Robust Artificial Intelligence Tool for Atrial Fibrillation Diagnosis: Novel Development Approach Incorporating Both Atrial Electrograms and Surface ECG and Evaluation by Head-to-Head Comparison With Hospital-Based Physician ECG Readers.

BACKGROUND: Atrial fibrillation (AF) increases risk of embolic stroke, and in postoperative patients, increases cost of care. Consequently, ECG screening for AF in high-risk patients is important but labor-intensive. Artificial intelligence (AI) may reduce AF detection workload, but AI development presents challenges. METHODS AND RESULTS: We used a novel approach to AI development for AF detection using both surface ECG recordings and atrial epicardial electrograms obtained in postoperative cardiac patients. Atrial electrograms were used only to facilitate establishing true AF for AI development; this permitted the establishment of an AI-based tool for subsequent AF detection using ECG records alone. A total of 5 million 30-second epochs from 329 patients were annotated as AF or non-AF by expert ECG readers for AI training and validation, while 5 million 30-second epochs from 330 different patients were used for AI testing. AI performance was assessed at the epoch level as well as AF burden at the patient level. AI achieved an area under the receiver operating characteristic curve of 0.932 on validation and 0.953 on testing. At the epoch level, testing results showed means of AF detection sensitivity, specificity, negative predictive value, positive predictive value, and F1 (harmonic mean of positive predictive value and sensitivity) as 0.970, 0.814, 0.976, 0.776, and 0.862, respectively, while the intraclass correlation coefficient for AF burden detection was 0.952. At the patient level, AF burden sensitivity and positive predictivity were 96.2% and 94.5%, respectively. CONCLUSIONS: Use of both atrial electrograms and surface ECG permitted development of a robust AI-based approach to postoperative AF recognition and AF burden assessment. This novel tool may enhance detection and management of AF, particularly in patients following operative cardiac surgery.

Long-Term Results and Risk Factors of Treatment for Post-Infarction Ventricular Septal Rupture: A Single-Center Experience.

BACKGROUND: Ventricular septal rupture (VSR) following myocardial infarction (MI) is a rare but lethal complication. We analyzed the long-term results and risk factors for survival in the treatment of VSR. METHODS: From January 2012 to December 2021, 115 consecutive patients with post-MI VSR were admitted to our hospital. Depending on different treatment methods patients were divided into following three groups: medical, transcatheter intervention, and surgical repair. During the study, relevant clinical data, operation-related conditions, and follow-up data were analyzed. The Kaplan-Meier method and log-rank test were used to determine the cumulative incidence of mortality. The independent risk factors for patient mortality were evaluated by multivariate logistic regression. RESULTS: The mean follow-up time was 43.4 ± 34.7 months. The overall in-hospital, 30-day, and long-term mortality rates were 24.3%, 38.3%, and 51.3%, respectively. In the medical group, the in-hospital and 30-day mortality rates were 46.7 % (21/45) and 82.2 % (37/45), respectively, with only three patients alive at follow-up. In the transcatheter intervention group, 30-day and long-term mortality rates were 12% and 28%, respectively. In the surgical repair group, 30-day and long-term mortality rates were 8.9% and 22.2%, respectively. Compared with the surgery-group patients, patients with transcatheter intervention had a longer time from VSR to intervention. Logistic regression analysis revealed that age, previous infarction, Killip class, serum creatinine, Troponin T, N-terminal pro-B-type natriuretic peptide, and medical strategy were risk factors for all-cause mortality. CONCLUSIONS: The 30-day and long-term outcomes of patients treated with surgical repair and transcatheter intervention were significantly better than medically treated patients.

Gut Microbiota in Patients with Postoperative Atrial Fibrillation Undergoing Off-Pump Coronary Bypass Graft Surgery.

