Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease: known knowns and known unknowns.

The Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease (CKD) updates the KDIGO 2012 guideline and has been developed with patient partners, clinicians, and researchers around the world, using robust methodology. This update, based on a substantially broader base of evidence than has previously been available, reflects an exciting time in nephrology. New therapies and strategies have been tested in large and diverse populations that help to inform care; however, this guideline is not intended for people receiving dialysis nor those who have a kidney transplant. The document is sensitive to international considerations, CKD across the lifespan, and discusses special considerations in implementation. The scope includes chapters dedicated to the evaluation and risk assessment of people with CKD, management to delay CKD progression and its complications, medication management and drug stewardship in CKD, and optimal models of CKD care. Treatment approaches and actionable guideline recommendations are based on systematic reviews of relevant studies and appraisal of the quality of the evidence and the strength of recommendations which followed the "Grading of Recommendations Assessment, Development, and Evaluation" (GRADE) approach. The limitations of the evidence are discussed. The guideline also provides practice points, which serve to direct clinical care or activities for which a systematic review was not conducted, and it includes useful infographics and describes an important research agenda for the future. It targets a broad audience of people with CKD and their healthcare, while being mindful of implications for policy and payment.

Patients' Perspectives on Plans Generated During Primary Care Visits and Self-Reported Adherence at 3 Months: Data From a Randomized Trial.

BACKGROUND: Effective primary care necessitates follow-up actions by the patient beyond the visit. Prior research suggests room for improvement in patient adherence. OBJECTIVE: This study sought to understand patients' views on their primary care visits, the plans generated therein, and their self-reported adherence after 3 months. METHODS: As part of a large multisite cluster randomized pragmatic trial in 3 health care organizations, patients completed 2 surveys-the first within 7 days after the index primary care visit and another 3 months later. For this analysis of secondary outcomes, we combined the results across all study participants to understand patient adherence to care plans. We recorded patient characteristics and survey responses. Cross-tabulation and chi-square statistics were used to examine bivariate associations, adjusting for multiple comparisons when appropriate. We used multivariable logistic regression to assess how patients' intention to follow, agreement, and understanding of their plans impacted their plan adherence, allowing for differences in individual characteristics. Qualitative content analysis was conducted to characterize the patient's self-reported plans and reasons for adhering (or not) to the plan 3 months later. RESULTS: Of 2555 patients, most selected the top box option (9=definitely agree) that they felt they had a clear plan (n=2011, 78%), agreed with the plan (n=2049, 80%), and intended to follow the plan (n=2108, 83%) discussed with their provider at the primary care visit. The most common elements of the plans reported included reference to exercise (n=359, 14.1%), testing (laboratory, imaging, etc; n=328, 12.8%), diet (n=296, 11.6%), and initiation or adjustment of medications; (n=284, 11.1%). Patients who strongly agreed that they had a clear plan, agreed with the plan, and intended to follow the plan were all more likely to report plan completion 3 months later (P<.001) than those providing less positive ratings. Patients who reported plans related to following up with the primary care provider (P=.008) to initiate or adjust medications (P≤.001) and to have a specialist visit were more likely to report that they had completely followed the plan (P=.003). Adjusting for demographic variables, patients who indicated intent to follow their plan were more likely to follow-through 3 months later (P<.001). Patients' reasons for completely following the plan were mainly that the plan was clear (n=1114, 69.5%), consistent with what mattered (n=1060, 66.1%), and they were determined to carry through with the plan (n=887, 53.3%). The most common reasons for not following the plan were lack of time (n=217, 22.8%), having decided to try a different approach (n=105, 11%), and the COVID-19 pandemic impacted the plan (n=105, 11%). CONCLUSIONS: Patients' initial assessment of their plan as clear, their agreement with the plan, and their initial willingness to follow the plan were all strongly related to their self-reported completion of the plan 3 months later. Patients whose plans involved lifestyle changes were less likely to report that they had "completely" followed their plan. TRIAL REGISTRATION: ClinicalTrials.gov NCT03385512; https://clinicaltrials.gov/study/NCT03385512. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/30431.

Australian National Standards of Care for Childhood-onset Heart Disease (CoHD Standards). 1st Edition.

