Incidence and risk factors for new-onset atrial fibrillation following coronary artery bypass grafting: A systematic review and meta-analysis

Intestinal Microbiota and Derived Metabolites in Myocardial Fibrosis and Postoperative Atrial Fibrillation

The high incidence of atrial fibrillation (AFib) following cardiac surgery (postoperative atrial fibrillation, POAF) relies on specific surgical features. However, in the setting of POAF, the role of the microbiome in the modulation of cardiac fibrosis is still not clear. This study aimed to analyze the effect of the microbiome and its main metabolic product (trimethylamine-N-oxide, TMAO) in the fibrosis of myocardial tissue, to investigate its role in POAF. Patients undergoing elective cardiac surgery with cardiopulmonary bypass, central atrio-caval cannulation and no history of AFib, were included. A fragment of the right atrium was analyzed for qualitative and mRNA-quantitative evaluation. A preoperative blood sample was analyzed with enzyme-linked immunosorbent assay (ELISA). A total of 100 patients have been included, with POAF occurring in 38%. Histologically, a higher degree of fibrosis, angiogenesis and inflammation has been observed in POAF. Quantitative evaluation showed increased mRNA expression of collagen-1, collagen-3, fibronectin, and transforming growth factor beta (TGFb) in the POAF group. ELISA analysis showed higher levels of TMAO, lipopolysaccharide and TGFb in POAF, with similar levels of sP-selectin and zonulin. TMAO ≥ 61.8 ng/mL (odds ratio, OR 2.88 [1.35-6.16], p = 0.006), preoperative hemoglobin < 13.1 g/dL (OR 2.37 [1.07-5.24], p = 0.033) and impaired right ventricular function (OR 2.38 [1.17-4.83], p = 0.017) were independent predictors of POAF. Also, TMAO was significantly associated with POAF by means of increased fibrosis. Gut microbiome product TMAO is crucial for myocardial fibrosis, which is a key factor for POAF. Patients in preoperative sinus rhythm who will develop POAF have increased genetic expression of pro-fibrotic genes and enhanced fibrosis in histological staining. Elevated TMAO level (≥61.8 ng/mL) is an independent risk factor for POAF.

Predictive Capability of Metabolic Panels for Postoperative Atrial Fibrillation in Cardiac Surgery Patients

INTRODUCTION

Postoperative atrial fibrillation (POAF) occurs in up to 65% of cardiac surgery patients and is associated with an increased risk for stroke and mortality. Electrolyte disturbances in sodium (Na+), potassium (K+), total calcium (Ca2+), chloride (Cl-), and magnesium (Mg2+) are predisposing factors for POAF, but these imbalances are yet to be used to predict POAF. The purpose of this study is to determine whether the development of POAF can be predicted by blood plasma ionic composition.

METHODS

Metabolic panels of patients with no prior history of atrial fibrillation who did (n = 763) and did not develop POAF (n = 2144) after cardiac surgery were obtained from the Carilion Clinic electronic medical record system. We initially evaluated serum Na+, K+, Ca2+, Cl-, and Mg2+ in the two groups using descriptive statistics via scatter and spaghetti plots and then with predictive modeling via logistic regression and random forest models.

RESULTS

Neither scatter nor spaghetti plots of electrolyte data revealed a significant difference between those who did and did not develop POAF. Two logistic regression models and two random forest models with POAF status as the outcome were generated using the first observation for each electrolyte and the coefficient of the linear regression, which was obtained from a linear fit of the scatter plot. The random forest model using the first observation had a sensitivity of only 12.2%, but all four models had specificities more than 97%.

CONCLUSIONS

Neither of the two logistic regression nor two random forest models were able to effectively predict the development of POAF from plasma ionic concentrations, but the random forest models effectively classified patients who would not develop POAF.

