Theodoros Karapanayiotides

Dr. Theodoros Karapanayiotides

2nd Department of Neurology, AHEPA University Hospital, Aristotle University of Thessaloniki, School of Medicine, Faculty of Health Sciences, Thessaloniki, Greece
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Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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11 May 2004 in Neurology
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TKTheodoros Karapanayiotides
Theodoros Karapanayiotides
BPBartlomiej Piechowski-Jozwiak
Bartlomiej Piechowski-Jozwiak
GMG. van Melle
G. van Melle
JBJ. Bogousslavsky
J. Bogousslavsky
GDG. Devuyst
G. Devuyst
Background: Although diabetes mellitus (DM) is a risk factor for stroke, it is unclear whether stroke features are different in diabetic vs nondiabetic individuals. Objective: To assess the role of DM in stroke patients. Methods: Risk factors, etiology, lesion topography, clinical features, and outcome were assessed in 611 diabetic individuals (history of DM or fasting plasma glucose level of ≥7.0 mmol/L) among 4,064 consecutive patients of the Lausanne Stroke Registry. Results: Patients with DM were 5.3 years older than non-DM patients. After multivariate analysis, DM was associated with lower relative prevalence of intracerebral hemorrhage (ICH; odds ratio [95% CI]: 0.63 (0.45 to 0.9); p = 0.022), higher relative prevalence of subcortical infarction (SCI; 1.34 [1.11 to 1.62]; p = 0.009), and higher relative frequency of small-vessel (SVD; 1.78 [1.31 to 3.82]; p = 0.012) and large-artery (LAD; 2.02 [1.31 to 2.02]; p = 0.002) disease. In the cohort of diabetic stroke patients, there was no interaction of DM with either hypertension or age for the outcomes of ICH, SCI, SVD, and LAD. Moderate to severe deficit on admission (31.1 vs 31.6%; p = 0.4) and poor functional outcome at 1 month (14.1 vs 15.3%; p = 0.24) did not differ in patients with DM compared with non-DM patients. In multivariate analysis, neither DM (0.86 [0.63 to 1.11]; p = 0.15) nor hypertension (1.09 [0.91 to 1.39]; p = 0.32) was associated with poor functional outcome. Conclusions: Diabetic stroke patients are associated with specific patterns of stroke type, etiology, and topography but not with poor functional outcome. There was no interaction between DM and hypertension or age.

28 April 2020 in Frontiers in Neurology
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IKIoanna Koutroulou
Ioanna Koutroulou
GTGeorgios Tsivgoulis
Georgios Tsivgoulis
DTDimitrios Tsalikakis
Dimitrios Tsalikakis
DKDimitris Karacostas
Dimitris Karacostas
NGNikolaos Grigoriadis
Nikolaos Grigoriadis
TKTheodoros Karapanayiotides
Theodoros Karapanayiotides
Introduction: Percutaneous closure of patent foramen ovale (PFO) in selected patients with cryptogenic cerebrovascular ischemic events (CEs) decreases the risk of recurrent stroke; however, optimal patient selection criteria are still under investigation. Candidates for PFO closure are usually selected from the pool of CE patients with a high risk of Paradoxical Embolism (RoPE) score. The RoPE score calculates the probability that PFO is causally related to stroke, based on PFO prevalence in patients with CE compared with that in healthy subjects. The latter has been set at 25% based on the average of autopsy and transesophageal echocardiography (TEE) studies. Methods: We conducted a comprehensive review of studies investigating PFO prevalence in general population and in patients with CE and non-CE using autopsy, TEE, transcranial Doppler (TCD) or transthoracic echocardiography (TTE). Studies were excluded if they (1) reported data from referred subjects with underlying cerebrovascular disease or (2) did not specify etiologically the events. Results: In healthy/control subjects, PFO prevalence was 24.2% (1,872/7,747) in autopsy studies, 23.7% (325/1,369) in TEE, 31.3% (111/355) in TCD, and 14.7% (186/1,267) in TTE studies. All diagnostic modalities included PFO prevalence was higher in CE compared with healthy/control population [odds ratio (OR) = 3.1, 95% confidence interval (CI) = 2.5–3.8] and compared with non-CE (OR = 2.3, 95% CI = 2.0–2.6). In patients with CE, PFO prevalence in the young compared to the old was higher when the diagnostic modality was TEE (48.9 vs. 27.3%, p < 0.0001, OR = 2.6 with 95% CI = 2.0–3.3) or TCD (58.1 vs. 41%, OR = 1.9, 95% CI = 1.6–2.5), but not TTE (53.3 vs. 37.5%, p = 0.16). Regarding non-CE, PFO prevalence in the young compared to the old was higher when the diagnostic modality was TEE (20 vs. 12.9%, OR = 1.7, 95% CI = 1.0–2.8) but not TTE (10.4 vs. 7.8%, p = 0.75) or TCD (22.8 vs. 20.1%, p = 0.56). Conclusions: Given the limitations of autopsy and TEE studies, there is good reason not to take a fixed 25% PFO prevalence for granted. The estimation of degree of causality may be underestimated or overestimated in populations with PFO prevalence significantly lower or higher than the established. Given the high sensitivity, non-invasive nature, low cost, and repeatability of TCD, future large-scale TCD-based studies should investigate potential heterogeneity in PFO prevalence in different healthy racial/ethnic populations.

