Piloting a novel algorithm for glucose control in the coronary care unit: the RECREATE (REsearching Coronary REduction by Appropriately Targeting Euglycemia) trial

Stress Induced Hyperglycemia in the Context of Acute Coronary Syndrome: Definitions, Interventions, and Underlying Mechanisms

Elevation of glucose level in response to acute coronary syndrome (ACS) has been recognized as stress induced hyperglycemia (SIH). Plenty of clinical studies have documented that SIH occurs very common in patients hospitalized with ACS, even in those without previously known diabetes mellitus. The association between elevated blood glucose levels with adverse outcome in the ACS setting is well-established. Yet, the precise definition of SIH in the context of ACS remains controversial, bringing confusions about clinical management strategy. Several randomized trials aimed to evaluate the effect of insulin-based therapy on outcomes of ACS patients failed to demonstrate a consistent benefit of intensive glucose control. Mechanisms underlying detrimental effects of SIH on patients with ACS are undetermined, oxidative stress might play an important role in the upstream pathways leading to subsequent harmful effects on cardiovascular system. This review aims to discuss various definitions of SIH and their values in predicting adverse outcome in the context of ACS, as well as the effect of intensive glucose control on clinical outcome. Finally, a glimpse of the underlying mechanisms is briefly discussed.

Stress-Induced Hyperglycaemia in Non-Diabetic Patients with Acute Coronary Syndrome: From Molecular Mechanisms to New Therapeutic Perspectives

Stress-induced hyperglycaemia (SIH) at hospital admission for acute coronary syndrome is associated with poor outcome, especially in patients without known diabetes. Nevertheless, insulin treatment in these subjects was not correlated with the reduction of mortality. This is likely due to the fact that SIH in the context of an acute coronary syndrome, compared to that in known diabetes, represents an epiphenomenon of other pathological conditions, such as adrenergic and renin-angiotensin system over-activity, hyperglucagonaemia, increase of circulating free fatty acids and pancreatic beta-cell dysfunction, which are not completely reversed by insulin therapy and so worsen the prognosis. Thus, SIH may be considered not only as a biomarker of organ damage, but also as an indicator of a more complex therapeutic strategy in these subjects. The aim of this review is to analyse the molecular mechanisms by which SIH may favour a worse prognosis in non-diabetic patients with acute coronary syndrome and identify new therapeutic strategies, in addition to insulin therapy, for a more appropriate treatment and improved outcomes.

Glycemic Variability Is a Powerful Independent Predictive Factor of Midterm Major Adverse Cardiac Events in Patients With Diabetes With Acute Coronary Syndrome

OBJECTIVE

Acute glucose fluctuations are associated with hypoglycemia and are emerging risk factors for cardiovascular outcomes. However, the relationship between glycemic variability (GV) and the occurrence of midterm major cardiovascular events (MACE) in patients with diabetes remains unclear. This study investigated the prognostic value of GV in patients with diabetes and acute coronary syndrome (ACS).

RESEARCH DESIGN AND METHODS

This study included consecutive patients with diabetes and ACS between January 2015 and November 2016. GV was assessed using SD during initial hospitalization. MACE, including new-onset myocardial infarction, acute heart failure, and cardiac death, were recorded. The predictive effects of GV on patient outcomes were analyzed with respect to baseline characteristics and cardiac status.

RESULTS

A total of 327 patients with diabetes and ACS were enrolled. MACE occurred in 89 patients (27.2%) during a mean follow-up of 16.9 months. During follow-up, 24 patients (7.3%) died of cardiac causes, 35 (10.7%) had new-onset myocardial infarction, and 30 (9.2%) were hospitalized for acute heart failure. Multivariable logistic regression analysis showed that GV >2.70 mmol/L, a Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) score >34, and reduced left ventricular ejection fraction of <40% were independent predictors of MACE, with odds ratios (ORs) of 2.21 (95% CI 1.64-2.98; P < 0.001), 1.88 (1.26-2.82; P = 0.002), and 1.71 (1.14-2.54; P = 0.009), respectively, whereas a Global Registry of Acute Coronary Events (GRACE) risk score >140 was not (OR 1.07 [0.77-1.49]; P = 0.69).

