Coronary Surgery Research Articles

Obscure Rare Cause of Recurrent Angina in Post CABG Patient: Coronary-Subclavian Steal Syndrome

Coronary subclavian steal syndrome (CSSS) is a rare and unrecognized complication of coronary bypass grafting surgery when a left internal mammary artery (LIMA) graft is utilized for left anterior descending (LAD) artery revascularization without knowing left subclavian artery status. We describe a case of a 67-year-old male, with a known history of triple vessel coronary artery disease (CAD) managed with CABGx3 in March 2003. The patient presented after 16 years with complaints of recurrent angina for the past 15 years which aggravates on exertion, especially of left hand. Recurrent hospitalizations and repeated Coronary angiograms (CAG) as well as CT Coronary angiography failed to diagnose the cause of angina. Subclavian angiography and subsequent methodical clinical examination during the present admission revealed left subclavian origin stenosis which was successfully revascularized by deployment of a stent resulting in convincing relief in the patient’s angina.

Assessing the Nursing Workload in the Cardiothoracic Intensive Care Unit: Comparative Study.

This study aimed to assess nursing workload in Cardiac Intensive Care Unit (CICU) after three cardiothoracic surgery procedures during first four postoperative days using Nursing Activities Score (NAS) and Nine Equivalents of Nursing Manpower Use Score (NEMS) systems, to compare their performance for that purpose and to investigate association between nursing workload and type of surgery. A comparative study. The research environment includes CICU of the University Hospital for Cardiovascular Diseases in Serbia. A total of 808 patients who underwent coronary, valvular, or combined surgery, resulting in 2282 filled NAS and NEMS pairs chart. Statistical analysis was performed using SPSS-19. The correlation between NAS and NEMS was tested by Spearman's correlation coefficient. Differences were considered statistically significant at p < 0.05. The lowest median of cumulative NAS 176 (175-257) and NEMS 76 (64-91) had coronary surgery patients, the highest NAS 224.5 (178-334.5) and NEMS 83 (69-121) had those with combined surgery; this difference was statistically significant (p < 0.001). The median of both scores decreased after surgery, with the following values from the first to the fourth postoperative day: NAS from 104 (102-105) to 81 (74-85) and NEMS from 46 (42-46) to 30 (30-37). The difference in mean values of both scores between the first and the fourth postoperative day was statistically significant (p < 0.001). NAS and NEMS were in a positive, strong correlation (r = 0.913; p < 0.005). Both scores can be used to measure nursing workload, identify the required number of nurses in CICU, and support task allocation. NAS may have an advantage because it better describes extensive postoperative monitoring and care needed for cardiac surgery patients. Nursing workload is associated with type of surgery, with the highest workload measured in patients who underwent combined surgery procedure and on the first postoperative day.

Development of a predictive model for adherence to pharmacological treatment in ischemic heart disease: consideration of psychosociocultural, neuropsychological, and mental health variables

