Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 0 0 2026 08 16 2513 2513 Mahmood Hosseinzadeh Maleki Department of Cardiac Surgery, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran Motahareh Zakian Galugahi Department of Extra-Corporeal Circulation (ECC), Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. Ali Moradi Orthopedic Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. Mehdi Fathi Department of Anesthesiology, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. Nahid Zirak Department of Anesthesiology, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. Arezoo Orooji Department of Epidemiology and Biostatistics, Faculty of Health Sciences, Mashhad University of Medical Sciences, Mashhad, Iran. Benyamin Fazli Department of Anesthesiology, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. Mohsen Yaghubi Department of Extra-Corporeal Circulation (ECC), Razavi Hospital, Imam Reza International University, Mashhad, Iran. 2026 07 13 2026 08 16 Background: Myocardial ischemia-reperfusion injury remains a major cause of morbidity after pediatric cardiac surgery. Terminal warm-blood cardioplegia (Hotshot) has demonstrated myocardial protective effects in adult populations. Nonetheless, its efficacy in congenital heart surgery, particularly regarding arrhythmia control and inotropic requirements, has not been established in randomized trials. Methods: In this outcome-assessor-blinded, parallel-group randomized controlled trial, 100 pediatric patients (age, 1 month-6 years) with congenital heart defects (RACHS-1 categories 1 through 2) undergoing cardiopulmonary bypass were randomized 1:1 to receive either 2 minutes of antegrade warm-blood Hotshot (37 °C; 10 to 15 mL/kg) immediately before aortic cross-clamp removal (intervention group, n=50) or no intervention (control group, n=50). The primary outcome was the incidence of any postoperative arrhythmia requiring intervention. Secondary outcomes included the vasoactive-inotropic score (VIS) at 24 and 72 hours post-surgery, intensive care unit (ICU) length of stay, and mechanical ventilation duration. Analysis was performed on a per-protocol basis after excluding patients with protocol violations and withdrawal of consent. Statistical analyses were performed using SPSS software (version 24.0, SPSS Inc, Chicago, IL). A P value of less than .05 was considered statistically significant. Results: A total of 96 patients (49 in the intervention group and 47 in the control group) completed the trial. The primary outcome, incidence of postoperative arrhythmias, showed a nonsignificant trend toward reduction in the Hotshot group (Hotshot, 10/49 [20.4%] vs control, 14/47 [29.8%]; relative risk, 0.68; 95% CI, 0.33 to 1.41; P=.10). However, the study was underpowered to detect the anticipated difference based on adult-derived effect estimates. The Hotshot group had significantly lower VIS at 24 hours (mean [SD] score, 6.8 [2.1] vs 10.4 [2.4]; P<.001) and 72 hours (3.2 [1.4] vs 7.6 [1.9]; P<.001), as well as a shorter ICU stay (4.1 [1.1] vs 6.7 [1.2] days; P=.003). Mechanical ventilation duration (P=.27), cardiopulmonary bypass time (P=.44), and aortic cross-clamp time (P=.56) were similar between groups. Conclusion: In pediatric congenital heart surgery, terminal warm-blood Hotshot did not significantly reduce postoperative arrhythmias but was associated with lower VIS scores and a shorter ICU stay. The observed reduction in postoperative arrhythmias did not reach statistical significance, but the study was underpowered for this outcome. These findings suggest a potential myocardial protective effect that warrants confirmation in larger, adequately powered multicenter trials with long-term follow-up and biomarker assessment. https://jthc.tums.ac.ir/index.php/jthc/article/view/2513 https://jthc.tums.ac.ir/index.php/jthc/article/download/2513/1295

Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 0 0 2026 08 16 2514 2514 Seyyedeh Marzieh Salami Department of Radiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran Mohadeseh Zadehmir Department of Radiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran Nezarali Muolaei Pulmonary Diseases, Infectious Diseases and Tropical Medicine Research Center, Research Institute of Cellular and Molecular Sciences in Infectious Diseases, Zahedan University of Medical Sciences, Zahedan, Iran Ahmad Ali Davar Department of Radiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran Saeedeh Sarhadi Department of Community Medicine, School of Medicine, Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran Amin Mashhadi Department of Radiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran 2026 07 14 2026 08 16 Background: In this study, we aimed to examine the association between coronary artery calcium (CAC) burden and the severity of multiple organ dysfunction syndrome (MODS) in mechanically ventilated patients with COVID-19. Methods: We retrospectively evaluated 160 patients with COVID-19 who required invasive mechanical ventilation and were admitted to the intensive care unit. CAC was assessed visually on nongated, noncontrast chest computed tomography (CT) using a semiquantitative Weston scoring system. The extent of organ dysfunction was quantified using the Sequential Organ Failure Assessment (SOFA) score. Associations between CAC burden and SOFA score were examined using the Pearson correlation and one-way analysis of variance, while independent associations were evaluated using multivariable linear regression. Results: The mean (SD) SOFA score was 5.15 (2.73), and the mean (SD) CAC burden was 4.02 (3.31). In the overall cohort, CAC burden was positively correlated with SOFA score (r=.260; P=.001). This association was more pronounced among patients without pre-existing comorbidities (r=.402; P=.002). However, CAC burden was not independently associated with SOFA score in the multivariable regression model (β=0.009; P=.91). Age (β=0.043; P=.01) and chronic kidney disease (β=2.648; P<.001) were the principal independent correlates of SOFA score after adjustment for clinical covariates. Conclusion: Although higher CAC burden was associated with higher SOFA scores in unadjusted analyses, this relationship was not independent after multivariable adjustment. CAC assessment on nongated chest CT may provide contextual information regarding underlying vascular disease; however, it should not be interpreted as an isolated marker of organ dysfunction severity, and its incremental clinical value requires confirmation in larger prospective studies. https://jthc.tums.ac.ir/index.php/jthc/article/view/2514 https://jthc.tums.ac.ir/index.php/jthc/article/download/2514/1296