BACKGROUND: Post-operative atrial fibrillation (POAF) is one of the most common complications of cardiac surgery. However, the underlying mechanism is not well understood. Alterations in the gut microbiota are associated with the development of atrial fibrillation (AF). The aim of this study was to explore the relationship between gut microbiota and POAF. METHODS: Fecal samples were collected before surgery from 45 patients who underwent coronary artery bypass grafting with POAF and 90 matched patients without POAF (1:2). 16S rRNA sequencing was used to detect the microbiome profiles of 45 POAF patients and 89 matched patients (one sample in the no-POAF group was deleted owing to low quality after sequencing). Plasma 25-hydroxy vitamin D level was measured by ELISA. RESULTS: Compared to the patients without POAF, gut microbiota composition was remarkably changed in the patients with POAF, with an increase in Lachnospira, Acinetobacter, Veillonella and Aeromonas, and a decrease in Escherichia-Shigella, Klebsiella, Streptococcus, Brevundimonas and Citrobacter. Furthermore, plasma 25-hydroxy vitamin D levels were decreased in POAF patients and negatively correlated with an abundance of Lachnospira. CONCLUSIONS: The gut microbiota composition between patients with and without POAF is significantly different, implying that gut microbiota may play a role in the pathogenesis of POAF. Further studies are needed to fully clarify the role of gut microbiota in the initiation of AF.

Preventive Effect of Berberine on Postoperative Atrial Fibrillation.

BACKGROUND: Postoperative atrial fibrillation (POAF) is one of the most common complications of cardiac surgery, but the underlying factors governing POAF are not well understood. The aim of this study was to investigate the efficacy of berberine administration on POAF. METHODS: We conducted a randomized, double-blind, placebo-controlled trial with patients who underwent isolated coronary artery bypass grafting in China to study the impact of oral berberine on the incidence of POAF. A total of 200 patients who underwent coronary artery bypass grafting were randomized into the berberine group (n=100) and the placebo group (n=100). All patients underwent 7-day continuous telemetry and Holter monitoring. RESULTS: The primary outcome was the incidence of POAF at 7 days. Secondary outcomes included clinical outcomes, POAF burden, intestinal endotoxin, and serum inflammatory biomarker levels. The POAF incidence was reduced from 35% to 20% under berberine treatment (hazard ratio, 0.5 [95% CI, 0.29-0.78]; P=0.0143). Perioperative mortality and morbidity did not differ between the 2 groups. POAF burden and the dose of amiodarone were significantly reduced in the berberine group. Oral berberine significantly decreased lipopolysaccharide, CRP (C-reactive protein), and IL (interleukin)-6 levels. Elevated lipopolysaccharide after surgery has been associated with POAF. CONCLUSIONS: Our results showed that administration of berberine may be effective for reducing the occurrence of POAF after coronary artery bypass grafting. REGISTRATION: URL: https://www.chictr.org.cn; Unique identifier: ChiCTR2000028839.

Survival and risk factors associated with surgical repair of ventricular septal rupture after acute myocardial infarction: A single-center experience.

Objective: To analyze the survival and risk factors associated with the surgical treatment of ventricular septal rupture (VSR) after acute myocardial infarction (AMI). Methods: We retrospectively analyzed 45 consecutive patients with VSR after AMI whose procedures were performed in the Department of Cardiovascular Surgery at the General Hospital of Northern Theater Command between January 2012 and December 2021. Relevant clinical data, surgery-related conditions, and follow-up data of all patients were summarized. Patients were divided into the survival group and the death group. The Kaplan-Meier method and log-rank test were used to determine the cumulative incidence of all-cause mortality. Multivariate logistic regression was used to evaluate the independent risk factors for all-cause mortality. Results: The average postoperative follow-up time was 42.1 ± 34.1 months. The overall mortality rate was 20% (9/45 patients) and the operative mortality rate was 8.9% (4/45 patients). Logistic analysis showed that the death group had higher serum creatinine (127.32 ± 47.82 vs. 82.61 ± 27.80 µmol/L, respectively; P = 0.0238) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) [8,654.00 pg/mL (6,197.00-11,949.00 pg/mL) vs. 4,268.96 pg/mL (1,800.00-7,894.00 pg/mL), respectively; P = 0.0134] levels than the survival group. The cardiopulmonary bypass time (CPB) was longer in the death group than in the survival group [131.00 min (121.00-184.00 min) vs. 119.00 min (103.00-151.50 min), respectively; P = 0.0454]. Significantly more red blood cells were transfused in the death group than in the survival group [11.60 units (6.10-16.50) vs. 3.75 units (0.00-7.00 units), respectively; P = 0.0025]. Intra-aortic balloon pump (IABP) implantation (P = 0.016) and ventilation time (P = 0.0022) were risk factors for mortality. A 1-month landmark analysis showed that compared with patients with VSR to surgical time >14 days, patients who underwent surgery within 14 days had a higher rate of all-cause mortality (25.00 vs. 3.33%; log-rank P = 0.023). Patients with VSR within 14 days also had a higher rate of residual shunts that were higher than moderate. Multivariate analysis showed that transfusion of red blood cells and NT-proBNP level were risk factors for all-cause mortality, as well as major adverse cardiovascular and cerebrovascular events. Conclusions: Surgical repair resulted in good outcomes for patients with VSR after AMI. Patients with VSR to surgical time >14 days had a lower rate of all-cause mortality. Treatment strategies for VSR should be based on the patient's condition and comprehensively determined through real-time evaluation and monitoring.