Abstract Introduction Adherence to pharmacological treatment recommendations is the main preventable cause of rehospitalization and premature mortality in patients diagnosed with ischemic heart disease, which in turn, is permeated by modifiable psychosocial risk factors such as anxiety, depression, stress, type A behavior pattern, inhibitory control, attitudes and behavioral beliefs towards the disease and treatment. The objective of this study was to develop and test a model to predict adherence to pharmacological treatment in patients with ischemic heart disease undergoing coronary revascularization surgery based on psychosocial, neuropsychological and mental health variables. Material and Methods Cross-sectional study with a sample of 691 patients between 45 and 82 years of age (M= 52 years, SD= 12.15), 46% women and 54% men, diagnosed with ischemic heart disease and undergoing coronary revascularization surgery. Anthropometric, cardiovascular and psychosocial risk factors were evaluated. The scales were designed and validated to assess adherence to pharmacological treatment in ischemic heart disease by means of EFA and CFA, which showed adequate internal consistency indicators and psychometric properties. Results Using the AMOS v.24 statistical package, a path analysis was performed for the variable of adherence to pharmacological treatment, with attitudes toward the disease and treatment, behavioral beliefs, and inhibitory control (executive function) as direct predictors, explaining 54% of the variance in adherence to pharmacological treatment in ischemic heart disease, and the model fit indices were: χ2(33) =261. 19; CMIN/DF= 7.91; TLI= .893; NFI= .815; IFI= .901; CFI= .900; AGFI= .822, SRMR= 2.727; RMSEA=.053. Conclusions The findings of this research contribute to the understanding of adherence to pharmacological treatment in ischemic heart disease as a process and not only as an isolated construct, in which mental health intervenes interacting with psychosocial and cultural aspects of the patient with respect to their disease and pharmacological treatment and in turn provides evidence that inhibitory control as an executive function. This provides evidence that inhibitory control as an executive function is useful for understanding adherence to pharmacological treatment, which shows the need to incorporate in the hospital setting comprehensive psychological evaluations and interventions that allow us to predict adherence to pharmacological treatment of ischemic heart disease in order to intervene in the processes involved, which could contribute to the prevention of rehospitalization and premature mortality.

Assessment of surgical revascularization completeness with quantitative myocardial blood flow distribution derived from CCTA in severe coronary artery disease

Abstract Background Complete revascularization remained the "holy grail" in the treatment of patients with severe coronary artery disease (CAD). However, there is no universally accepted definition of complete revascularization after coronary bypass graft surgery (CABG). The current assessment methods are visual, categorical, and biased by the operator's intention. Moreover, no method to date provides an individualized quantification of residual ischemia burden. Purpose We aim to provide an individualized method to assess the completeness of surgical revascularization through quantitative myocardial blood flow distribution derived from coronary computed tomography angiography (CCTA) that could reflect the actual functional ischemia burden after CABG. Methods Patients with 3VD and/or left main CAD were enrolled in the first-in-human FAST TRACK CABG trial for surgical revascularization guided solely by CCTA and fractional flow reserve derived from CCTA (FFRCT). Following CABG, the study protocol mandated a 30-day follow-up CCTA, which provides graft patency and topographical adequacy of the bypass graft anastomoses. The pre- and post-CABG CCTA were analyzed. The FFRCT value and percent myocardial blood flow distribution (%MBF) were computed for all 16 SYNTAX score segments using the validated method of Keulards et al(1). On pre-CABG CCTA, the myocardium located distal to the site where the FFRCT value dropped below 0.80 on the vessel centerline was considered ischemic, and the %MBF of the subtended myocardium was summed into the total percent ischemic myocardium (Figure 1). Following CABG, the segment was considered adequately revascularized when a non-narrowed graft was anastomosed distally to the site of FFRCT≤0.8 on the pre-operative CCTA. The change in percent ischemic myocardium and the residual ischemic burden were calculated for each patient (Figure 2). Results CCTA, FFRCT, and %MBF were obtained pre- and post-CABG in 96 patients, and the percent ischemic myocardium was computed per patient. At baseline, the average percent ischemic myocardium was 72.0(19.1)%. Post-CABG, the residual percent ischemic myocardium was 13.6(15.1)%. Residual percent ischemic myocardium &amp;lt;10% was achieved in 44 patients (44.8%). The first diagonal branch(n=13), distal LCX(n=12), and the first obtuse marginal branch(n=10) were the most frequent segments not revascularized, which subtended an average MBF of 12.2(3.5)%, 16.7(8.4)%, and 11.3(7.3)%, respectively. The main reason for inadequate revascularization was surgical deferral, with graft occlusion accounting for only 13.6% of the residual ischemic segments. Conclusion Percent ischemic myocardium and the completeness of surgical revascularization can be assessed with CCTA-derived %MBF. This novel method allows clinicians to assess the individualized ischemia burden and the completeness of revascularization that could be incorporated into personalized CABG planning.Figure 1Figure 2

Evolution of Coronary Surgery.

