Antonios Kourliouros

King's College London, Londinium, England, United Kingdom

Are you Antonios Kourliouros?

Claim your profile

Publications (51)110.83 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Statin pretreatment in patients undergoing cardiac surgery is understood to prevent postoperative atrial fibrillation (AF). However, this is based on observational and limited randomized trial evidence, resulting in uncertainty about any genuine anti-arrhythmic benefits of these agents in this setting. We therefore aimed to quantify precisely the association between statin pretreatment and postoperative AF among patients undergoing cardiac surgery. A detailed search of MEDLINE and PubMed databases (1st January 1996 to 31st July 2012) was conducted, followed by a review of the reference lists of published studies and correspondence with trial investigators to obtain individual-participant data for meta-analysis. Evidence was combined across prospective, randomized clinical trials that compared the risk of postoperative AF among individuals randomized to statin pretreatment or placebo/control medication before elective cardiac surgery. Postoperative AF was defined as episodes of AF lasting ≥5 min. Overall, 1105 participants from 11 trials were included; of them, 552 received statin therapy preoperatively. Postoperative AF occurred in 19% of these participants when compared with 36% of those not treated with statins (odds ratio 0.41, 95% confidence interval 0.31-0.54, P < 0.00001, using a random-effects model). Atrial fibrillation prevention by statin pretreatment was consistent across different subgroups. Short-term statin pretreatment may reduce the risk of postoperative AF among patients undergoing cardiac surgery. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.
    No preview · Article · Mar 2015 · Europace
  • Source
    Joseph Thompson · Rynda Nitiahpapand · Prashan Bhatti · Antonios Kourliouros
    [Show abstract] [Hide abstract]
    ABSTRACT: Vitamin D deficiency has been linked with hypertension, coronary artery disease, and stroke, but there is no consensus regarding the possible association between vitamin D deficiency and atrial fibrillation (AF). Vitamin D negatively regulates the renin-angiotensin-aldosterone-system (RAAS), mediates calcium homeostasis, binds to vitamin D receptors on cardiac myocytes, and has antioxidant properties that may reduce levels of reactive oxygen species (ROS) in the atria, which contribute to inflammation and proarrhythmic substrate formation. As vitamin D status is a readily modifiable risk factor this association has potential clinical implications. An extensive search of the literature identified six studies that specifically investigated vitamin D status and AF. Results were equivocal with three studies identifying a positive association between vitamin D deficiency and AF, whilst two studies suggested there may be no association. Additionally, one study indicated that elevated vitamin D levels are associated with AF. Whilst the weight of the evidence suggests that there may be an association between vitamin D deficiency and AF, incomparable study designs and methodological limitations hinder interpretation of the current body of evidence. Further work taking into account considerations raised within this paper is required to better understand the relationship between vitamin D status and AF. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    Full-text · Article · Feb 2015 · International Journal of Cardiology
  • James S Davis · Antonios Kourliouros · Ranjit Deshpande · Naveen Cavale
    [Show abstract] [Hide abstract]
    ABSTRACT: In recent years, the use of negative pressure wound therapy (NPWT) devices has changed the way sternal wound infections are being managed. It is not uncommon for deep sternal wound infections to occur together with mediastinal or even pleural collections requiring underwater seal drainage. In these patients in whom there is a communication between the pleural and mediastinal cavities, the concomitant use of an NPWT device negates the pressure gradient within the pleural and mediastinal drains, allowing suppurative fluid to stagnate. We present a novel technique to address this limitation of NPWT devices in patients with sternal wound infections that communicate with a pleural collection. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
    No preview · Article · Nov 2014 · Interactive Cardiovascular and Thoracic Surgery
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a case of surgical implantation of biventricular epicardial pacing leads and a defibrillating patch via lower half mini sternotomy. Although median sternotomy is routinely used for this purpose, lower half mini sternotomy could provide the surgeon with the same surgical field exposure and a faster post operative recovery.
