Influence of an antidiabetic treatment with sulfonylurea drugs on long-term survival after acute myocardial infarction in patients with type 2 diabetes. The LAngendreer Myocardial infarction and Blood glucose in Diabetic patients Assessment (LAMBDA)

Glucose-lowering therapy and cardiovascular outcomes in patients with type 2 diabetes mellitus and acute coronary syndrome

Diabetes is a common comorbidity in patients hospitalized for an acute coronary syndrome event, and prevalence is increasing. Among patients hospitalized with acute myocardial infarction, diabetes can be an independent predictor of mortality and new cardiovascular events; both short- and long-term outcomes are worse for patients with diabetes relative to those without, and undiagnosed diabetes is associated with greater mortality. The impact of glycemic control on cardiovascular outcomes and the best approach to treat hyperglycemia upon hospital admission for acute coronary syndrome in patients with or without known diabetes remain open questions. This review assesses available evidence for hyperglycemia management at the time of admission for acute coronary syndrome and, thereafter, finds that (1) admission plasma glucose plays a role in predicting adverse events, especially in patients with unknown diabetes; (2) glycated haemoglobin is a likely predictor of events in patients with unknown diabetes; and (3) hypoglycemia at the time of acute myocardial infarction hospital admission is an important predictor for mortality in patients with and without diabetes. Whether glucose-targeted insulin and glucose infusion have advantages over glucose-insulin-potassium infusion remains controversial. Evidence for the effect of novel glucose-lowering agents used at the time of an acute cardiovascular event is limited and requires more dedicated studies.

Association of sulphonylurea treatment with all-cause and cardiovascular mortality: a systematic review and meta-analysis of observational studies

We conducted a meta-analysis of cohort and case-control studies to evaluate all-cause and cardiovascular (CV) mortality of patients with type 2 diabetes mellitus (T2DM) who received sulphonylurea (SU) treatment, when compared to any other diabetes treatment. Only studies reporting raw data on mortality during SU treatment were included. Data were combined using random-effects (RE) models. Unadjusted odds ratios (ORs) are presented. Of 4991 publication titles and abstracts reviewed, 20 studies (n = 551,912 patients) were included. For cohort studies (n = 276,050), patients receiving SU monotherapy or combination treatment had significantly higher all-cause and CV mortality risks compared to any non-SU treatment [all-cause, 13 studies: OR = 1.92, 95% confidence interval (CI) = 1.48-2.49; CV, 5 studies: OR = 2.72, 95% CI = 1.95-3.79]. Validity was limited by the high treatment group heterogeneity (I (2) > 90%) and study-inherent biases/design differences. In conclusion, patients receiving SU treatment had increased all-cause and CV mortality risks. However, the meta-analysis was limited by the high heterogeneity of non-randomized studies.

Cardiovascular disease and glycemic control in type 2 diabetes: now that the dust is settling from large clinical trials

The relationship between glucose control and cardiovascular outcomes in type 2 diabetes has been a matter of controversy over the years. Although epidemiological evidence exists in favor of an adverse role of poor glucose control on cardiovascular events, intervention trials have been less conclusive. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) study, the Action in Diabetes and Vascular Disease (ADVANCE) study, and the Veterans Affairs Diabetes Trial (VADT) have shown no beneficial effect of intensive glucose control on primary cardiovascular endpoints in type 2 diabetes. However, subgroup analysis has provided evidence suggesting that the potential beneficial effect largely depends on patients’ characteristics, including age, diabetes duration, previous glucose control, presence of cardiovascular disease, and risk of hypoglycemia. The benefit of strict glucose control on cardiovascular outcomes and mortality may be indeed hampered by the extent and frequency of hypoglycemic events and could be enhanced if glucose-lowering medications, capable of exerting favorable effects on the cardiovascular system, were used. This review examines the relationship between intensive glucose control and cardiovascular outcomes in type 2 diabetes, addressing the need for individualization of glucose targets and careful consideration of the benefit/risk profile of antidiabetes medications.

Sulfonylureas and prognosis after myocardial infarction in patients with diabetes: a population-based follow-up study

BACKGROUND

The cardiovascular safety, including risk of myocardial infarction (MI), of individual sulfonylureas (SUs) may differ. It remains uncertain whether treatment with individual SUs influences prognosis following MI.