CONCLUSIONS

A GV cutoff value of >2.70 mmol/L was the strongest independent predictive factor for midterm MACE in patients with diabetes and ACS.

Hyperglycemia in Acute Coronary Syndromes: From Mechanisms to Prognostic Implications

Numerous studies have documented that hyperglycemia is frequent in patients hospitalized with acute coronary syndromes, affects patients with and without established diabetes, and is associated with adverse outcomes, with incremental increase in risk of mortality and complications observed across the spectrum of glucose elevations. This article reviews present knowledge about the association between glucose levels and outcomes of patients hospitalized with acute coronary syndromes; describes available data regarding inpatient glucose management in this patient group, and comparative data across the spectrum of critically ill hospitalized patients; addresses some controversies in this field; and offers practical recommendations for patient management based on existing data.

WITHDRAWN: Targeting intensive glycaemic control versus targeting conventional glycaemic control for type 2 diabetes mellitus

The Cochrane Metabolic and Endocrine Disorders Group withdrew this review as of Issue 7, 2015 because the involvement of two authors (C Hemmingsen and SS Lund) being employed in pharmaceutical companies. The authors of the review and the Cochrane Metabolic and Endocrine Disorders Group did not find that this was a breach of the rules of the Cochrane Collaboration at the time when it was published. However, after the publication of the review, the Cochrane Collaboration requested withdrawal of the review due to the employment of the two authors. A new protocol for a review to cover this topic will be published. This will have a new title and a markedly improved protocol fulfilling new and important developments and standards within the Cochrane Collaboration as well as an improved inclusion and search strategy making it necessary to embark on a completely new review project.

The editorial group responsible for this previously published document have withdrawn it from publication.

Targeting intensive glycaemic control versus targeting conventional glycaemic control for type 2 diabetes mellitus

BACKGROUND

Patients with type 2 diabetes mellitus (T2D) have an increased risk of cardiovascular disease and mortality compared to the background population. Observational studies report an association between reduced blood glucose and reduced risk of both micro- and macrovascular complications in patients with T2D. Our previous systematic review of intensive glycaemic control versus conventional glycaemic control was based on 20 randomised clinical trials that randomised 29 ,986 participants with T2D. We now report our updated review.

OBJECTIVES

To assess the effects of targeted intensive glycaemic control compared with conventional glycaemic control in patients with T2D.

SEARCH METHODS

Trials were obtained from searches of The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, LILACS, and CINAHL (all until December 2012).

SELECTION CRITERIA

We included randomised clinical trials that prespecified targets of intensive glycaemic control versus conventional glycaemic control targets in adults with T2D.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risk of bias and extracted data. Dichotomous outcomes were assessed by risk ratios (RR) and 95% confidence intervals (CI). Health-related quality of life and costs of intervention were assessed with standardized mean differences (SMD) and 95% Cl.

