Sonay Oğuz

Sonay Oğuz

*This is an algorithmically generated author record based on publicly available information.

Sonay Oğuz has a total of 36 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Association of the HIGS score with permanent pacemaker implantation and mortality after transcatheter aortic valve implantation

    by Özkan Karaca, Burak Toprak, Nihat Söylemez, Mustafa Ekici, Abdulkadir Bilgiç, Ahmet Turhan Kılıç, Samet Yılmaz, Ali Orçun Sürmeli, Sonay Oğuz, Mehmet Ballı, et al.

    Aortic stenosis is one of the most common valvular diseases, particularly in the elderly population, and its incidence is steadily increasing in aging societies [1]. Severe symptomatic aortic steno...

  • Open Access

    Time-Dependent Changes in NLR, PLR, SII, and SIRI During Intraoperative Cardiopulmonary Bypass in CABG Patients and Their Association with In-Hospital Mortality

    by Burak Toprak, Abdulkadir Bilgiç, Rahime Akın, Mustafa Ekici, Ahmet Turhan Kılıç, Özkan Karaca, Nihat Söylemez, Sonay Oğuz, Mehmet Ballı, Mahmut Yılmaz, et al.

    Background: Systemic inflammation plays a central role in determining postoperative outcomes in patients undergoing isolated coronary artery bypass grafting with cardiopulmonary bypass. Traditional inflammatory indices such as the neutrophil-to-lymphocyte ratio and the platelet-to-lymphocyte ratio have prognostic value; however, their dynamic behavior during cardiopulmonary bypass remains insufficiently characterized. More comprehensive indices, including the systemic immune-inflammation index and the systemic inflammatory response index, may help characterize early intraoperative inflammatory activity; however, their prognostic relevance should be regarded as exploratory and requires prospective validation. Methods: This retrospective nested case–control study included 245 patients who underwent isolated coronary artery bypass grafting, and intraoperative inflammatory indices during cardiopulmonary bypass were evaluated. Because of the nested case–control design, mortality cases were intentionally overrepresented to improve statistical power; therefore, the observed mortality rate does not reflect the true institutional mortality rate. Inflammatory indices (NLR, PLR, SII, and SIRI) were calculated at induction, at the 5th, 45th, and 90th minutes during cardiopulmonary bypass, and in the early postoperative period. Associations between these indices and in-hospital mortality were evaluated using univariate and multivariable logistic regression analyses. Predictive performance was assessed using receiver operating characteristic (ROC) curve analysis and the area under the curve (AUC). Results: The final enriched analytical sample consisted of 51 mortality cases and 194 randomly sampled surviving controls. During cardiopulmonary bypass, inflammatory indices, particularly at the 5th minute, were significantly higher in patients who experienced mortality (p < 0.001 for all major indices). SII demonstrated the strongest predictive performance at the 5th minute (AUC = 0.790), followed by SIRI (AUC = 0.765), PLR (AUC = 0.687), and NLR (AUC = 0.681). In multivariable analysis, SII and SIRI measured at the 5th minute remained independent predictors of mortality. The addition of 5th-minute SII to the limited study-specific clinical model, which included age, ejection fraction, and preoperative creatinine, improved exploratory discrimination for in-hospital mortality (with AUC increasing from 0.698 to 0.797). Conclusions: Early intraoperative assessment of inflammatory indices during cardiopulmonary bypass may provide additional prognostic information in patients undergoing coronary artery bypass grafting. Composite indices, particularly SII and SIRI, showed stronger exploratory discrimination than traditional inflammatory markers in this enriched analytical sample. However, these findings should be considered hypothesis-generating and require prospective external validation before use in perioperative risk stratification or clinical decision-making can be recommended.


  • Open Access

    Prognostic Nutritional Index and In-Hospital Mortality After Coronary Artery Bypass Grafting: An Exploratory Analysis in Relation to Surgical Risk Scores

    by Burak Toprak, Nihat Söylemez, Menaf Akın Sert, Özkan Karaca, Mustafa Ekici, Ali Orçun Sürmeli, Abdulkadir Bilgiç, Samet Yılmaz, Sonay Oğuz, Mehmet Ballı, et al.

