Effects of glucose and fatty acids on myocardial ischaemia and arrhythmias

Rationale, design, and baseline characteristics for a large international trial of cardiovascular disease prevention in people with dysglycemia: the ORIGIN Trial (Outcome Reduction with an Initial Glargine Intervention)

AIMS

Impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and diabetes arise due to insufficient insulin secretion and are risk factors for cardiovascular (CV) events. Thus, targeting normal fasting glucose levels with insulin may reduce CV events. Previous studies suggest that omega-3 fatty acid supplements may reduce CV death; however, their effect in high-risk dysglycemic individuals is not known.

METHODS

People aged > or = 50 years with evidence of CV disease and with IFG, IGT, newly detected or established diabetes (on 0 or 1 oral agent), and a local glycated hemoglobin < 150% of the upper limit of normal for that assay were recruited and allocated to (a) either 1 daily injection of insulin glargine with the dose titrated to achieve a fasting plasma glucose < or = 5.3 mmol/L (95 mg/dL), or standard glycemic care; and (b) either omega-3-acid ethyl esters 90 (1 g consisting of EPA 465 mg and DHA 375 mg) or identical placebo, according to a 2 x 2 factorial design. The 2 different primary outcomes for the insulin and omega-3 fatty acid arms are CV events and CV death, respectively.

RESULTS

A total of 12,612 (mean age 64, 35% women) people in 40 countries were randomized during a 2-year period ending December 2005. Eighty-two percent had established diabetes, 6% had new diabetes, and 12% had IGT or IFG; the mean fasting plasma glucose was 7.3 mmol/L (131 mg/dL).

CONCLUSIONS

The ORIGIN trial will determine whether or not either or both of these interventions can reduce CV events.

In patients with ST-segment elevation myocardial infarction with cardiogenic shock treated with percutaneous coronary intervention, admission glucose level is a strong independent predictor for 1-year mortality in patients without a prior diagnosis of diabetes

BACKGROUND

Primary percutaneous coronary intervention (PCI) reduces mortality in patients with ST-segment elevation myocardial infarction (STEMI) complicated by cardiogenic shock (CS). Despite PCI, mortality in CS is still approximately 50%. Admission glucose concentration is an independent predictor of mortality in patients with STEMI and is associated with the occurrence of CS. Whether admission glucose is also a predictor of mortality in CS patients treated with primary PCI is unexplored. We therefore assessed the relation between admission glucose concentration and 1-year mortality in patients with STEMI with CS without a prior diagnosis of diabetes on admission and treated with PCI.

METHODS

We investigated a cohort of 208 consecutive patients with STEMI without a prior diagnosis of diabetes with CS on admission. Patients were classified according to glucose levels at admission: <7.8 mmol/L (group 1, n = 57), 7.8 to 11 mmol/L (group 2, n = 71), and >11.0 mmol/L (group 3, n = 80).

RESULTS

The overall 1-year mortality was 38%. One-year mortality was 21%, 27%, and 60% in groups I, II, and III, respectively (P < .001). In a multivariate logistic regression analysis, the odds for mortality increased by 16% for every 1 mmol/L increase in plasma glucose concentration (OR 1.155, 95% CI 1.070-1.247), after adjustment for left ventricular ejection fraction <40%, age older than 75 years, male sex, and thrombolysis in myocardial infarction 3 flow after PCI.

CONCLUSIONS

In patients with STEMI with CS and without a prior diagnosis of diabetes undergoing primary PCI, admission glucose concentration is a very strong independent predictor for 1-year mortality. Further studies are warranted to determine whether concomitant glycometabolic regulation in patients with STEMI treated with PCI, particularly those with CS, will improve clinical outcome.

Baseline glucose and left ventricular remodeling after acute myocardial infarction

In patients with acute myocardial infarction (AMI), the mechanisms behind the increased mortality related to glucose levels (GL) are poorly understood. The main purpose of this study is to analyze the relationship between baseline glucose and left ventricular enlargement (LVE). We analyzed 52 patients with a first ST-elevation AMI <24 h of evolution. Glucose levels were obtained upon admission (median time, 3 h after the beginning of chest pain). The median GL was 123.5 mg/dl, and patients above this limit were considered hyperglycemic (n=26). Left ventricular enlargement was analyzed comparing two radionuclide ventriculographies, the first obtained within 4 days post-AMI (median, 55 h) and the second 6 months later (median, 188.5 days), taking into account the difference in the obtained end-systolic volumes. Myocardial reperfusion was evaluated comparing ST resolution between a first ECG done immediately upon hospital arrival with a second ECG performed 2 h after treatment. By univariate analysis, LVE correlated significantly with baseline hyperglycemia (P<.001), failed reperfusion by ECG criteria (P<.001), and no use of ACE inhibitors or AT1 blockers (P=.046) and aspirin (P=.046). A history of previous diabetes did not correlate significantly with LVE at 6 months. In the adjusted model, basal hyperglycemia (P<.001) and failed reperfusion (P=.001) were the only variables independently correlated with LVE. In conclusion, baseline glucose is a powerful and independent predictor of LVE after AMI, which reinforces the importance of a tight glucose control during the initial phase of the disease.

[Hyperglycemia and mortality in critically ill children]

Several pathologic conditions are accompanied by stress-induced hyperglycemia in non-diabetic individuals which influences mortality and morbidity.

AIMS

Prospective studies in adults support that glycemic control is an independent predictor of survival and normoglycemia has a beneficial effect on the outcome of patients. Few data are available in children, however a retrospective study documented significant correlation between mortality and duration, intensity and peak value of hyperglycemia. In the present study, the authors investigated the relationship between blood glucose level and pathological process in a multidisciplinary pediatric intensive care department retrospectively.

RESULTS

It has been shown that highest blood glucose values were associated with fatal outcome independent of diagnosis (mean: 14,38 mmol/l) and with septicemia independent of final outcome (mean: 13,97 mmol/l). Patients with fatal outcome were hyperglycemic during the total duration (mean: 7,59 mmol/l) and on the last day (mean: 7,00 mmol/l) of treatment. Patients who survived had significantly lower blood glucose over the whole duration (mean: 6,52 mmol/l; p < 0,01) and on the last day of treatment (mean: 5,28 mmol/l; p < 0,01) than those who died. Percent of treatment days with blood glucose > = 6,1 mmol/l was significantly lower in case of survival as compared with fatal cases (42,68 vs. 74.07 %; p < 0,01) and the highest rate was observed in those with fatal septcemia (mean: 76,52 %).

CONCLUSIONS

These data support that, similarly to adults, critical condition in children induces sustained hyperglycemia and higher peak values and longer duration of elevated blood glucose are associated with higher mortality rate. Septicemia proved to be potent inductor of abnormalities of carbohydrate metabolism.

Impact of fasting glycemia on short-term prognosis after acute myocardial infarction

OBJECTIVE

The prognosis of patients with acute myocardial infarction (MI), according to the new criteria for impaired fasting glucose (IFG) (FG 100-126 mg/dl), has not been evaluated.

RESEARCH DESIGN AND METHODS

A total of 2353 patients with acute MI and surviving at d 5 after admission were analyzed for short-term morbidity and mortality. FG was obtained at d 4 and 5. Patients were classified as diabetes mellitus (known diabetes or FG > or = 126 mg/dl), high IFG (110 < or = FG < 126 mg/dl), low IFG (100 < or = FG < 110 mg/dl), and normal fasting glucose (NFG) (FG < 100 mg/dl).