Evolution of Coronary Surgery.

Influence of patient characteristics and discharge destination on circulatory system diseases readmissions among older heart failure patients

IntroductionHeart failure (HF) prevalence is rising, particularly among older people, constituting a significant cause of hospitalization. Discharge destinations, including nursing homes (NH), play a crucial role in post-hospitalization outcomes but remain underexplored. MethodsA retrospective study utilizing the Spanish National Health System's Minimum Basic Data Set identified older HF patients (≥75 years) discharged from acute hospitals between 2016 and 2019. Patient demographics, comorbidities, and discharge destinations were analyzed. Predictors of 30-day readmissions for circulatory system diseases and NH admission were assessed using multilevel logistic regression models. ResultsOf 157,330 index episodes, 2.8 % were discharged to NH, more frequently in females. Thirty-day readmission incidence was 9.3 %, with HF exacerbations accounting for 80.6 % of cases. Predictors of 30-day readmission included renal failure (OR: 1.38), severe hematological disorders (OR: 1.30), and history of coronary revascularization surgery (OR: 1.23), while discharge to NH lowered the risk (OR: 0.70). Admission to NH was associated with neurological diseases (OR: 3.27), cardiogenic shock (OR: 3.19), stroke (OR: 2.68), advanced cancer (OR: 2.51), with higher likelihood among females (OR: 1.23). After propensity score-matched analysis, patients discharged to NH had significantly lower 30-day readmission rates than those discharged home (6.4 % vs. 28.9 %, adjusted OR: 0.169). ConclusionDischarge to NH is infrequent but associated with lower readmission risk for older HF patients. Female gender, specific comorbidities, and acute conditions influence NH admission. Enhanced collaboration between HF units and NH is crucial for optimizing post-hospitalization outcomes. Further research and policy initiatives are needed to improve care coordination and reduce HF readmissions.

Ling gui shen fu decoction ameliorates cardiac injury in ischemic heart disease rats by regulating ANP32A/HIF2α/HMGB1 signal route

Purpose: To investigate the effect of ling gui shen fu decoction (LGSFD) on cardiac injury and cardiomyocyte apoptosis in rats with ischemic heart disease (IHD), and to elucidate the underlying molecular mechanism. Methods: An IHD rat model was established by performing coronary artery occlusion surgery on the left anterior descending (LAD) of rats. The rats were assigned equally to 5 groups: sham-operated group (sham group), IHD group, IHD + perindopril group, IHD + low- dose LGSFD group (IHD + LGSFD-L group), and IHD + high-dose LGSFD group (IHD+LGSFD-H group). The LGSFD was given via gavage. A hypoxia-induced cardiomyocyte model was established by subjecting H9C2 cells to hypoxia. Then, LGSFD-containing serum or blank serum was used to treat the hypoxic rat cardiomyocytes (H9C2). The severity of cardiac injury and extent of apoptotic changes in cardiomyocytes was determined using hematoxylin-eosin (H&amp;E) staining and TUNEL staining, while immunoblotting was used to measure the protein expressions of ANP32A, p-AKT, AKT, HIF-2α, p-mTOR, mTOR and HMGB1. Results: The cardiac injury of rats in the LGSFD groups was significantly reversed, relative to the IHD group (p &lt; 0.05). Moreover, LGSFD reduced the level of apoptosis in hypoxia- induced H9C2 cells and upregulated the concentrations of ANP32A, p-AKT, HIF-2α and p-mTOR. However, the expression levels of HMGB1 were decreased in the heart tissues of IHD rats and hypoxic H9C2 cells. Silencing of ANP32A with ANP32A siRNA (siANP32A) down- regulated ANP32A, p-AKT, HIF-2α and p-mTOR, but up-regulated apoptosis and expression levels of HMGB1 in hypoxic H9C2 cells. Conclusion: LGSFD ameliorates cardiac injury in IHD rats by inhibiting cardiomyocyte apoptosis via the ANP32A/HIF-2α/HMGB1 axis. Further investigations are recommended into the specific mechanism of LGSFD effect using clinical samples, in order to facilitate its clinical development.

