Intensive management of hyperglycaemia in acute coronary syndromes. Study design and rationale of the BIOMArCS 2 glucose trial

IGF-1 is not related to long-term outcome in hyperglycemic acute coronary syndrome patients

PURPOSE

Insulin-like growth factor-1 (IGF-1) has been associated with both protective and detrimental effects on the development of ischemic heart disease. The relationship between IGF-1 levels and major adverse cardiovascular events (MACE) in acute coronary syndrome (ACS) patients remains unclear. This study aimed to investigate the relationship between IGF-1 admission levels in hyperglycemic ACS patients and: (1) MACE over a 5 years follow-up, (2) type 2 diabetes at discharge, and (3) post-ACS myocardial infarct size and dysfunction.

METHODS

This was a post hoc analysis of the BIOMArCS-2 randomized controlled trial. From July 2008 to February 2012, 276 ACS patients with admission plasma glucose level between 140 and 288 mg/dL were included. Records of the composite of all-cause mortality and recurrent non-fatal myocardial infarction were obtained during 5 years follow-up. Venous blood samples were collected on admission. IGF-1 was measured batchwise after study completion. Oral glucose tolerance test was performed to diagnose type 2 diabetes, whereas infarct size and left ventricular function were assessed by myocardial perfusion scintigraphy (MPS) imaging, 6 weeks post-ACS.

RESULTS

Cumulative incidence of MACE was 24% at 5 years follow-up. IGF-1 was not independently associated with MACE (HR:1.00 (95%CI:0.99-1.00), p = 0.29). Seventy-eight patients (28%) had type 2 diabetes at discharge, and the highest quartile of IGF-1 levels was associated with the lowest incidence of diabetes (HR:0.40 (95%CI:0.17-0.95), p = 0.037). IGF-1 levels were not associated with post-ACS myocardial infarct size and dysfunction.

CONCLUSIONS

IGF-1 carries potential for predicting type 2 diabetes, rather than long-term cardiovascular outcomes and post-ACS myocardial infarct size and dysfunction, in hyperglycemic ACS patients.

One-Year Outcome of Intensive Insulin Therapy Combined to Glucose-Insulin-Potassium in Acute Coronary Syndrome: A Randomized Controlled Study

Background

A number of factors may offset the cardioprotective effects of glucose‐insulin‐potassium (GIK) on outcome of patients with acute coronary syndrome, such as hyperglycemia induced by this cocktail infusion. We performed a study to evaluate the effect of intensive insulin therapy in association with GIK on 1‐year outcome in patients hospitalized for acute coronary syndrome.

Methods and Results

In a randomized prospective controlled trial we included 772 patients with non–ST‐segment elevation acute coronary syndrome. Patients were randomized into 3 groups: GIKI₂ group, who received GIK with intensive insulin therapy for 24 hours; GIK group, who received GIK with nonintensive insulin therapy; and control group, who received usual care. The primary outcome criteria were the rates of major cardiovascular events combining death, reinfarction, and stroke rate at 1 year. In addition, we measured platelet function assay‐100 and plasminogen activator inhibitor‐1 at admission and 24 hours later. Based on an intention‐to‐treat analysis, major cardiovascular events at 1 year was 12.8% in the GIKI₂ group, 15.5% in the GIK group, and 20.5% in the placebo group; the difference was significant between the GIK₂ and control groups (P=0.01). Platelet function assay‐100 at 24 hours decreased significantly from baseline in the control group but not in the GIKI₂ group. Plasminogen activator inhibitor‐1 decreased significantly in the GIKI₂ group but significantly increased in the control group. Minor hypoglycemic events were more frequent in the GIKI₂ group compared with other groups.

Conclusions

GIKI₂ led to improvement of 1‐year outcome rates in patients with non–ST‐segment elevation acute coronary syndrome. This beneficial effect was associated with a decrease in platelet reactivity and an increase on fibrinolysis tests.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00965406.

Hematological Parameters Improve Prediction of Mortality and Secondary Adverse Events in Coronary Angiography Patients: A Longitudinal Cohort Study

Prediction of primary cardiovascular events has been thoroughly investigated since the landmark Framingham risk score was introduced. However, prediction of secondary events after initial events of coronary artery disease (CAD) poses a new challenge. In a cohort of coronary angiography patients (n = 1760), we examined readily available hematological parameters from the UPOD (Utrecht Patient Oriented Database) and their addition to prediction of secondary cardiovascular events. Backward stepwise multivariable Cox regression analysis was used to test their ability to predict death and major adverse cardiovascular events (MACE). Continuous net reclassification improvement (cNRI) and integrated discrimination improvement (IDI) measures were calculated for the hematological parameters on top of traditional risk factors to assess prediction improvement. Panels of 3 to 8 hematological parameters significantly improved prediction of death and adverse events. The IDIs ranged from 0.02 to 0.07 (all P < 0.001) among outcome measures and the cNRIs from 0.11 to 0.40 (P < 0.001 in 5 of 6 outcome measures). In the hematological panels red cell distribution width (RDW) appeared most often. The multivariable adjusted hazard ratio of RDW per 1 standard deviation (SD) increase for MACE was 1.19 [1.08-1.32], P < 0.001. Routinely measured hematological parameters significantly improved prediction of mortality and adverse events in coronary angiography patients. Accurately indicating high-risk patients is of paramount importance in clinical decision-making.

Diabetes mellitus and acute coronary syndrome: lessons from randomized clinical trials

Diabetes mellitus is a major independent risk factor for acute coronary syndrome (ACS). In addition, diabetic patients with ACS suffer from increased mortality compared to their nondiabetic peers. Driven by multiple pathophysiological disturbances, such patients are predisposed to a proinflammatory, prothrombotic state, which may lead to plaque rupture. To counteract this more complex biology, several therapies and strategies have emerged, with some having unique preferential benefits in this population. Antiplatelet agents such as aspirin and clopidogrel have long been standard of care. Dose adjustment of these therapies remains the subject of continued research. Along with medical therapy, ACS diabetic patients preferentially benefit from primary percutaneous intervention compared to fibrinolysis. However, with advances in reperfusion techniques, the optimal strategy has yet to be determined. With these differences in ACS treatment responses, diabetic individuals may not just be a high-risk group, but may actually constitute a fundamentally different population, requiring dedicated clinical trials and individualized treatment regimens.