RESULTS

Among the 2353 patients, 968 (41%) had diabetes mellitus, 262 (11%) had high IFG, 332 (14%) had low IFG, and 791 (34%) had NFG. Compared with NFG patients, 30-d cardiovascular mortality was increased in high but not low IFG subjects. In-hospital heart failure was increased in high IFG subjects (42 vs. 20% for NFG, P < 0.0001) but not low IFG subjects (21 vs. 20%). High IFG, but not low IFG, was an independent factor associated with 30-d cardiovascular mortality [odds ratio 2.33 (1.55-3.47)] and in-hospital heart failure [odds ratio 1.70 (1.36-2.07)]. The optimal threshold levels of FG on the receiver-operating characteristic curves were 114 and 112 mg/dl to predict mortality and in-hospital heart failure, respectively.

CONCLUSION

The present study, based on a nonselected cohort of MI patients, underscores the high prevalence of IFG (25%) and highlights the clinical relevance of 110 mg/dl, but not 100 mg/dl, as a cutoff value to define the risk for worse outcome.

The role of hyperglycemia in acute ischemic stroke

Stroke remains a leading cause of death and long-term disability in the developed world. Reperfusion and anti-thrombotic therapies are of limited benefit for the majority of patients following acute ischemic stroke, and increasing interest has focused on therapeutic approaches that seek to modulate infarct evolution. Animal and human studies have linked hyperglycemia in the acute phase of ischemic stroke to worse clinical outcomes regardless of the presence of pre-existing diabetes mellitus. Experimental data suggest that elevated blood glucose may directly contribute to infarct expansion through a number of maladaptive metabolic pathways, and that treatment with insulin may attenuate these adverse effects. In this review, we analyze the relationship between elevated serum glucose and acute cerebrovascular ischemia, and critically appraise the potential of a clinical strategy that targets euglycemia in all acute stroke patients.

Emerging drugs for acute and chronic heart failure: current and future developments

Heart failure continues to be a major public health issue. Although angiotensin-converting enzyme inhibitors and beta-adrenergic blockers have been broadly used as evidence-based therapies in heart failure, morbidity and mortality remains high. Furthermore, treatment for acute decompensated heart failure and diastolic heart failure (or 'heart failure with preserved ejection fraction') is far from perfect. This review provides a broad overview of some of the novel compounds under investigation for the treatment of heart failure. Novel strategies include drugs that aim to alleviate congestion and improve hemodynamics, drugs that preserve renal function, drugs that reduce arterial and myocardial stiffness, drugs that module myocardial contractility, drugs that affect metabolic and hormonal balance, and drugs that act on existing and novel physiologic targets.

Reduction of surgical mortality and morbidity in diabetic patients undergoing cardiac surgery with a combined intravenous and subcutaneous insulin glucose management strategy

OBJECTIVE

To determine if glucose management in postcardiothoracic surgery patients with a combined intravenous (IV) and subcutaneous (SC) insulin regimen reduces mortality and morbidity in patients with diabetes and stress-induced hyperglycemia.

RESEARCH DESIGN AND METHODS

Retrospective review of 614 consecutive patients who underwent cardiothoracic (CT) surgery in 2005 was performed to evaluate the incidence and treatment of postoperative hyperglycemia and operative morbidity and mortality. Hyperglycemic patients (glucose >6.05 mmol/l) were treated with IV insulin in the intensive care unit (ICU) followed by SC insulin (outside ICU). Subgroup analysis was performed on 159 coronary artery bypass grafting (CABG)-only patients.

RESULTS

Among all CT surgeries, patients with a preoperative diagnosis of diabetes had higher rates of postoperative mortality (7.3 vs. 3.3%; P = 0.03) and pulmonary complications (19.5 vs. 11.6%; P = 0.02) but had similar rates of infections and cardiac, renal, and neurological complications on univariate analysis. However, on multivariate analysis, a preoperative diagnosis of diabetes was not a significant factor in postoperative mortality or pulmonary complications. In CABG-only patients, no significant differences were seen in outcomes between diabetic and nondiabetic patients. Independent of diabetic status, glucose > or =11 mmol/l on ICU admission was predictive of higher rates of mortality and renal, pulmonary, and cardiac postoperative complications.

CONCLUSIONS

A combination of IV insulin (in the ICU) and SC insulin (outside the ICU), a less costly and less nursing-intensive therapy than 3 days of IV insulin postoperatively, results in a reduction of the increased surgical morbidity and mortality in diabetic patients after CT surgery.

Intensive insulin therapy in the intensive cardiac care unit

Treatment in the intensive cardiac care unit (ICCU) enables rigorous control of vital parameters such as heart rate, blood pressure, body temperature, oxygen saturation, serum electrolyte levels, urine output and many others. The importance of controlling the metabolic status of the acute cardiac patient and specifically the level of serum glucose was recently put in focus but is still underscored. This review aims to explain the rationale for providing intensive control of serum glucose levels in the ICCU, especially using intensive insulin therapy and summarizes the available clinical evidence suggesting its effectiveness.

Impact of the metabolic syndrome on the clinical outcomes of non-clinically diagnosed diabetic patients with acute coronary syndrome

The aim of this study is to explore the impact of metabolic syndrome (MS) on the outcome of patients with non-clinically diagnosed diabetes with acute coronary syndrome (ACS) based on a comprehensive nationwide registry during a 1-year follow-up. In the ACS Israeli Survey, 1,060 consecutive patients with non-clinically diagnosed diabetes were admitted due to ACS; 359 patients with MS features on admission were compared with 701 subjects without MS. A modified National Cholesterol Education Program Adult Treatment Panel III definition of MS was used in patients who presented with > or =3 of the 5 components: (1) hyperglycemia, defined as occasional blood glucose on admission >140 mg/dl; (2) preexisting hypertension; (3) body mass index >28 kg/m(2); (4) high-density lipoprotein cholesterol < or =40 mg/dl (men) or < or =50 mg/dl (women); and (5) triglycerides > or =150 mg/dl. Patients with MS were more frequently women (27% vs 12%, p = 0.001), were in Killip > or =II on admission (19% vs 14%, p = 0.03), and had higher 30-day (5.0% vs 1.7%, p = 0.002) and 1-year (8.9% vs 4.6%, p = 0.005) crude mortality rates. Patients with hyperglycemia (glucose >140 mg/dl) and MS had higher 30-day mortality rates compared with patients with hyperglycemia without MS (8.3% vs 2.5%, p <0.05). Multivariate analysis identified MS as a strong independent predictor of 30-day and 1-year mortality with hazard ratios of 2.54 (95% confidence interval 1.22 to 5.31) and 1.96 (95% confidence interval 1.18 to 3.24), respectively. In conclusion, MS defined early at admission is a strong independent predictor of mortality and morbidity in patients with non-clinically diagnosed diabetes with ACS.

Implications of hyperglycaemia and ethnicity in patients with acute coronary syndromes in New Zealand

BACKGROUND

Admission blood glucose (ABG) is an independent predictor of death in patients with acute ST elevation myocardial infarction (STEMI). In New Zealand, mortality following myocardial infarction is disproportionally higher in Maori. Little information, however, exists concerning the predictive value of ABG in non-ST elevation acute coronary syndromes (NSTEACS) events or indeed if similar ethnic differences exist in outcome in this patient population.