Impact of Multi versus Single Arterial Coronary Bypass Graft Surgery on Postoperative Atrial Fibrillation

The effect of multi-arterial (MA) versus single arterial (SA) coronary bypass graft surgery on postoperative atrial fibrillation (POAF) was not investigated. From May 2017 to May 2024, the patients with CYP2C19*2 or *3 allele receiving coronary artery grafting and post-operational aspirin 100 mg/day and clopidogrel 75mg/day were retrospectively reviewed and assigned into MA or SA group. The primary endpoint was the incidence rate of POAF in first week. The secondary endpoints were POAF burden, platelet aggregation, systemic immune-inflammation (SII) index and heart rate variability (HRV). The study included 58 cases in MA group and 174 cases in SA group. The incidence of POAF was 17% in MA group contrasting with 42% in SA group (hazard ratio: 0.353; 95% confidence interval: 0.218 to 0.569, P=0.0012). A lower POAF burden was observed in MA group than that in SA group (2 h [1, 5] versus 10 h [6, 20], P=0.02). Platelet aggregation (arachidonic acid, 46%±10% vs. 56%±8%, P<0.01; adenosine diphosphate, 58%±17% vs. 75%±13%, P<0.01) and inflammation response index (neutrophil-lymphocyte ratio, 26±4 vs. 28±5, P=0.006; SII index, 5019±771 vs. 5382±1204, P=0.032) was notably lower in MA group than those in SA group at one day after CABG. Holter electrocardiogram showed a higher HRV value in standard deviation of normal-to-normal RR intervals, and decreased low-frequency/high-frequency ratio in MA group. In conclusion, MA was associated with a lower incidence rate of POAF, and paralleled with a lower AF burden, platelet aggregation, inflammation reaction and a higher parasympathetic nerve tone compared with SA regimen.

Outcome after the early use of intra-aortic balloon pump in coronary bypass graft surgery in cases with impaired myocardial function.

Outcome after the early use of intra-aortic balloon pump in coronary bypass graft surgery in cases with impaired myocardial function.

Atrial Fibrillation Surgery in Australia: Are We Doing Enough?

This study aimed to examine contemporary burden and treatment trends of atrial fibrillation (AF) in patients undergoing cardiac surgery in Australia and New Zealand. This allows comparison of contemporary practice with the Society of Thoracic Surgeons guideline recommendations for the surgical treatment of AF in patients undergoing cardiac surgery. A 10-year retrospective review of the Australian & New Zealand Society of Cardiac & Thoracic Surgeons National Cardiac Surgery Database was performed, examining all adult cardiac surgery patients from 2011 to 2021. Patients were grouped by the presence or absence of AF, and simple descriptive statistical analysis was performed to assess baseline demographics and premorbid condition of the patients. The incidence of AF was analysed by type of surgery. Trends for surgical treatment of AF were then analysed using simple descriptive statistics, examining isolated left atrial appendage ligation, isolated surgical ablation, and combined ligation and ablation. In the last 10 years, the Australian & New Zealand Society of Cardiac & Thoracic Surgeons database has recorded 140,680 patients who underwent cardiac surgery. Atrial fibrillation (AF) was present in 21,077 patients (14%). Patients with AF were generally older (72.25 vs 66.65 years; p<0.001). Among patients undergoing cardiac surgery, AF was more common in female than in male patients (18% vs 13%, respectively). Patients with AF more often had a higher classification of dyspnoea according to the New York Heart Association and lower ejection fractions compared with their AF-free counterparts. The incidence of AF as a comorbid condition was more frequent in patients undergoing mitral valve surgery or combined coronary artery bypass grafting and valve surgery (aortic, mitral, or both) compared with those undergoing isolated coronary or aortic surgery. Only 11.90% (n=2,509) of patients with AF received a combined ablation and left atrial appendage ligation, and 19.54% (n=693) of those received a Cox-Maze IV ablation. The burden of concomitant AF in patients undergoing cardiac surgery in Australia is higher than previously reported (14% vs 5%-11%). Despite strong recommendation for the surgical management of AF in patients undergoing cardiac surgery and clear evidence of its benefit, both left atrial appendage ligation and surgical ablation independently or concomitantly remain heavily underutilised in this cohort.