These first Australian National Standards of Care for Childhood-onset Heart Disease (CoHD Standards) have been developed to inform the healthcare requirements for CoHD services and enable all Australian patients, families and carers impacted by CoHD (paediatric CoHD and adult congenital heart disease [ACHD]) to live their best and healthiest lives. The CoHD Standards are designed to provide the clarity and certainty required for healthcare services to deliver excellent, comprehensive, inclusive, and equitable CoHD care across Australia for patients, families and carers, and offer an iterative roadmap to the future of these services. The CoHD Standards provide a framework for excellent CoHD care, encompassing key requirements and expectations for whole-of-life, holistic and connected healthcare service delivery. The CoHD Standards should be implemented in health services in conjunction with the National Safety and Quality Health Service Standards developed by the Australian Commission on Safety and Quality in Health Care. All healthcare services should comply with the CoHD Standards, as well as working to their organisation's or jurisdiction's agreed clinical governance framework, to guide the implementation of structures and processes that support safe care.

Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Management of ANCA-Associated Vasculitis.

In 2021, the Kidney Disease: Improving Global Outcomes (KDIGO) Guideline for the Management of Glomerular Diseases was published. KDIGO is committed to providing the nephrology community with periodic updates, based on new developments for each disease. For patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), avacopan received regulatory approval in late 2021, leading to this KDIGO guideline update. In addition, the evidence supporting a lower-dose glucocorticoid induction regimen or even complete replacement of glucocorticoids has become stronger. Herein, an executive summary of the most important guideline changes from the AAV chapter is provided as a quick reference.

Endocuff With or Without Artificial Intelligence-Assisted Colonoscopy in Detection of Colorectal Adenoma: A Randomized Colonoscopy Trial.

INTRODUCTION: Both artificial intelligence (AI) and distal attachment devices have been shown to improve adenoma detection rate and reduce miss rate during colonoscopy. We studied the combined effect of Endocuff and AI on enhancing detection rates of various colonic lesions. METHODS: This was a 3-arm prospective randomized colonoscopy study involving patients aged 40 years or older. Participants were randomly assigned in a 1:1:1 ratio to undergo Endocuff with AI, AI alone, or standard high-definition (HD) colonoscopy. The primary outcome was adenoma detection rate (ADR) between the Endocuff-AI and AI groups while secondary outcomes included detection rates of polyp (PDR), sessile serrated lesion (sessile detection rate [SDR]), and advanced adenoma (advanced adenoma detection rate) between the 2 groups. RESULTS: A total of 682 patients were included (mean age 65.4 years, 52.3% male), with 53.7% undergoing diagnostic colonoscopy. The ADR for the Endocuff-AI, AI, and HD groups was 58.7%, 53.8%, and 46.3%, respectively, while the corresponding PDR was 77.0%, 74.0%, and 61.2%. A significant increase in ADR, PDR, and SDR was observed between the Endocuff-AI and AI groups (ADR difference: 4.9%, 95% CI: 1.4%-8.2%, P = 0.03; PDR difference: 3.0%, 95% CI: 0.4%-5.8%, P = 0.04; SDR difference: 6.4%, 95% CI: 3.4%-9.7%, P < 0.01). Both Endocuff-AI and AI groups had a higher ADR, PDR, SDR, and advanced adenoma detection rate than the HD group (all P < 0.01). DISCUSSION: Endocuff in combination with AI further improves various colonic lesion detection rates when compared with AI alone.

Carotid wave analysis in young adults with a history of adolescent anorexia nervosa: a case control study.

BACKGROUND: Anorexia nervosa (AN) is associated with abnormalities that may increase the risk of future cardiovascular disease. This study assessed the cardiovascular health of individuals who recovered from AN during adolescence by conducting wave power analysis. METHODS: Former AN patients discharged from the Royal Children's and Monash Children's Hospitals (N = 17) in Melbourne, Australia underwent ultrasound imaging of the right carotid artery. Wave power analysis was conducted to assess biomechanical interactions of the cardiovascular system. Patient measures were compared to healthy controls (N = 51). RESULTS: Eighty-eight percent of the former AN patients and controls were female, aged approximately 25 years, with a healthy body mass index. Mean carotid flow and pulsatility index were not different between groups. Carotid arterial strain and distensibility were lower, and the wave speed and beta stiffness index higher in the former AN patients. Characteristic impedance was not different nor were the forward and backward wave amplitudes. However, wave reflection indices (ratios of backward-to-forward compression wave area, and wave-related effect on pressure and hydraulic power) were 12-18% lower in the former AN patients (p < 0.05). CONCLUSIONS: Increased carotid artery stiffness and reduced wave reflection are evident in young adults who recovered from adolescent AN. This may relate to an adaptive process that helps to maintain or restore flow and characteristic impedance despite increased vessel stiffness, with this warranting future investigation.

