Elective Coronary Artery Bypass Grafting Research Articles

The effect of non-significant internal carotid artery stenoses on the results of cognitive training and electroencephalographic indicators in cardiac surgery patients

The effect of atherosclerotic lesions of the carotid arteries (CA) on the success of the cognitive function recovery procedures in cardiac patients has not been sufficiently studied. This study aims to evaluate the effects of cognitive rehabilitation depending on the presence of CA stenosis in patients after coronary artery bypass grafting (CABG) using neurophysiological indicators.Material and methods. The cohort prospective study involved 85 patients (16 of them women), aged 45 to 75 years, admitted for elective CABG. All patients underwent standard clinical and instrumental, neurological, extended neuropsychological and neurophysiological examination.Results. After multi-task training, the patients with CA stenosis had higher levels of high-frequency beta power (13-30 Hz), while the spectral power of the alpha1 rhythm (8-10 Hz) in this group was lower compared to patients without stenosis. In the case of successful cognitive rehabilitation (absence of POCD) at 11–12 days after CABG, compared with the group with POCD, patients without stenoses had higher total power of alpha 1 power and lower — beta power than patients with stenoses CA.Conclusion. The absence of CA stenosis in the patients with successful completion of multi-tasking training contributed to the optimization of brain activity with an increase of alpha power. Whereas the patients with CA stenosis were characterized by an increase in high-frequency brain activity, both in the case of successful multi-tasking training and in its absence, in the early postoperative period of CABG. This study may serve as a basis for the development of special cognitive rehabilitation programs for patients with atherosclerotic lesions of the carotid system.

Long-term monocyte activation after coronary artery bypass grafting: an exploratory prospective observational study

Major surgery such as coronary artery bypass grafting (CABG) is associated with an increased post-operative risk of atherosclerotic cardiovascular events. Cells of the innate immune system can adopt a long-lasting pro-inflammatory and atherogenic phenotype after brief exposure to exogenous or endogenous inflammatory stimuli, a process called “trained immunity”. We hypothesized that the surgery-induced inflammation leads to sustained alterations in monocyte function, which promote the subsequent occurrence of cardiovascular events. Blood from 13 patients undergoing elective CABG was obtained before, 3-7 days (median 4) after, and 6-8 weeks (median 6) weeks after surgery. At 3-7 days postoperatively, circulating C-reactive protein (CRP) concentration, leukocyte counts and ex vivo Peripheral Blood Mononuclear Cell (PBMC) IL-6, TNFα and IL-1Ra production after stimulation (with various inflammatory stimuli) were significantly increased. Simultaneously, there was a reduction in monocyte HLA-DR expression. 6-8 weeks after CABG there was an ongoing systemic pro-inflammatory state with higher CRP concentrations, increased stimulated ex vivo PBMC IL-6 production, changes in monocytes subsets, and a higher expression of CCR2 on monocytes compared to baseline. In conclusion, CABG induces a persistent systemic inflammatory reaction with a sustained activated monocyte phenotype. This might contribute to the increased atherosclerotic cardiovascular event risk observed in cardiac surgery patients.

Association of soluble ST2 with heart failure and other comorbidities in patients with severe coronary heart disease

