocardial infarction, target lesion revascularization, stent thrombosis, type of drug-eluting stents used, or procedure-related renal failure were seen. No differences were found in death or MACE rates at 1 year after adjusting for age, gender, race, systemic hypertension, peripheral artery disease, and a history of chronic renal failure between the 2 groups (weighted log-rank statistic, p = 0.37 and p = 0.37, respectively). In patients presenting with acute myocardial infarction, those with DM were sicker than those without DM. In conclusion, after correction for co-morbid conditions, no difference was seen in the 1-year MACE or death rates between those with and without DM who presented with acute myocardial infarction and were treated with drug-eluting stents.

Effects of improved metabolic control on platelet reactivity in patients with type 2 diabetes mellitus following coronary angioplasty

The aim of this study was to investigate the impact of improved metabolic control on platelet reactivity in patients with type 2 diabetes undergoing percutaneous coronary intervention (PCI). Twenty-two patients were randomised to intensive insulin or conventional treatment for diabetes. Platelet P-selectin expression was analysed before and three months after PCI. Metabolic control, as measured by level of glycosylated haemoglobin (HbA1c) and platelet P-selectin expression, was similar in the two treatment groups after three months. However, six of the 12 patients in the intensive group had increased levels of HbA1c after three months and three patients of the 10 in the conventionally treated group showed improved metabolic control. A re-analysis was performed, based on metabolic control. It showed that patients with improved control at three months (HbA1c 6.1% +/- 0.7 at baseline; 5.7% +/- 0.5 at three months; p<0.01; n=9) had lower ADP-induced P-selectin expression (p<0.05) than patients with worsened glycaemic control (HbA1c 5.9% +/- 1.0 at baseline; 6.5% +/- 1.4 at three months; p<0.01; n=13). Levels of HbA1c and fasting glucose were correlated to P-selectin expression (R=0.34 and R=0.31; p<0.05). We conclude from this study that improved glycaemic control reduces platelet reactivity in type 2 diabetes patients following PCI.

Predictors of long-term outcome following percutaneous coronary intervention in patients with type 2 diabetes mellitus

OBJECTIVES

Diabetes has a major impact on the long-term outcome following percutaneous coronary intervention, being a major risk factor for restenosis. We aimed at assessing the clinical, hemodynamic and angiographic factors that predict outcome in this high-risk group.

METHODS

Diabetic patients who underwent percutaneous coronary intervention during the period 1996-2000 were identified retrospectively, and their medical records, hemodynamic data and angiograms studied at the time of their procedure. Angiographic data were analyzed to determine procedural factors, quantitative angiographic results of their percutaneous coronary intervention and severity and extent scores of coronary artery disease. Clinical follow-up was obtained in 99.7% to a mean time of 782+/-153 days after percutaneous coronary intervention.

RESULTS

A total of 327 consecutive diabetic patients underwent percutaneous coronary intervention on 389 lesions. The overall procedural success rate was 96.2%; however, during follow-up, 40.2% of patients had an adverse cardiac event. The strongest independent predictors of adverse outcome were presence of renal disease, need for medical diabetic treatment, and the extent of coronary artery disease as assessed by the extent score, but not the duration of diabetes or glycemic control. Other factors, which are often predictive of short-term outcome in a general population, such as vessel diameter, lesion length, and severity of coronary artery disease, were not predictive of outcome.

CONCLUSIONS

In patients with type 2 diabetes mellitus, the extent of the coronary arteries involved with atheroma as well as systemic factors such as renal involvement are the best predictors of long-term outcome following percutaneous coronary intervention.

Diabetes mellitus and coronary artery disease: therapeutic considerations

Diabetes mellitus affects about 6% of the U.S. population and represents a significant public health challenge, with numbers of those affected increasing every year. The most common cause of death in these patients is macrovascular disease, with coronary disease being the predominant form. The pathophysiology of coronary disease in patients with diabetes is complex and involves elements of hyperglycemia, dyslipidemia, hyperinsulinemia, as well as a procoagulant vascular milieu. First-generation trials looking at revascularization of multivessel disease in patients with diabetes have had long clinical follow-up periods and seem to consistently favor coronary bypass grafting over percutaneous interventions; however, newer trials that include the use of stents and glycoprotein IIb/IIIa inhibitor therapy as part of the latter strategy have raised some interesting questions, so that the issue remains controversial and by no means settled.