Anorexia nervosa (AN) is an eating disorder which may cause permanent changes in the heart and blood vessels. Blood flow properties can provide information on the health of a patient's heart and blood vessels. In this study of young adults who recovered from adolescent AN, blood flow analysis revealed altered properties compared to controls who had never experienced an eating disorder. These alterations may help to maintain or restore blood flow despite unhealthy changes in the blood vessels themselves. Further investigation is needed to better understand how the heart and blood vessels change during and after AN to guide treatments and ongoing care. Regular assessment of the heart and blood vessels after AN recovery could identify and monitor possible health risks early.

Executive summary of the KDIGO 2024 Clinical Practice Guideline for the Management of Lupus Nephritis.

The Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for the Management of Glomerular Diseases was published in 2021. Since then, the pace of drug development for glomerular diseases has accelerated, due in large part to rapidly accumulating insights into disease pathogenesis from genetic and molecular studies of afflicted patients. To keep the Glomerular Diseases Guideline as current as possible, KDIGO made a commitment to the nephrology community to provide periodic updates, based on new developments for each disease. After the 2021 guideline was published, two novel drugs received regulatory approval for the management of lupus nephritis, leading to the first KDIGO guideline update. Herein, an executive summary of the most important guideline changes from the Lupus Nephritis chapter is provided as a quick reference.

Clinical Experience of Intrafractional Motion Monitoring of Patients Under Head and Neck Radiation Therapy Using ExacTrac Dynamic System.

Purpose: The combination of surface-guided radiation therapy (SGRT) and image-guided radiation therapy (IGRT) can provide complementary information of patient positioning throughout treatments. The ExacTrac Dynamic (EXTD) system is a combined SGRT and IGRT system that can provide real-time motion detection via optical surface and thermal tracking during treatment delivery, with stereoscopic x-ray for positional verification. The purpose of this study was to examine the performance of EXTD for intrafractional motion monitoring using real clinical cases. Methods and Materials: Treatment log files exported from EXTD for 40 patients with 335 fractions were retrospectively analyzed. Frequency of beam-hold triggered during treatments were recorded, with the comparison of shifts detected by optical surface tracking (EXTD_Thml) and x-ray verification (EXTD_Xray). Results: Among the 335 fractions, automatic beam-holds were triggered 41 times, followed by x-ray positional verification with internal anatomy. The difference of shifts detected by EXTD_Thml and EXTD_Xray were less than 1 mm and 1° in translational and rotational directions, respectively. After x-ray verification, none of them required the application of positional correction. Conclusions: The availability of x-ray imaging with optical surface tracking in EXTD is essential to verify whether geometric shifts are required to correct patient position. Considering the ability of continuous monitoring of patient positions with optical surface tracking and internal imaging, EXTD is an effective tool for intrafractional motion monitoring during radiation therapy.

Bex-Nikaidoh operation and the impact of double root translocation on outcomes.