    Full-text · Article · Jan 2013 · Journal of Cardiothoracic Surgery
  • A. Kourliouros · D. Mukherjee · T. Athanasiou
    [Show abstract] [Hide abstract]
    ABSTRACT: Conversion is the process of institution of cardiopulmonary bypass as a preemptive or, more frequently, emergency measure to manage intraoperative complications arising during off-pump coronary artery bypass surgery. The incidence of conversion appears to be around 8% and in most cases is the result of hemodynamic compromise or anatomical considerations hindering the safe conduct of off-pump surgery. Although clinical outcomes following conversion have not been systematically analyzed until recently, it has been shown that it can lead to 6-fold increase in mortality, as well as a considerable increase in stroke, myocardial infarction, renal and respiratory failure and infection. This chapter provides an overview of the definitions, frequency and risk factors for conversion, examines its effect on postoperative outcomes, focuses on the implications of conversion in clinical practice and recommends strategies to prevent its occurrence.
    No preview · Article · Dec 2012
  • Source
    Dayal Mukherjee · Jerry Cheriyan · Antonios Kourliouros · Thanos Athanasiou
    [Show abstract] [Hide abstract]
    ABSTRACT: A best evidence topic was written according to a structured protocol. The question addressed was 'is the saphenous vein graft or right gastroepiploic artery a better conduit for revascularization of the right coronary artery?' One hundred and five articles were found using a designated search, of which 10 articles were found to represent the best available evidence to answer the clinical question. Of these 10 articles, two were reports of a randomized controlled trial and represented the highest level of evidence, whereas eight articles were retrospective observational studies. All were published between 2002 and 2012. Outcome measures varied considerably, but mostly included graft patency at varying periods of follow-up. The randomized evidence suggested that the saphenous vein had better early (6-month) and mid-term (3-year) graft patency than the right gastroepiploic artery when used for right coronary artery revascularization. The use of the saphenous vein was also found to be predictive of superior graft function using multivariate regression; however, a more recent propensity score analysis identified gastroepiploic-right coronary grafts to yield superior very long-term (>10 years) clinical outcomes. Overall, based on the best quality evidence and in view of technical limitations and flow characteristics of the right gastroepiploic artery, it appears that saphenous vein grafts may offer superior outcomes for revascularization of the right coronary artery in most cases, and should be preferentially used.
    Preview · Article · Jul 2012 · Interactive Cardiovascular and Thoracic Surgery
  • Antonios Kourliouros · Thanos Athanasiou

    No preview · Article · May 2012 · Heart (British Cardiac Society)
  • Source
    Dayal Mukherjee · Jerry Cheriyan · Antonios Kourliouros · Thanos Athanasiou
    [Show abstract] [Hide abstract]
    ABSTRACT: A best evidence topic was written according to a structured protocol. The question addressed was whether the right internal thoracic artery (RITA) provides a superior outcome for revascularization of the right coronary artery (RCA) compared with the saphenous vein graft (SVG). Using a designated search strategy, 226 articles were found, of which five represented the best available evidence. The authors, journal, date, country of publication, study type, patient group studied, relevant outcomes and results were tabulated. Of these five studies, one offered level I evidence (data from a randomized trial) and four were level II studies (reports of observational data). The outcome measures varied considerably, but most included graft patency at varying levels of the follow-up. The randomized data showed strong evidence favouring the SVG, mainly in terms of mid-term patency. With the exception of a large cohort study that demonstrated the superior patency of the RITA compared with the SVG in the right coronary territory, the observational studies showed better results for SVG in graft patency, reintervention and cardiovascular complication rate. Overall, and in view of the methodological limitations and the different weight of evidence among studies, it appears that the SVG may offer a superior outcome for revascularization of the RCA when compared with the RITA.