Abstract Background Circulating levels of soluble suppression of tumorigenicity-2 (sST2) reflect vascular congestion, inflammation, and fibrosis. sST2 has been proposed as a useful biomarker to predict the mortality and hospitalization due to heart failure. However, there is limited evidence regarding the relationship between sST2 and heart failure, as well as other comorbidities, in severe coronary heart disease (CAD). Purpose This study aims to measure the circulating levels of soluble ST2 (sST2) in a large population of patients with severe CAD to determine its association with heart failure, cardiac function, inflammation, and other important comorbidities. Methods This subanalysis is part of the ongoing perspective observational study. Available serum samples from 520 patients undergoing elective coronary artery bypass grafting (CABG) were analysed for sST2 levels. The inclusion criteria were written informed consent and age between 18-85 years. Exclusion criteria for this analysis were severe valvular disease, severe chronic obstructive pulmonary disease, oxygen therapy, nocturnal positive airway pressure support or mechanical ventilation, and the need for catecholamines or circulatory assist devices. The circulating levels of human sST2 were measured from frozen serum (-80°C) using commercially available ELISA kits. The plasma was diluted 100 times to detect sST2 levels (assay range of 31.2 - 2,000 pg/mL). Two measurements were taken to account as means for intra-assay variabilities. Logarithmic transformation was used to convert non-normal distributed data. Student t' test and linear regression were applied to categorical or continuous variables as appropriate. Results sST2 levels (median 20.4 ng/ml, [IQR 15.5 – 28.8]) significantly predict worse left ventricular ejection fraction (β = -0.164, p = 0.006), and significantly correlate with levels of NT-proBNP (β = 3.263, p < 0.001), hs-Troponin T (β = 3.391, p < 0.001), high-sensitivity C-reactive protein (β = 2.472, p = 0.014) and heart failure (p= 0.002). Interestingly, common comorbidities such as chronic kidney disease (estimated glomerular filtration rate < 60 mL/min/1.73 m2, p = 0.004), diabetes mellitus (p = 0.001) and higher levels of glycated haemoglobin (HbA1c, β = 3.615, p < 0.001) showed also a significant association with sST2 levels. No significant association of sST2 was observed with arterial hypertension (p = 0.190), atrial fibrillation (p = 0.289), obesity (BMI ≥ 30 kg/m2, p = 0.302), sleep apnoea (apnoea-hypopnoea index ≥ 15/h, p = 0.068), peripheral artery disease (p = 0.823), or previous stroke (p = 0.861). Conclusion(s) Circulating levels of sST2 significantly correlate with heart failure, NT-proBNP, hs-TnT, and hs-CRP in patients with severe CAD. Additionally, sST2 levels were found to be elevated in patients with diabetes mellitus and chronic kidney disease.

Semaglutide improves contractile function in isolated human atrium

Abstract Background Recently, the results of the STEP-HFpEF trial were announced, in which high-dose treatment with the antidiabetic glucagon-like-peptide 1 agonist semaglutide resulted in a significant improvement of HFpEF-associated symptoms and reduction of NT-proBNP levels. Interestingly, treatment effects were independent of initial body weight and left-ventricular ejection fraction, sparking interest regarding the precise mechanism of action. Purpose We tested the effects of acute semaglutide treatment in isolated human right-atrial trabeculae. Methods Trabeculae were prepared from right atrial appendage biopsies from 32 patients undergoing elective coronary artery bypass grafting and/or valve surgery. Regular contractions were elicited by electrical field stimulation (1Hz, 5V/50ms, 37°C). Paired experiments were performed simultaneously per patient with a control group and one exposed to semaglutide (100 or 300nM). Developed tension was analysed at steady state after 30 min. Arrhythmias were defined as deviations from baseline not arising from electrical stimulation. L-type calcium channel blockade was achieved with nifedipine (2µM) in some experiments. Rapid cooling contraction was elicited to assess sarcoplasmic reticulum Ca2+ content (RCC1) by rapidly superfusing the trabeculae with chilled solution (2°C). After a short rewarming period of 10s to 37°C, RCC was repeated to assess the Na+/Ca2+ exchanger function (RCC2). Statistical analysis was conducted using paired t-test or Wilcoxon test as appropriate (for 2 groups) and one-way ANOVA with test for trend (for >2 groups). Results Exposure to semaglutide increased developed tension by over 3-fold in human atrial trabeculae in a dose-dependent manner: from 3.14±1.14 for control to 5.43±2.35mN/mm2 for 100nM semaglutide (p=0.03 vs. control) to 12.5±3.53 for 300nM semaglutide (p=0.004 vs. control, mean±SEM, fig. A-D, p=0.005 for linear trend). L-type calcium channel blockade with nifedipine blunted developed tension overall but did not abolish the effect of semaglutide (fig. E, p=0.02). In contrast, the developed tensions upon RCC1 and RCC2 were increased by semaglutide (300nM) compared to control, while the ratio of RCC2:RCC1 was elevated by semaglutide, indicating both increased SR Ca2+ reuptake and less external Ca2+ removal in the presence of semaglutide (fig. H-J). Relaxation time to 50% of baseline was unaltered (not shown), while relaxation time to 90% of baseline was mildly prolonged by semaglutide at 300 nM (fig. F). No increase in the rate of arrhythmias was observed by semaglutide treatment (fig. G). Conclusion Acute exposure of human atrial trabeculae to semaglutide results in a strong positive inotropic effect in a dose-dependent manner without increasing the propensity for arrhythmias. This effect is most likely due to increased SR Ca2+ reuptake. Treatment of heart failure patients with high-dose semaglutide can improve atrial function, which may ameliorate symptoms.

