Nemanja Aleksic

Background/Objectives: Postoperative bleeding remains a major complication following coronary artery bypass grafting (CABG), contributing to transfusion requirements, reintervention, and morbidity. The objective of this study was to assess the clinical significance of preoperative platelet function testing and postoperative viscoelastic testing in patients undergoing elective isolated on-pump CABG. Methods: This prospective observational study included 708 patients undergoing surgery between January 2023 and January 2025. Preoperative platelet function was assessed with Multiplate^® impedance aggregometry (ADPHS and ASPI), and postoperative coagulation was assessed with ClotPro^® after cardiopulmonary bypass. The prespecified Multiplate thresholds were population- and assay-specific and were not intended as universal cutoffs. Postoperative bleeding was defined by cumulative chest-tube drainage during the first 24 h. Results: In unadjusted analyses, low ADPHS values (≤602.5 AU·min) were associated with higher platelet transfusion, cryoprecipitate use, and overall transfusion, and ADPHS showed modest discrimination for blood loss > 500 mL/24 h (AUC = 0.61, p = 0.041). Low ASPI values (≤453 AU·min) were associated with increased cryoprecipitate use and showed modest discrimination for blood loss > 1000 mL/24 h (AUC = 0.62, p = 0.005). After multivariable adjustment for baseline differences, neither ADPHS ≤ 602.5 (adjusted OR 1.01, 95% CI 0.74–1.39, p = 0.936) nor ASPI ≤ 453 (adjusted OR 0.89, 95% CI 0.64–1.23, p = 0.475) was independently associated with postoperative bleeding > 500 mL/24 h. Postoperative ClotPro^® parameters showed statistically significant associations with transfusion and bleeding, but their discriminatory performance was limited. Conclusions: Perioperative platelet function and viscoelastic test results were associated with bleeding and transfusion outcomes in unadjusted analyses, but discrimination was modest, and the platelet function cutoffs were not independently associated with bleeding > 500 mL after adjustment. These findings support a complementary hemostatic assessment role for combined POC testing but do not establish a standalone predictive model or an implementable transfusion algorithm.

Background: Postoperative delirium (POD) is a neurocognitive syndrome affecting patients undergoing surgery. It is a frequent complication of coronary artery bypass grafting (CABG) and is associated with higher morbidity, mortality and treatment costs. This study aimed to investigate the relationship between gaseous microemboli (GME) load during cardiopulmonary bypass (CPB) and subsequent POD in patients undergoing CABG. Methods: In total, 102 patients undergoing elective on-pump CABG were evaluated in this observational study. An ultrasonic microbubble counter, with probes placed on the arterial and venous lines, was used during CPB to evaluate the GME load for each patient. During the first postoperative week, the patients were examined for the presence of POD. Results: Patients diagnosed with POD had higher number of bubbles in the arterial CPB line (5382.8 (4127.8–6637.8) vs. 2389.4 (2033.9–2745.0), p < 0.001), higher volume of bubbles in both the venous (24.2 µL (16.8–31.6) vs. 12.4 µL (9.7–15.1), p = 0.004) and arterial lines (1.82 µL (1.43–2.21) vs. 0.29 µL (0.22–0.36), p < 0.001), lower quality factor (QF) values (p = 0.039), a lower venoarterial reduction in bubble number (83.0% (77.8–88.1) vs. 92.4% (90.9–93.8), p = 0.001) and a lower venoarterial reduction in bubble volume (88.8% (85.4–92.2) vs. 96.3% (95.2–97.3), p < 0.001) compared to the patients without POD. Older age (p = 0.005), a lower reduction in bubble volume (p < 0.001) and lower QF values (p = 0.004) were significant independent predictors of POD. Conclusions: Our findings indicate a strong association between GME and the occurrence of POD, which entails that all available actions should be implemented to prevent their generation and facilitate the elimination of GME from the CPB circuit.