    Preview · Article · May 2012 · Interactive Cardiovascular and Thoracic Surgery
  • [Show abstract] [Hide abstract]
    ABSTRACT: Optimal thromboprophylaxis following bioprosthetic aortic valve replacement (AVR) remains controversial. The main objective, which is the effective prevention of central nervous or peripheral embolic events, especially in the early postoperative period, will have to be weighed against the haemorrhagic risk that is associated with the utilization of different antithrombotic regimes. Most governing bodies in cardiovascular medicine have issued recommendations on thromboprophylaxis after the surgical implantation of aortic bioprostheses. However, the level of evidence to support these recommendations remains low, largely due to the inherent limitations of conducting appropriately randomized and adequately powered clinical research in this area. It is apparent from the recent surveys and large registries that there is a great variability in antithrombotic practice at an institutional or individual-clinician level reflecting this controversy and the lack of robust evidence. While organizational, financial or conceptual limitations could hinder the conduct and availability of conclusive research on optimal thromboprophylaxis after aortic bioprosthesis, it is imperative that all evidence is presented in a systematic way in order to assist the decision-making for the modern clinician. In this review, we provide an outline of the current recommendations for thromboprophylaxis, followed by a comprehensive and analytical presentation of all comparative studies examining anticoagulation vs. antiplatelet therapy after bioprosthetic AVR.
    No preview · Article · Apr 2012 · Interactive Cardiovascular and Thoracic Surgery
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Vacuum-assisted closure (VAC) has recently been adopted as an acceptable modality for management of sternotomy wound infections. Although generally efficacious, the use of negative pressure devices has been associated with complications such as bleeding, retention of sponge, and empyema. We report the first case of greater omental hernia as a rare complication of vacuum-assisted closure of sternal wound infection following coronary artery bypass grafting.
    Full-text · Article · Feb 2012
  • Source
    Sonia Rasoli · Mohamed Zeinah · Thanos Athanasiou · Antonios Kourliouros
    [Show abstract] [Hide abstract]
    ABSTRACT: A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was what the optimal intraoperative anticoagulation strategy should be in patients undergoing off-pump coronary artery bypass graft (CABG) surgery. A total of 157 papers were identified using the reported search, of which 8 were judged to represent the best evidence. The authors, journal, date, country of publication, study type, patient group studied, relevant outcomes and results were tabulated. The quality of clinical trials was assessed. Off-pump CABG is currently considered as a safe and effective alternative to CABG with the use of cardiopulmonary bypass, especially in the presence of off-pump expertise and certain pathologies. Although most technical steps in off-pump revascularization are standardized, it appears that there is inconsistency in intraoperative anticoagulation practice. Surveys conducted in the USA and Europe confirm the lack of uniform policy, with heparin dose ranging between 70 and 500 U/kg and from full-dose protamine to no reversal of anticoagulation. Although the quality of evidence is low, there is a trend for utilization of heparin at 150 U/kg, followed by half-dose protamine reversal, which appears to provide adequate anticoagulation for the safe conduct of anastomoses and thromboprophylaxis without significantly increasing the risk of postoperative bleeding. However, more research is necessary before firm recommendations can be made.
    Preview · Article · Feb 2012 · Interactive Cardiovascular and Thoracic Surgery

  • No preview · Article · Jan 2012 · The Annals of thoracic surgery
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Surgical repair of ascending aortic disease involving the aortic root most commonly involves the direct ana stomosis of the coronary ostia to the composite aortic graft. Occasionally, when direct aortocoronary ana stomosis is not safe or technically challenging--such as in cases of extreme aortic dilatation, calcification and reoperations--the Cabrol technique and its modification can provide a safe and effective alternative. As the Cabrol is often reserved as a second line or bailout procedure, there is insufficient evidence to support the optimal imaging assessment and follow up of patients who have undergone this complex aortic recon struction. We present the case of a patient where emergency replacement of the aortic root took place with a modified Cabrol aortocoronary anastomosis. We discuss the usefulness, findings and limitations of modern noninvasive imaging modalities that can provide a complete functional and anatomical assessment of this surgical technique.