    Background: Coronary anatomical complexity is commonly used for perioperative risk assessment in patients undergoing coronary artery bypass grafting (CABG), although it may not fully reflect systemic biological vulnerability. This study aimed to evaluate the association between the Prognostic Nutritional Index (PNI), a nutritional–immune marker derived from serum albumin and lymphocyte counts, and in-hospital mortality after CABG in relation to coronary anatomical complexity and established surgical risk scores. Methods: In this single-center retrospective cohort study, 324 consecutive patients who underwent isolated CABG between April 2024 and April 2025 were analyzed. The PNI was calculated according to the standard Onodera formula using preoperative serum albumin and total lymphocyte count. Associations with in-hospital mortality were evaluated using univariable and multivariable logistic regression analyses. Discriminative performance was assessed using receiver operating characteristic curve analysis, while exploratory analyses evaluating the additional prognostic contribution of the PNI beyond surgical risk scores were performed using nested model comparison and reclassification analyses. Internal validation and calibration analyses were also performed. Results: In-hospital mortality occurred in 26 patients. Preoperative and postoperative PNI values were significantly lower in patients who experienced in-hospital mortality. In multivariable analysis, the postoperative PNI remained independently associated with in-hospital mortality, whereas the preoperative PNI lost statistical significance after adjustment for clinical, renal, and surgical risk parameters. Receiver operating characteristic analysis demonstrated modest discriminative ability for the preoperative PNI (AUC: 0.742, 95% CI: 0.661–0.823). Exploratory analyses suggested a modest improvement in model discrimination and risk classification after the addition of the PNI to STS-based models; however, the overall incremental prognostic contribution remained limited. Calibration and internal validation analyses demonstrated acceptable agreement between predicted and observed mortality risk. Conclusions: The postoperative PNI demonstrated a stronger and independent association with in-hospital mortality than the preoperative PNI, suggesting that early postoperative nutritional–immune deterioration may reflect the magnitude of perioperative physiological stress and evolving clinical deterioration after CABG. Although lower preoperative PNI values were associated with mortality in univariable analyses, this association was no longer statistically significant after adjustment for clinical, renal, and surgical risk parameters. These findings indicate that postoperative nutritional–immune status may provide complementary biological information beyond conventional risk models; however, its clinical utility requires confirmation in larger prospective multicenter studies.


  • Open Access

    Effect of Clopidogrel on Early Inflammatory Response and In-Hospital Outcomes in Patients with Myocardial Infarction

    by Özkan Karaca, Burak Toprak, Mustafa Ekici, Nihat Söylemez, Ali Orçun Sürmeli, Ahmet Turhan Kılıç, Sonay Oğuz, Mehmet Ballı, Rıdvan Bora, Mahmut Yılmaz, et al.

    Background: Inflammation plays a central role in the pathophysiology and clinical progression of acute myocardial infarction (MI). Although clopidogrel is known to exert potential anti-inflammatory effects in addition to platelet inhibition, the behavior of the early inflammatory response after treatment initiation and its prognostic significance remain unclear. This study aimed to evaluate dynamic inflammatory changes during the early post-treatment period and their association with in-hospital outcomes in patients with ST-elevation myocardial infarction. Methods: This retrospective, observational, single-center study included 300 patients with ST-elevation myocardial infarction treated with clopidogrel loading therapy. Systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), and delta neutrophil index (DNI) were evaluated before treatment and 24–48 h after therapy. In-hospital mortality and major adverse in-hospital outcomes were analyzed. Receiver operating characteristic analysis and multivariable logistic regression models were used to determine prognostic performance and independent predictors. Results: Contrary to the expected anti-inflammatory effect, all inflammatory markers significantly increased after clopidogrel therapy (all p < 0.05). Patients with persistent or increased inflammatory response demonstrated significantly higher rates of in-hospital mortality and major adverse outcomes. Post-treatment SIRI showed the strongest predictive performance for mortality (AUC: 0.81, 95% CI: 0.75–0.87), followed by ΔSIRI (AUC: 0.79). Multivariable analyses identified higher post-treatment inflammatory burden and dynamic inflammatory increases, particularly post-DNI and ΔSIRI, as independent predictors of mortality and adverse clinical course. Conclusions: Early inflammatory activation after clopidogrel therapy is strongly associated with poor in-hospital outcomes in patients with acute myocardial infarction. Persistent or increasing inflammatory burden may reflect an uncontrolled inflammatory response despite antiplatelet treatment and may serve as a practical and powerful prognostic marker for early risk stratification.