A Genotype-Phenotype Analysis of Glutathione Peroxidase 4 in Human Atrial Myocardium and Its Association with Postoperative Atrial Fibrillation

Heterogeneity in the incidence of postoperative atrial fibrillation (POAF) following heart surgery implies that underlying genetic and/or physiological factors impart a higher risk of this complication to certain patients. Glutathione peroxidase-4 (GPx4) is a vital selenoenzyme responsible for neutralizing lipid peroxides, mediators of oxidative stress known to contribute to postoperative arrhythmogenesis. Here, we sought to determine whether GPX4 single nucleotide variants are associated with POAF, and whether any of these variants are linked with altered GPX4 enzyme content or activity in myocardial tissue. Sequencing analysis was performed across the GPX4 coding region within chromosome 19 from a cohort of patients (N = 189) undergoing elective coronary artery bypass graft (−/+ valve) surgery. GPx4 enzyme content and activity were also analyzed in matching samples of atrial myocardium from these patients. Incidence of POAF was 25% in this cohort. Five GPX4 variants were associated with POAF risk (permutated p ≤ 0.05), and eight variants associated with altered myocardial GPx4 content and activity (p < 0.05). One of these variants (rs713041) is a well-known modifier of cardiovascular disease risk. Collectively, these findings suggest GPX4 variants are potential risk modifiers and/or predictors of POAF. Moreover, they illustrate a genotype−phenotype link with this selenoenzyme, which will inform future mechanistic studies.

Resting heart rate as a preoperative predictor of postoperative atrial fibrillation after pulmonary thromboendarterectomy

BACKGROUND

As a marker of the autonomic nervous system, resting heart rate is a predictor of postoperative atrial fibrillation (POAF). However, its predictive value for POAF after pulmonary thromboendarterectomy (PTE) has not been adequately studied.

METHODS

We enrolled 97 patients who underwent PTE in our hospital from December 2016 to November 2021 in this retrospective study. Almost all preoperative characteristics, including electrocardiogram, demographics, hematologic and biochemical indices, echocardiography, and pulmonary hemodynamics, were compared between patients with and without POAF. Multivariate logistic regression analysis was used to identify the independent risk factors for POAF after PTE.

RESULTS

Overall, 21 patients (21.6%) suffered from POAF after PTE. Compared with patients without POAF, those with POAF were older (p = .049), with a higher resting heart rate (p = .012), and higher platelet count (p = .040). In the binary logistic regression analysis, the resting heart rate (odds ratio [OR] = 1.043, 95% confidence interval [CI] = 1.009-1.078, p = .012) and age (OR = 1.051, 95% CI = 1.003-1.102, p = .037) were independent risk factors for POAF after PTE. The optimal cutoff point of resting heart rate was 89.5 with sensitivity and specificity of 47.6% and 77.6%. When the cutoff value of the age was 54.5, its sensitivity for predicting POAF was 71.4%, with a specificity of 59.2%.

CONCLUSIONS

POAF is common after PTE surgery, and the incidence may be underestimated. The resting heart rate and age are independent preoperative risk factors for POAF after PTE. Considering the lower predictive power of the resting heart and age, further large-scale studies are needed.

Prevalence and impact of diabetes in hospitalized COVID-19 patients: A systematic review and meta-analysis

BACKGROUND

Diabetes is a cardiometabolic comorbidity that may predispose COVID-19 patients to worse clinical outcomes. This study sought to determine the prevalence of diabetes in hospitalized COVID-19 patients and investigate the association of diabetes severe COVID-19, rate of acute respiratory distress syndrome (ARDS), mortality, and need for mechanical ventilation by performing a systematic review and meta-analysis.

METHODS

Individual studies were selected using a defined search strategy, including results up until July 2021 from PubMed, Embase, and Cochrane Central Register of Controlled Trials. A random-effects meta-analysis was performed to estimate the proportions and level of association of diabetes with clinical outcomes in hospitalized COVID-19 patients. Forest plots were generated to retrieve the odds ratios (OR), and the quality and risk assessment was performed for all studies included in the meta-analysis.