Serial quantitative stress perfusion cardiac magnetic resonance in patients undergoing coronary artery bypass grafting; prediction of symptomatic benefit

Abstract Background Serial multiparametric cardiovascular magnetic resonance (CMR) in patients undergoing coronary artery bypass grafting (CABG) may provide mechanistic insight into dynamic and persistent abnormalities of the myocardium in patients with stable coronary artery disease (CAD). Objectives To assess for dynamic CMR markers of myocardial hypoperfusion and cardiac remodelling in patients undergoing CABG. Methods Patients with CAD awaiting elective CABG were recruited into an observational cohort study. Baseline evaluation included bloods, Seattle Angina Questionnaire-7, and adenosine stress perfusion CMR. Automated fully quantitative stress and rest myocardial blood flow was calculated, alongside assessment of the visual ischaemic burden. Native and post-contrast septal T1 indices were also measured. Repeat evaluation at 6-12 months post CABG was performed. Results Of 43 patients who underwent serial evaluation with CMR (mean age 62.1±9.3, median LVEF 68% [IQR: 62-73%]), there was improvement in the median visual ischaemic burden (18% [IQR: 11-21] vs 42% [IQR: 27-51], P<0.001), mean global stress myocardial blood flow (1.5±0.5 ml/min/g vs 1.3±0.5 ml/min/g, P=0.002) and median global myocardial perfusion reserve (2.4 [IQR: 1.7-2.8] vs 1.7 [IQR: 1.4-2.2], P=0.002) following CABG. Greater improvement in the SAQ-7 summary score was associated with a larger visual ischaemic burden at baseline (ρ=0.44, P=0.004) and a greater decrease in the visual ischaemic burden following CABG (ρ=-0.38, P=0.02). Quantitative MBF metrics did not associate with baseline or change in SAQ-7 summary score. Mean LV extracellular matrix volume decreased following CABG (16.6±3.6ml/m2 vs 18.2±4.6ml/m2, P=0.009). Conclusion Multiparametric CMR identifies dynamic changes in markers of myocardial perfusion and interstitial fibrosis in patients following CABG. Visual assessment of inducible myocardial hypoperfusion may identify patients who will derive the most symptomatic benefit from CABG. The results, however, suggest an important degree of residual inducible ischaemia and an unclear clinical role for CMR-derived MBF calculations.Serial CMR perfusion dataAssociation of SAQ with perfusion

Evaluation of referral pathways for coronary artery bypass surgery patients; comparison on clinical outcomes, quality of life and process parameters

Objective To compare clinical outcomes, quality of life and process parameters of coronary artery bypass grafting (CABG) patients treated in a regional hub-and-spokes network. Methods Data from patients who underwent elective CABG from 2016 to 2020 at a Dutch heart center ('hub') were grouped by referral pathways by the cardiologist: internal (A) and four external (B–E). Clinical outcomes, quality of life, and process parameters were evaluated. Results In 690 CABG patients, no significant differences in baseline characteristics and clinical outcomes between care pathways were revealed. Hub-treated patients had shorter median hospital (7 days, IQR 6–8; p<.01) and preoperative stays (1 day, IQR 1–1; p<.01) compared to those treated at spokes. Within 8 weeks, 97.2% had outpatient visits, with pathways A, C, and E attending more frequently than B and D. Time to first visit ranged from 31–44 days. Cardiac rehabilitation began at 6 weeks for 40.4% of patients, with higher rates in Pathways B and D (66.4% and 50.0%) compared to the hub, C, and E (27.2% and 33.7%; p<0.001). Conclusion The study revealed notable variations in process parameters among different care pathways within a hub-and-spoke model for CABG patients, while maintaining comparable clinical outcomes and quality of life.

Thromboelastography with Platelet Mapping to Optimize Surgical Timing in Coronary Artery Bypass Grafting Patients on P2Y12 Receptor Blockers Therapy.