    Full-text · Article · Nov 2011 · Hellenic journal of cardiology: HJC = Hellēnikē kardiologikē epitheōrēsē
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Atrial fibrillation (AF) is the most common sustained arrhythmia that is associated with significant morbidity and mortality. Current available therapies remain inadequate in symptom control and secondary prevention and are often associated with significant side effects. The mechanisms underlying the pathogenesis of AF are poorly understood, although electrophysiological remodeling has been described as an important initiating step. Recently, increasing evidence implicates oxidative stress and inflammation in the pathogenesis of AF. We searched the literature for evidence to support the use of antioxidant vitamins C and E in the prevention of AF. These vitamins, through their reactive-oxygen-species- (ROS-) scavenging effect, have shown a role in AF prevention in both animal and small clinical studies. The available evidence, however, is currently insufficient to support recommendations for their use in the wider patient population. Larger-scale clinical studies are required to confirm these preliminary results. Research is also required to further the understanding of the processes involved in the pathogenesis of AF and the role of antioxidant therapies to prevent the arrhythmia.
    Full-text · Article · Aug 2011 · Cardiology Research and Practice
  • [Show abstract] [Hide abstract]
    ABSTRACT: Postoperative atrial fibrillation (POAF) affects approximately 30% of patients undergoing elective cardiac surgery. While its pathogenesis is multifactorial, increasing evidence supports a role for oxidative stress in the electrophysiological remodelling associated with AF. Although prophylactic antioxidants appear to be a potentially attractive pharmacotherapy, there is still uncertainty regarding their efficacy. This study aims to provide a quantitative summary of the current evidence surrounding antioxidant vitamins and POAF prevention. A systematic literature review identified five randomised controlled trials incorporating 567 patients (n = 284 antioxidant, n = 283 control). These were meta-analysed using random effects modelling. Heterogeneity, subgroup analysis, quality scoring and risk of bias were assessed. Primary endpoints were the incidence of POAF and all-cause arrhythmia. Secondary endpoints were length of stay in the intensive care unit (ITU) and length of hospital stay. Vitamins C and E significantly reduced the incidence of POAF (OR 0.43, 95% CI 0.21 to 0.89) and all-cause arrhythmia (OR 0.54, 95% CI 0.29 to 0.99) compared with controls. A significant reduction in both ITU stay (weighted mean difference (WMD) -0.44, 95% CI -0.70 to -0.17) and hospital stay (WMD -1.11, 95% CI -1.70 to -0.52) was also seen in the antioxidant group, without significant heterogeneity. The prophylactic use of vitamins C and E may significantly reduce the incidence of POAF and all-cause arrhythmia following cardiac surgery. However, the overall quality of current studies is poor and further research should focus on adequately powered randomised controlled trials that standardise AF reporting, antioxidant protocol and the use of concomitant agents. Cost analysis should be considered to establish the potential economic benefit of antioxidant vitamin prophylaxis in POAF.
    No preview · Article · Aug 2011 · Heart (British Cardiac Society)
  • Source
    Nicholaos Kakouros · Jeffrey J Rade · Antonios Kourliouros · Jon R Resar
    [Show abstract] [Hide abstract]
    ABSTRACT: Patients with diabetes mellitus have an increased prevalence of vascular disease. Pathologic thrombosis associated with atherosclerotic plaque rupture is a major cause of morbidity and mortality. Platelets are intimately involved in the initiation and propagation of thrombosis. Evidence suggests that platelets from patients with type 2 diabetes have increased reactivity and baseline activation compared to healthy controls. We review the pathophysiology of platelet hyperreactivity in DM patients and its implications in clinical practice, with particular focus on acute coronary syndromes, percutaneous coronary intervention, and novel antiplatelet agents.