Background and Objectives: The aim of this study was to estimate the prevalence of silent coronary artery disease (CAD) in asymptomatic patients with severe aortic stenosis (AS) and assess long-term prognosis in terms of major adverse cardiovascular event (MACE)-free survival. Materials and Methods: This was a prospective study conducted at the Clinic for Cardiac Surgery, University Clinical Center of Serbia, in asymptomatic patients with severe AS, normal LVEF and stress test without signs of myocardial ischemia. Adverse cardiovascular events (cardiac death, myocardial infarction and any hospitalization due to heart disease) was monitored during one year of follow up. Results: A total of 116 asymptomatic patients with severe AS were included in the study. The average age was 67.3 ± 9.6 years, and 56.9% of patients were men. The most common cause of AS was degenerative valvular disease (83.5%). The incidence of significant CAD was 30 out of 116 patients (25.9%). The median Society for Thoracic Surgeons (STS) predicted risk of mortality score was 1.62% (25th to 75th percentile: 1.15–2.76%). The overall mean gradient across aortic valve (Pmean) was 52.30 mmHg ± 12.16, and the mean indexed AVA (AVAi) was 0.37 ± 0.09 cm²/m². The mean LVEF was 68.40% ± 8.01%. Early surgery for aortic valve replacement was performed in 55 patients (55.2%), while 52 (44.8%) patients received conservative treatment. Twenty-two patients (42.3%) in the conservative treatment group underwent surgery during follow up. There were a total of 44 (37.9%) patients with MACE during one year of follow up. Univariate Cox regression analyses identified the following significant risk factors for MACE-free survival: presence of CAD and early conservative treatment (p = 0.004), age (p = 0.003), diabetes mellitus (p = 0.016) and STS score (p = 0.039). According to multivariate analysis, the presence of CAD with early conservative treatment was the most important predictor of MACE-free survival in asymptomatic patients with severe aortic stenosis (p ≤ 0.001). Conclusions: Early surgery for aortic valve replacement in asymptomatic patients with severe AS and concomitant CAD is beneficial for long-term survival.

Minimalno invazivna koronarna hirurgija poslednjih decenija predstavlja jedno od najdinamičnijih polja kardiohirurgije, sa ciljem da se obezbede jednaki ili superiorni rezultati u poređenju sa standardnim hirurskim pristupom medijalnom sternotomijom, uz smanjenje hirurške traume i brži oporavak pacijenata. Najčešće korišćena tehnika je MIDCAB (minimally invasive direct coronary artery bypass), koja se izvodi kroz malu anterolateralnu torakotomiju, bez upotrebe ekstrakorporalne cirkulacije. Ova metoda se prvenstveno primenjuje kod izolovanih lezija na LAD arteriji, uz odlične dugoročne rezultate grafta levom unutrašnjom torakalnom arterijom. Dalji razvoj doveo je do uvođenja TECAB (totally endoscopic coronary artery bypass) procedura, koje se izvode u potpunosti endoskopski, često uz asistenciju robotskog sistema. Robotička hirurgija omogućila je veću preciznost, skraćujući period rehabilitacije i poboljšavajući estetski ishod. Iako je dostupnost ograničena, iskustva vodećih centara ukazuju na rastuću ulogu ove tehnike u budućnosti. Poseban značaj imaju hibridne strategije - kombinacija PCI i minimalno invazivne hirurgije, kojima se obezbeđuje optimalna revaskularizacija kod tro-sudovne koronarne bolesti, uz smanjenje invazivnosti i individualizaciju terapije. Aktuelna istraživanja fokusirana su na dugoročne rezultate, kvalitet života i ekonomske aspekte, a dostupni podaci potvrđuju da minimalno invazivna koronarna hirurgija donosi manje postoperativnog bola, kraće zadržavanje u bolnici i brži povratak svakodnevnim aktivnostima. U narednim godinama očekuje se dalji razvoj tehnologije - napredniji robotski sistemi, širi spektar endovaskularnih i hibridnih procedura, kao i preciznija selekcija pacijenata uz pomoć veštačke inteligencije i personalizovane medicine. Minimalno invazivna koronarna hirurgija danas više nije eksperimentalna opcija, već standard u odabranim indikacijama, a njena dalja ekspanzija biće uslovljena dostupnošću tehnologije, edukacijom hirurga i multidisciplinarnim pristupom.