MAIN RESULTS

Twenty-eight trials with 34,912 T2D participants randomised 18,717 participants to intensive glycaemic control versus 16,195 participants to conventional glycaemic control. Only two trials had low risk of bias on all risk of bias domains assessed. The duration of the intervention ranged from three days to 12.5 years. The number of participants in the included trials ranged from 20 to 11,140. There were no statistically significant differences between targeting intensive versus conventional glycaemic control for all-cause mortality (RR 1.00, 95% CI 0.92 to 1.08; 34,325 participants, 24 trials) or cardiovascular mortality (RR 1.06, 95% CI 0.94 to 1.21; 34,177 participants, 22 trials). Trial sequential analysis showed that a 10% relative risk reduction could be refuted for all-cause mortality. Targeting intensive glycaemic control did not show a statistically significant effect on the risks of macrovascular complications as a composite outcome in the random-effects model, but decreased the risks in the fixed-effect model (random RR 0.91, 95% CI 0.82 to 1.02; and fixed RR 0.93, 95% CI 0.87 to 0.99; P = 0.02; 32,846 participants, 14 trials). Targeting intensive versus conventional glycaemic control seemed to reduce the risks of non-fatal myocardial infarction (RR 0.87, 95% CI 0.77 to 0.98; P = 0.02; 30,417 participants, 14 trials), amputation of a lower extremity (RR 0.65, 95% CI 0.45 to 0.94; P = 0.02; 11,200 participants, 11 trials), as well as the risk of developing a composite outcome of microvascular diseases (RR 0.88, 95% CI 0.82 to 0.95; P = 0.0008; 25,927 participants, 6 trials), nephropathy (RR 0.75, 95% CI 0.59 to 0.95; P = 0.02; 28,096 participants, 11 trials), retinopathy (RR 0.79, 95% CI 0.68 to 0.92; P = 0.002; 10,300 participants, 9 trials), and the risk of retinal photocoagulation (RR 0.77, 95% CI 0.61 to 0.97; P = 0.03; 11,212 participants, 8 trials). No statistically significant effect of targeting intensive glucose control could be shown on non-fatal stroke, cardiac revascularization, or peripheral revascularization. Trial sequential analyses did not confirm a reduction of the risk of non-fatal myocardial infarction but confirmed a 10% relative risk reduction in favour of intensive glycaemic control on the composite outcome of microvascular diseases. For the remaining microvascular outcomes, trial sequential analyses could not establish firm evidence for a 10% relative risk reduction. Targeting intensive glycaemic control significantly increased the risk of mild hypoglycaemia, but substantial heterogeneity was present; severe hypoglycaemia (RR 2.18, 95% CI 1.53 to 3.11; 28,794 participants, 12 trials); and serious adverse events (RR 1.06, 95% CI 1.02 to 1.10; P = 0.007; 24,280 participants, 11 trials). Trial sequential analysis for a 10% relative risk increase showed firm evidence for mild hypoglycaemia and serious adverse events and a 30% relative risk increase for severe hypoglycaemia when targeting intensive versus conventional glycaemic control. Overall health-related quality of life, as well as the mental and the physical components of health-related quality of life did not show any statistical significant differences.

AUTHORS' CONCLUSIONS

Although we have been able to expand the number of participants by 16% in this update, we still find paucity of data on outcomes and the bias risk of the trials was mostly considered high. Targeting intensive glycaemic control compared with conventional glycaemic control did not show significant differences for all-cause mortality and cardiovascular mortality. Targeting intensive glycaemic control seemed to reduce the risk of microvascular complications, if we disregard the risks of bias, but increases the risk of hypoglycaemia and serious adverse events.

Glucose variability: An emerging target for the treatment of diabetes mellitus

Alterations in glucose metabolism in individuals with diabetes have been considered for many years, as they appear at first glance, i.e., simply as hyperglycemia, and its surrogate marker, glycated hemoglobin (HbA1c), used both to estimate the risk of developing diabetic complications and to define the targets and measure the efficacy of diabetes treatments. However, over time diabetes-related glycemic alterations have been considered in more complex terms, by attempting to identify the role of fasting glycemia, postprandial glycemia and hypoglycemia in the overall assessment of the disease. This set of evaluations has led to the concept of glucose variability. Although intuitively easy to understand, it cannot be equally simply translated into terms of definition, measuring, prognostic and therapeutic impact. The literature available on glucose variability is extensive yet confused, with the only common element being the need to find out more on the subject. The purpose of this manuscript is not only to review the most recent evidence on glucose variability, but also to help the reader to better understand the available measurement options, and how the various definitions can differently be related with the development of diabetic complications. Finally, we provide how new and old drugs can impact on glucose variability.

LOGIC-insulin algorithm-guided versus nurse-directed blood glucose control during critical illness: the LOGIC-1 single-center, randomized, controlled clinical trial

OBJECTIVE

Tight blood glucose control (TGC) in critically ill patients is difficult and labor intensive, resulting in poor efficacy of glycemic control and increased hypoglycemia rate. The LOGIC-Insulin computerized algorithm has been developed to assist nurses in titrating insulin to maintain blood glucose levels at 80-110 mg/dL (normoglycemia) and to avoid severe hypoglycemia (<40 mg/dL). The objective was to validate clinically LOGIC-Insulin relative to TGC by experienced nurses.