Comparison of De Ritis Rate for Del Nido Versus Blood Cardioplegia in Patients Who Underwent Coronary Artery Bypass Graft Under Cardiopulmonary Bypass

Aim: Within the scope of this research, we aimed to compare the liver function tests, liver enzymes and De Ritis ratio (AST/ALT) of patients given Del Nido cardioplegia and blood cardioplegia in coronary heart surgery. Methods: This retrospective study included a total of 80 patients who underwent CPB-guided coronary heart surgery (CABG) with 40 Del Nido cardioplegia solutions and 40 blood cardioplegia solutions. CPB-guided coronary heart surgery patients given Del Nido cardioplegia solution were determined as the first group (Group 1), and patients given blood cardioplegia were determined as the second group (Group 2). Results: Preoperative and postoperative aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin, direct bilirubin, and gamma-glutamyl transferase (GGT) levels of the groups were similar (p

Long-term results of outpatient rehabilitation after coronary artery bypass graft surgery

Aim. To assess the impact of adherence to various outpatient rehabilitation programs during the first three months after coronary artery bypass grafting (CABG) on the development of cardiovascular events over four years of follow-up.Materials and Methods. The study evaluated the influence of adherence to outpatient cardiac rehabilitation programs on the incidence of cardiovascular events in patients following open coronary artery revascularization surgery. Adherence to cardiac rehabilitation was assessed over a threemonth period, and the observation period for cardiovascular events extended to four years from the time of the surgery.Results. During the first year of observation, we did not find significant differences in the effectiveness and safety of outpatient cardiac rehabilitation programs. However, we revealed statistically significant differences in the patient adherence to physical training. Over the four-year observation period, a higher number of cardiovascular events were recorded in the group of patients who were non-adherent to physical training. Statistically significant differences were observed with regards to the incidence of myocardial infarction and cardiovascular death.Conclusion. Adherence to recommendations following open revascularization procedures is crucial for the prognosis of myocardial infarction and cardiovascular death. Modern methods of providing medical care in the outpatient phase of cardiac rehabilitation enable patients to engage in effective and safe physical training comparable to those conducted in specialized cardiac rehabilitation facilities under the direct supervision of medical personnel.

How to advance from minimally invasive coronary artery bypass grafting to totally endoscopic coronary bypass grafting: challenges in Europe versus United States of America.

Robotic coronary and intra-cardiac surgery has been available for more than 25 years. In this period, multiple studies have demonstrated the beneficial effects of robotic surgery over conventional open surgery. Throughout the years, technical developments have enabled us to perform totally endoscopic coronary artery bypass (TECAB) grafting. But these techniques remained in the hands of a small group of pioneers because of a lack of structured training programs and the absence of long-term results at that time. Currently, a renewed interest and a wide dispersion of robotic platforms, thanks to use of robotics in other disciplines, has led to an exponential increase in robotic cardiac centers both in Europe and USA. Nonetheless, this increase was slowed down in Europe as a result of the uncertainty introduced by the implementation of a revised regulatory framework for medical devices [Regulation 2017/745, 'Medical Device Regulation' ('MDR')]. The MDR was introduced with the goal of increasing patient safety and supporting innovation. Implementing the MDR has proven to be exceptionally challenging and risks to the supply of essential devices have been identified. Changes to both regulatory and market dynamics led to a circumstance where the only available robotic platform for cardiac surgery decided to cease marketing of essential accessories for conducting surgery. This resulted in the disappearance of dedicated tools such as the Endowrist stabilizer, essential for TECAB, and the atrial retractor which is essential for intra-cardiac surgery. In the mean-time, further clinical evidence was published demonstrating the superiority of robotic cardiac surgery over other minimally invasive approaches. This has demonstrated the need to better define the clinical evidence requirements for regulatory purposes to ensure that dedicated tools for evidence-based interventions in robotic coronary surgery remain available such that TECAB can continue in Europe.