Leptin Alleviates Inflammatory Response in Myocardial Ischemia Reperfusion Injury.

Objective: To investigate the role of leptin in regulating cell inflammation and protecting myocardium after myocardial ischemia-reperfusion injury in rats through signaling pathway at tissue and molecular protein levels. Methods: Healthy female SD rats were randomly divided into 4 groups, which were sham, I/R group, leptin low-dose intervention group, and high-dose intervention group (40 µg/kg and 80 µg/kg, respectively). Cardiac hemodynamics, myocardial enzymology, inflammatory indices, and pathological changes were observed. Western blot was used to observe the expression of PI3K, AKT, and NFκB protein by leptin. Results: Leptin can improve the hemodynamics of cardiac ischemia-reperfusion rats, improve the expression of myocardial enzymology, reduce the release of cardiac and serum inflammatory factors, increased PI3k, AKT, and NFκB expression, and reduce the occurrence of inflammation from the perspective of gross pathology, thus protecting the body. Conclusion: Leptin pretreatment can reduce MIRI injury, and the protective mechanism may be that leptin upregulates PI3K-AKT-NFκB expression in myocardial tissue to reduce inflammation and promote repair of I/R injury.

The Effect of Acute Kidney Injury on TGF-ß1 and Smad3 in Patients with Coronary Heart Disease after Off-Pump Coronary Artery Bypass Grafting.

Background: Acute kidney injury (AKI) is one of the most common and serious complications for coronary disease (CAD) patients, suffering from coronary artery bypass surgery (CABG). AKI occurs in nearly 30% of cardiac surgery patients, including CABG patients, affecting renal function, prolonging hospitalization time, and increasing all-cause mortality. TGF-ß1 and Smad3 are sensitive biomarkers in evaluating kidney function. Therefore, comparing the TGF-ß1 and Smad3 levels between the AKI patients and non-AKI patients after CABG surgery might have an important significance for identifying the risk degree of AKI and applying effective preventive measures after CABG surgery. Objective: This study aims at comparing the TGF-ß1 and Smad3 levels between the AKI patients and non-AKI patients after CABG surgery to identify the risk degree of AKI and apply effective preventive measures after CABG surgery in clinics. Materials and Methods: A total of 25 proper patients, diagnosed as coronary disease (CAD) and undergoing AKI after CABG, were selected as the AKI group. The 25 participants, who did not suffer from AKI after CABG, were recruited using the case-control matching method in SPSS 25.0 software as the non-AKI group. Also, corresponding surgical specimens (tissues) and samples of blood were collected from them. Histopathological analysis and immunofluorescent microscopy of lesion artery and kidney of patients, who have been treated with kidney transplants, were performed on surgical specimens to find the pathological and histological change difference between the two groups. RT-PCR and Western blot were conducted to quantify the levels of TGF-ß1 and Smad3 expression in serum for the patients of AKI and non-AKI groups, respectively. Results: Serious renal fibrosis was noted in patients of the AKI group. In addition, by H&E staining of the lesion artery, severe histopathological changes including smooth muscles proliferation with endothelial cell infiltration, focal degeneration and disruptions, and less collagen accumulation were found in the lesion artery of patients from the AKI group. Higher levels of TGF-ß1 and Smad3 were observed in serum of patients of the AKI group. Conclusion: : The increased levels of TGF-ß1 and Smad3 in serum might be risk factors for triggering AKI for CAD patients undergoing CABG.

Calcium-Induced Autonomic Denervation in Patients With Post-Operative Atrial Fibrillation.