METHODS

We conducted a nationwide population-based follow-up study among all Danish patients hospitalized with first-time MI from 1996 to 2004. From the national health databases, we identified 3930 MI patients who used SUs at the time of admission. We computed mortality rates and rates of MI and heart failure readmission according to type of SU and used Cox's proportional hazards regression analysis to compute hazard ratios (HRs) as estimates of relative risk controlling for differences in prognostic covariates.

RESULTS

The 30-day and 1-year mortality after MI among SU users was 22.0% and 35.3%, respectively. We found no substantial differences in 30-day and 1-year mortality among users of different SUs. Use of gliclazide in monotherapy showed a trend towards lower mortality; adjusted HR of 1-year mortality 0.70 (95% CI: 0.48-1.00). Users of the different SUs appeared to have similar risks of new MI and heart failure following MI.

CONCLUSIONS

The prognosis after MI was not substantially influenced by the choice of SU.

Risk of coronary artery disease associated with initial sulphonylurea treatment of patients with type 2 diabetes: a matched case-control study

AIMS

This study sought to assess the risk of developing coronary artery disease (CAD) associated with initial treatment of type 2 diabetes with different sulphonylureas.

METHODS

In type 2 diabetic patients, cases who developed CAD were compared retrospectively with controls that did not. The 20-year risk of CAD at diagnosis of diabetes, using the UKPDS risk engine, was used to match cases with controls.

RESULTS

The 76 cases of CAD were compared with 152 controls. The hazard of developing CAD (95% CI) associated with initial treatment increased by 2.4-fold (1.3-4.3, P=0.004) with glibenclamide; 2-fold (0.9-4.6, P=0.099) with glipizide; 2.9-fold (1.6-5.1, P=0.000) with either, and was unchanged with metformin. The hazard decreased 0.3-fold (0.7-1.7, P=0.385) with glimepiride, 0.4-fold (0.7-1.3, P=0.192) with gliclazide, and 0.4-fold (0.7-1.1, P=0.09) with either.

CONCLUSIONS

Initiating treatment of type 2 diabetes with glibenclamide or glipizide is associated with increased risk of CAD in comparison to gliclazide or glimepiride. If confirmed, this may be important because most Indian patients receive the cheaper older sulphonylureas, and present guidelines do not distinguish between individual agents.

Type of preadmission glucose-lowering treatment and prognosis among patients hospitalised with myocardial infarction: a nationwide follow-up study

AIMS/HYPOTHESIS

We examined whether the type of preadmission glucose-lowering treatments explained differences in mortality rate and risk of readmission with myocardial infarction (MI) and heart failure following first-time hospitalisation for MI in patients with type 2 diabetes mellitus.

METHODS

We conducted a nationwide population-based follow-up study among all Danish patients hospitalised with first-time MI from 1996 to 2004. Data on use of glucose-lowering drugs and other medications, comorbidities, socioeconomic status, laboratory findings, readmission with MI and heart failure, and death were obtained from medical databases. We computed mortality rates and rates of MI and heart failure readmission, according to type of glucose-lowering treatment and used Cox's proportional hazards regression analysis to compute hazard ratios (HRs) as estimates of relative risks.

RESULTS

We identified 8,494 MI patients with type 2 diabetes mellitus. The overall cumulative 30 day and 1 year mortality rates were 22.2 and 36.6%, respectively. Patients not receiving any glucose-lowering drugs (adjusted 30 day HR: 0.79, 95% CI: 0.57-1.10) and users of any combination (adjusted 30 day HR: 1.43, 95% CI: 0.98-2.09) had the lowest and highest mortality rates, respectively, when compared with users of sulfonylureas. We found that glycaemic control had no impact on the risk estimates in a subanalysis including biochemical laboratory data. We found no differences in the risk of new MI and heart failure between the different glucose-lowering agents.

CONCLUSIONS/INTERPRETATION

Type of preadmission glucose-lowering treatment in monotherapy is not associated with substantial differences in prognosis following hospitalisation with MI. However, patients treated with any combination had increased mortality rates.

Sulfonylureas and the risk of myocardial infarction

Patients with diabetes mellitus have an increased risk of coronary artery diseases such as myocardial infarction. Sulfonylureas are used in the treatment of diabetes mellitus and have been linked with adverse cardiovascular effects due to an apparent effect on myocardial ischemic preconditioning. Individual sulfonylureas differ pharmacologically and may have different effects. Although the hypotheses were stimulated by animal studies and experimental studies using intermediate end points, data on the possible clinical implications in humans remain sparse. However, recent data seem reassuring.