5 March 2025 in EP Europace
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Wolfram Doehner, MD, PhDWolfram Doehner, MD, PhD
Wolfram Doehner, MD, PhD
Giuseppe BorianiGiuseppe Boriani
Giuseppe Boriani
TPTatajana Potpara
Tatajana Potpara
CBCarina Blomstrom-Lundqvist
Carina Blomstrom-Lundqvist
RPRod Passman
Rod Passman
ACA John Camm
A John Camm
Atrial fibrillation (AF) is one of the most common cardiac diseases and a complicating comorbidity for multiple associated diseases. Many clinical decisions regarding AF are currently based on the binary recognition of AF being present or absent with the categorical appraisal of AF as continued or intermittent. Assessment of AF in clinical trials is largely limited to the time to (first) detection of an AF episode. Substantial evidence shows, however, that the quantitative characteristic of intermittent AF has a relevant impact on symptoms, onset, and progression of AF and AF-related outcomes, including mortality. Atrial fibrillation burden is increasingly recognized as a suitable quantitative measure of intermittent AF that provides an estimate of risk attributable to AF, the efficacy of antiarrhythmic treatment, and the need for oral anticoagulation. However, the diversity of assessment methods and the lack of a consistent definition of AF burden prevent a wider clinical applicability and validation of actionable thresholds of AF burden. To facilitate progress in this field, the AF burden Consensus Group, an international and multidisciplinary collaboration, proposes a unified definition of AF burden. Based on current evidence and using a modified Delphi technique, consensus statements were attained on the four main areas describing AF burden: Defining the characteristics of AF burden, the recording principles, the clinical relevance in major clinical conditions, and implementation as an outcome in the clinic and in clinical trials. According to this consensus, AF burden is defined as the proportion of time spent in AF expressed as a percentage of the recording time, undertaken during a specified monitoring duration. A pivotal requirement for validity and comparability of AF burden assessment is a continuous or near-continuous duration of monitoring that needs to be reported together with the AF burden assessment. This proposed unified definition of AF burden applies independent of comorbidities and outcomes. However, the disease-specific actionable thresholds of AF burden need to be defined according to the targeted clinical outcomes in specific populations. The duration of the longest episode of uninterrupted AF expressed as a time duration should also be reported when appropriate. A unified definition of AF burden will allow for comparability of clinical study data to expand evidence and to establish actionable thresholds of AF burden in various clinical conditions. This proposed definition of AF burden will support risk evaluation and clinical treatment decisions in AF-related disease. It will further promote the development of clinical trials studying the clinical relevance of intermittent AF. A unified approach on AF burden will finally inform the technology development of heart rhythm monitoring towards validated technology to meet clinical needs.

1 January 2005 in Stroke
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Journal Article
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TKTheodoros Karapanayiotides
Theodoros Karapanayiotides
RMReto Meuli
Reto Meuli
GDGerald Devuyst
Gerald Devuyst
BPBartlomiej Piechowski-Jozwiak
Bartlomiej Piechowski-Jozwiak
ADAnnelise Dewarrat
Annelise Dewarrat
JBJulien Bogousslavsky
Julien Bogousslavsky
Background and Purpose— Hyperperfusion syndrome (HS) after carotid endarterectomy (CEA) has been related to impaired cerebrovascular autoregulation in a chronically hypoperfused hemisphere. Our aim was to provide new insight into the pathophysiology of the HS using magnetic resonance imaging (MRI) studies with diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI). Methods— Five out of 388 consecutive patients presented 2 to 7 days after CEA, partial seizures (n=5), focal deficits (n=5), and intracerebral hemorrhage (n=3). In 4 patients, using sequential examinations, we identified vasogenic or cytotoxic edema by DWI; we assessed relative interhemispheric difference (RID) of cerebral blood flow (CBF) by PWI; and we measured middle cerebral artery mean flow velocities (MCA Vm) by transcranial Doppler (TCD). Results— None of the patients presented pathological DWI hyperintensities, consistent with the absence of acute ischemia or cytotoxic edema. In 2 patients, we found an MRI pattern of reversible vasogenic edema similar to that observed in the posterior leukoencephalopathy syndrome. Middle cerebral artery (MCA) mean flow velocities (Vm) were not abnormally increased at any time. PWI documented a 20% to 44% RID of CBF in favor of the ipsilateral to CEA hemisphere. Conclusions— HS can occur in the presence of moderate relative hyperperfusion of the ipsilateral hemisphere. MCA Vm values may not accurately reflect RID of CBF over the cortical convexity. We suggest that the hemodynamic pathogenetic mechanisms of the HS are more complicated than hitherto believed and that they may be more accurately described by the term “reperfusion syndrome.”

