Koray Durak

Mr. Koray Durak

Radboud UMC, Nijmegen, The Netherlands
+1

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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24 November 2020 in Artificial Organs
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Journal Article
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RZRashad Zayat
Rashad Zayat
SKSebastian Kalverkamp
Sebastian Kalverkamp
OGOliver Grottke
Oliver Grottke
KDKoray Durak
Koray Durak
MDMichael Dreher
Michael Dreher
AKAlex Kersten
Alex Kersten
The role of extracorporeal membrane oxygenation (ECMO) in the management of critically ill COVID‐19 patients remains unclear. Our study aims to analyze the outcomes and risk factors from patients treated with ECMO. This retrospective, single‐center study includes 17 COVID‐19 patients treated with ECMO. Univariate and multivariate parametric survival regression identified predictors of survival. Nine patients (53%) were successfully weaned from ECMO and discharged. The incidence of in‐hospital mortality was 47%. In a univariate analysis, only four out of 83 pre‐ECMO variables were significantly different; IL‐6, PCT, and NT‐proBNP were significantly higher in non‐survivors than in survivors. The Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) score was significantly higher in survivors. After a multivariate parametric survival regression, IL‐6, NT‐proBNP and RESP scores remained significant independent predictors, with hazard ratios (HR) of 1.069 [95%‐CI: 0.986‐1.160], P = .016 1.001 [95%‐CI: 1.000‐1.001], P = .012; and .843 [95%‐CI: 0.564‐1.260], P = .040, respectively. A prediction model comprising IL‐6, NT‐proBNP, and RESP score showed an area under the curve (AUC) of 0.87, with a sensitivity of 87.5% and 77.8% specificity compared to an AUC of 0.79 for the RESP score alone. The present study suggests that ECMO is a potentially lifesaving treatment for selected critically ill COVID‐19 patients. Considering IL‐6 and NT‐pro‐BNP, in addition to the RESP score, may enhance outcome predictions.