An increasing number of patients attending coronary artery bypass grafting (CABG) receive preoperative antiplatelet drugs (acetylsalicylic acid, clopidogrel, prasugrel, ticagrelor). The optimal assessment of preoperative platelet function is the aim of this study for a shorter surgical timing in patients undergoing elective coronary artery bypass grafting. This study was performed on patients presenting for first-time isolated CABG on therapy with an P2Y12 receptor blockers loading dose (clopidogrel [300 mg] or prasugrel [60 mg] or ticagrelor [180 mg]) or P2Y12 receptor blockers maintenance therapy at least for five days (clopidogrel [75 mg once daily], prasugrel [10 mg once daily], ticagrelor [90 mg twice daily]). All patients received simultaneously acetylsalicylate acid (100 mg daily). Exclusion criterion was emergency CABG regardless of preoperative antiplatelet and anticoagulant therapy. All patients' data were recorded in an Excel® file and analyzed using RStudio® software. Forty-eight consecutive adult patients presenting for CABG were enrolled. Preoperative thromboelastography-platelet mapping showed platelet resistance to P2Y12 blockers receptor - 25% for clopidogrel (6/24), 33% for ticagrelor (6/18), 33% for prasugrel (2/6), and this data was useful to obtain a shorter CABG waiting time in comparison with current guidelines (2.7 vs. five days for clopidogrel, 2.5 vs. five days for ticagrelor, 3.3 vs. seven days for prasugrel). Preoperative thromboelastography-platelet mapping is helpful to detect harmful P2Y12 receptor blockers resistance and to minimize CABG waiting time avoiding unnecessary and life-threatening delays.

Chronic postoperative pain syndrome and its neuropathic component in long-term period of coronary artery bypass grafting

Background: Along with increased safety and quality of the early postoperative period, 6.9% of patients who undergo sternotomy experience chronic pain at the surgical site. The significance of this issue is underestimated, with a third of these patients developing a neuropathic component of chronic pain syndrome. Aim: To assess the severity of acute and chronic postoperative pain following sternotomy and to identify predictors of the neuropathic component of chronic pain syndrome. Materials and methods: Out of 115patients who underwent elective coronary artery bypass grafting (CABG) randomized according to method of anesthesia, two study groups were formed based on the results of a telephone survey: a general anesthesia group (GA, n=28) and a combined anesthesia group (CA, n=34). As part of the posthoc analysis, a logistic regression model was built to predict chronic neuropathic pain syndrome based on gender, age, anesthesia method, and factors assessing the severity of the perioperative period and myocardial impairment. Results: Chronic postoperative pain syndrome was identified in 25.8% of patients, with a neuropathic component confirmed in 19.4% of cases. Pain severity at rest in the GA and CA groups was 2.0 (1.0) and 3.0 (3.0) points on a numeric rating scale one hour after extubation, and 2.0 (2.0) and 2.0 (2.0) points by the end of the first postoperative day (p=0.193 and 0.610, respectively). The logistic regression model achieved an AUROC of 0,82 (95% CI 0,68–0,96) with c2(10)=10.62, p=0.39. Conclusions: Neuropathic pain was diagnosed in 19.4% of patients following CABG. The use of regional anesthesia and the severity of acute pain did not impact the development of neuropathic pain syndrome in the long-term period after surgery. The proposed model for predicting the neuropathic component of chronic pain syndrome after CABG requires further improvement.

Characteristics of gene expression in epicardial adipose tissue and subcutaneous adipose tissue in patients at risk for heart failure undergoing coronary artery bypass grafting

BackgroundEpicardial adipose tissue (EAT) surrounds the heart and is hypothesised to play a role in the development of heart failure (HF). In this study, we first investigated the differences in gene expression between epicardial adipose tissue (EAT) and subcutaneous adipose tissue (SAT) in patients undergoing elective coronary artery bypass graft (CABG) surgery (n = 21; 95% male). Secondly, we examined the association between EAT and SAT in patients at risk for HF stage A (n = 12) and in pre-HF patients, who show signs but not symptoms of HF, stage B (n = 9).ResultsThe study confirmed a distinct separation between EAT and SAT. In EAT 17 clusters of genes were present, of which several novel gene modules are associated with characteristics of HF. Notably, seven gene modules showed significant correlation to measures of HF, such as end diastolic left ventricular posterior wall thickness, e’mean, deceleration time and BMI. One module was particularly distinct in EAT when compared to SAT, featuring key genes such as FLT4, SEMA3A, and PTX3, which are implicated in angiogenesis, inflammation regulation, and tissue repair, suggesting a unique role in EAT linked to left ventricular dysfunction. Genetic expression was compared in EAT across all pre-HF and normal phenotypes, revealing small genetic changes in the form of 18 differentially expressed genes in ACC/AHA Stage A vs. Stage B.ConclusionsThe roles of subcutaneous and epicardial fat are clearly different. We highlight the gene expression difference in search of potential modifiers of HF progress. The true implications of our findings should be corroborated in other studies since HF ACC/AHA stage B patients are common and carry a considerable risk for progression to symptomatic HF.