AIM

To assess the predictive value of ABG and ethnicity in individuals admitted with acute coronary syndromes (ACS) on mortality.

METHODS

A retrospective analysis of hospital discharge diagnosis of all ACS between 1 January 1999 and 31 December 2002 at Waikato hospital, Hamilton, New Zealand. The primary outcome was all-cause mortality.

RESULTS

There were 4408 episodes of ACS with 1091 (25%) due to STEMI. There were 806 (18%) deaths. The presence of diabetes mellitus (DM) or an elevated ABG, in the absence of a history of DM, was associated with poor patient outcome. Early mortality is seen in individuals presenting with STEMI. People in the highest glucose category were older, more likely to be Maori, had a higher percentage of people with diabetes and remained in hospital longer, regardless of ACS type, than those in the lowest glucose category. Diabetes was more common in Maori (33%) than in Europeans (17.5%); p < 0.001. Significant risk factors for mortality were age, gender, diabetes, ethnicity, glucose and STEMI. For each mmol/l increase in glucose there is a 4.3% increase risk of dying. Adjusting for age and gender, Maori have a much higher mortality than Europeans (RR 2.12; p < 0.00001) regardless of ACS type (STEMI or NSTEACS).

CONCLUSIONS

Our study confirms the higher mortality following ACS, of Maori compared to New Zealanders of European origin. A raised ABG is a marker of this increased risk in all patients with ACS.

Effects of omega-3 polyunsaturated fatty acids on metabolically active hormones in patients post-myocardial infarction

BACKGROUND

Long-chain omega-3 polyunsaturated fatty acids (PUFA) supplementation is used as a therapeutic secondary prevention strategy among post-myocardial infarction (MI) patients. The effects of omega-3 PUFA on markers of energy homeostasis among post-MI patients are unclear.

METHODS

We investigated the effects of Omacor (a pharmaceutical capsule formulation of highly refined, concentrated omega-3 PUFA; Solvay Healthcare, Southampton, UK; 1 g/day) in addition to usual care (cardiovascular therapy) in a pilot randomised study of 35 post-MI men. Following randomisation to Omacor (n=16), or 'usual care' controls (n=19), fasting levels of insulin, non-esterified fatty acids (NEFA), triglycerides, glucose and adipocytokines (adiponectin, leptin and tumour necrosis factor (TNF)-alpha), as indices of markers of energy homeostasis, were measured at baseline and after 3-month treatment.

RESULTS

There were no baseline differences in age, body mass index, blood pressure, fasting triglycerides, plasma glucose, NEFA and adipocytokines between the two treatment arms (P=0.07). There were no significant changes in metabolically active hormones within groups after 3-month treatment. Across arms, the direction of baseline to follow-up changes in insulin levels were significantly different (P= 0.03), with a mean increase with Omacor (+3.39 mU/ml) and a decrease among controls (-17.6 mU/ml), without associated deteriorating changes in triglycerides, NEFA or plasma glucose.

CONCLUSION

This pilot study suggests that Omacor had little effect on glycaemic control among male post-MI patients. However, Omacor was associated with raised insulin levels, compared to usual care; thus, a metabolic basis for the cardioprotective action of Omacor, outside of its lipid lowering effects, merits further investigation.

Effects of Propofol and Midazolam on Lipids, Glucose, and Plasma Osmolality during and in the Early Postoperative Period Following Coronary Artery Bypass Graft Surgery: A Randomized Trial

It is not clear how levels of serum lipids and glucose and plasma osmolality change during propofol infusion in the pre- and postoperative period of coronary artery bypass graft surgery (CABG). This prospective, randomized, controlled trial evaluated changes in these parameters during propofol or midazolam infusion during and in the early postoperative period following surgery. Twenty patients undergoing CABG were randomized preoperatively into two groups: 10 patients received propofol (induction 1.5 mg/kg, maintenance 1.5 mg kg(-1) h(-1)) and 10 patients received midazolam (induction 0.5 mg/kg, maintenance 0.1 mg kg(-1) h(-1)). Both groups also received fentanyl (induction 20 mug/kg, maintenance 10 microg kg(-1)). Serum lipids, glucose, and plasma osmolality were measured preinduction, precardiopulmonary bypass, at the end of cardiopulmonary bypass, at the end of surgery, and 4 and 24 h postoperatively. In the propofol group, we observed a significant increase in triglycerides and very low-density lipoprotein levels 4 h postoperatively. In the midazolam group, we observed a significant decrease in low-density lipoprotein, cholesterol at the end of cardiopulmonary bypass, end of surgery, and 4 and 24 h postoperatively and significant increase in osmolality at the end of cardiovascular bypass. Changes in glucose levels did not differ significantly different between the two groups. In patients with normal serum lipids, glucose, and plasma osmolality undergoing CABG, propofol infusion for maintenance anesthesia is not associated with dangerous changes in serum lipids, glucose, and plasma osmolality compared with midazolam. A propofol infusion technique for maintenance of anesthesia for cardiac surgery where serum lipids and glucose may be of concern could be recommended as an alternative to midazolam.

Evaluation of an intensive insulin protocol for septic patients in a medical intensive care unit*

OBJECTIVE

Intensive insulin therapy to normalize blood glucose may improve outcome in intensive care unit patients. We prospectively evaluated the implementation of an intensive insulin protocol in medical intensive care patients to identify and overcome obstacles that this complex therapy creates.

DESIGN

This prospective, quality assessment study was designed to establish a standard protocol for glucose control in critically ill patients.

SETTING

The study took place in the medical intensive care unit at the Medical University of South Carolina, a tertiary care center.

PATIENTS

Patients diagnosed with sepsis and two consecutive blood glucose measurements of >120 mg/dL were included in the study.

INTERVENTIONS

The protocol, targeting blood glucose of 80-120 mg/dL, was a multidisciplinary initiative involving extensive education of house staff before subject enrollment. Based on predefined criteria, patients were monitored daily for glycemic control, inclusion criteria, and protocol adherence. Protocol improvements were assessed at 6 and 12 months via nursing surveys.

MEASUREMENTS AND MAIN RESULTS

Seventy patients receiving insulin infusion for >8 hrs were included in data analysis, accounting for 4,920 glucose readings. Eighty-six hypoglycemic events were recorded, with the number of events decreasing from 7.6% to 0.3% by the final version of the protocol. Average duration on protocol was 6 days, and average time to target range was 5.4 hrs. Identifiable causes of hypoglycemia and survey results led to four protocol revisions by study completion.

CONCLUSIONS

In comparison to studies suggesting that normoglycemia is an easily achievable goal, our protocol often recorded glucose values <80 mg/dL, although values <60 mg/dL were rare and usually due to protocol violations. In the interval before automated glucose-sensing insulin infusion devices become available for the intensive care unit, the current protocol is available to assist others in achieving target glucose levels shown to improve mortality rate in an intensive care unit population.