Cardiac Self-efficacy, Illness Perception and Health-Related Quality of Life in Patients with Ischemic Cardiomyopathy

Introduction: Illness perception and positive illness beliefs are protective factors that enhance the management of cardiac disease and improve HRQOL. The aim was to determine the relationship of cardiac self-efficacy and illness perception with HRQOL in patients with ischemic cardiopathy candidates for coronary artery bypass grafting surgery. Method: Cross-correlational study. 87 hospitalized patients with coronary artery disease requiring coronary revascularization surgery were recruited from a Cardiac Surgery Unit of a Hospital in Mexico City. Results: The study included 79.3% male patients with an average age of 63 years (S.D.=8.6). The correlation coefficient indicated a positive relationship between HRQOL and cardiac self efficacy (p=0.001), and a negative association between HRQOL and illness perception (p=0.001). Multiple regression analysis demonstrated a significant impact of illness perception and cardiac self-efficacy on the variability of HRQOL (p=0.046, β=0.200 and p=0.001, β=-0.412, respectively), regardless of the patient's age, gender, and education. Conclusion: Both cardiac self-efficacy and illness perception were found to be significantly linked to all aspects of health-related quality of life. These factors played a crucial role in explaining the variability of HRQOL regardless of the patient's age, gender, and education level. Patients who feel capable of managing the challenges posed by their illness tend to have a more positive perception of their HRQOL. Conversely, negative beliefs about heart disease were associated with a lower HRQOL.

Influence of the use of a walking diary on mobility in patients in cardiac rehabilitation phase 1: a randomized clinical trial

INTRODUCTION: Inpatient rehabilitation is extremely important for patients recovering from cardiac surgery. Although a walking diary is routinely used in clinical practice, it has yet to be adequately tested and reported in the literature. OBJECTIVES: To establish whether the use of a walking diary affects the number of steps taken following cardiac surgery and whether this is related to the patient’s level of cardiac anxiety. METHODS: An open, controlled, randomized clinical trial was conducted with adult patients submitted to elective valve and/or coronary surgery, who had no motor impairment. All the participants used a pedometer to register the number of steps taken over five consecutive days in the hospital. Twenty-nine individuals were randomized to create an intervention group that used the walking diary as a treatment strategy, while twenty-three were allocated to a control group. The Mann-Whitney test was used to compare the number of steps between the two groups, while Spearman’s correlation coefficient was performed to evaluate the relationship between the number of steps and the level of cardiac anxiety. Statistical significance was defined as p&lt;0.05. RESULTS: The groups were similar regarding their demographic, clinical and surgical characteristics. There was no difference between the groups regarding the total number of steps taken: control group=1,496 (477.5 - 2992.5) vs. intervention group=1,468.5 (494.2 - 2,678) (p=0.902). CONCLUSION: The use of the walking diary had no effect on the number of steps taken and was unassociated with the level of cardiac anxiety in inpatients following cardiac surgery.

