Ilse Vanhorebeek

Guidelines for pre-operative cardiac risk assessment and perioperative cardiac management in non-cardiac surgery

The American College of Cardiology, American Heart Association, and the European Society of Cardiology are all in the process of completing updated versions of our Guidelines for Perioperative Care. Our respective writing committees are undertaking a careful analysis of all relevant validated studies and always incorporate appropriate new trials and meta-analyses into our evidence review. In the interim, our current joint position is that the initiation of beta blockers in patients who will undergo non-cardiac surgery should not be considered routine, but should be considered carefully by each patients treating physician on a case-by-case basis. Please see the expression of concern which is free to view in Eur Heart J (2013) 34 (44): 3460; doi: 10.1093/eurheartj/eht431. AAA : abdominal aortic aneurysm ACC : American College of Cardiology ACE : angiotensin-converting enzyme ACS : acute coronary syndrome AHA : American Heart Association AR : aortic regurgitation ARB : angiotensin receptor blocker AS : aortic stenosis AF : atrial fibrillation BBSA : β-blocker in spinal anaesthesia BNP : brain natriuretic peptide CABG : coronary artery bypass grafting CARP : coronary artery revascularization prophylaxis CASS : coronary artery surgery study CI : confidence interval COX-2 : cyclooxygenase-2 COPD : chronic obstructive pulmonary disease CPET : cardiopulmonary exercise testing CPG : Committee for Practice Guidelines CRP : C-reactive protein CT : computed tomography cTnI : cardiac troponin I cTnT : cardiac troponin T CVD : cardiovascular disease DECREASE : Dutch Echocardiographic Cardiac Risk Evaluating Applying Stress Echo DES : drug-eluting stent DIPOM : Diabetes Postoperative Mortality and Morbidity DSE : dobutamine stress echocardiography ECG : electrocardiography ESC : European Society of Cardiology FEV1 : forced expiratory volume in 1 s FRISC : fast revascularization in instability in coronary disease HR : hazard ratio ICU : intensive care unit IHD : ischaemic heart disease INR : international normalized ratio LMWH : low molecular weight heparin LQTS : long QT syndrome LR : likelihood ratio LV : left ventricular MaVS : metoprolol after surgery MET : metabolic equivalent MI : myocardial infarction MR : mitral regurgitation MRI : magnetic resonance imaging MS : mitral stenosis NICE-SUGAR : normoglycaemia in intensive care evaluation and survival using glucose algorithm regulation NSTEMI : non-ST-segment elevation myocardial infarction NT-proBNP : N-terminal pro-brain natriuretic peptide NYHA : New York Heart Association OPUS : orbofiban in patients with unstable coronary syndromes OR : odds ratio PaCO2 : mixed expired volume of alveolar and dead space gas PAH : pulmonary arterial hypertension PETCO2 : end-tidal expiratory CO2 pressure PCI : percutaneous coronary intervention PDA : personal digital assistant POISE : PeriOperative ISchaemic Evaluation trial QUO-VADIS : QUinapril On Vascular ACE and Determinants of ISchemia ROC : receiver operating characteristic SD : standard deviation SMVT : sustained monomorphic ventricular tachycardia SPECT : single photon emission computed tomography SPVT : sustained polymorphic ventricular tachycardia STEMI : ST-segment elevation myocardial infarction SVT : supraventricular tachycardia SYNTAX : synergy between percutaneous coronary intervention with taxus and cardiac surgery TACTICS : treat angina with aggrastat and determine cost of therapy with an invasive or conservative strategy TIA : transient ischaemic attack TIMI : thrombolysis in myocardial infarction TOE : transoesophageal echocardiography UFH : unfractionated heparin VCO2 : carbon dioxide production VE : minute ventilation VHD : valvular heart disease VKA : vitamin K antagonist VO2 : oxygen consumption VPB : ventricular premature beat VT : ventricular tachycardia Guidelines and Expert Consensus Documents aim to present management and recommendations based on the relevant evidence on a particular subject in order to help physicians to select the best possible management strategies for the individual patient suffering from a specific condition, taking into account not only the impact on outcome, but also the risk–benefit ratio of particular diagnostic or therapeutic means. Guidelines are no substitutes for textbooks. The legal implications of medical guidelines have been discussed previously.1 A great number of Guidelines and Expert Consensus Documents have been issued in recent years by the European Society of Cardiology (ESC) and also by other organizations or related societies. Because of the impact on clinical practice, quality criteria for development of guidelines have been established in order to make all decisions transparent to the user. The recommendations for formulating and issuing ESC guidelines and Expert Consensus Documents can be found on the ESC website in the guidelines section (www.escardio.org). In brief, experts in the field are selected and undertake a comprehensive review of the published evidence for management and/or prevention of a given condition. …