RESEARCH DESIGN AND METHODS

The investigator-initiated LOGIC-1 study was a prospective, parallel-group, randomized, controlled clinical trial in a single tertiary referral center. A heterogeneous mix of 300 critically ill patients were randomized, by concealed computer allocation, to either nurse-directed glycemic control (Nurse-C) or algorithm-guided glycemic control (LOGIC-C). Glycemic penalty index (GPI), a measure that penalizes both hypoglycemic and hyperglycemic deviations from normoglycemia, was the efficacy outcome measure, and incidence of severe hypoglycemia (<40 mg/dL) was the safety outcome measure.

RESULTS

Baseline characteristics of 151 Nurse-C patients and 149 LOGIC-C patients and study times did not differ. The GPI decreased from 12.4 (interquartile range 8.2-18.5) in Nurse-C to 9.8 (6.0-14.5) in LOGIC-C (P < 0.0001). The proportion of study time in target range was 68.6 ± 16.7% for LOGIC-C patients versus 60.1 ± 18.8% for Nurse-C patients (P = 0.00016). The proportion of severe hypoglycemic events was decreased in the LOGIC-C group (Nurse-C 0.13%, LOGIC-C 0%; P = 0.015) but not when considered as a proportion of patients (Nurse-C 3.3%, LOGIC-C 0%; P = 0.060). Sampling interval was 2.2 ± 0.4 h in the LOGIC-C group versus 2.5 ± 0.5 h in the Nurse-C group (P < 0.0001).

CONCLUSIONS

Compared with expert nurses, LOGIC-Insulin improved efficacy of TGC without increasing rate of hypoglycemia.

Guidelines for the use of an insulin infusion for the management of hyperglycemia in critically ill patients

OBJECTIVE

To evaluate the literature and identify important aspects of insulin therapy that facilitate safe and effective infusion therapy for a defined glycemic end point.

METHODS

Where available, the literature was evaluated using Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to assess the impact of insulin infusions on outcome for general intensive care unit patients and those in specific subsets of neurologic injury, traumatic injury, and cardiovascular surgery. Elements that contribute to safe and effective insulin infusion therapy were determined through literature review and expert opinion. The majority of the literature supporting the use of insulin infusion therapy for critically ill patients lacks adequate strength to support more than weak recommendations, termed suggestions, such that the difference between desirable and undesirable effect of a given intervention is not always clear.

RECOMMENDATIONS

The article is focused on a suggested glycemic control end point such that a blood glucose ≥ 150 mg/dL triggers interventions to maintain blood glucose below that level and absolutely <180 mg/dL. There is a slight reduction in mortality with this treatment end point for general intensive care unit patients and reductions in morbidity for perioperative patients, postoperative cardiac surgery patients, post-traumatic injury patients, and neurologic injury patients. We suggest that the insulin regimen and monitoring system be designed to avoid and detect hypoglycemia (blood glucose ≤ 70 mg/dL) and to minimize glycemic variability.Important processes of care for insulin therapy include use of a reliable insulin infusion protocol, frequent blood glucose monitoring, and avoidance of finger-stick glucose testing through the use of arterial or venous glucose samples. The essential components of an insulin infusion system include use of a validated insulin titration program, availability of appropriate staffing resources, accurate monitoring technology, and standardized approaches to infusion preparation, provision of consistent carbohydrate calories and nutritional support, and dextrose replacement for hypoglycemia prevention and treatment. Quality improvement of glycemic management programs should include analysis of hypoglycemia rates, run charts of glucose values <150 and 180 mg/dL. The literature is inadequate to support recommendations regarding glycemic control in pediatric patients.

CONCLUSIONS

While the benefits of tight glycemic control have not been definitive, there are patients who will receive insulin infusion therapy, and the suggestions in this article provide the structure for safe and effective use of this therapy.

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.