OBJECTIVES: The Bex-Nikaidoh operation can effectively relieve left ventricular outflow tract obstruction. However, if a conduit is used for right ventricular outflow tract reconstruction, a late reoperation can be anticipated. We examined the impact of double root translocation on outcomes. METHODS: We performed a retrospective single-centre study of patients who underwent aortic root translocation between 2006 and 2019. RESULTS: Aortic root translocation was performed in 23 patients at a median age of 1.6 years [interquartile range (IQR) 0.9-2.5]. Concomitant repairs were done in 52.2% of patients (12/23) including the Senning atrial switch in 34.8% (8/23). The right ventricular outflow tract was reconstructed with valved conduits in 39.1% (9/23), direct anastomoses in 4.35% (1/23) and pulmonary autografts in 56.5% of patients (13/23). Aortic cross-clamp time was significantly longer in patients with double root translocation [308 min (IQR 270-259) vs 209 min (IQR 179-281), P = 0.02]; 2 patients in this group required temporary mechanical circulatory support. There were no early deaths. Median follow-up time was 7.5 years (IQR 3.3-10.5). The estimated 10-year survival was 90% [95% confidence interval (CI): 47.3%, 98.5%]. There was no recurrent left ventricular outflow tract obstruction. Freedom from any reoperation was 64.2% (95% CI: 40.8%, 80.3%) at 3 years and 44.5% (95% CI: 21.2%, 65.5%) at 6 years. The main indication for late reoperation was conduit degeneration. Freedom from a right ventricular outflow tract reoperation was significantly higher, and the number of reoperations per patient was lower when a double root translocation had been performed (P = 0.03). CONCLUSIONS: The Bex-Nikaidoh operation effectively relieved left ventricular outflow tract obstruction. A double root translocation further increased procedural complexity but was associated with better mid-term freedom from a right ventricular outflow tract reoperation. It should be considered in suitable patients.

Transition to Adulthood for Extremely Preterm Survivors.

OBJECTIVE: To compare transition into adulthood of survivors born extremely preterm (EP; <28 weeks' gestation) or extremely low birth weight (ELBW; <1000 g) in the postsurfactant era with term-born controls. METHODS: Prospective longitudinal cohort study of all EP/ELBW survivors born in the State of Victoria, Australia between January 1, 1991 and December 31, 1992 and matched term-born controls. Outcomes include educational attainment, employment, financial status, romantic partnering, living arrangements, parenthood, physical health and mental health, risk-taking behaviors, life satisfaction, and interpersonal relationships at 25 years. RESULTS: Data were available from 165 EP/ELBW and 127 control participants. Overall, there was little evidence for differences between the EP/ELBW and control groups on most comparisons after adjustment for social risk and multiple births. However, compared with controls, the EP/ELBW group was more likely to have their main source of income from government (adjusted odds ratio [aOR] 2.49, 95% confidence interval [CI] 1.21-5.13; P = .01) and to have never moved out of the parental home (aOR 2.13, 95% CI 1.27-3.58; P = .01), and fewer had ever engaged in smoking (aOR 0.52, 95% CI 0.28-0.98; P = .04), binge drinking (aOR 0.41, 95% CI 0.18-0.93; P = .03), or street drugs (aOR 0.56, 95% CI 0.32-0.98; P = .04). CONCLUSIONS: Aside from clinically important differences in main income source, leaving the parental home, and reduced risk-taking behavior, survivors born EP/ELBW in the era since surfactant was introduced are transitioning into adulthood similarly to term-born controls in some areas assessed but not all.

Lessons learnt in the first year of an Australian pediatric cardio oncology clinic.

BACKGROUND: Modern oncological therapies together with chemotherapy and radiotherapy have broadened the agents that can cause cardiac sequelae, which can manifest for pediatric oncology patients while on active treatment. Recommendations for high-risk patients who should be monitored in a pediatric cardio-oncology clinic have previously been developed by expert Delphi consensus by our group. In 2022 we opened our first multidisciplinary pediatric cardio-oncology clinic adhering to these recommendations in surveillance and management. OBJECTIVES: Our pediatric cardio-oncology clinic aimed to: (i) Document cardiovascular toxicities observed within a pediatric cardio-oncology clinic and. (ii) Evaluate the applicability of the Australian and New Zealand Pediatric Cardio-Oncology recommendations. METHODS: Monthly multidisciplinary cardio-oncology clinics were conducted in an Australian tertiary pediatric hospital. Structured standardised approaches to assessment were built into the electronic medical record (EMR). All patients underwent baseline echocardiogram and electrocardiogram assessment together with vital signs in conjunction with standard history and examination. RESULTS: Nineteen (54%) individuals had a documented cardiovascular toxicity or pre-existing risk factor prior to referral. The two most common cardiovascular toxicities documented during clinic review included Left Ventricular Dysfunction (LVD) and hypertension. Of note 3 (8.1%) patients had CTCAE grade III LVD. An additional 10 (27%) patients reviewed in clinic had CTCAE grade I hypertension. None of these patients had hypertension noted within their referral. Cascade testing for cardiac history was warranted in 2 (5.4%) of patients. CONCLUSIONS: Pediatric cardio-oncology clinics are likely beneficial to documenting previously unrecognised cardiotoxicity and relevant cardiac family histories, whilst providing an opportunity to address lifestyle risk factors.