Coronary artery bypass grafting in octogenarians: a nomogram for predicting all-cause mortality

BackgroundThe benefits and risks of coronary artery bypass grafting (CABG) in octogenarians remain unclear. This study aimed to identify the predictors of increased risk of all-cause mortality in octogenarian patients after CABG.MethodsWe retrospectively analyzed the data of 1636 octogenarians who underwent isolated elective on-pump CABG between 2007 and 2016. The primary endpoint was mortality from any cause. The Kaplan–Meier curve was generated for mortality. A univariate Cox regression was performed for preprocedural and procedural variables. The Akaike information criterion (AIC) using the Cox proportional hazard model was applied to determine the strongest predictors. We designed a nomogram based on the selected variables to calculate the mortality risk after one, five, and ten years. The bootstrap resampling based on the C-index was performed to validate the final model. Calibration plots were created at different time points.ResultsThe mean age of the patients was 82.03 years (SD = 1.74), and 74% were male. In a median follow-up of 9.2 (95% CI 9.0,9.5) years, 626 (38.2%) patients died. After the selection of best predictors based on AIC, the multivariable Cox regression showed that ejection fraction < 40 (HR 1.41, 95% CI 1.21–1.65, P < 0.001), two-vessel disease (HR: 0.59, 95% CI 0.40–0.89, P = 0.012), peripheral vascular disease (HR 1.52, 95% CI 1.05–2.21, P = 0.027), and valvular heart disease (HR 1.45, 95% CI 1.24–1.69, P < 0.001) were the significant predictors of all-cause mortality.ConclusionOctogenarians who undergo CABG have a high mortality risk, influenced by several preprocedural and procedural risk factors. The proposed nomogram can be considered for optimizing the management of this vulnerable age group.Clinical registration number IR.TUMS.THC.REC.1400.081.Graphical abstract

Impact of preoperative diaphragmatic breathing exercise on postoperative oxygenation and hospital length of stay in patients with elective coronary artery bypass graft: A narrative review

Impact of preoperative diaphragmatic breathing exercise on postoperative oxygenation and hospital length of stay in patients with elective coronary artery bypass graft: A narrative review

Impact of Age on Ultrastructural Changes in Internal Thoracic Artery in Patients Undergoing Coronary Artery Bypass Grafting

AIM: Age is a known risk factor for cardiovascular disease and plays a role in the atherosclerotic process. The purpose of this study was to look at the impact of aging and associated risk factors on the ultrastructure of internal thoracic arteries in patients undergoing coronary artery bypass grafting. MATERIALS&amp;METHODS: We enrolled 27 patients undergoing elective coronary artery bypass grafting at our institute between August-October 2018. Age groups were classified into three: 50-59, 60-69, and 70-79 years. A 2-mm distal portion of the vessel was excised when the ITA was surgically harvested. Transmission electron microscopy was used to investigate the ultrastructural changes. Cell structure, tissue edema, and endothelial mitochondria were all assessed and rated by using semiquantitative analysis. RESULTS: The ultrastructure of the vessel wall exhibited no significant changes in Group-I. Endothelial wall irregularity with endothelial cells of varying thickness was seen in Group-II. Group-III showed subendothelial edema and localized endothelial wall discontinuity. These changes were particularly severe in the elderly and patients with comorbidities. The greatest permanent cell alterations, such as massive vacuoles and organelle loss, were identified in two patients with kidney failure and hypertension. The average scores assessing the severity of changes in endotohelial cell structure (P  .001), tissue edema (P  .001), and mitochondria (P  .001) were significantly different between groups showing more severe changes with aging. CONCLUSIONS: In elderly patients with comorbidities, the ITA endothelium may exhibit severe ultrastructural alterations, with the most permanent abnormalities reported in those with hypertension and kidney failure. However, The ITA remains the gold standard in CABG with its native resistance to atherosclerosis.