Changing scenario in chronic ischemic heart disease: therapeutic implications

Over the last 30 years, considerable progress has been made in drug therapy for chronic ischemic heart disease (IHD). Most pharmacologic therapies act by reducing myocardial oxygen consumption, increasing coronary blood flow, improving ventricular relaxation, dilating collateral vessels, and reducing peripheral resistances. Despite "optimal" medical therapy, a large fraction of patients continue to present with angina and myocardial ischemia. Coronary angioplasty (percutaneous transluminal coronary angioplasty) may improve symptoms, but several subgroups of patients, including the elderly, or those who have diabetes mellitus or heart failure, represent high-risk populations that do not always benefit from coronary revascularization. Epidemiologic studies show that life expectancy is longer compared with previous decades and that the prevalence of diabetes is increasing sharply worldwide. In addition, the prevalence of heart failure is growing because of the decreased death rate from acute myocardial infarction and improved survival of patients who have undergone coronary revascularization. We focus on this changing scenario of chronic IHD and propose an innovative approach to the treatment of angina in this context.

Glycemia in acute coronary syndromes

Diabetes is an established major factor of poor prognostis after an acute coronary syndrome. Recent studies have addressed the impact of abnormal glucose metabolism at the acute phase in patients without known diabetes. It has been found that abnormal glycemia regulation is more common than normal regulation in patients presenting with acute coronary syndrome, whatever the method used to evaluate blood glucose metabolism. High blood glucose at admission, whether fasting or not, are associated with worse outcome after an acute coronary syndrome, ie. by increased mortality and development of severe heart failure. The prognosistic value of glycemia is valuable for both short and long term outcomes. Admission glycemia measurement allows therapeutic strategies at the acute phase. Fasting glycemia and oral glucose tolerance test performed during the hospital stay discloses valuable diagnostic information and provide useful tools for secondary prevention. Moreover, fasting glycemia is a more powerful predictor for short term outcome after myocardial infarction than admission glycemia. The mechanisms by which hyperglycemia deteriorates the cardiovascular prognosis, in particular for left ventricular dysfunction, are not fully understood. Stress hyperglycemia may be a marker of extensive cardiac damage, reflecting a surge of stress hormones such as catecholamines and cortisol that participate to insulinresistance and affect fatty acid and glucose homeostasis. Recent findings also argue for a direct deleterious effect of hyperglycemia on myocardium.

A randomized clinical trial of trimetazidine, a partial free fatty acid oxidation inhibitor, in patients with heart failure

OBJECTIVES

This study sought to assess whether the long-term addition of trimetazidine to conventional treatment could improve functional class, exercise tolerance, and left ventricular function in patients with heart failure (HF).

BACKGROUND

Previous small studies have shown that trimetazidine may be beneficial in terms of left ventricular function preservation and control of symptoms in patients with post-ischemic HF.

METHODS

Fifty-five patients with HF were randomly allocated in an open-label fashion to either conventional therapy plus trimetazidine (20 mg three times daily) (28 patients) or conventional therapy alone (27 patients). Mean follow-up was 13 +/- 3 months. At study entry and at follow-up, all patients underwent exercise testing and two-dimensional echocardiography. Among the others, New York Heart Association (NYHA) functional class and ejection fraction (EF) were evaluated.

RESULTS

In the trimetazidine group, NYHA functional class significantly improved compared with the conventional therapy group (p < 0.0001). Treatment with trimetazidine significantly decreased left ventricular end-systolic volume (from 98 +/- 36 ml to 81 +/- 27 ml, p = 0.04) and increased EF from 36 +/- 7% to 43 +/- 10% (p = 0.002). On the contrary, in the conventional therapy group, both left ventricular end-diastolic and -systolic volumes increased from 142 +/- 43 ml to 156 +/- 63 ml, p = 0.2, and from 86 +/- 34 ml to 104 +/- 52 ml, p = 0.1, respectively; accordingly, EF significantly decreased from 38 +/- 7% to 34 +/- 7% (p = 0.02).

CONCLUSIONS

In conclusion, long-term trimetazidine improves functional class and left ventricular function in patients with HF. This benefit contrasts with the natural history of the disease, as shown by the decrease of EF in patients on standard HF therapy alone.

Perioperative glucose control in the diabetic or nondiabetic patient

Patients with diabetes are more likely to undergo surgery than nondiabetics, and maintaining glycemic control in subjects with diabetes can be challenging during the perioperative period. Surgery in diabetic patients is associated with longer hospital stay, higher health care resource utilization, and greater perioperative mortality. In addition, several observational and interventional studies have indicated that hyperglycemia is associated with adverse clinical outcomes in surgical and critically ill patients. This paper reviews the pathophysiology of hyperglycemia during trauma and surgical stress and will provide practical recommendations for the preoperative, intraoperative, and postoperative care of diabetic patients.

Glucose-insulin-potassium therapy in the era of coronary revascularization

Glucose-insulin-potassium (GIK) utilization in the treatment of acute myocardial infarction (AMI) has been studied since the early 1960s with varying results. It is well established that ischemic myocardial cells convert from aerobic metabolism of glucose to toxic anaerobic free fatty acid (FFA) metabolism for the production of energy. It has been hypothesized that administration of GIK during coronary revascularization would decrease the degree of myocardial damage. Earlier clinical trials, before the revascularization era, demonstrated a potential role for GIK therapy to reduce the mortality and morbidity associated with AMI. In recent years, GIK therapy has been incorporated into current revascularization methods without clear evidence as to its efficacy. Based on the most current studies, it has been determined that GIK therapy is not beneficial in patients with AMI, regardless of revascularization status, and therefore should not be used.

Relation of hyperglycemia to ST-segment resolution after reperfusion for acute myocardial infarction (from Observatoire des Infarctus de Côte-d'Or Survey [RICO])

Hyperglycemia has been shown to be a powerful predictor of worse outcome after ST-segment-elevation myocardial infarction (STEMI), which could be related to impaired myocardial reperfusion. This study investigated the association between hyperglycemia and ST-segment resolution (STR) after thrombolysis. From the French regional Observatoire des Infarctus de Côte-d'Or survey, admission glucose in 371 patients with STEMIs who were treated by lysis<12 hours was analyzed. The single worst lead electrocardiogram before and 90 minutes after lysis was analyzed, and patients were divided into 3 groups according to the degree of STR: none (<30%), partial (30% to 70%), or complete (>or=70%). Of the 371 patients, 101 (27.2%) had no STR, 124 (33.4%) had partial STR, and 146 (39.4%) had complete STR. STR decreased with increasing glycemia (p=0.029), and patients with hyperglycemia (glycemia>or=11 mmol/L) were more likely to have no STR. Moreover, hyperglycemia was an independent predictor of incomplete STR even after adjustment for potential confounders (odds ratio 2.348, 95% confidence interval 1.212 to 4.547). In conclusion, the present study suggests a strong association between hyperglycemia and electrocardiographic signs of reperfusion in patients with STEMIs after lysis and suggests the usefulness of evaluating early glycemic control in the setting of reperfusion for acute myocardial infarction.