Waterpipe smoking is associated with presence and severity of coronary artery disease: a propensity score-matched study

BackgroundThe prevalence of waterpipe smoking (WPS) has been increasing worldwide. This trend is alarming as WPS can negatively impact cardiovascular health. In the present study, we explored the association between WPS and the presence and severity of CAD.MethodsThis study was a retrospective analysis of patients who underwent diagnostic coronary angiography at Tehran Heart Center between April 2021 and May 2022. Patients with a previous history of percutaneous coronary intervention and coronary surgery were excluded. Waterpipe smokers were matched with non-smokers based on age, gender, and cigarette smoking using a 1:4 propensity score matching model. Stenosis ≥ 50% in any coronary artery was considered a CAD diagnosis. Gensini score was also calculated to measure the severity of the CAD.ResultsWe reviewed the medical records of 8699 patients, including 380 waterpipe smokers. After matching, 1520 non-smokers with similar propensity scores to the waterpipe smokers were selected. Waterpipe smokers were more likely to have CAD than non-smokers (OR: 1.29; 95% CI: 1.04–1.60, P = 0.021). In addition, WPS increased the natural logarithm of the Gensini score by 1.24 (95% CI: 1.04–1.48, P = 0.014) in patients with atherosclerotic coronary disease.ConclusionWPS may increase the risk of CAD independent of age, gender, and cigarette smoking. In addition, among patients with any degree of atherosclerosis in coronary arteries (GS > 0), WPS may lead to higher average GS, suggesting more severe atherosclerosis.Graphical

The Beneficial Effect of the SGLT2 Inhibitor Dapagliflozin in Alleviating Acute Myocardial Infarction-Induced Cardiomyocyte Injury by Increasing the Sirtuin Family SIRT1/SIRT3 and Cascade Signaling.

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have a variety of cardiovascular and renoprotective effects and have been developed as novel agents for the treatment of heart failure. However, the beneficial mechanisms of SGLT2i on cardiac tissue need to be investigated further. In this study, we established a mouse model of acute myocardial infarction (AMI) using coronary artery constriction surgery and investigated the role of dapagliflozin (DAPA) in protecting cardiomyocytes from hypoxic injury induced by AMI. In vitro experiments were done using hypoxic cultured H9c2 ventricular cells to verify this potential mechanism. Expression of the SIRT family and related genes and proteins was verified by qPCR, Western blotting and immunofluorescence staining, and the intrinsic potential mechanism of cardiomyocyte death due to AMI and hypoxia was comprehensively investigated by RNA sequencing. The RNA sequencing results of cardiomyocytes from AMI mice showed that the SIRT family may be mainly involved in the mechanisms of hypoxia-induced cardiomyocyte death. In vitro hypoxia-induced ventricular cells showed the role of dapagliflozin in conferring resistance to hypoxic injury in cardiomyocytes. It showed that SIRT1/3/6 were downregulated in H9c2 cells in a hypoxic environment, and the addition of dapagliflozin significantly increased the gene and protein expression of SIRT1, 3 and 6. We then verified the underlying mechanisms induced by dapagliflozin in hypoxic cardiomyocytes using RNA-seq, and found that dapagliflozin upregulated the hypoxia-induced gene downregulation, which includes ESRRA, EPAS1, AGTRAP, etc., that associated with SIRTs-related and apoptosis-related signaling to prevent H9c2 cell death. This study provides laboratory data for SGLT2i dapagliflozin treatment of AMI and confirms that dapagliflozin can be used to treat hypoxia-induced cellular necrosis in cardiomyocytes, in which SIRT1 and SIRT3 may play an important role. This opens up further opportunities for SGLT2i in the treatment of heart disease.

Abstract We043: MYCN is a regulator of cardiomyocyte proliferation and regeneration in the mammalian heart