Background and Objectives: Despite advances in surgical techniques, industry adjuncts, and cerebral perfusion techniques, the in-hospital mortality rate of type A acute dissection (TAAD) remains at 15–30%. This study aimed to investigate the influence of different extents of aortic resection on survival and quality of life (QoL) after long-term follow-up. Materials and Methods: A retrospective observational trial was performed, including 165 patients operated upon for TAAD. Patients were divided into two groups according to the extent of their aortic repair: the first group comprised patients who had ascending aorta replacement and the second included patients who had hemiarch or total arch replacement. The groups were compared with regard to their baseline characteristics, operative characteristics, survival, complications, and QoL during nine years of follow-up. Results: The mean follow-up time was 75.6 months (1–108 months). The mean survival in the ascending aorta repair group was 89.651 (81.242–98.061) months and was 54.801 (40.053–69.548) months in the hemiarch and arch group; the difference between the groups was significant (log-rank p < 0.001). The rate of new postoperative neurological deficits was statistically higher in the hemiarch and arch group (17.5% vs. 8.4%, p = 0.045), the most common being stroke, and was also more frequent in the hemiarch and arch group than in the ascending aorta group (with statistical significance (15.7% vs. 6.5%)). The mean SF-12 physical score from the QoL questionnaire was higher in the ascending aorta replacement group than in the hemiarch and arch group (50.1 ± 7.3 vs. 44.0 ± 11.9, p = 0.017). Additionally, the mean SF-12 mental score was higher in the ascending aorta replacement group (52.3 ± 7.3 vs. 47.1 ± 12.8, p = 0.032). Conclusions: A more aggressive approach involving aortic arch repair means a lower survival rate and lesser quality of life after long-term follow-up in comparison with the replacement of the ascending aorta. If clinically applicable, a more defensive strategy may be considered.

Introduction/Aim: Heart transplantation (HTX) is the gold standard for the treatment of patients in symptomatic terminal stadium of heart failure. This study aimed to investigate the long-term results of the HTX and to determine the independent survival predictors after HTX within The Serbian Heart Transplantation program. Methods: A retrospective observational study was performed. The study included 44 patients that were subjected to heart transplantation from 2013 to 2021 within the The Serbian Heart Transplantation program. All the patients were included in the National heart transplantation waiting list according to the contemporary ISHLT criteria. The study included all the patients subjected to HTX, as well as the ones who received long-term circulatory support preoperatively. The data were obtained from the medical history records and follow-up visits. Results: The average survival of all patients was 1611.8 days (1306.9 - 1916.7). The median length of patient follow-up was 637.4 days (1-2028 days). Six-year patient survival was 70.5%. Cox's regression analysis determined that independent predictors of worse outcome were as follows: age of the recipient, body mass index of the recipient, previous CVI, preoperative chronic renal insufficiency, pulmonary hypertension, infection in the postoperative course, as well as the need for mechanical circulatory support in the immediate postoperative course. Conclusion: The Serbian Heart Transplantation program demonstrated the survival rate comparable to the HTX centers worldwide and in ISHLT registry. The independent risk factors should be carefully analyzed for our study population and taken into consideration when planning the procedure.