The relationship between tricuspid annular plane systolic excursion on transesophageal echocardiography and the incidence of postoperative acute kidney injury in patients undergoing coronary artery bypass grafting surgery: a multicenter prospective cohort study

BackgroundTo date, the relationship between the Transesophageal Echocardiography (TEE) monitoring indicator tricuspid annular plane systolic excursion (TAPSE) and the incidence of postoperative acute kidney injury (AKI) in Coronary Artery Bypass Grafting(CABG) patients remains unknown. The main objective of this study was to explore the relationship between the TAPSE and the incidence of AKI in CABG patients.MethodsThis was a multicenter prospective cohort study was conducted between September 2021 and July 2022. Among 266 patients aged at least 18 years who underwent elective CABG, 140 were included.ResultsWe measured TAPSE via M-mode TEE via the mid-esophageal (ME) right ventricle(RV) inflow-outflow view (60°). All echocardiographic measurements were performed three separate times at each time point: T0 (before the start of CABG), T2 (approximately 5 ∼ 10 min after neutralization of protamine) and T3 (before leaving the operating room), and then averaged. Serum creatinine was measured 1 day before and within 7 days after CABG. There was no statistically significant association between the TEE-monitoring indicator TAPSE and the incidence of postoperative AKI in patients who underwent CABG.ConclusionsThe TAPSE was not significantly correlated with postoperative AKI incidence and could not predict the early occurrence of postoperative AKI in CABG patients. TEE needs more evaluation for clinical efficacy of predicting the early occurrence of postoperative AKI in isolated CABG.

The oxytocin-oxytocin receptors system — a new pathogenetic mechanism in the development of diabetic phenotype of heart failure with preserved ejection fraction in women

Aim. To determine the pathogenetic role of the oxytocinergic system in the development of myocardium structural and functional changes in women with heart failure with preserved ejection fraction (HFpEF) associated with type 2 diabetes mellitus (DM2T) (diabetic phenotype of HFpEF).Material and methods. The study included 60 women aged 67.0±4.9 years with HFpEF stage I-IIA, FC I-III, 30 of them had DM2T who were admitted for elective coronary artery bypass grafting. The development of HFpEF is caused by coronary artery disease (CAD) and arterial hypertension (AH). Prior to surgery, all patients underwent a standard examination, blood levels of NT-proBNP, oxytocin (Ox), echocardiography were determined to find the types of left ventricular (LV) myocardial remodeling and diastolic dysfunction (DD). Myocardium biopsies of the right atrium auricle obtained during coronary bypass surgery were studied by microscopy, morphometry and immunohistochemistry (the expression of oxytocin receptors (OxR), a marker of proliferation ki-67).Results. According to echocardiography, eccentric LV hypertrophy (46.7/36.7%) and DD type 2 (47/17%, p=0.003) prevailed in the group of women with the diabetic phenotype of HFpEF. A higher content of NT-proBNP (480.72±241.87/434.46±282.78 ng/ml, p=0.06) and a lower concentration of Ox (102.11±35.89/320.37±294.71 pg/ml, p=0.0016) in blood serum were established, as well as an increase in the number of cardiomyocytes (CMC) with a high expression level OxR (63.69±19.47/12.16±23.09%, p=0.000) in patients with the diabetic phenotype of HFpEF. Negative associations were determined between the blood level of Ox and the CMC diameter (r=-0.10, p=0.020), the area of their cytoplasm (r=-0.16, p=0.000) and the area of the nuclei (r=-0.11, p=0.015) in patients of both groups. A decrease in Ox concentration in the blood of patients with diabetic phenotype of HFpEF was accompanied by an increase in the number of CMCs with a high level of OxR expression (r=-0.63, p=0.000).Conclusion. The study has shown the important involvement of oxytocinergic signaling pathways in the HFpEF pathogenesis. HFpEF associated with DM2T in women was characterized by more unfavorable structural and functional changes in the myocardium, a significant increase in the number of hypertrophied CMCs with a high level of OxR expression and Ox decrease in blood serum. The mechanisms of the first-established significant increase in the content of Ox in the blood of patients with HFpEF without diabetes and its significant decrease in patients with diabetic phenotype of HFpEF leading to more pronounced structural and functional changes in the myocardium, require further study.

Unlocking vascular vitality: Exploring the impact of LIMA harvesting technique on endothelial health

BackgroundThis study investigates the impact of different harvesting techniques on the morphology and endothelial function of the left internal mammary artery (LIMA) grafts in coronary artery bypass grafting (CABG). MethodsFifty-three patients undergoing elective CABG were randomly assigned to two groups based on the harvesting technique: traditional clipping and nonclipping. Histological analyses revealed that arteries in the nonclipped group exhibited greater dilation and preserved endothelial integrity compared to the control group. ResultsThe nonclipped group exhibited greater arterial dilation and preserved endothelial integrity compared to the clipped group. Immunostaining for endothelial nitric oxide synthase (eNOS) showed significantly higher expression in the nonclipped group, conversly COX-2 staining showed fewer expression in the nonclipped group indicating better endothelial function preservation. ConclusionThese findings suggest that maintaining perfusion during LIMA harvesting may improve endothelial function and potentially enhance graft patency in the long term. Further research is warranted to validate these results and optimize harvesting techniques for CABG procedures.