Guidelines for pre-operative cardiac risk assessment and perioperative cardiac management in non-cardiac surgery: The task force for preoperative cardiac risk assessment and perioperative cardiac management in non-cardiac surgery of the European society of Cardiology (ESC) and endorsed by the European society of anaesthesiology (ESA)

ESC Committee for Practice Guidelines (CPG): Alec Vahanian (Chairperson) (France), Angelo Auricchio (Switzerland), Jeroen J. Bax (The Netherlands), Claudio Ceconi (Italy), Veronica Dean (France), Gerasimos Filippatos (Greece), Christian Funck-Brentano (France), Richard Hobbs (UK), Peter Kearney (Ire

Intensive insulin therapy protects the endothelium of critically ill patients.

The vascular endothelium controls vasomotor tone and microvascular flow and regulates trafficking of nutrients and biologically active molecules. When endothelial activation is excessive, compromised microcirculation and subsequent cellular hypoxia contribute to the risk of organ failure. We hypothesized that strict blood glucose control with insulin during critical illness protects the endothelium, mediating prevention of organ failure and death. In this preplanned subanalysis of a large, randomized controlled study, intensive insulin therapy lowered circulating levels of ICAM-1 and tended to reduce E-selectin levels in patients with prolonged critical illness, which reflects reduced endothelial activation. This effect was not brought about by altered levels of endothelial stimuli, such as cytokines or VEGF, or by upregulation of eNOS. In contrast, prevention of hyperglycemia by intensive insulin therapy suppressed iNOS gene expression in postmortem liver and skeletal muscle, possibly in part via reduced NF-kappaB activation, and lowered the elevated circulating NO levels in both survivors and nonsurvivors. These effects on the endothelium statistically explained a significant part of the improved patient outcome with intensive insulin therapy. In conclusion, maintaining normoglycemia with intensive insulin therapy during critical illness protects the endothelium, likely in part via inhibition of excessive iNOS-induced NO release, and thereby contributes to prevention of organ failure and death.

