Challenges in the conduct of large simple trials of important generic questions in resource-poor settings: the CREATE and ECLA trial program evaluating GIK (glucose, insulin and potassium) and low-molecular-weight heparin in acute myocardial infarction

Quality of inpatient care in public and private hospitals in Sri Lanka

OBJECTIVE

To compare the quality of inpatient clinical care in public and private hospitals in Sri Lanka.

METHODS

A retrospective, cross-sectional comparison was done of inpatient quality, in a sample of 11 public and 10 private hospitals in three of 25 districts. Data were collected for 55 quality indicators from medical records of 2523 public and 1815 private inpatient admissions. These covered treatment of asthma, acute myocardial infarction (AMI), childbirth and five other conditions, along with outcome indicators, and medicine prescribing indicators.

RESULTS

Overall quality scores were better in the public sector than the private sector (77 vs 69%). Performance was similar for management of AMI and childbirth and somewhat better in the private sector for management of asthma. The public sector performed better in those indicators that are not constrained by resources (94 vs 81%), but worse in indicators that are highly resource intensive (10 vs 31%). Quality was comparable in assessment and investigation, but the public sector performed better in treatment and management (70 vs 62%) and drug prescribing (68 vs 60%), and modestly worse in terms of outcomes (92 vs 97%).

CONCLUSIONS

For a range of indicators where comparisons were possible, quality of inpatient clinical care in Sri Lanka was comparable to levels reported from upper-middle income Asian countries, and often approaches that in developed countries, although the findings cannot be generalized. Quality in the public sector is better than in the private sector in many areas, despite spending being substantially less. Quality in public hospitals is resource constrained, and needs greater government investment for improvement, but when resource limitations are not critical, the public sector appears able to deliver equal or better quality than the private sector. Overall similarities in quality between the two sectors suggest the importance of physician training and other factors.

A predictive model to identify patients with suspected acute coronary syndromes at high risk of cardiac arrest or in-hospital mortality: An IMMEDIATE Trial sub-study,,

BACKGROUND

The IMMEDIATE Trial of emergency medical service use of intravenous glucose-insulin-potassium (GIK) very early in acute coronary syndromes (ACS) showed benefit for the composite outcome of cardiac arrest or in-hospital mortality.

OBJECTIVES

This analysis of IMMEDIATE Trial data sought to develop a predictive model to help clinicians identify patients at highest risk for this outcome and most likely to benefit from GIK.

METHODS

Multivariable logistic regression was used to develop a predictive model for the composite endpoint cardiac arrest or in-hospital mortality using the 460 participants in the placebo arm of the IMMEDIATE Trial.

RESULTS

The final model had four variables: advanced age, low systolic blood pressure, ST elevation in the presenting electrocardiogram, and duration of time since ischemic symptom onset. Predictive performance was good, with a C statistic of 0.75, as was its calibration. Stratifying patients into three risk categories based on the model's predictions, there was an absolute risk reduction of 8.6% with GIK in the high-risk tertile, corresponding to 12 patients needed to treat to prevent one bad outcome. The corresponding values for the low-risk tertile were 0.8% and 125, respectively.

CONCLUSIONS

The multivariable predictive model developed identified patients with very early ACS at high risk of cardiac arrest or death. Using this model could assist treating those with greatest potential benefit from GIK.

Glucose-insulin-potassium solution protects ventricular myocytes of neonatal rat in an in vitro coverslip ischemia/reperfusion model

Background and Objectives

The benefit of high glucose-insulin-potassium (GIK) solution in clinical applications is controversial. We established a neonatal rat ventricular myocyte (NRVM) in vitro coverslip ischemia/reperfusion (I/R) model and investigated the effects of GIK solution on suppressing reactive oxygen species (ROS) and upregulating O-GlcNacylation, which protects cells from ischemic injury.