The identification of new factors and mechanisms that can promote the repair and regeneration of the adult injured mammalian heart are necessary as the adult heart has limited ability to repair itself. We identified MYCN as a downstream effector of the sonic hedgehog (SHH) signaling cascade during cardiomyocyte proliferation in the neonatal heart. Although the protooncogene, MYCN, has been shown to be an essential factor during embryonic heart development, its role in regenerating the adult heart has not been established. Here, we define MYCN as a critical regulator of cardiomyocyte (CM) proliferation and regeneration using genetic mouse models and in vivo modified RNA (modRNA) delivery. In these studies, we conditionally deleted Mycn in the neonatal heart (P0). Immunohistochemical (IHC) analysis of P3 neonatal hearts demonstrated significantly (p &lt; 0.05) decreased expression of Ki67 and pH3 in the absence of Mycn compared to control (no 4-OHT) hearts. This observation was further validated in isolated CMs and neonatal P7 hearts pulsed with EdU which demonstrated a significant decrease in EdU+ CMs in the absence of Mycn compared to control. Single-nucleus RNA-sequencing results from control and Mycn CKO P4 ventricles revealed a severe depletion of the proliferative and regenerative cardiomyocyte population in the Mycn CKO hearts. We then ligated the left anterior descending coronary artery (LAD) to produce an ischemic cardiac injury in control and Mycn CKO P2 neonatal mice. Echocardiography one-month following the LAD surgeries demonstrated that the Mycn CKO failed to recover baseline cardiac function compared to their control counterparts who achieved complete recovery. RNAseq analysis of control and Mycn CKO hearts 1 month following LAD ligations demonstrated that muscle developmental pathways were significantly downregulated in the Mycn CKO group compared to the control. We then delivered either GFP (control) or Mycn modRNA intramuscularly into the border zone following LAD coronary artery ligation surgeries in adult (2-6 month old) mice. We observed that the Mycn modRNA treated mice had significantly improved cardiac function at one month and two months following injury/delivery compared to controls. These results identify MYCN as an important regulator of CM proliferation and heart regeneration.

The impact of incomplete revascularization on survival in minimal invasive off-pump coronary artery surgery: a propensity score analysis of 1,149 cases.

Minimally invasive concepts are increasingly influential in modern cardiac surgery. This study aimed to evaluate the effect of completeness of revascularization on clinical outcomes and overall survival in minimally invasive, thoracoscopic coronary artery bypass grafting (CABG) surgery. We retrospectively evaluated a consecutive series of 1,149 patients who underwent minimally invasive off-pump CABG with single, double, or triple-vessel revascularization between 2007 and 2018. Of these patients, 185 (16.1%) had incomplete revascularization (IR) (group I), and 964 (83.9%) had complete revascularization (CR) (group C). We used gradient boosted propensity score estimation to account for possible confounding variables. Median age was 69 years, interquartile range (IQR) 60-76 years, and median EuroSCORE II was 4, IQR 2-7. Of the 1,149 patients, 495 patients suffered from two vessel disease (VD) and 353 presented with three VD. Long-term median follow-up 5.58 (3.27-8.48) years was available for 1,089 patients (94.8%). The incidence of recurrent or persisting angina, myocardial infarction, redo-bypass surgery, and stroke during follow-up did not differ significantly between groups. During follow-up, there were 47 deaths in group I and 172 deaths in group C. The 1-, 3-, 5-, 8-, and 10-year unadjusted survival rates were 94%, 84%, 75%, 62%, and 51% for group I, and 97%, 94%, 88%, 77%, and 72% for group C, respectively (long-rank test P<0.001), favouring CR. Following risk adjustment the long-rank test P value for survival was 0.23. In minimally invasive coronary surgery, IR resulted in decreased long-term survival, but did not achieve statistical significance after risk adjustment. However, IR should only be used in carefully selected cases.

The Impact of the COVID Pandemic on Hospital Transfer Times and Post Operative Outcomes Following Coronary Artery Bypass Graft (CABG) Surgery: An Extension of the Nepean Acute Coronary Syndrome Bypass Graft Surgery Audit (NABA: 2020–2023)

The Impact of the COVID Pandemic on Hospital Transfer Times and Post Operative Outcomes Following Coronary Artery Bypass Graft (CABG) Surgery: An Extension of the Nepean Acute Coronary Syndrome Bypass Graft Surgery Audit (NABA: 2020–2023)