Reduced Cortisol Metabolism during Critical Illness

BACKGROUND Critical illness is often accompanied by hypercortisolemia, which has been attributed to stress-induced activation of the hypothalamic-pituitary-adrenal axis. However, low corticotropin levels have also been reported in critically ill patients, which may be due to reduced cortisol metabolism. METHODS In a total of 158 patients in the intensive care unit and 64 matched controls, we tested five aspects of cortisol metabolism: daily levels of corticotropin and cortisol; plasma cortisol clearance, metabolism, and production during infusion of deuterium-labeled steroid hormones as tracers; plasma clearance of 100 mg of hydrocortisone; levels of urinary cortisol metabolites; and levels of messenger RNA and protein in liver and adipose tissue, to assess major cortisol-metabolizing enzymes. RESULTS Total and free circulating cortisol levels were consistently higher in the patients than in controls, whereas corticotropin levels were lower (P<0.001 for both comparisons). Cortisol production was 83% higher in the patients (P=0.02). There was a reduction of more than 50% in cortisol clearance during tracer infusion and after the administration of 100 mg of hydrocortisone in the patients (P≤0.03 for both comparisons). All these factors accounted for an increase by a factor of 3.5 in plasma cortisol levels in the patients, as compared with controls (P<0.001). Impaired cortisol clearance also correlated with a lower cortisol response to corticotropin stimulation. Reduced cortisol metabolism was associated with reduced inactivation of cortisol in the liver and kidney, as suggested by urinary steroid ratios, tracer kinetics, and assessment of liver-biopsy samples (P≤0.004 for all comparisons). CONCLUSIONS During critical illness, reduced cortisol breakdown, related to suppressed expression and activity of cortisol-metabolizing enzymes, contributed to hypercortisolemia and hence corticotropin suppression. The diagnostic and therapeutic implications for critically ill patients are unknown. (Funded by the Belgian Fund for Scientific Research and others; ClinicalTrials.gov numbers, NCT00512122 and NCT00115479; and Current Controlled Trials numbers, ISRCTN49433936, ISRCTN49306926, and ISRCTN08083905.).

Mitochondrial alterations caused by defective peroxisomal biogenesis in a mouse model for Zellweger syndrome (PEX5 knockout mouse)

Zellweger syndrome (cerebro-hepato-renal syndrome) is the most severe form of the peroxisomal biogenesis disorders leading to early death of the affected children. To study the pathogenetic mechanisms causing organ dysfunctions in Zellweger syndrome, we have recently developed a knockout-mouse model by disrupting the PEX5 gene, encoding the targeting receptor for most peroxisomal matrix proteins (M Baes, P Gressens, E Baumgart, P Carmeliet, M Casteels, M Fransen, P Evrard, D Fahimi, PE Declercq, D Collen, PP van Veldhoven, GP Mannaerts: A mouse model for Zellweger syndrome. Nat Genet 1997, 17:49-57). In this study, we present evidence that the absence of functional peroxisomes, causing a general defect in peroxisomal metabolism, leads to proliferation of pleomorphic mitochondria with severe alterations of the mitochondrial ultrastructure, changes in the expression and activities of mitochondrial respiratory chain complexes, and an increase in the heterogeneity of the mitochondrial compartment in various organs and specific cell types (eg, liver, proximal tubules of the kidney, adrenal cortex, heart, skeletal and smooth muscle cells, neutrophils). The changes of mitochondrial respiratory chain enzymes are accompanied by a marked increase of mitochondrial manganese-superoxide dismutase, as revealed by in situ hybridization and immunocytochemistry, suggesting increased production of reactive oxygen species in altered mitochondria. This increased oxidative stress induced probably by defective peroxisomal antioxidant mechanisms combined with accumulation of lipid intermediates of peroxisomal beta-oxidation system could contribute significantly to the pathogenesis of multiple organ dysfunctions in Zellweger syndrome.

Effect of tolerating macronutrient deficit on the development of intensive-care unit acquired weakness: a subanalysis of the EPaNIC trial