Materials and Methods

NRVMs were isolated from postnatal day 3-4 Sprague-Dawley rat pups and grown in Dulbecco's modified Eagle's medium containing high glucose (4.5 g/L), fetal bovine serum, and penicillin/streptomycin. The effects of the GIK solution on ROS production, apoptosis, and expression of O-GlcNAc and O-GlcNAc transferase (OGT) were investigated in the coverslip I/R model.

Results

Covering the 24-well culture plates for 3 hr with 12 mm diameter coverslips resulted in the appropriate ischemic shock. Glucose and insulin synergistically reduced ROS production, protected NRVM dose-dependently from apoptosis, and altered O-GlcNAc and OGT expression.

Conclusion

The high GIK solution protected NRVM from I/R injury in vitro by reducing ROS and altering O-GlcNacylation.

Nonantithrombotic medical options in acute coronary syndromes: old agents and new lines on the horizon

Acute coronary syndromes (ACS) constitute a spectrum of clinical presentations ranging from unstable angina and non-ST-segment elevation myocardial infarction to ST-segment myocardial infarction. Myocardial ischemia in this context occurs as a result of an abrupt decrease in coronary blood flow and resultant imbalance in the myocardial oxygen supply-demand relationship. Coronary blood flow is further compromised by other mechanisms that increase coronary vascular resistance or reduce coronary driving pressure. The goals of treatment are to decrease myocardial oxygen demand, increase coronary blood flow and oxygen supply, and limit myocardial injury. Treatments are generally divided into disease-modifying agents or interventions that improve hard clinical outcomes and other strategies that can reduce ischemia. In addition to traditional drugs such as β-blockers and inhibitors of the renin-angiotensin-aldosterone system, newer agents have expanded the number of molecular pathways targeted for treatment of ACS. Ranolazine, trimetazidine, nicorandil, and ivabradine are medications that have been shown to reduce myocardial ischemia through diverse mechanisms and have been tested in limited fashion in patients with ACS. Attenuating the no-reflow phenomenon and reducing the injury compounded by acute reperfusion after a period of coronary occlusion are active areas of research. Additionally, interventions aimed at ischemic pre- and postconditioning may be useful means by which to limit myocardial infarct size. Trials are also underway to examine altered metabolic and oxygen-related pathways in ACS. This review will discuss traditional and newer anti-ischemic therapies for patients with ACS, exclusive of revascularization, antithrombotic agents, and the use of high-intensity statins.

Lessons learned in the conduct of a global, large simple trial of treatments indicated for schizophrenia

Large, "practical" or streamlined trials (LSTs) are used to study the effectiveness and/or safety of medicines in real world settings with minimal study imposed interventions. While LSTs have benefits over traditional randomized clinical trials and observational studies, there are inherent challenges to their conduct. Enrollment and follow-up of a large study sample of patients with mental illness pose a particular difficulty. To assist in overcoming operational barriers in future LSTs in psychiatry, this paper describes the recruitment and observational follow-up strategies used for the ZODIAC study, an international, open-label LST, which followed 18,239 persons randomly assigned to one of two treatments indicated for schizophrenia for 1 year. ZODIAC enrolled patients in 18 countries in North America, South America, Europe, and Asia using broad study entry criteria and required minimal clinical care intervention. Recruitment of adequate numbers and continued engagement of both study centers and subjects were significant challenges. Strategies implemented to mitigate these in ZODIAC include global study expansion, study branding, field coordinator and site relations programs, monthly site newsletters, collection of alternate contact information, conduct of national death index (NDI) searches, and frequent sponsor, contract research organization (CRO) and site interaction to share best practices and address recruitment challenges quickly. We conclude that conduct of large LSTs in psychiatric patient populations is feasible, but importantly, realistic site recruitment goals and maintaining site engagement are key factors that need to be considered in early study planning and conduct.