16 April 2021 in The Thoracic and Cardiovascular Surgeon
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KDKoray Durak
Koray Durak
AKAlexander Kersten
Alexander Kersten
OGOliver Grottke
Oliver Grottke
RZRashad Zayat
Rashad Zayat
MDMichael Dreher
Michael Dreher
SKSebastian Kalverkamp
Sebastian Kalverkamp
Background Extracorporeal membrane oxygenation (ECMO) is a potential treatment option in critically ill COVID-19 patients suffering from acute respiratory distress syndrome (ARDS) if mechanical ventilation (MV) is insufficient; however, thromboembolic and bleeding events (TEBE) during ECMO treatment still need to be investigated. Methods We conducted a retrospective, single-center study including COVID-19 patients treated with ECMO. Additionally, we performed a univariate analysis of 85 pre-ECMO variables to identify factors influencing incidences of thromboembolic events (TEE) and bleeding events (BE), respectively. Results Seventeen patients were included; the median age was 57 years (interquartile range [IQR]: 51.5–62), 11 patients were males (65%), median ECMO duration was 16 days (IQR: 10.5–22), and the overall survival was 53%. Twelve patients (71%) developed TEBE. We observed 7 patients (41%) who developed TEE and 10 patients (59%) with BE. Upper respiratory tract (URT) bleeding was the most frequent BE with eight cases (47%). Regarding TEE, pulmonary artery embolism (PAE) had the highest incidence with five cases (29%). The comparison of diverse pre-ECMO variables between patients with and without TEBE detected one statistically significant value. The platelet count was significantly lower in the BE group (n = 10) than in the non-BE group (n = 7) with 209 (IQR: 145–238) versus 452 G/L (IQR: 240–560), with p = 0.007. Conclusion This study describes the incidences of TEE and BE in critically ill COVID-19 patients treated with ECMO. The most common adverse event during ECMO support was bleeding, which occurred at a comparable rate to non-COVID-19 patients treated with ECMO. + Both authors contributed equally to this study. Koray Durak has collected the data (60%), performed data Analysis (55%) and wrote the first version of the manuscript (100%). Alex Kersten contributed to the Study design (50%), performed ECMO implantation (35%), collected the data (40%), performed data analysis (45%), supervised the writing process of the first version of the manuscript, critically revised the manuscript. The above mentioned contribution justify a contributed equally authorship of both authors Koray Durak and Alex Kersten. Received: 28 November 2020 Accepted: 18 January 2021 Publication Date: 16 April 2021 (online) © 2021. Thieme. All rights reserved. Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Verified
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TATeresa Autschbach
Teresa Autschbach
NHNima Hatam
Nima Hatam
KDKoray Durak
Koray Durak
OGOliver Grottke
Oliver Grottke
Michael DreherMichael Dreher
Michael Dreher
AKAlexander Kersten
Alexander Kersten
It remains unclear to what extent the outcomes and complications of extracorporeal membrane oxygenation (ECMO) therapy in COVID-19 patients with acute respiratory distress syndrome (ARDS) differ from non-COVID-19 ARDS patients. In an observational, propensity-matched study, outcomes after ECMO support were compared between 19 COVID-19 patients suffering from ARDS (COVID group) and 34 matched non-COVID-19 ARDS patients (NCOVID group) from our historical cohort. A 1:2 propensity matching was performed based on respiratory ECMO survival prediction (RESP) score, age, gender, bilirubin, and creatinine levels. Patients’ characteristics, laboratory parameters, adverse events, and 90-day survival were analyzed. Patients’ characteristics in COVID and NCOVID groups were similar. Before ECMO initiation, fibrinogen levels were significantly higher in the COVID group (median: 493 vs. 364 mg/dL, p < 0.001). Median ECMO support duration was similar (16 vs. 13 days, p = 0.714, respectively). During ECMO therapy, patients in the COVID group developed significantly more thromboembolic events (TEE) than did those in the NCOVID group (42% vs. 12%, p = 0.031), which were mainly pulmonary artery embolism (PAE) (26% vs. 0%, p = 0.008). The rate of major bleeding events (42% vs. 62%, p = 0.263) was similar. Fibrinogen decreased significantly more in the COVID group than in the NCOVID group (p < 0.001), whereas D-dimer increased in the COVID group (p = 0.011). Additionally, 90-day mortality did not differ (47% vs. 74%; p = 0.064) between COVID and NCOVID groups. Compared with that in non-COVID-19 ARDS patients, ECMO support in COVID-19 patients was associated with comparable in-hospital mortality and similar bleeding rates but a higher incidence of TEE, especially PAE. In contrast, coagulation parameters differed between COVID and NCOVID patients.

30 January 2026 in European Heart Journal
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Closed access
NGNoemi Glarner
Noemi Glarner
CPChristian Puelacher
Christian Puelacher
DGDanielle M Gualandro
Danielle M Gualandro
MPMirjam Pargger
Mirjam Pargger
KDKoray Durak
Koray Durak
CMChristian Mueller
Christian Mueller
Background and Aims: Peri-operative myocardial infarction/injury (PMI) is a common cardiac complication following non-cardiac surgery. It remains unclear whether involvement of cardiologists in the management of patients developing PMI improves outcomes. Methods: This multicentre, prospective study included high-risk patients undergoing non-cardiac surgery, eligible for the institutional PMI active surveillance and response programme. Due to staffing constraints, cardiologist evaluation of patients with PMI was inconsistently available on weekends, on public holidays, or when care for more urgent patients had to be prioritized, allowing a comparison between patients receiving cardiologist evaluation and those who did not. The primary endpoint was major adverse cardiac events, defined as a composite of cardiovascular death, myocardial infarction, acute heart failure, and life-threatening arrhythmia at 365 days. The secondary endpoint was all-cause death at 365 days. Cox proportional hazards models were used to evaluate the association between cardiologist evaluation and outcomes. Results: Among 14 294 patients, 1048 developed PMI and were eligible for this analysis, of whom 614 patients (58.6%) received post-operative cardiologist evaluation. Baseline characteristics were similar between groups. After adjustment, cardiologist evaluation was independently associated with lower risk of major adverse cardiac events (adjusted hazard ratio .54, P = .001) and all-cause death (adjusted hazard ratio .65, P = .037) at 365 days. Sensitivity analyses confirmed these findings. Patients receiving cardiology evaluation were more likely to undergo non-invasive cardiac imaging and to receive dual antiplatelet and statin therapy. Conclusions: Cardiologist evaluation of patients with PMI following major non-cardiac surgery was associated with a reduced risk of major adverse cardiac events and all-cause mortality at 365 days after surgery, suggesting that interdisciplinary management may improve post-operative outcomes.