Left atrial appendage emptying velocity and left ventricular function as predictors of inotropic support in patients undergoing elective off-pump coronary artery bypass grafting

Abstract Background: Patients undergoing elective off-pump coronary artery bypass grafting (CABG) are at risk of hemodynamic instability, ischemia, arrhythmia, and dysfunction. These events need to be managed by pharmacological supports or relieving of mechanical obstruction (octopus) of the heart to maintain the hemodynamic stability. There is a paucity of data on the effect of left ventricular (LV) dysfunction on left atrial appendage (LAA) emptying velocity. We evaluated the relationship between LV function and LAA emptying velocity and requirement of inotropic support perioperatively. Materials and Methods: In this prospective open-label all-comer study, fifty patients undergoing elective off-pump CABG under general anesthesia, we measured LAA emptying velocity by pulsed wave Doppler and evaluated if it could predict the need for inotropes perioperatively. It is a case series of 50 patients without a comparator arm. We measured pulsed wave Doppler across the mitral valve leaflet and early mitral inflow velocity (Evel) and late mitral inflow velocity, tissue Doppler at the lateral annulus of the mitral valve (e’) and also calculated the ratio of Evel and e’. Need for inotrope in the intraoperative and postoperative period was captured perioperatively. Vasoactive-inotropic score (VIS) was calculated for all the patients. Results: The VIS was significant (P &lt; 0.0001, with odds ratio of 131.6 and confidence interval of 95% (0.9–1). However, there was no significant correlation between ejection fraction (EF) and VIS (P = 0.87). In patients with the need of inotropes, LAA emptying velocity was significantly increased in the postgrafting period as compared to the pregrafting period (75.64 cm/s vs. 57.9 cm/s, P &lt; 0.001). Conclusion: The assessment of LAA emptying velocity value was a useful predictor of the need of inotropic support during off-pump surgery, especially during Obtuse marginal and Ramus grafting. This study paves the need of larger case–control studies to validate the findings.

Comparison of Pulmonary Outcome in Minimally Invasive (TCRAT) and Full Sternotomy CABG.

Pulmonary complications are among the main causes of increased mortality, and morbidity, as well as prolonged intensive care unit (ICU) and hospital stay after cardiac surgery. Recently, a sternum-sparing concept of minimally invasive total coronary revascularization via anterior minithoracotomy (TCRAT) was introduced. A higher risk of pulmonary injury could be anticipated due to the thoracic incision and the longer duration of surgery. Pulmonary complications in TCRAT were compared to standard coronary artery bypass grafting (CABG) via full median sternotomy (FS). Records of 151 consecutive TCRAT (from September 2021 to November 2022) and 229 consecutive FS patients (from January 2017 to December 2018) patients, who underwent elective or urgent CABG, were analyzed. Preoperative baseline characteristics (age, sex, body mass index, diabetes, hypertension, chronic obstructive pulmonary disease, smoking status, left ventricular ejection fraction, pulmonary hypertonus, and EuroScore II) were comparable between groups. Differences between examined groups examined were found for the pulmonary parameters: Horowitz index 6 hours after operation (TCRAT 270 ± 72 vs. FS 293 ± 73, p < 0.05), pneumothorax (TCRAT 0% vs. FS 2.6%, p < 0.05), bronchoscopies (TCRAT 5.9% vs. FS 1.7%, p < 0.05), and pleural effusion (TCRAT 8.6% vs. FS 3.5%, p < 0.05). Moreover, there were differences between groups with regard to mean ICU stay (TCRAT 2.4 ± 3.0 days vs. FS 1.8 ± 1.8 days, p < 0.05), stroke (TCRAT 0% vs. FS 1.3%, p < 0.05), and hospital stay (TCRAT 10.9 ± 8.5 days vs. FS 13.2 ± 9.3 days, p < 0.05). There were no differences regarding atelectasis, reintubations, tracheostomies, ventilation time, and mortality. Pulmonary complications in terms of pleural effusions were more common with TCRAT, however, without substantial impact on clinical outcome.

To be or not to be on: aspirin and coronary artery bypass graft surgery.