Management of hyperglycemia in a hospitalized patient with diabetes mellitus and cardiovascular disease

Hyperglycemia in patients with and without known diabetes is a common finding in patients hospitalized with cardiovascular disease, and is associated with poor outcomes. Investigators have been examining the role of insulin to treat patients with acute myocardial infarction since the 1960's. Until the 1990's most studies evaluated fixed doses of glucose-insulin-potassium (GIK) infusions. The Diabetes Mellitus Insulin-Glucose Infusion in Acute Myocardial Infarction (DIGAMI) trial, published in 1995, evaluated the role of adjustable-dose insulin infusion to lower blood glucose. Its promising results spurred further interest and a number of trials evaluating the use of insulin to lower blood glucose in hospitalized patients - many of which included patients with cardiovascular disease - have been conducted over the last two decades with conflicting results. This manuscript reviews the epidemiology and pathophysiology of hyperglycemia in hospitalized patients, summarizes the evidence for benefits and harms of using insulin to treat hyperglycemic patients hospitalized with cardiovascular disease, and offers some practical management considerations.

The role of insulin therapy and glucose normalisation in patients with acute coronary syndrome

Patients with acute myocardial infarction (AMI) and diabetes mellitus, as well as patients admitted with elevated blood glucose without known diabetes, have impaired outcome. Therefore intensive glucose-lowering therapy with insulin (IGL) has been proposed in diabetic or hyperglycaemic patients and has been shown to improve survival and reduce incidence of adverse events. The current manuscript provides an overview of randomised controlled trials investigating the effect of IGL. Furthermore, systematic glucose-insulin-potassium infusion (GIK) has been studied to improve outcome after AMI. In spite of positive findings in some early studies, GIK did not show any beneficial effects in recent clinical trials and thus this concept has been abandoned. While IGL targeted to achieve normoglycaemia improves outcome in patients with AMI, achievement of glucose regulation is difficult and carries the risk of hypoglycaemia. More research is needed to determine the optimal glucose target levels in AMI and to investigate whether computerised glucose protocols and continuous glucose sensors can improve safety and efficacy of IGL.

Targeting malonyl CoA inhibition of mitochondrial fatty acid uptake as an approach to treat cardiac ischemia/reperfusion

Cardiovascular disease is the major cause of death and disability in the world, with ischemic heart disease accounting for the vast majority of this health problem. Current treatments for ischemic heart disease are primarily aimed at either increasing blood and oxygen supply to the heart or decreasing the heart's oxygen demand. A novel treatment strategy involves increasing the efficiency of oxygen use by the heart. During and following ischemia, the heart can become inefficient in using oxygen, due in part to an excessive use of fatty acids as a source of fuel. One potential strategy to increase cardiac efficiency is to inhibit this use of fatty acid oxidation as a fuel source, while stimulating the use of glucose oxidation as a fuel source, which allows the heart to produce energy more efficiently and reduces the acidosis associated with ischemia/reperfusion, both of which are beneficial to the heart. Malonyl CoA is a potent endogenous inhibitor of cardiac fatty acid oxidation, secondary to inhibition of carnitine palmitoyl transferase-I, the gatekeeper of mitochondrial fatty acid uptake. Malonyl CoA is synthesized in the heart by acetyl CoA carboxylase and degraded by malonyl CoA decarboxylase (MCD). Strategies aimed at increasing cardiac malonyl CoA levels, such as via inhibition of MCD, are associated with a decrease in fatty acid oxidation rates, and a parallel increase in glucose oxidation rates. This is associated with a decrease in acidosis and an improvement in cardiac function and efficiency during and following ischemia. Therefore, targeting malonyl CoA is a novel exciting approach for the treatment of cardiac ischemia/reperfusion.

Insulin therapy in acute coronary syndromes: an appraisal of completed and ongoing randomised trials with important clinical end points

Insulin therapy was first proposed as an adjunctive therapy in patients with acute coronary syndromes (ACS) in the 1960s. Since then, numerous randomised clinical trials have been conducted to determine the efficacy and to define the role of insulin therapy in ACS. This review will discuss: 1) completed trials of insulin therapy in ACS, including both glucose-insulin-potassium (GIK) approaches and non-GIK approaches; 2) trials of insulin therapy in critically ill non-ACS patients and the lessons from these trials that can be applied to trials of insulin in ACS patients; and 3) a summary of ongoing and planned trials of insulin in ACS patients.