    Full-text · Article · Aug 2011 · International Journal of Endocrinology
  • Source

    Full-text · Article · Jul 2011 · Hellenic journal of cardiology: HJC = Hellēnikē kardiologikē epitheōrēsē
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Atrial fibrillation (AF) is an important cause of morbidity and mortality after cardiac surgery. The pathogenesis of AF appears to be multifactorial but little is known about the cause-effect relationship of substrate modifications with the onset of the arrhythmia. With the use of modern proteomics, this study aims to identify preexisting changes in the left atrium of patients susceptible to postoperative AF. We analyzed 20 matched patients undergoing elective, first-time coronary artery bypass grafting with no history of AF. They were divided into 2 equal groups according to the development of postoperative AF. Proteomic analysis was performed in left atrial tissue obtained during surgery using two-dimensional difference in gel electrophoresis techniques. Mass spectrometry identified proteins that were differentially expressed in patients who developed AF against those who remained in sinus rhythm. Proteomic analysis of left atrial tissue identified 19 differentially expressed protein spots between patients who developed postoperative AF and their sinus rhythm counterparts. In patients who developed AF, proteins associated with oxidative stress and apoptosis (peroxiredoxin 1, apoptosis-inducing factor, and 96S protease regulatory subunit 8) as well as acute phase response components (apolipoprotein A-I, fibrinogen) were found to be increased. Conversely, the expression of proteins responsible for glycolysis (enolase) and pyruvate metabolism (pyruvate dehydrogenase) was reduced. We describe protein changes that precede the development of postoperative AF and which might be suggestive of increased oxidative stress and glycolytic inhibition in the left atrium of patients predilected to AF.
    Full-text · Article · Jul 2011 · The Annals of thoracic surgery
  • [Show abstract] [Hide abstract]
    ABSTRACT: Coronary artery bypass surgery can offer excellent results when performed with cardiopulmonary bypass (on pump) or without cardiopulmonary bypass (off pump). The debate as to which technique is superior remains unanswered. Intra-operative conversion from off- to on-pump coronary surgery is a relatively unexplored phenomenon, which cannot be assessed within randomised controlled trial design. We aimed to assess the effect of off-pump conversion on patient mortality. Medline, Embase, Cochrane and Google Scholar databases were systematically reviewed for studies published between 1980 and 2010 that compared the incidence of mortality between converted and non-converted off-pump patients. Publication bias and heterogeneity were assessed and data were extracted independently by multiple observers. We undertook a meta-analysis of these studies using random effects modelling. A total of 17 studies fulfilled our inclusion criteria, containing data for 18,870 off-pump coronary artery bypass operations spanning a decade (1998-2008), involving 920 cases of conversion. Overall, conversion increased mortality by an odds ratio of 6.18 (95% confidence interval 4.65-8.20), whereas emergency conversion further raised the odds ratio of mortality to 6.99 (95% confidence interval 5.18-9.45). The conversion from off- to on-pump cardiac surgery may significantly increase the chance of an adverse outcome, whereas emergency conversion confers a significant rise in mortality. The risk of conversion should be discussed when obtaining the patient's informed consent and its prevention warrants serious consideration by cardiac surgeons and cardiac surgical training programmes.
    No preview · Article · Jun 2011 · European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Atrial fibrillation (AF) is associated with substantial morbidity, mortality, and economic burden and confers a lifetime risk of up to 25%. Current medical management involves thromboembolism prevention, rate, and rhythm control. An increased understanding of AF pathophysiology has led to enhanced pharmacological and medical therapies; however this is often limited by toxicity, variable symptom control, and inability to modulate the atrial substrate. Surgical AF ablation has been available since the original description of the Cox Maze procedure, either as a standalone or concomitant intervention. Advances in novel energy delivery systems have allowed the development of less technically demanding procedures potentially eliminating the need for median sternotomy and cardiopulmonary bypass. Variations in the definition, duration, and reporting of AF have produced methodological limitations impacting on the validity of interstudy comparisons. Standardization of these parameters may, in future, allow us to further evaluate clinical endpoints and establish the efficacy of these techniques.
    Full-text · Article · Jun 2011 · Cardiology Research and Practice