Aspirin's role in secondary prevention for patients with known coronary artery disease (CAD) is well established, validated by numerous landmark trials over the past several decades. However, its perioperative use in coronary artery bypass graft (CABG) surgery remains contentious due to the delicate balance between the risks of thrombosis and bleeding. While continuation of aspirin in patients undergoing CABG following acute coronary syndrome is widely supported due to the high risk of re-infarction, the evidence is less definitive for elective CABG procedures. The literature indicates a significant benefit of aspirin in reducing cardiovascular events in CAD patients, yet its impact on perioperative outcomes in CABG surgery is less clear. Some studies suggest increased bleeding risks without substantial improvement in cardiac outcomes. Specific to elective CABG, evidence is mixed, with some data indicating no significant difference in thrombotic or bleeding complications whether aspirin is continued or withheld preoperatively. Advancements in pharmacological therapies and perioperative care have evolved significantly since the initial aspirin trials, raising questions about the contemporary relevance of earlier findings. Individualized patient assessments and the development of risk stratification tools are needed to optimize perioperative aspirin use in CABG surgery. Further research is essential to establish clearer guidelines and improve patient outcomes. The objective of this review is to critically evaluate the existing evidence into the optimal management of perioperative aspirin in elective CABG patients.

Risk stratification of postoperative atrial fibrillation in isolated off-pump coronary artery bypass grafting: focus on left atrial strain characteristics

Aim. To explore the potential of using left atrial strain parameters obtained through transthoracic speckle-tracking echocardiography for predicting new-onset postoperative atrial fibrillation (POAF) in patients undergoing off-pump coronary artery bypass grafting (CABG).Material and methods. The study included 111 patients with coronary artery disease referred for elective CABG. There were following exclusion criteria: recurrent or combined cardiac surgery, cerebral stroke, prior atrial tachyarrhythmia episodes, on-pump CABG, patients with NYHA class 4 heart failure. Patients included in the study underwent transthoracic speckle tracking echocardiography before surgery to assess the reservoir, conduit and contractile left atrial (LA) functions. After off-pump CABG, patients were prospectively observed until discharge from the hospital to record the primary end point — the first-time persistent POAF episode.Results. During follow-up, POAF was recorded in 11 patients (10%). The median endpoint registration was 4 days. The groups formed depending on the end point achievement were comparable in basic clinical and demographic characteristics and analyzed ultrasound parameters. In the majority of the patients studied, a decrease in LA function was detected. Disorders of the conduit (n=94, 85%) and reservoir functions (n=85) were dominant.Conclusion. The results obtained may indicate that there is no relationship between the LA myocardial strain parameters obtained during preoperative screening and the risk of POAF in patients with coronary artery disease who underwent off-pump CABG.

The Association of Cerebral Autoregulation Dysfunction and Postoperative Memory Impairment in Cardiac Surgery Patients.

Background and Objectives: Cardiac surgery is associated with various durations of cerebral autoregulation (CA) impairment and can significantly impact cognitive function. Cognitive functions such as memory, psychomotor speed, and attention are significantly impacted after cardiac surgery, necessitating prioritization of these areas in cognitive function tests. There is a lack of research connecting cerebral autoregulation impairment to specific cognitive function domains after cardiac surgery. This study aimed to determine if impaired cerebral autoregulation is associated with postoperative memory impairment and to test the hypothesis that the duration of this impairment affects the development of postoperative memory issues. Materials and Methods: A prospective study was conducted in 2021-2023. After approval of the Ethics Committee and with patient's written consent, 83 adult patients undergoing elective on-pump coronary artery bypass graft (CABG) surgery were enrolled. All patients were assessed for cognitive function 1 day before surgery using the Mini-Mental state examination (MMSE-2) test as a screening tool and the Hopkins Verbal Learning Test-Revised (HVLT-R) to assess memory specifically. To diagnose possible memory impairment (IM), all patients underwent a repeat assessment of cognitive function on the 7th-10th postoperative day. Cerebral autoregulation monitoring using transcranial Doppler was performed. Cerebral autoregulation status index (Mx) was recorded using Intensive Care Brain Monitoring System software, 9.1.5.23 (Cambridge, UK). Results: According to our research, the incidence of postoperative memory impairment is 30.1%. Temporary cerebral autoregulation impairment occurs in all patients undergoing elective in-pump CABG surgery. The duration of the single longest CA impairment event in seconds (LCAI) and the LCAI dose were higher in patients with postoperative memory impairment, p = 0.006 and p < 0.007, respectively. Conclusions: Cerebral autoregulation impairment is important in developing memory loss after cardiac surgery. The duration and dose of the LCAI event are predictive of postoperative memory impairment.