Role of AMP-activated protein kinase in healthy and diseased hearts

The heart is capable of utilizing a variety of substrates to produce the necessary ATP for cardiac function. AMP-activated protein kinase (AMPK) has emerged as a key regulator of cellular energy homeostasis and coordinates multiple catabolic and anabolic pathways in the heart. During times of acute metabolic stresses, cardiac AMPK activation seems to be primarily involved in increasing energy-generating pathways to maintain or restore intracellular ATP levels. In acute situations such as mild ischemia or short durations of severe ischemia, activation of cardiac AMPK appears to be necessary for cardiac myocyte function and survival by stimulating ATP generation via increased glycolysis and accelerated fatty acid oxidation. Whereas AMPK activation may be essential for adaptation of cardiac energy metabolism to acute and/or minor metabolic stresses, it is unknown whether AMPK activation becomes maladaptive in certain chronic disease states and/or extreme energetic stresses. However, alterations in cardiac AMPK activity are associated with a number of cardiovascular-related diseases such as pathological cardiac hypertrophy, myocardial ischemia, glycogen storage cardiomyopathy, and Wolff-Parkinson-White syndrome, suggesting the possibility of a maladaptive role. Although the precise role AMPK plays in the diseased heart is still in question, it is clear that AMPK is a major regulator of cardiac energy metabolism. The consequences of alterations in AMPK activity and subsequent cardiac energy metabolism in the healthy and the diseased heart will be discussed.

Free fatty acids are independently associated with all-cause and cardiovascular mortality in subjects with coronary artery disease

CONTEXT

Free fatty acids (FFAs) are associated with several cardiovascular risk factors and exert harmful effects on the myocardium.

OBJECTIVE

The aim of our study was to elucidate the relationship between FFAs and mortality in subjects who underwent coronary angiography.

DESIGN, SETTING, AND PARTICIPANTS

Ludwigshafen Risk and Cardiovascular Health is a prospective cohort study of Caucasians who had undergone coronary angiography at baseline (1997-2000). During a median time of follow-up of 5.38 yr, 513 deaths had occurred among 3315 study participants with measured FFAs.

MAIN OUTCOME MEASURE

Hazard ratios for mortality according to FFA levels were measured.

RESULTS

At the fourth quartile of FFAs, fully adjusted hazard ratios for death from any cause and cardiovascular causes were 1.58 (P = 0.002) and 1.83 (P = 0.001), respectively. In persons with angiographic coronary artery disease (CAD), stable CAD, and unstable CAD, the predictive value of FFAs was similar to that in the entire cohort, but the association did not attain statistical significance in persons without CAD analyzed separately. FFA levels were not related to the presence of angiographic CAD but were elevated in subjects with unstable CAD, compared with probands with stable CAD. Furthermore, FFAs increased with the severity of heart failure and were positively correlated with N-terminal pro-B-type natriuretic peptide (P < 0.001).

CONCLUSIONS

FFA levels independently predict all-cause and cardiovascular mortality in subjects with angiographic CAD. A possible diagnostic use of FFAs warrants further studies, but our results may underline the importance of therapeutic approaches to influence FFA metabolism.

The anti-ischemic effect of trimetazidine in patients with postprandial myocardial ischemia is unrelated to meal composition

BACKGROUND

Previous studies provide evidence for a significant reduction of coronary flow reserve after ingestion of meals of different compositions. A possible role of hyperinsulinemia and increased free fatty acid levels, which are deleterious during acute myocardial ischemia and reperfusion, has been hypothesized. We assessed in patients with stable coronary disease the effects of high-fat meals (HFMs) and high-carbohydrate meals (HCMs) on ischemic threshold and stress left ventricular function on placebo and after partial fatty acid inhibition by trimetazidine (TMZ).

METHODS

Ten patients (9 men, age 68 +/- 7 years) were allocated to placebo and TMZ (40 mg TID), both administered in the 24 hours preceding testing, according to a randomized double-blind study design. All patients underwent stress (treadmill exercise testing according to the Bruce protocol) echocardiography after fasting (8 hours) and after an HFM and HCM (2 hours) either on placebo or on TMZ. Time to 1-mm ST-segment depression (time to 1 mm) and stress wall motion score index (WMSI) were evaluated.

RESULTS

An HFM did not affect exercise variables compared with fasting, whereas an HCM resulted in a reduction of the ischemic threshold (time to 1 mm from 402 +/- 141 to 292 +/- 123 seconds, P = .025). Compared with placebo, TMZ improved time to 1 mm after fasting, HFM, and HCM (432 +/- 153 vs 402 +/- 141, 439 +/- 118 vs 380 +/- 107, 377 +/- 123 vs 292 +/- 123, F(1,9) = 26.91, P = .0006). Compared with placebo, on TMZ, stress WMSI decreased from 1.55 +/- 0.25 to 1.29 +/- 0.14 after fasting, from 1.57 +/- 0.10 to 1.39 +/- 0.28 after HFM, and from 1.64 +/- 0.21 to 1.39 +/- 0.21 after HCM (F(1,9) = 37.04, P = .0002). Interestingly, stress WMSI on TMZ was never different from rest WMSI on placebo.

CONCLUSIONS

In patients with coronary disease, exercise testing after an HCM results in more severe myocardial ischemia compared with that after an HFM. The observed beneficial effects of the partial fatty acid inhibitor TMZ seem to be unrelated to meal composition and are possibly caused by the better glucose use induced by the drug.

Identification of a novel peptide that interferes with the chemical regulation of connexin43

The carboxyl-terminal domain of connexin43 (Cx43CT) is involved in various intra- and intermolecular interactions that regulate gap junctions. Here, we used phage display to identify novel peptidic sequences that bind Cx43CT and modify Cx43 regulation. We found that Cx43CT binds preferentially to peptides containing a sequence RXP, where X represents any amino acid and R and P correspond to the amino acids arginine and proline, respectively. A biased "RXP library" led to the identification of a peptide (dubbed "RXP-E") that bound Cx43CT with high affinity. Nuclear magnetic resonance data showed RXP-E-induced shifts in the resonance peaks of residues 343 to 346 and 376 to 379 of Cx43CT. Patch-clamp studies revealed that RXP-E partially prevented octanol-induced and acidification-induced uncoupling in Cx43-expressing cells. Moreover, RXP-E increased mean open time of Cx43 channels. The full effect of RXP-E was dependent on the integrity of the CT domain. These data suggest that RXP-based peptides could serve as tools to help determine the role of Cx43 as a regulator of function in conditions such as ischemia-induced arrhythmias.

Glucose-insulin and potassium infusions in septic shock

Glucose-insulin and potassium (GIK) infusions are beneficial in treating ischemic myocardial depression. Myocardial depression is also an important feature in septic shock. We describe two cases of pressor-resistant hypodynamic septic shock that responded to high-dose GIK infusions. In each case, hemodynamic profiles improved sufficiently to allow withdrawal of vasopressor agents. Further assessment of GIK in patients with hypodynamic septic shock is necessary to confirm efficacy and prognostic significance.

Is There a Rationale for Insulin Therapy in Pre-Diabetic Individuals?