Purpose To translate, culturally adapt and validate the Coronary Revascularisation Outcome Questionnaire (CROQ), a disease-specific tool for measuring health-related quality of life (HRQoL) in patients with ischaemic heart disease (IHD), into Serbian language (CROQ-S). Methods Validation study was performed at the Clinic for Cardiac Surgery and Clinic for Cardiology, University Clinical Centre of Serbia. We included a convenience sample of 600 patients with IHD divided into four groups. Acceptability, reliability and validity of the CROQ-S were assessed. Results CROQ-S was acceptable to patients as demonstrated by less than 1% of missing data for each single item. Cronbach's Alpha was higher than the criterion of 0.70 for all scales in each version except the Cognitive Functioning scale which only met this criterion in the CABG pre-revascularisation version. Mean values of item-total correlations were greater than 0.30 for all scales except the Cognitive Functioning scale in both the pre-revascularisation groups. Compared to the original version, exploratory factor analysis in our study showed more factors; however, the majority of items had a factor loading greater than 0.3 on the right scale. Correlations of CROQ-S scales with the 36-Item Short Form Health Survey and Seattle Angina Questionnaire showed the expected pattern whereby scales measuring similar constructs were most highly correlated. Conclusion CROQ-S is an acceptable, reliable and valid disease-specific instrument for measuring HRQoL in this sample of Serbian speaking patients with IHD both before and after coronary revascularisation. However, the Cognitive Functioning scale did not meet all the psychometric criteria and further validation of its responsiveness is required.

Background: Heart failure is the most frequent cause of pulmonary artery hypertension (PAH) and its severity may predict the development of heart failure (HF) and is known to be a prognostic factor of poor outcome after heart transplant (HTx). The aim of this study was to investigate the impact of preoperative PAH related to left-sided HF on long-term survival after HTx and to identify the hemodynamic parameters of PAH that predict survival after HTx. Methods: A prospective observational trial was performed, and it included 44 patients subjected to heart transplantation. Patients were divided into two groups: The first one with the preoperative diagnosis of PAH and the second one without the PAH diagnosed prior to the HTx. The two groups were compared for baseline characteristics, operative characteristics, survival, and hemodynamic parameters obtained by right heart catheterization. Survival was analyzed using Kaplan Meyer analysis, and Cox regression analysis was performed to determine independent predictors of survival. Results: The median follow-up time was 637.4 days (1-2028 days). The median survival within the group of patients with preoperative PAH was 1144 days (95% CI 662.884-1625.116) and 1918.920 days (95% CI 1594.577-2243.263) within the group of patients without PAH (P = .023), HR 0.279 (95% [CI]: 0.086-0.910; P = .034. The 30-day mortality in patients within PAH group was significantly higher, six versus two patients in the non PAH group (χ2 = 5.103, P < .05), while the long-term outcome after this period did not differ between the groups. Patients with preoperative PAH had significantly higher values of MPAP, PCWP, TPG and PVRI, while CO and CI did not differ between the two groups. Mean PVRI was 359.1 ± 97.3 dyn·s·cm-5 in the group with preoperative PAH and 232.2 ± 22.75 dyn·s·cm-5 in the group without PAH, P < .001. TPG values were 11.95 ± 5.08 mmHg in the PAH group while patients without PAH had mean values of 5.16 ± 1.97 mmHg, P < .001. Cox regression analysis was done for the aforementioned parameters. Hazard ratio for worse survival after HTx for elevated values of PVRI was 1.006 (95% [CI]: 1.001-1.012; P = .018) TPG had a hazard ratio of 1.172 (95% [CI]: 1.032-1.233; P = .015). Conclusion: Pulmonary artery hypertension is an independent risk factor for higher 30-day mortality after HTx, while it does not affect the long-term outcome. Hemodynamic parameters obtained by right heart catheterization in heart transplant candidates could predict postoperative outcome. PVRI and TPG have been identified as independent predictors of higher 30-day postoperative mortality.