  • Open Access

    Systemic capillary leak syndrome during cardiac surgery

    by Halil Fatih Aşgün, Sonay Oğuz

    Systemic capillary leak syndrome is defined as excessive fluid and protein extravasation caused by microvascular hyperpermeability. It is a very rare condition, and may occur during or after any surgery without preceding symptoms or a suggestive history. It has been reported in pediatric cardiac surgery patients, and is not expected in adults. In this article, we present a 75-year-old female case of severe systemic capillary leak developed during coronary artery bypass grafting combined with dual valve replacement. To the best of our knowledge, this is the first adult case in the literature having an acute attack of systemic capillary leak syndrome during cardiac surgery.


  • Vasküler Kompresyon Sendromları

    by Kübra Erdoğan, Kemal Emre Özen, Fatma Şimşek, Mümin Alper Erdoğan, Volkan Kızılgöz, Sadık Volkan Emren, Rahman Bilal Gediz, Nur Dikmen Yaman, Sonay Oğuz, Vural Polat, et al.

    Vasküler Kompresyon Sendromları kitabı bu alandaki ihtiyacın sonucu olarak ortaya çıkmıştır. Ülkemiz ve dünya vasküler cerrahi literatüründe benzer bir kaynak bulunmamaktadır dolayısıyla bu açığı kapatması açısından önemli bir adım olarak değerlendirilebilir. Vasküler kompresyonlar konusunda daha yolun çok başında olduğumuzu ve aslında buz dağının görünen kısmı ile ilgili bilgi sahibi olduğumuzu söyleyebiliriz. Bu kitabın ana konusu vasküler yapılarda meydana gelen kompresyonlardır. Yani vasküler kompresyonların bir sebep değil sonuç olduğu klinik durumlar kitaba dâhil edilmiştir. Vasküler yapıların neden olduğu diğer kompresyon sendromları ayrı bir kitabın konusu olabilir. Dolaşım Sistemi Anatomisi Kübra ERDOĞAN Kemal Emre ÖZEN Dolaşım Sistemi Histoloji ve Embriyolojisi Fatma ŞİMŞEK Dolaşım ve Damar Sistemi Fizyolojisi Mümin Alper ERDOĞAN Vasküler Kompresyon Sendromları ve Görüntüleme Yöntemleri Volkan KIZILGÖZ Kardiyak Kompresyon Sendromları Sadık Volkan EMREN Rahman Bilal GEDİZ Baş ve Boyun Bölgesi Vasküler Kompresyon Sendromları Nur Dikmen YAMAN Gövde ve Gövde Duvarı Vasküler Kompresyon Sendromları Sonay OĞUZ Üst Ekstremite Vasküler Kompresyon Sendromları Nur Dikmen YAMAN Abdomen Vasküler Kompresyon Sendromları Vural POLAT Pelvis Kompresyon Sendromları Fatih ADA Cemil AY Alt Ekstremite Kompresyon Sendromları Fatih ADA Ferit KASIMZADE

  • Relationship between First Values of Red Cell Distribution Width, Mean Platelet Volume, Platelet Distribution Width, and Hospital Mortality in Acute Deep Venous Thrombosis

    by Sonay Oguz

    Objective: To determine the relationship between red cell distribution width (RDW), mean platelet volume (MPV), platelet distribution width (PDW) values and mortality in acute deep vein thrombosis (DVT). Study Design: Descriptive study. Place and Duration of Study: Canakkale Onsekiz Mart University Health Practice and Research Hospital, Turkey, from 2015 to 2020. Methodology: Hospitalised cases of acute DVT were detected. Discharged patients (externe group -EG), mortal course (mortality group - MG) and control group ( healthy persons without thrombosis - CG) were formed. Statistical significance of the first values of RDW, MPV and PDW between groups was evaluated. In addition, the difference between the groups was evaluated according to the age, gender, platelet count, and level of the thrombosis (proximal, distal). Results: There was a significant increase in RDW values between CG and EG (13.63 +/- 1.37 vs. 15.97 +/- 3.20; p=0.012), CG and MG (13.63 +/- 1.37 vs. 17.85 +/- 3.73; p=0.003). There was a significant increase in PDW values between CG and MG (16.78 +/- 0.41 vs. 18.05 +/- 1.07; p<0.001) and between EG and MG (16.98 +/- 0.51 vs. 18.05 +/- 1.07; p<0.001). There was no significant difference in other variables. Conclusion: The results show that increased RDW values may be associated with deep venous thrombosis; and increased PDW values may be associated with mortality. Following RDW and PDW values, which are fast, inexpensive and widely available, can be useful as an early predictor of thrombosis and poor prognosis.