Type 2 diabetes mellitus is usually preceded by impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG), which are often referred to as pre-diabetes. Individuals with IGT demonstrate beta-cell dysfunction, insulin resistance, and increased hepatic glucose production; IGT and IFG are risk factors for both diabetes and cardiovascular disease. Type 2 diabetes is associated with micro- and macrovascular complications that lead to excessive mortality and morbidity and the risk of microvascular complications extends to people with pre-diabetes. Maintaining good glycemic control in type 2 diabetes can reduce the risk of developing chronic disease-associated complications. Most individuals who develop type 2 diabetes appear to pass through a stage of IFG or IGT; thus, early intervention (lifestyle and/or pharmacologic) in individuals with pre-diabetes may help prevent cardiovascular disease and the development of type 2 diabetes.The use of exogenous insulin treatment offers the potential to reduce the cardiovascular risk in individuals with type 2 diabetes or pre-diabetes through effective reductions in blood glucose and lipid levels, and in the associated tissue damage resulting from their chronic elevations. However, there are barriers associated with insulin initiation in both type 2 diabetes and pre-diabetes (e.g. hypoglycemia, weight gain, the possible unpredictable action of long-acting insulin, and the need for injections). Insulin glargine, with its flat time-action profile, near 24-hour duration of action, reduced risk of hypoglycemia, and improved glycemic control compared with insulin suspension isophane (neutral protamine hagedorn [NPH] insulin), may help to overcome some of these barriers.Initial results from a small study have indicated the feasibility of treating individuals with pre-diabetes to near-normoglycemia using a regimen of low-dose insulin glargine plus caloric restriction. This is being followed up in the ongoing ORIGIN (Outcomes Reduction with Initial Glargine INtervention) study, which will investigate whether treatment to near-normoglycemia with insulin glargine in individuals with IGT, IFG, or new-onset type 2 diabetes can reduce cardiovascular morbidity and mortality compared with conventional management of these conditions, and whether the rate of progression to type 2 diabetes can be similarly reduced.Further studies are needed to investigate the potential benefits of insulin therapy in individuals with pre-diabetes.

Improved myocardial protection during coronary artery surgery with glucose-insulin-potassium: A randomized controlled trial

OBJECTIVE

We sought to assess the role of glucose-insulin-potassium in providing myocardial protection in nondiabetic patients undergoing coronary artery surgery with cardiopulmonary bypass.

METHODS

A prospective, randomized, double-blind, placebo-controlled trial was conducted at a single-center university hospital performing adult cardiac surgery. Two hundred eighty nondiabetic adult patients undergoing first-time elective or urgent isolated multivessel coronary artery bypass grafting were prospectively randomized to receive glucose-insulin-potassium infusion or placebo (dextrose 5%) before, during, and for 6 hours after surgical intervention. Anesthetic, cardiopulmonary bypass, myocardial protection, and surgical techniques were standardized. The primary end point was postreperfusion cardiac index. Secondary end points were systemic vascular resistance index, the incidence of low cardiac output episodes, inotrope and vasoconstrictor use, and biochemical-electrocardiographic evidence of myocardial injury. The incidence of dysrhythmias and infections requiring treatment was recorded prospectively.

RESULTS

The glucose-insulin-potassium group experienced higher cardiac indices (P < .001) throughout infusion and reduced vascular resistance (P < .001). The incidence of low cardiac output episodes was 15.9% (22/138) in the glucose-insulin-potassium group and 27.5% (39/142) in the placebo group (P = .021). Inotropes were required in 18.8% (26/138) of the glucose-insulin-potassium group and 40.8% (58/142) of the placebo group (P < .001). Fewer patients in the glucose-insulin-potassium group (12.3% [16/133]) versus those in the placebo group (23.4% [32/137]) had significant myocardial injury (P = .017). Noncardiac morbidity was not different.

CONCLUSION

Glucose-insulin-potassium therapy improves early postoperative cardiovascular performance, reduces inotrope requirement, and might reduce myocardial injury. These potential benefits are not at the expense of increased noncardiac morbidity.

Admission glucose concentrations independently predict early and late mortality in patients with acute myocardial infarction treated by primary or rescue percutaneous coronary intervention

BACKGROUND

In patients with acute myocardial infarction (MI), increased plasma glucose levels at hospital admission are associated with worse outcome. We aimed to assess the predictive value of admission glucose concentrations on short- and long-term mortality in patients with acute MI undergoing primary or rescue percutaneous coronary intervention (PCI).

METHODS

We analyzed the 30-day and long-term (mean follow-up 3.7 years) outcome of 978 patients prospectively included in a single-center registry of patients with acute MI treated with PCI within 24 hours after onset of symptoms. Patients were classified according to plasma glucose levels at admission: < 7.8 mmol/L (group I, n = 322), 7.8 to 11 mmol/L (group II, n = 348), and > 11.0 mmol/L (group III, n = 308).

RESULTS

Mortality at 30 days was 1.2% in group I, 6.3% in group II, and 16.6% in group III (P < .001). After multivariate adjustment for age, the presence of cardiogenic shock, and TIMI 3 flow after PCI, the association of mortality with glucose classification remained significant (P value for trend = .003). The relative risk of death at 30 days for group III versus group I was 3.9 (95% CI 1.2-13.2). During long-term follow-up, mortality was similar in groups I and II. However, in group III adjusted mortality remained significantly increased compared with group I (relative risk 1.76, CI 1.01-3.08).

CONCLUSIONS

In patients undergoing emergency PCI for acute MI, glucose levels at hospital admission are predictive for short- and long-term survival. Knowledge of admission glucose levels may improve initial bedside risk stratification.

The acute reperfusion management of STEMI in patients with impaired glucose tolerance and type 2 diabetes

Diabetes mellitus (DM) remains an important predictor for mortality in patients with ST-segment Elevation Myocardial Infarction (STEMI) although the use of reperfusion therapy has resulted in a considerable improvement of survival. Of importance, newly diagnosed diabetic patients and those with fasting glycaemia in the diabetes range have even worse outcomes compared to patients with known diabetes. Overall, 50% of all patients presenting with STEMI have abnormal glucose metabolism of which fewer than 50% are known diabetics. Obviously, the efficacy of reperfusion therapy in reopening the occluded artery is similar in STEMI patients with or without impaired fasting glycaemia, while the pre-existing decreased myocardial perfusion in STEMI patients with impaired fasting glycaemia persists after successful epicardial revascularisation. There is no doubt that improving microvascular perfusion within the ischaemic myocardium remains the ultimate goal of managing STEMI patients with impaired glucose metabolism. Identification of defective myocardial perfusion together with an aggressive antithrombotic regimen, reduction of the inflammatory response of the ischaemic myocardium and improvement of glycaemia control represent promising therapeutic approaches that deserve additional specific clinical investigations. This review examines all these important issues.

The association between hyperglycaemia on admission and 180-day mortality in acute myocardial infarction patients with and without diabetes

AIM

To evaluate the association between hyperglycaemia on admission, previously known diabetes and 180-day mortality in acute myocardial infarction (AMI) patients.

METHODS

The study population consisted of 779 consecutive AMI patients from the Myocardial Infarction Registry in Estonia who had an admission venous plasma glucose level recorded and who were admitted to the Tartu University Clinics within a period of 2 years. Logistic regression analysis was used to estimate crude and adjusted odds ratios (OR) with 95% confidence interval (95% CI).

RESULTS

In patients without a history of diabetes, glucose level was < or = 11.0 mmol/l in 556 patients (group 1) and > 11.0 mmol/l in 109 patients (group 2). Of those with diabetes, glucose level was < or = 11.0 mmol/l in 30 patients (group 3) and > 11.0 mmol/l in 84 patients (group 4). Non-diabetic hyperglycaemic patients underwent more resuscitations outside of hospital (group 2, 31.2% vs. group 1, 2.0% vs. group 3, 6.7% vs. group 4, 6.0%, P < 0.0001) and had a higher 180-day mortality compared with other groups (group 2, 47.7% vs. group 1, 14.1% vs. group 3, 26. 7% vs. group 4, 29.8%, P < 0.0001). After adjustment for potentially confounding factors, hyperglycaemic non-diabetic (OR 4.35, 95% CI 1.79-10.59), but not diabetic (OR 1.79, 95% CI 0.62-5.15) status, remained an independent predictor of 180-day mortality.