The malonyl CoA axis as a potential target for treating ischaemic heart disease

Cardiovascular disease is the leading cause of death and disability for people living in western societies, with ischaemic heart disease accounting for the majority of this health burden. The primary treatment for ischaemic heart disease consists of either improving blood and oxygen supply to the heart or reducing the heart's oxygen demand. Unfortunately, despite recent advances with these approaches, ischaemic heart disease still remains a major health problem. Therefore, the development of new treatment strategies is still required. One exciting new approach is to optimize cardiac energy metabolism, particularly by decreasing the use of fatty acids as a fuel and by increasing the use of glucose as a fuel. This approach is beneficial in the setting of ischaemic heart disease, as it allows the heart to produce energy more efficiently and it reduces the degree of acidosis associated with ischaemia/reperfusion. Malonyl CoA is a potent endogenous inhibitor of cardiac fatty acid oxidation, secondary to inhibiting carnitine palmitoyl transferase-I, the rate-limiting enzyme in the mitochondrial uptake of fatty acids. Malonyl CoA is synthesized in the heart by acetyl CoA carboxylase, which in turn is phosphorylated and inhibited by 5'AMP-activated protein kinase. The degradation of myocardial malonyl CoA occurs via malonyl CoA decarboxylase (MCD). Previous studies have shown that inhibiting MCD will significantly increase cardiac malonyl CoA levels. This is associated with an increase in glucose oxidation, a decrease in acidosis, and an improvement in cardiac function and efficiency during and following ischaemia. Hence, the malonyl CoA axis represents an exciting new target for the treatment of ischaemic heart disease.

Randomized Trials in Vulnerable Populations

Many persons enrolled in clinical trials can be considered vulnerable, and such trials often raise concerns because of the diminished ability of vulnerable persons to consider and protect their own interests. However, this research is necessary to answer important questions, such as which interventions are effective, which have no impact, and which do more harm than good. In this article, we identified six specific challenges associated with randomized clinical trials in vulnerable populations and have suggested several potential solutions to overcome these challenges. First addressed were macro issues, such as the scope of the problem, and research capacity in terms of funding and investigators. Next, we have addressed research ethics review, informed consent, regulatory hurdles, and serious adverse event reporting. As clinical trials are expanding globally, all stakeholders (investigators, granting agencies, REBs, DSMBs, regulatory bodies, universities, hospitals, clinicians, patients, and family members) should be aware of the challenges we have outlined, and work collaboratively toward effective solutions that improve the quality, quantity, safety, and relevance of clinical trials for vulnerable persons around the world. Clinical Trials 2008; 5: 61—69. http://ctj.sagepub.com

Importance and challenges of studying marketed drugs: what is a phase IV study? Common clinical research designs, registries, and self-reporting systems

The new drug application database submitted to the US Food and Drug Administration for drug approval (phases I-III or phases 1-3) is limited both in scope and size. Although randomized controlled trials, the hallmark of phase III trials, are the gold standard for the drug-approval process, they invariably have a number of limitations, including relatively small sample sizes, selective populations, short follow-up, the use of intermediate (surrogate) endpoints (almost always), and limited generalizability. The challenges of monitoring drugs once approved are also numerous. After approval by the Food and Drug Administration, marketed drugs undergo continued scrutiny, and this scrutiny is increasing because of problems that have surfaced with some drugs after their approval. Postmarketing research includes a variety of study designs and the use of registries and self-reporting of drug side effects. Along with this has come great confusion about what postmarketing research is and what a phase IV study is. Among the important strengths of phase IV research are the exposure of a broader range of patients to the drug under study, resulting in more "real-world" information about the drug's safety and efficacy, and consideration of a broader range of clinical endpoints. As a result, phase IV, or postmarketing research, has become an integral part of the drug evaluation process for a wide range of agents. The authors discuss the different types of study designs that are common under the phase IV terminology and provide some examples. They also discuss the use of registries and self-reporting of adverse events using the MedWatch System.