Prevention, Diagnosis, Evaluation, and Treatment of Hepatitis C in Chronic Kidney Disease: Synopsis of the Kidney Disease: Improving Global Outcomes 2022 Clinical Practice Guideline.

DESCRIPTION: The Kidney Disease: Improving Global Outcomes (KDIGO) 2022 clinical practice guideline on prevention, diagnosis, evaluation, and treatment of hepatitis C in chronic kidney disease (CKD) is an update of the 2018 guideline from KDIGO. METHODS: The KDIGO Work Group (WG) updated the guideline, which included reviewing and grading new evidence that was identified and summarized. As in the previous guideline, the WG used the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach to appraise evidence and rate the strength of recommendations and used expert judgment to develop recommendations. New evidence led to updating of recommendations in the chapters on treatment of hepatitis C virus (HCV) infection in patients with CKD (Chapter 2), management of HCV infection before and after kidney transplant (Chapter 4), and diagnosis and management of kidney disease associated with HCV infection (Chapter 5). Recommendations in chapters on detection and evaluation of hepatitis C in CKD (Chapter 1) and prevention of HCV transmission in hemodialysis units (Chapter 3) were not updated because of an absence of significant new evidence. RECOMMENDATIONS: The 2022 updated guideline includes 43 graded recommendations and 20 ungraded recommendations, 7 of which are new or modified on the basis of the most recent evidence and consensus among the WG members. The updated guidelines recommend expanding treatment of hepatitis C with sofosbuvir-based regimens to patients with CKD glomerular filtration rate categories G4 and G5, including those receiving dialysis; expanding the donor pool for kidney transplant recipients by accepting HCV-positive kidneys regardless of the recipient's HCV status; and initiating direct-acting antiviral treatment of HCV-infected patients with clinical evidence of glomerulonephritis without requiring kidney biopsy. The update also addresses the use of immunosuppressive regimens in such patients.

Self-amplifying mRNA seasonal influenza vaccines elicit mouse neutralizing antibody and cell-mediated immunity and protect ferrets.

Currently licensed influenza vaccines focus immune responses on viral hemagglutinin (HA), while the other major surface glycoprotein neuraminidase (NA) is not tightly controlled in inactivated vaccine formulations despite evidence that anti-NA antibodies reduce clinical disease. We utilized a bicistronic self-amplifying mRNA (sa-mRNA) platform encoding both HA and NA from four seasonal influenza strains, creating a quadrivalent influenza vaccine. sa-mRNA vaccines encoding an NA component induced the production of NA-inhibiting antibodies and CD4+ T-cell responses in both monovalent and quadrivalent formulations. Including NA in the vaccine enabled cross-neutralization against antigenically drifted strains and provided greater protection than HA alone upon A(H3N2) challenge in ferrets. These results demonstrate that next-generation bicistronic sa-mRNA vaccines expressing HA and NA induce potent antibodies against both viral coat proteins, as well as vaccine-specific cell-mediated immunity. When formulated as a quadrivalent seasonal influenza vaccine, the sa-mRNA platform provides an opportunity to increase the breadth of protection through cross-neutralizing anti-NA antibodies.

Potential benefits of prenatal diagnosis of TGA in Australia may be outweighed by the adverse effects of earlier delivery: likely causation and potential solutions.

OBJECTIVE: Prenatal diagnosis of transposition of great arteries (TGA) is expected to improve postoperative outcomes after neonatal arterial switch operation (ASO); however, published reports give conflicting results. We aimed to determine the association between prenatal diagnosis and early postoperative outcomes after neonatal ASO. METHODS: Cohort study involving 243 newborns who underwent ASO (70% prenatally diagnosed) between 2010 and 2019. Multivariable regression was used to determine the association between prenatal diagnosis and (a) birth characteristics and (b) postoperative outcomes. RESULTS: Gestational age and birthweight centile were lower and small-for-gestational-age more common (11.8% vs 1.4%) in those diagnosed prenatally. Among births which followed labour induction or prelabour caesarean, prenatal diagnosis was associated with earlier gestation at birth (mean (SD), 38.5 (1.6) vs 39.2 (1.4), p=0.01). Among births which followed spontaneous labour, prenatal diagnosis was associated with earlier gestation at labour onset (38.2 (1.8) vs 39.2 (1.4), p=0.01). Prenatal diagnosis was associated with longer postoperative mechanical ventilation (incidence rate ratio 1.74, 95% CI 1.37 to 2.21), intensive care (1.70, 1.31 to 2.21) and hospital length of stay (1.37, 1.14 to 1.66) after ASO. Gestational age mediated up to 60% of the effect of prenatal diagnosis on postoperative outcomes. CONCLUSION: Among newborns undergoing ASO for TGA, prenatal diagnosis is associated with poorer early postoperative outcomes. In addition to minimising iatrogenic factors (such as planned births) resulting in earlier births, evaluation of other dynamics following a prenatal diagnosis which may result in poor fetal growth and earlier onset of spontaneous labour is important.