CONCLUSIONS

AMI patients with hyperglycaemia on admission, independent of a history of diabetes, represent a high-risk population for 180-day mortality. The worst outcome occurs in non-diabetic hyperglycaemic patients. Further studies are warranted to clarify the questions of hyperglycaemia treatment in AMI patients.

The Brugada ECG pattern in a neonate

We report a neonate resuscitated from sudden death with a Brugada ECG pattern several days after the initial event. The baby was subsequently diagnosed with a fatty acid oxidation disorder (medium chain Acyl-CoA dehydrogenase deficiency or MCAD). We speculate that free fatty acid accumulation can give rise to the Brugada ECG pattern.

Blood glucose: a strong risk factor for mortality in nondiabetic patients with cardiovascular disease

BACKGROUND

The prognostic significance of blood glucose (BG) for nondiabetic patients in a stable chronic phase of cardiovascular disease (CVD) has been sparsely investigated, especially for glucose within the normal range. In particular, it is unknown if for these patients there is a graded relation of mortality to glucose or if there is a lower threshold.

METHODS

We used the Framingham Heart Study 30-year data to determine 2-year all-cause, cardiovascular mortality (CVM), and non-CVM risk adjusted for age, sex, and typical cardiovascular risk factors (systolic blood pressure, total cholesterol, body mass index, cigarette smoking, and use of antihypertensive drugs) by levels of random whole BG for non-glucose-intolerant subjects (glucose intolerance includes diabetes mellitus) with existing CVD.

RESULTS

There were steep graded relations of 2-year all-cause, CVM, and non-CVM to BG throughout the normal and subdiabetic range with no evidence of a lower threshold. Two-year mortality continuously increased from 2.99% at the bottom of the normal range (BG = 60 [plasma equivalent = 67] mg/dL) to 7.23% at the top of the normal range (89 [plasma equivalent = 100] mg/dL) (a 2.42-fold increase) and then continued to further continuously increase, reaching 11.38% at 119 [plasma equivalent = 133] mg/dL, the top of the glucose range considered (P for trend < .0001). There were analogous steep increases for CVM and non-CVM.

CONCLUSIONS

Blood glucose, even within the normal range, is a strong independent predictor of 2-year all-cause, CVM, and non-CVM in nondiabetic subjects with CVD and therefore of prognostic significance for these high-risk patients.

Metabolic and Hemodynamic Effects of High-Dose Insulin Treatment in Aortic Valve and Coronary Surgery

BACKGROUND

Glucose and insulin have been used as an adjuvant therapy in cardiac surgery because of their potentially beneficial effects on myocardial metabolism and contractile function. This study evaluated the effects of high-dose insulin on systemic metabolism and hemodynamics after combined heart surgery.

METHODS

Forty elective patients scheduled for combined aortic valve replacement and coronary artery bypass surgery were randomly assigned to receive either high-dose insulin treatment (short-acting insulin 1 IU.kg(-1).h(-1) with 30% glucose 1.5 mL.kg(-1).h(-1) administered separately) or control treatment (saline). The blood glucose levels were maintained within a targeted range by adjusting the rate of glucose infusion in the treatment group and by short-acting insulin bolus doses in the control group.

RESULTS

The lactate clearance was faster (p = 0.046), and the lactate levels (p = 0.016), blood glucose levels (p < 0.001), and free fatty acid levels (p < 0.001) were lower in the insulin group postoperatively. Besides, there was lesser need for dobutamine support (p = 0.013) and a trend toward better cardiac indices. Insulin treatment increased the respiratory quotient (p < 0.001), but there were no differences between the groups with regard to systemic oxygen consumption or energy expenditure measured by indirect calorimetry. The average glucose uptake in the insulin group was 7.1 g/kg in 24 hours (28 kcal.kg(-1).day(-1)).

CONCLUSIONS

The high-dose insulin treatment was associated with lower blood glucose levels, better preserved myocardial contractile function, and less need for inotropic support, and hence led to lower lactate levels postoperatively. The protocol is safe, but requires strict control of blood glucose level.

Optimizing treatment of diabetes and cardiovascular disease with combined alpha,beta-blockade

BACKGROUND

Cardiovascular risk factors of the diabetic patient should be treated as aggressively as those of the nondiabetic patient who has had a myocardial infarction. beta-Blockers are established to reduce cardiovascular risk in patients with hypertension, coronary heart disease, and heart failure. Despite this benefit of beta-blockers, physicians have been reluctant to use them in patients with diabetes, in whom they are even more effective, because of the negative effects on carbohydrate and lipid metabolism.

OBJECTIVE

This paper reviews (based on a Medline literature search to December 2004) the relationship between diabetes and cardiovascular risk factors, describes the metabolic consequences of insulin resistance, and discusses the impact of different beta-blockers on the treatment of cardiovascular disease in patients with diabetes.

RESULTS

There is a large cardioprotective benefit with the use of beta-blockers in patients with diabetes; however, metabolic risks are associated with some beta-blockers. Newer, vasodilating, nonselective beta-blockers do not have the same adverse metabolic consequences observed with earlier beta-blockers. Recent evidence has shown that they have a neutral effect on metabolic parameters and lipid profile. They do not promote insulin resistance and can be used safely in heart failure patients with diabetes.

CONCLUSIONS

Nonselective vasodilating beta-blockers, such as carvedilol, may be used in patients with cardiovascular disease and diabetes without the same negative metabolic consequences seen with the use of earlier generation beta-blockers.

Relation of chronic and acute glycemic control on mortality in acute myocardial infarction with diabetes mellitus

Acute hyperglycemia during myocardial infarction predicts adverse short-term outcomes and mortality in diabetic patients. Conversely, chronic hyperglycemia is associated with an increased incidence of long-term cardiovascular complications, although its effect on acute hyperglycemic response and mortality after acute myocardial infarction is unknown. We investigated the prognostic relation of the glucose concentration at admission and the baseline average glycohemoglobin on acute myocardial infarction mortality. Of 808 consecutive diabetic patients with acute myocardial infarction, the most significant independent predictor of in-hospital mortality was the glucose concentration at admission. Baseline glycohemoglobin strongly correlated with admission hyperglycemia but did not predict mortality independently.