BACKGROUND: Post-operative atrial fibrillation (POAF) is associated with worse long-term cardiovascular outcomes. OBJECTIVES: This study hypothesized that injecting calcium chloride (CaCl2) into the major atrial ganglionated plexi (GPs) during isolated coronary artery bypass grafting (CABG) can reduce the incidence of POAF by calcium-induced autonomic neurotoxicity. METHODS: This proof-of-concept study randomized 200 patients undergoing isolated, off-pump CABG to CaCl2 (n = 100) or sodium chloride (sham, n = 100) injection. Two milliliters of CaCl2 (5%) or sodium chloride (0.9%) was injected into the 4 major atrial GPs during CABG. All patients received 7-day continuous telemetry and Holter monitoring. The primary outcome was incidence of POAF (≥30 s) in 7 days. Secondary outcomes included length of hospitalization, POAF burden, average ventricular rate during AF, plasma level of inflammatory markers, and actionable antiarrhythmic therapy to treat POAF. RESULTS: The POAF incidence was reduced from 36% to 15% (hazard ratio: 0.366; 95% confidence interval: 0.211 to 0.635; p = 0.001). Length of hospitalization did not differ between the 2 groups. POAF burden (first 7 post-operative days), the use of amiodarone or esmolol, and the incidence of atrial couplets and nonsustained atrial tachyarrhythmias were significantly reduced in the CaCl2 group. Heart rate variability data showed a decrease in both high-frequency and low-frequency power in the CaCl2 group with a preserved low-frequency/high-frequency ratio, suggesting that the sympathetic/parasympathetic balance was not perturbed by CaCl2 injection. CONCLUSIONS: Injection of CaCl2 into the 4 major atrial GPs reduced the POAF hazard by 63%. Inhibition of GP function by Ca-mediated neurotoxicity may underlie the therapeutic effect. (Calcium Autonomic Denervation Prevents Postoperative Atrial Fibrillation; ChiCTR1800019276).

Blockade of the Notch Signaling Pathway Promotes M2 Macrophage Polarization to Suppress Cardiac Fibrosis Remodeling in Mice With Myocardial Infarction.

Myocardial infarction (MI) is regarded as a serious ischemic heart disease on a global level. The current study set out to explore the mechanism of the Notch signaling pathway in the regulation of fibrosis remodeling after the occurrence of MI. First, experimental mice were infected with recombination signal binding protein J (RBP-J) shRNA and empty adenovirus vector, followed by the establishment of MI mouse models and detection of cardiac function. After 4 weeks of MI, mice in the sh-RBP-J group were found to exhibit significantly improved cardiac function relative to the sh-NC group. Moreover, knockdown of RBP-J brought about decreased infarct area, promoted cardiac macrophages M2 polarization, reduced cardiac fibrosis, and further decreased transcription and protein expressions of inflammatory factors and fibrosis-related factors. Furthermore, downregulation of cylindromatosis (CYLD) using si-CYLD reversed the results that knockdown of RBP-J inhibited fibrogenesis and the release of inflammatory factors. Altogether, our findings indicated that the blockade of Notch signaling promotes M2 polarization of cardiac macrophages and improves cardiac function by inhibiting the imbalance of fibrotic remodeling after MI.

Surgical Management of Severe Ischaemic Mitral Regurgitation.

BACKGROUND: Coronary artery bypass graft surgery (CABG) with mitral valve surgery is undisputed in severe ischaemic mitral regurgitation (IMR) treatment, but the controversy is whether mitral valve replacement (MVR) or mitral valvuloplasty (MVP) should be used. METHODS: Data was collected from 130 cases of severe IMR patients who underwent CABG and MVP or MVR from June 2010 to June 2015 to compare the short-term efficacy of CABG with MVP or MVR in the treatment of severe IMR patients. There were 70 cases in the MVP group and 60 in the MVP group. The postoperative major cardiac cerebral vascular events and left ventricular ejection fraction (LVEF), left ventricular end-systolic diameter (LVESD), and left ventricular end-diastolic diameter (LVEDD) were recorded. RESULTS: Eleven patients died in hospital, the remaining patients were followed up for 12 months; 18 patients died. The cumulative survival rate and the major cardiac cerebrovascular events were not significantly different. There was no significant change in LVEF, but LVEDD, LVESD and systolic pulmonary artery pressure (sPAP) improved significantly, and there was no difference between the groups. In the MVR group, the rate of postoperative moderate or severe mitral regurgitation patients was significantly less than that in the MVP group. CONCLUSION: The short-term survival rate, reversal of left ventricular remodelling and major cardiac or cerebrovascular events post-CABG combined with MVP were not significantly different to those with CABG combined with MVR in the treatment of severe IMR, but long-term efficacy remains to be observed.