2 December 2017 in Journal of the American Heart Association
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Journal Article
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MPMaurizio Paciaroni
Maurizio Paciaroni
GAGiancarlo Agnelli
Giancarlo Agnelli
NFNicola Falocci
Nicola Falocci
GTGeorgios Tsivgoulis
Georgios Tsivgoulis
KVKostantinos Vadikolias
Kostantinos Vadikolias
VCValeria Caso
Valeria Caso
Background: The optimal timing to administer non–vitamin K oral anticoagulants ( NOAC s) in patients with acute ischemic stroke and atrial fibrillation is unclear. This prospective observational multicenter study evaluated the rates of early recurrence and major bleeding (within 90 days) and their timing in patients with acute ischemic stroke and atrial fibrillation who received NOAC s for secondary prevention. Methods and Results: Recurrence was defined as the composite of ischemic stroke, transient ischemic attack, and symptomatic systemic embolism, and major bleeding was defined as symptomatic cerebral and major extracranial bleeding. For the analysis, 1127 patients were eligible: 381 (33.8%) were treated with dabigatran, 366 (32.5%) with rivaroxaban, and 380 (33.7%) with apixaban. Patients who received dabigatran were younger and had lower admission National Institutes of Health Stroke Scale score and less commonly had a CHA 2 DS 2 ‐ VAS c score >4 and less reduced renal function. Thirty‐two patients (2.8%) had early recurrence, and 27 (2.4%) had major bleeding. The rates of early recurrence and major bleeding were, respectively, 1.8% and 0.5% in patients receiving dabigatran, 1.6% and 2.5% in those receiving rivaroxaban, and 4.0% and 2.9% in those receiving apixaban. Patients who initiated NOAC s within 2 days after acute stroke had a composite rate of recurrence and major bleeding of 12.4%; composite rates were 2.1% for those who initiated NOACs between 3 and 14 days and 9.1% for those who initiated >14 days after acute stroke. Conclusions: In patients with acute ischemic stroke and atrial fibrillation, treatment with NOAC s was associated with a combined 5% rate of ischemic embolic recurrence and severe bleeding within 90 days.

20 November 2018 in Journal of the American Heart Association
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Journal Article
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MPMaurizio Paciaroni
Maurizio Paciaroni
FBFabio Bandini
Fabio Bandini
GAGiancarlo Agnelli
Giancarlo Agnelli
GTGeorgios Tsivgoulis
Georgios Tsivgoulis
SYShadi Yaghi
Shadi Yaghi
VCValeria Caso
Valeria Caso
Background: In patients with acute ischemic stroke and atrial fibrillation, early anticoagulation prevents ischemic recurrence but with the risk of hemorrhagic transformation ( HT ). The aims of this study were to evaluate in consecutive patients with acute stroke and atrial fibrillation (1) the incidence of early HT, (2) the time to initiation of anticoagulation in patients with HT , (3) the association of HT with ischemic recurrences, and (4) the association of HT with clinical outcome at 90 days. Methods and Results: HT was diagnosed by a second brain computed tomographic scan performed 24 to 72 hours after stroke onset. The incidence of ischemic recurrences as well as mortality or disability (modified Rankin Scale scores >2) were evaluated at 90 days. Ischemic recurrences were the composite of ischemic stroke, transient ischemic attack, or systemic embolism. Among the 2183 patients included in the study, 241 (11.0%) had HT . Patients with and without HT initiated anticoagulant therapy after a mean 23.3 and 11.6 days, respectively, from index stroke. At 90 days, 4.6% (95% confidence interval, 2.3–8.0) of the patients with HT had ischemic recurrences compared with 4.9% (95% confidence interval, 4.0–6.0) of those without HT ; 53.1% of patients with HT were deceased or disabled compared with 35.8% of those without HT . On multivariable analysis, HT was associated with mortality or disability (odds ratio, 1.71; 95% confidence interval, 1.24–2.35). Conclusions: In patients with HT , anticoagulation was initiated about 12 days later than patients without HT . This delay was not associated with increased detection of ischemic recurrence. HT was associated with increased mortality or disability.