Cellular energy status modulates translational control mechanisms in ischemic-reperfused rat hearts

Mechanisms regulating ischemia and reperfusion (I/R)-induced changes in mRNA translation in the heart are poorly defined, as are the factors that initiate these changes. Because cellular energy status affects mRNA translation under physiological conditions, it is plausible that I/R-induced changes in translation may in part be a result of altered cellular energy status. Therefore, the purpose of the studies described herein was to compare the effects of I/R with those of altered energy substrate availability on biomarkers of mRNA translation in the heart. Isolated adult rat hearts were perfused with glucose or a combination of glucose plus palmitate, and effects of I/R on various biomarkers of translation were subsequently analyzed. When compared with hearts perfused with glucose plus palmitate, hearts perfused with glucose alone exhibited increased phosphorylation of eukaryotic elongation factor (eEF)2, the alpha-subunit of eukaryotic initiation factor (eIF)2, and AMP-activated protein kinase (AMPK), and these hearts also exhibited enhanced association of eIF4E with eIF4E binding protein (4E-BP)1. Regardless of the energy substrate composition of the buffer, phosphorylation of eEF2 and AMPK was greater than control values after ischemia. Phosphorylation of eIF2alpha and eIF4E and the association of eIF4E with 4E-BP1 were also greater than control values after ischemia but only in hearts perfused with glucose plus palmitate. Reperfusion reversed the ischemia-induced increase in eEF2 phosphorylation in hearts perfused with glucose and reversed ischemia-induced changes in eIF4E, eEF2, and AMPK phosphorylation in hearts perfused with glucose plus palmitate. Because many ischemia-induced changes in mRNA translation are mimicked by the removal of a metabolic substrate under normal perfusion conditions, the results suggest that cellular energy status represents an important modulator of I/R-induced changes in mRNA translation.

Substrate dependence of the postischemic cardiomyocyte recovery: Dissociation between functional, metabolic and injury markers

Defining the substrate that influences the most favourably the myocardial post-ischemic recovery is subject of debates, due to dissociation between functional and biochemical benefits. Hence, we studied the effects of either glucose or different fatty acids on the functional and metabolic recovery of post-ischemic cardiomyocytes in a substrate-free hypoxia model of simulated ischemia-reperfusion. Rat cardiomyocytes were submitted to a 2.5 h simulated ischemia followed by a 2 h reoxygenation without substrate (control), or with either glucose, octanoic acid, oleic acid, or elaidic acid. During simulated ischemia, electromechanical function gradually disappeared while the cellular viability and mitochondrial function declined. During control simulated reperfusion, cardiomyocytes recovered near normal function but a significant reduction in the action potential amplitude and rate persisted. The addition of glucose or oleic acid during simulated reperfusion promoted a faster, better and sustain functional recovery. Amongst the fatty acids, the functional recovery was slower with elaidic and octanoic acids as compared with oleic acid. The mitochondrial function was better improved during simulated reperfusion with glucose than with the tested fatty acids, among which elaidic acid was the less unfavourable. Paradoxically, the addition of whichever substrate during simulated reperfusion tended to worsen the cellular viability. Thus, cardiomyocytes recovery strongly relies on the characteristics of the substrate supplied at the onset of simulated reperfusion: glucidic or lipidic nature, chain-length, insaturation degree. Moreover, these data suggest that defining the appropriateness of a given substrate for the post-ischemic cardiomyocyte recovery is closely related to the functional and the biological endpoints in consideration.

Thiazolidinediones, peripheral oedema and congestive heart failure: what is the evidence?

Cardiovascular disease is the most common complication of type 2 diabetes mellitus (type 2 DM), accounting for approximately 80% of deaths. While atherosclerotic vascular disease accounts for much of the cardiovascular morbidity and mortality among diabetic patients, congestive heart failure (CHF) is another key complication associated with diabetes, with an incidence three to five times greater in diabetic patients than in those without diabetes. One of the most promising developments in the treatment of type 2 DM has been the introduction of the thiazolidinedione (TZD) class of drugs, which appear to have pleiotropic effects beyond glycaemic control. Enthusiasm has been tempered, however, by concerns for safety in patients with CHF, given reports of worsening heart failure symptoms and peripheral oedema. With the growing epidemic of type 2 DM and the increasing use of TZDs, such concern has important therapeutic implications for a population of patients with a high prevalence of often subclinical systolic and diastolic dysfunction. This review provides an overview of the currently available data regarding the effects of TZDs on fluid retention and cardiac function. Particular emphasis is placed on the mechanisms of development of peripheral oedema and its significance in patients with impaired left ventricular function. TZDs are well known to cause an expansion in plasma volume; there has also been concern that TZDs may have direct toxic effects on the myocardium, leading to impaired cardiac function. Studies to date do not support this hypothesis and in fact there is growing evidence from animal models and human trials that treatment with TZDs actually improves cardiac function. There are also preclinical data to suggest TZDs may protect the myocardium in the setting of ischaemic insult or the toxic effects of myocardial lipid deposition. Ongoing clinical trials examining the use of these agents in patients at risk for heart failure will probably provide further insight into the aggregate cardiovascular effects of this promising class of medications.

Effects of trimetazidine on myocardial preconditioning in anesthetized rats

Trimetazidine is a widely used anti-ischemic agent, but its effect on myocardial preconditioning in anesthetized animals has not been investigated. The aim of this study was to examine the effects of trimetazidine on ischemic preconditioning and carbachol preconditioning in anesthetized rats. Ischemic preconditioning, induced by 5-min coronary artery occlusion and 5-min reperfusion, decreased the incidence of ventricular tachycardia and abolished the occurrence of ventricular fibrillation during 30-min ischemia. Trimetazidine (10 mg/kg, i.v.) alone attenuated these parameters of arrhythmia. Carbachol infusion induced preconditioning with a marked depression of mean arterial blood pressure, heart rate and ventricular tachycardia. The marked reductions in parameters of arrhythmia induced by ischemic preconditioning and carbachol preconditioning were preserved in the presence of trimetazidine. Arrhythmia scores and myocardial infarct size were significantly reduced with ischemic preconditioning or carbachol preconditioning and were not inhibited by trimetazidine. These results show that trimetazidine protects the heart against ischemia-induced arrhythmias, reduces myocardial infarct size, preserves the effects of ischemic preconditioning and pharmacological preconditioning, and is able to mimic ischemic preconditioning in anesthetized rats.

The relation between hyperglycemia and outcomes in 2,471 patients admitted to the hospital with community-acquired pneumonia

OBJECTIVE

To examine whether hyperglycemia at the time of presentation was associated with outcomes in patients admitted to non-intensive care settings with community-acquired pneumonia (CAP).

RESEARCH DESIGN AND METHODS

Prospective cohort study of consecutive patients admitted to six hospitals between 15 November 2000 and 14 November 2002.

RESULTS

Of the 2,471 patients in this study (median age 75 years), 279 (11%) had serum glucose at presentation >11 mmol/l: 178 of the 401 patients (44%) with a prior diagnosis of diabetes and 101 of the 2,070 patients (5%) without a history of diabetes. Of patients hospitalized with CAP, 9% died and 23% suffered an in-hospital complication. Compared with those with values < or =11 mmol/l, patients with an admission glucose >11 mmol/l had an increased risk of death (13 vs. 9%, P = 0.03) and in-hospital complications (29 vs. 22%, P = 0.01). Compared with those patients with admission glucose < or =6.1 mmol/l, the mortality risk was 73% higher (95% CI 12-168%) and the in-hospital complication risk was 52% higher (12-108%) in patients with admission glucose >11 mmol/l. Even after adjustment for factors in the Pneumonia Severity Index, hyperglycemia on admission remained significantly associated with subsequent adverse outcomes: for each 1-mmol/l increase, risk of in-hospital complications increased 3% (0.2-6%).

CONCLUSIONS

Hyperglycemia on admission is independently associated with adverse outcomes in patients with CAP, with the increased risks evident at lower glucose levels than previously reported.