Objective. Coronary artery bypass grafting (CABG) represents the significant source of increased oxidative stress (OS). We aimed to follow the OS status parameters (i.e., ischemia‐modified albumin (IMA), malondialdehyde (MDA), superoxide anion, prooxidant‐antioxidant balance (PAB), total oxidant status (TOS), total antioxidant status (TAS), and superoxide‐dismutase (SOD)) change through the predefined study times in two different surgical procedures, i.e., cardiopulmonary bypass (CPB) and off‐pump coronary artery bypass grafting (OPCAB). Additionally, we aimed to investigate those OS status parameters in specific study times according to SYNTAX score (SS), an established angiographic score for evaluating the extensity and severity of coronary artery disease. Patients and Methods. A total of 107 patients that were planned to undergo CABG were included (i.e., 47 patients in OPCAB and 60 patients in CPB group). Blood samples were taken at 6 time intervals: before surgery (t1), immediately after intervention (t2), 6 h (t3), 24 h (t4), 48 h (t5), and 96 h after termination of the operation (t6). Results. IMA levels were higher in CPB than that in OPCAB baseline and rose in CPB group in t2 point. TOS decreased in both study groups, compared to baseline values, but without statistical significance. Superoxide anion and PAB significantly increased in t3‐t6 study times, in both groups. MDA significantly increased only in CPB group in t5 and t6 interval. MDA was significantly higher in CPB group compared to OPCAB in t6 study point. CPB patients had significantly lower TAS compared to OPCAB patients at the beginning and in t2 and t3 study points. They also had significantly lower SOD activities compared to OPCAB, baseline, and in several study points. Moreover, TAS, SOD, and TAS/TOS ratio were significantly lower, whereas PAB and TOS/TAS were significantly higher in patients with high SS compared to corresponding groups. SOD activity, IMA, and TAS level were the best predictors of high SS. Conclusion. CPB patients were in more severe ischemia baseline than OPCAB group and IMA rose in CPB patients immediately after the surgery end, but not later. Also, the antioxidant status was significantly lower, whereas the prooxidant status was significantly higher in patients with high SS compared to corresponding groups. SOD activity, IMA, and TAS level were the best predictors of CAD (as determined with SS), showing that SOD and IMA had very good discriminatory capability towards higher SS status.

Objective. Recent studies have shown that the red cell distribution width‐ (RDW‐) to‐platelet (PLT) count ratio (i.e., RPR) and the mean platelet volume (MPV)/PLT ratio (i.e. MPR) are more sensitive markers of atherosclerosis‐connected risk than RDW and PLT alone. The present study is aimed at investigating the oxidative stress status and these two new markers of platelet activation in two different heart surgery modalities: cardiopulmonary bypass (CPB) and off‐pump coronary artery bypass (OPCAB). We also aimed to test the possible relationship between RPR and MPR, respectively, and the severity and complexity of atherosclerotic plaque, measured as Syntax Score. Patients and Methods. A total of 107 patients encompassed this prospective study (i.e., 60 patients in CPB group and 47 patients in OPCAB). Blood samples were drawn at several time intervals: before skin incision (t1), immediately after intervention (t2), 6 h (t3), 24 h (t4), 48 h (t5), and 96 h after cessation of the operation (t6). Results. The values of RPR and MPR were similar in CPB and OPCAB before surgery and started to rise in t2 (i.e., immediately after the intervention). This increase lasted to t5 (i.e., 48 hours after the intervention), when it became the highest. After that, both markers started to regress about the 96^th hour after the beginning of surgery. Nominal values of both indices were higher in CPB than in OPCAB in all study points after the surgery. Furthermore, a significantly higher level of antioxidative parameters (i.e., total sulfhydryl groups and paraoxonase 1) in the OPCAB group compared to the CPB group was noted at t5 study point (i.e., 48 hours after the surgery), whereas no significant difference was noted in prooxidant levels (i.e., lipid hydroperoxides and advanced oxidation protein products) between these groups at this study point. MPR and RPR correlated positively with Syntax Score at several study points after the surgery completion. Syntax Score, MPR, and RPR showed good clinical accuracy in surgery‐related complication prediction ((AUC = 0.736), 95^th CI (0.616‐0.856), P = 0.003)). Conclusion. When combined, MPV, RDW, and platelet count, such as MPR and RPR, could be good predictors of coronary artery disease status, regarding the aspect of joint inflammation, oxidative stress, and thrombosis.