BACKGROUND Patients who are critically ill can develop so-called intensive-care unit acquired weakness, which delays rehabilitation. Reduced muscle mass, quality, or both might have a role. The Early Parenteral Nutrition Completing Enteral Nutrition in Adult Critically Ill Patients (EPaNIC) trial (registered with ClinicalTrials.gov, number NCT00512122) showed that tolerating macronutrient deficit for 1 week in intensive-care units (late parenteral nutrition [PN]) accelerated recovery compared with early PN. The role of weakness was unclear. Our aim was to assess whether late PN and early PN differentially affect muscle weakness and autophagic quality control of myofibres. METHODS In this prospectively planned subanalysis of the EPaNIC trial, weakness (MRC sum score) was assessed in 600 awake, cooperative patients. Skeletal muscle biopsies, harvested from 122 patients 8 days after randomisation and from 20 matched healthy controls, were studied for autophagy and atrophy. We determined the significance of differences with Mann-Whitney U, Median, Kruskal-Wallis, or χ(2) (exact) tests, as appropriate. FINDINGS With late PN, 105 (34%) of 305 patients had weakness on first assessment (median day 9 post-randomisation) compared with 127 (43%) of 295 patients given early PN (absolute difference -9%, 95% CI -16 to -1; p=0·030). Weakness recovered faster with late PN than with early PN (p=0·021). Myofibre cross-sectional area was less and density was lower in critically ill patients than in healthy controls, similarly with early PN and late PN. The LC3 (microtubule-associated protein light chain 3) II to LC3I ratio, related to autophagosome formation, was higher in patients given late PN than early PN (p=0·026), reaching values almost double those in the healthy control group (p=0·0016), and coinciding with less ubiquitin staining (p=0·019). A higher LC3II to LC3I ratio was independently associated with less weakness (p=0·047). Expression of mRNA encoding contractile myofibrillary proteins was lower and E3-ligase expression higher in muscle biopsies from patients than in control participants (p≤0·0006), but was unaffected by nutrition. INTERPRETATION Tolerating a substantial macronutrient deficit early during critical illness did not affect muscle wasting, but allowed more efficient activation of autophagic quality control of myofibres and reduced weakness. FUNDING UZ Leuven, Research Foundation-Flanders, the Flemish Government, and the European Research Council.

Insufficient Activation of Autophagy Allows Cellular Damage to Accumulate in Critically Ill Patients

CONTEXT Responses to critical illness, such as excessive inflammation and hyperglycemia, may trigger detrimental chain reactions that damage cellular proteins and organelles. Such responses to illness contribute to the risk of (nonresolving) multiple organ dysfunction and adverse outcome. OBJECTIVE We studied autophagy as a bulk degradation pathway able to remove toxic protein aggregates and damaged organelles and how these are affected by preventing hyperglycemia with insulin during critical illness. DESIGN AND SETTING Patients participated in a randomized study, conducted at a university hospital surgical/medical intensive care unit. PATIENTS We studied adult prolonged critically ill patients vs. controls. INTERVENTIONS Tolerating excessive hyperglycemia was compared with intensive insulin therapy targeting normoglycemia. MAIN OUTCOME MEASURES We quantified (ultra)structural abnormalities and hepatic and skeletal muscle protein levels of key players in autophagy. RESULTS Morphologically, both liver and muscle revealed an autophagy-deficiency phenotype. Proteins involved in initiation and elongation steps of autophagy were induced 1.3- to 6.5-fold by critical illness (P ≤ 0.01), but mature autophagic vacuole formation was 62% impaired (P = 0.05) and proteins normally degraded by autophagy accumulated up to 97-fold (P ≤ 0.03). Mitophagy markers were unaltered or down-regulated (P = 0.05). Although insulin preserved hepatocytic mitochondrial integrity (P = 0.05), it further reduced the number of autophagic vacuoles by 80% (P = 0.05). CONCLUSIONS Insufficient autophagy in prolonged critical illness may cause inadequate removal of damaged proteins and mitochondria. Such incomplete clearance of cellular damage, inflicted by illness and aggravated by hyperglycemia, could explain lack of recovery from organ failure in prolonged critically ill patients. These data open perspectives for therapies that activate autophagy during critical illness.

Glycemic and nonglycemic effects of insulin: how do they contribute to a better outcome of critical illness?