RESULTS

The total number of patients included in this study was 10 648, of whom 3112 had diabetes (29.23%). The overall pooled estimate of prevalence of diabetes in the meta-analysis cohort was 31% (95% CI, 0.25-0.38; z = 16.09, P < .0001). Diabetes significantly increased the odds of severe COVID-19 (OR 3.39; 95% CI, 2.14-5.37; P < .0001), ARDS (OR 2.55; 95% CI, 1.74-3.75; P = <.0001), in-hospital mortality (OR 2.44; 95% CI, 1.93-3.09; P < .0001), and mechanical ventilation (OR 3.03; 95% CI, 2.17-4.22; P < .0001).

CONCLUSIONS

Our meta-analysis demonstrates that diabetes is significantly associated with increased odds of severe COVID-19, increased ARDS rate, mortality, and need for mechanical ventilation in hospitalized patients. We also estimated an overall pooled prevalence of diabetes of 31% in hospitalized COVID-19 patients.

Association of Atrial Fibrillation With Patient Characteristics in Postoperative Coronary Artery Bypass Grafting Surgery

Introduction Atrial fibrillation (AF) after coronary artery bypass grafting (CABG) is correlated with poor patient outcomes. The study evaluated the association of patients' clinical and sociodemographic characteristics with the incidence of atrial fibrillation, postoperatively.  Methodology A longitudinal study was performed in the cardiology department of a tertiary care unit, Sindh, Pakistan between October 2019 and November 2020. All patients who underwent CABG surgery irrespective of gender aged 30 to 75 years were included in the study. Patients with a history of atrial fibrillation or severe left ventricular dysfunction were excluded from the study. The incidence of atrial fibrillation was determined by observing an irregular pattern on electrocardiography (ECG) with no definite P-wave and irregular R-R interval. The patients were monitored for seven postoperative days. The final outcome was measured on the seventh postoperative day.  Results A total of 247 patients with a mean age of 63.43 ± 9.72 were enrolled in the study. Out of the 247 patients, 9.7% developed new-onset atrial fibrillation, postoperatively. Age above 65 years was associated with the occurrence of AF but it was not statistically significant (p>0.05). Similarly, patients who developed AF were more likely to have a left ventricle ejection fraction (LVEF) of less than 35% than those without AF (66.67% vs 43.95%; p=0.033).  Conclusion A high rate of AF was observed in the study. Older age and impaired ventricular function were significantly associated with atrial fibrillation. It is recommended that hospitals should devise guidelines and protocols for the prevention and management of atrial fibrillation in patients undergoing cardiothoracic surgeries in order to minimize patient mortality and improve patient outcomes.

Perioperative risk factors for new-onset postoperative atrial fibrillation among patients after isolated coronary artery bypass grafting: A retrospective study

AIMS

Incidence of atrial fibrillation is considerably high after open heart surgery, which may prolong hospitalization and increase mortality. The aim of the present study is to investigate the perioperative risk factors for the occurrence of new-onset atrial fibrillation following isolated coronary artery bypass grafting.

DESIGN

A retrospective study.

METHODS

A total of 327 Korean patients recorded to have undergone first-time isolated coronary artery bypass grafting and no preoperative history of atrial fibrillation were included. The data were obtained from electronic health record from January 2010 to December 2019 at a tertiary care hospital. Predictors of new-onset atrial fibrillation after the surgery were identified by multivariate logistic regression analysis.

RESULTS

The incidence rate of new-onset atrial fibrillation after coronary artery bypass grafting was approximately 28.4%, and the highest occurrence rate was 44.1% on postoperative day 2. Our main finding showed that advanced age was the strongest predictor of atrial fibrillation after coronary artery bypass grafting. In addition, history of stroke and depression, chronic obstructive pulmonary disease and intraoperative use of intra-aortic balloon pump were shown to be the risk factors.

CONCLUSION

Our findings showed that approximately 28% patients had new-onset atrial fibrillation after the surgery. Healthcare professionals should proactively assess risk factors for postoperative atrial fibrillation and focus more on older adults with pre-existing comorbidities, such as stroke, depression and chronic obstructive pulmonary disease.