Verified
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KDKoray Durak
Koray Durak
KNKatharina Nubbemeyer
Katharina Nubbemeyer
RZRashad Zayat
Rashad Zayat
JSJan W. Spillner
Jan W. Spillner
SDSlavena Dineva
Slavena Dineva
AKAlexander Kersten
Alexander Kersten
Background: Abnormal liver function tests can identify severe cardiopulmonary failure. The aspartate transaminase/alanine transaminase (AST/ALT) ratio, or the De Ritis ratio, is commonly used to evaluate acute liver damage. However, its prognostic value in pulmonary embolism (PE) is unknown. Methods: Two cohorts, including patients with intermediate- and high-risk PEs, were established: one with an abnormal baseline AST/ALT ratio (>1) and another with a normal baseline AST/ALT ratio (<1). The primary outcome was a 60-day mortality. Secondary outcomes included peak N-terminal pro-brain-natriuretic-peptide (NT-proBNP) levels, complications, and the need for critical care treatment. To assess the effect of abnormal AST/ALT ratios, inverse probability weighted (IPW) analyses were performed. Results: In total, 230 patients were included in the analysis, and 52 (23%) had an abnormal AST/ALT ratio. After the IPW correction, patients with an abnormal AST/ALT ratio had a significantly higher mortality rate and peak NT-proBNP levels. The relative risks of 60-day mortality, shock development, use of inotropes/vasopressors, mechanical ventilation, and extracorporeal life support were 9.2 (95% confidence interval: 3.3–25.3), 10.1 (4.3–24), 2.7 (1.4–5.2), 2.3 (1.4–3.7), and 5.7 (1.4–23.1), respectively. Conclusions: The baseline AST/ALT ratio can be a predictor of shock, multiorgan failure, and mortality in patients with a pulmonary embolism.

1 January 2022 in Annals of Thoracic and Cardiovascular Surgery
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VDVasileios Drosos
Vasileios Drosos
KDKoray Durak
Koray Durak
RARüdiger Autschbach
Rüdiger Autschbach
JSJan Spillner
Jan Spillner
KNKatharina Nubbemeyer
Katharina Nubbemeyer
SKSebastian Kalverkamp
Sebastian Kalverkamp
Purpose: Blood loss along with inadequate evacuation after cardiac surgery leads to retained blood syndrome (RBS) in the pleural and/or pericardial cavity. Re-sternotomy is often needed for clot evacuation. Video-assisted thoracoscopic surgery (VATS) evacuation is a less-invasive procedure. However, sufficient evidence on safety and outcomes is lacking.Methods: Thirty patients who developed hemothorax and/or hemopericardium after cardiac surgery and underwent VATS evacuation between April 2015 and September 2020 were included in this retrospective single-center analysis.Results: The median patient age was 70 (interquartile range: IQR 62–75) years, body mass index (BMI) was 24.7 (IQR 22.8–29) kg/m2, time between initial cardiac surgery and VATS was 17 (IQR 11–21) days, 30% of the patients were female, 60% resided in the ICU, and 17% were nicotine users. Coronary artery bypass graft was the most frequent initial cardiac procedure. Median operation time was 120 (IQR 90–143) min, 23% of the patients needed an additional VATS, and the median length of hospital stay after VATS was 8 (IQR 5–14) days. All patients survived VATS, and we experienced no mortality related to the VATS procedure.Conclusion: In our study, VATS for evacuation of RBS after cardiac surgery was a feasible, safe, and efficient alternative approach to re-sternotomy in selected patients.