Multiple factors analysis on the recovery of left ventricular ejection fraction in the revascularized patients with ischaemic cardiomyopathy / 中国胸心血管外科临床杂志

@#Objective We probed how to predict left ventricular ejection fraction (LVEF) of the ischaemic cardiomyopathy (ICM) patients would be improved apparently after revascularization. Methods Between July 2010 and December 2015, 245 ICM patients (30%≤LVEF≤40%) with coronary bypass grafting (CABG) were retrospectively observed. Among them, 146 patients were accompanied by ischemic mitral regurgitation (IMR) (146/245, 59.6%), and 41 patients underwent mitral valvuloplasty or replacement because of more than moderate IMR. There were 13 patients early death, and other 232 patients who were followed up over 6 months were divided into two groups based on whether or not post-operative LVEF increased by 10%: a LVEF recovered group (group A, 124 patients) and a non-recovered group (group B, 108 patients). Results Preoperative NT-proBNP in the group A was significantly higher than that in the group B (P=0.036). There were less patients with myocardial infarction in the group A than that in the group B (P=0.047), and more with angina pectoris in the group A than that in the group B (P=0.024). There was no significant difference in the extent of mitral regurgitation or mitral surgery between the groups A and B (P>0.05). There were lower left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic volume (LVEDV) in the group A than those in the group B (P<0.05). Multivariate analysis revealed that preoperative LVEDD dilated apparently and no angina pectoris existed before surgery were independent risk factors for LVEF with no recovery in the ICM patients (30%≤LVEF≤40%) after revascularization. The LVEDD of 245 patients (including 13 early deaths) was 41-71 mm. We found that the ICM patients with LVEDD ≥60 mm were more likely to signify the unfavourable prognosis (χ2=8.63, P=0.003, OR=2.21, 95% confidence interval 1.25 to 3.91). Conclusion Preoperative LVEDD dilated and no angina pectoris before surgery are independent risk factors for LVEF with no recovery in the ICM patients (30%≤LVEF≤40%) after revascularization. LVEDD≥60 mm can be regarded as the preoperative forecasting factors for the unfavourable prognosis in the ICM patients (30%≤LVEF≤40%) after revascularization.

The evaluation of preoperative right ventricular diastolic dysfunction on coronary artery disease patients with left ventricular dysfunction.

OBJECTIVE: Early death following coronary artery bypass graft (CABG) surgery tends to occur in coronary heart disease (CHD) patients with significantly decreased left ventricular function. METHODS: The clinical data of 231 patients with preoperative left ventricular ejection fraction (LVEF) ≤ 35% who underwent CABG were retrospectively analyzed from June 2007 to October 2012. The patients were divided into 2 groups: group A contained 39 patients who suffered early postoperative death and group B contained 192 patients who had a successful CABG outcome. RESULTS: Multivariate analysis demonstrated that only significantly decreased preoperative right ventricular (RV) diastolic function (increase in Et/Et') and lack of suitable target bypass vessels were independent risk factors for early death after CABG surgery in patients with severely impaired left ventricular function (P = 0.003 and 0.002, respectively). Other factors, including age, intra-aortic balloon pump (IABP) implantation, ischemic mitral regurgitation (IMR) treatment, left atrial internal diameter, and end-diastolic left ventricular internal diameter, were not associated with early death following CABG. Preoperative Et/Et' ≥ 10 was significantly associated with early death after CABG in patients with severely impaired left ventricular function (χ(2) = 11.55, P < 0.001, odds ratio [OR] = 17.54, 95% confidence interval [CI]: 2.12-383.16). CONCLUSION: Decreased preoperative RV diastolic function and lack of suitable target bypass vessels are independent risk factors for early death following CABG in patients with severely impaired left ventricular function. Therefore, assessment of preoperative RV diastolic function will be helpful in predicting early death after CABG in these patients. Additionally, Et/Et' ≥ 10 is significantly associated with early death after CABG.