Purpose of reviewThis review gives an overview of the clinical outcome benefits associated with intensive insulin therapy administered to critically ill patients and of the progress in the unraveling of the mechanisms underlying these positive effects. Recent findingsIn a large, prospective, randomized, controlled study, strict blood glucose control with intensive insulin therapy strongly reduced mortality and morbidity of surgical intensive care patients. These results were recently confirmed in a more heterogeneous patient population admitted to a mixed medical-surgical intensive care unit. Most of the clinical benefits of intensive insulin therapy appear to be related to prevention of hyperglycemia, which has been demonstrated to adversely affect outcome. Part of the improvement is related to protection of the mitochondrial compartment and innate immunity from glucose toxicity. Also, direct insulin effects contribute to the improved outcome. The beneficial nonglycemic metabolic actions of insulin include a partial correction of the abnormal serum lipid profile and counteraction of the catabolic state evoked by critical illness. The prevention of excessive inflammation and myocardial protection illustrate other nonmetabolic direct anti-inflammatory and anti-apoptotic properties of insulin, although lowering of glucose levels may have played a role in these events as well. SummarySubstantial progress has been made in the understanding of the mechanisms underlying the improved survival and reduced morbidity with intensive insulin therapy in critical illness. More studies, however, are needed to further elucidate the exact pathways involved and the relative contribution of prevention of glucose toxicity and direct nonglycemic effects of insulin.

Absence of peroxisomes in mouse hepatocytes causes mitochondrial and ER abnormalities

Peroxisome deficiency in men causes severe pathology in several organs, particularly in the brain and liver, but it is still unknown how metabolic abnormalities trigger these defects. In the present study, a mouse model with hepatocyte‐selective elimination of peroxisomes was generated by inbreeding Pex5‐loxP and albumin‐Cre mice to investigate the consequences of peroxisome deletion on the functioning of hepatocytes. Besides the absence of catalase‐positive peroxisomes, multiple ultrastructural alterations were noticed, including hepatocyte hypertrophy and hyperplasia, smooth endoplasmic reticulum proliferation, and accumulation of lipid droplets and lysosomes. Most prominent was the abnormal structure of the inner mitochondrial membrane, which bore some similarities with changes observed in Zellweger patients. This was accompanied by severely reduced activities of complex I, III, and V and a collapse of the mitochondrial inner membrane potential. Surprisingly, these abnormalities provoked no significant disturbances of adenosine triphosphate (ATP) levels and redox state of the liver. However, a compensatory increase of glycolysis as an alternative source of ATP and mitochondrial proliferation were observed. No evidence of oxidative damage to proteins or lipids nor elevation of oxidative stress defence mechanisms were found. Altered expression of peroxisome proliferator‐activated receptor alpha (PPAR‐α) regulated genes indicated that PPAR‐α is activated in the peroxisome‐deficient cells. In conclusion, the absence of peroxisomes from mouse hepatocytes has an impact on several other subcellular compartments and metabolic pathways but is not detrimental to the function of the liver parenchyma. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/0270‐9139/suppmat/index.html). (HEPATOLOGY 2005.)

Tight Blood Glucose Control Is Renoprotective in Critically Ill Patients

Two large, prospective, randomized, controlled trials have shown a beneficial effect of intensive insulin therapy (IIT) on the kidney function of critically ill patients. The data from these trials were combined for performance of a more detailed analysis of the renoprotective effect of IIT. After exclusion of 41 patients with preadmission ESRD, the study sample comprised 2707 critically ill patients who were randomly assigned to conventional or IIT. A modified risk-injury-failure-loss-ESRD (mRIFLE) system was used to classify acute kidney injury such that mRIFLE-Injury and -Failure (mR-IF) corresponded to peak serum creatinine levels >/=2x and >/=3x the admission levels, respectively. IIT significantly reduced the incidence of mR-I or -F from 7.6 to 4.5% (P = 0.0006), and this renoprotective effect was most pronounced in patients who achieved strict normoglycemia. In surgical patients, IIT also significantly reduced oliguria (from 5.6 to 2.6%; P = 0.004) and the need for renal replacement therapy (from 7.4 to 4.0%; P = 0.008). In medical patients, the incidence of mR-I or -F decreased to a lesser extent, perhaps because a greater severity of illness at admission may have rendered preventive therapies less effective. In conclusion, this secondary analysis of two large, randomized, controlled trials suggests that IIT, with a goal of achieving normoglycemia, protects the renal function of critically ill patients.