IMPACT

Older adults with history of stroke, depression and comorbid chronic obstructive pulmonary disease should be carefully monitored closely during perioperative period. The study highlights that early assessment of new-onset postoperative atrial fibrillation can contribute to promote the quality of nursing care and frontline nurses may be a vital role in timely detection of atrial fibrillation after surgery. Prospective studies are required to identify the mechanisms connecting perioperative risk factors for atrial fibrillation after cardiac surgery.

Perioperative risk factors for new-onset postoperative atrial fibrillation after coronary artery bypass grafting: a systematic review

Background

Postoperative atrial fibrillation (POAF) is the most common cardiac dysrhythmia to occur after coronary artery bypass grafting (CABG). However, the risk factors for new-onset POAF after CABG during the perioperative period have yet to be clearly defined. Accordingly, the aim of our systematic review was to evaluate the perioperative predictors of new-onset POAF after isolated CABG.

Method

Our review methods adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. We searched seven electronic databases (PubMed, Embase, CINAHL, PsycArticles, Cochrane, Web of Science, and SCOPUS) to identify all relevant English articles published up to January 2020. Identified studies were screened independently by two researchers for selection, according to predefined criteria. The Newcastle–Ottawa Scale was used to evaluate the quality of studies retained.

Results

After screening, nine studies were retained for analysis, including 4798 patients, of whom 1555 (32.4%) experienced new-onset POAF after CABG. The incidence rate of new-onset POAF ranged between 17.3% and 47.4%. The following risk factors were identified: old age (p < 0.001), a high preoperative serum creatinine level (p = 0.001), a low preoperative hemoglobin level (p = 0.007), a low left ventricle ejection fraction in Asian patients (p = 0.001), essential hypertension (p < 0.001), chronic obstructive pulmonary disease (p = 0.010), renal failure (p = 0.009), cardiopulmonary bypass use (p = 0.002), perfusion time (p = 0.017), postoperative use of inotropes (p < 0.001), postoperative renal failure (p = 0.001), and re-operation (p = 0.005). All studies included in the analysis were of good quality.

Conclusions

The risk factors identified in our review could be used to improve monitoring of at-risk patients for early detection and treatment of new-onset POAF after CABG, reducing the risk of other complications and negative clinical outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02224-x.

Dose-response relationship among body mass index, abdominal adiposity and atrial fibrillation in patients undergoing cardiac surgery: a meta-analysis of 35 cohorts

Background

Whether overweight increases the risk of postoperative atrial fibrillation (POAF) is unclear, and whether adiposity independently contributes to POAF has not been comprehensively studied. Thus, we conducted a meta-analysis to clarify the strength and shape of the exposure-effect relationship between adiposity and POAF.

Methods

The PubMed, Cochrane Library, and EMBASE databases were searched for revelant studies (randomized controlled trials (RCTs), cohort studies, and nest-case control studies) reporting data regarding the relationship between adiposity and the risk of POAF.

Results

Thirty-five publications involving 33,271 cases/141,442 patients were included. Analysis of categorical variables showed that obesity (RR: 1.39, 95% CI [1.21–1.61]; P < 0.001), but not being underweight (RR: 1.44, 95% CI [0.90–2.30]; P = 0.13) or being overweight (RR: 1.03, 95% CI [0.95–1.11]; P = 0.48) was associated with an increased risk of POAF. In the exposure-effect analysis (BMI) was 1.09 (95% CI [1.05–1.12]; P < 0.001) for the risk of POAF. There was a significant linear relationship between BMI and POAF (P_nonlinearity = 0.44); the curve was flat and began to rise steeply at a BMI of approximately 30. Notably, BMI levels below 30 (overweight) were not associated with a higher risk of POAF. Additionally, waist obesity or visceral adiposity index was associated with the risk of POAF.

Conclusion

Based on the current evidence, our findings showed that high body mass index or abdominal adiposity was independently associated with an increased risk of POAF, while underweight or overweight might not significantly increase the POAF risk.