Safety and feasibility of adjunct autologous cord blood stem cell therapy during the Norwood heart operation.

BACKGROUND: We conducted this phase I, open-label safety and feasibility trial of autologous cord blood (CB) stem cell (CBSC) therapy via a novel blood cardioplegia-based intracoronary infusion technique during the Norwood procedure in neonates with an antenatal diagnosis of hypoplastic left heart syndrome (HLHS). CBSC therapy may support early cardiac remodeling with enhancement of right ventricle (RV) function during the critical interstage period. METHODS: Clinical grade CB mononucleated cells (CBMNCs) were processed to NetCord-FACT International Standards. To maximize yield, CBSCs were not isolated from CBMNCs. CBMNCs were stored at 4 °C (no cryopreservation) for use within 3 days and delivered after each cardioplegia dose (4 × 15 mL). RESULTS: Of 16 patients with antenatal diagnosis, 13 were recruited; of these 13 patients, 3 were not treated due to placental abruption (n = 1) or conditions delaying the Norwood for >4 days (n = 2) and 10 received 644.9 ± 134 × 106 CBMNCs, representing 1.5 ± 1.1 × 106 (CD34+) CBSCs. Interstage mortality was 30% (n = 3; on days 7, 25, and 62). None of the 36 serious adverse events (53% linked to 3 deaths) were related to CBMNC therapy. Cardiac magnetic resonance imaging before stage 2 (n = 5) found an RV mass index comparable to that in an exact-matched historical cohort (n = 22), with a mean RV ejection fraction of 66.2 ± 4.5% and mean indexed stroke volume of 47.4 ± 6.2 mL/m2 versus 53.5 ± 11.6% and 37.2 ± 10.3 mL/m2, respectively. All 7 survivors completed stage 2 and are alive with normal RV function (6 with ≤mild and 1 with moderate tricuspid regurgitation). CONCLUSIONS: This trial demonstrated that autologous CBMNCs delivered in large numbers without prior cryopreservation via a novel intracoronary infusion technique at cardioplegic arrest during Norwood palliation on days 2 to 3 of life is feasible and safe.

Numerical simulation of the cavopulmonary connection flow with conduit stenoses of varying configurations.

The circulation in the total cavopulmonary connection (TCPC) is a low-energy system which operation and efficiency are subjected to multiple factors. Some retrospective studies report that the abnormal narrowing of vessels in the system, i.e. stenosis, is one of the most dangerous geometric factors which can result in heart failure. In the present study, the effect of varying extracardiac conduit (ECC) stenosis on the hemodynamics in a surrogate TCPC model is investigated using high-fidelity numerical simulations. The efficiency of the surrogate TCPC model was quantified according to the power loss, relative perfusion in lungs and the percentage of conduit surface area with abnormally low and high wall shear stress for venous flow. Additionally, the impact of respiration and asymmetry in the stenosis geometry to the system was examined. The results show that the flow in the TCPC model exhibits pronounced unsteadiness even under the steady initial boundary conditions, while the uneven pulmonary flow distribution and the presence of the ECC stenosis amplify the chaotic nature of the flow. Energy efficiency of the system is shown to strongly correlate with amount of vortical structures in the model and their range of scales. Finally, the study demonstrates that the presence of respiration in the model adds to perturbations in the flow which causes increase in the power loss. Results obtained in the study provide valuable insights on how the ECC stenosis effect the flow in the surrogate TCPC model under different flow conditions.