Biochemical predictors of postoperative atrial fibrillation following cardiac surgery

Sex-Specific Cardiometabolic Determinants of Postoperative Atrial Fibrillation After Cardiac Surgery

BACKGROUND

Cardiometabolic diseases increase the risk of postoperative atrial fibrillation (POAF), a complication leading to higher long-term risk of major cardiovascular events (MACE). It remains unknown whether the effect of these risk factors differs according to sex. We sought to evaluate the sex-specific predictors of POAF after coronary artery bypass grafting (CABG).

METHODS

In a prospective registry of patients undergoing isolated CABG, we compared predictors of POAF between sexes with logistic regression models. Because of high prevalence of abdominal obesity in women, > 80% having a waist circumference (WC) ≥ 88 cm, median WC values were used to define abdominal obesity (men ≥ 102 cm, women ≥ 100 cm).

RESULTS

This analysis included 6177 individuals (17% women). Mean age was 65.6 ± 8.9 years. POAF occurred in 32% of men and 28% of women (P < 0.05). Compared with men, women with POAF had similar WC; higher prevalence of hypertension and diabetes; lower high-density lipoprotein (HDL)-cholesterol; and higher glucose, triglyceride, low- density lipoprotein (LDL)-cholesterol, and C-reactive protein levels (all P < 0.05). After adjustment, age and abdominal obesity were associated with POAF in both sexes (P < 0.05). The interaction of WC with sex suggested a worse impact of WC on POAF risk among women (adjusted odds ratio [OR], 1.97; 95% confidence interval [CI], 1.48-2.62 vs in men 1.33; 95% CI, 1.17-1.50; P for interaction = 0.01).

CONCLUSIONS

Abdominal obesity is a major predictor of POAF in both sexes, with higher risk in women. These results emphasize the need for enhanced strategies to manage abdominal obesity and its cardiometabolic consequences in the general population and the potential to develop sex-specific preventive interventions to reduce risk of POAF.

The association of hemoglobin with postoperative delirium and atrial fibrillation after cardiac surgery: a retrospective sub-study

BACKGROUND

Most cardiac surgery patients experience postoperative anemia. Delirium and Atrial Fibrillation (AF) are common and independent predictors of morbidity and mortality. Few reports examine their association with postoperative anemia. This study aims to quantify the association between anemia and these outcomes in patients undergoing cardiac surgery.

METHODS

This post-hoc analysis of the DECADE randomized controlled trial ran at six academic US hospitals. Patients aged 18-85 years with heart rate > 50 bpm undergoing cardiac surgery who had daily hemoglobin measurements in the first 5 Postoperative Days (POD) were included. Delirium was assessed twice daily with the Confusion Assessment Method for the ICU (CAM - ICU), preceded by the Richmond Agitation and Sedation Scale, with patients excluded from assessment if sedated. Patients had daily hemoglobin measurements, continuous cardiac monitoring plus twice-daily 12-lead electrocardiograms, up to POD4. AF was diagnosed by clinicians blinded to hemoglobin levels.

RESULTS

Five hundred and eighty-five patients were included. Mean postoperative hemoglobin Hazard Ratio (HR): 0.99 (95% CI 0.83, 1.19; p = 0.94) per 1 g.dL-1 hemoglobin decrease. 197 (34%) developed AF, mainly on POD = 2.3. Estimated HR = 1.04 (95% CI 0.93, 1.17; p = 0.51) per 1 g.dL-1 hemoglobin decrease.

CONCLUSIONS

Most patients undergoing major cardiac surgery were anemic in the postoperative phase. AF and delirium occurred in 34% and 12% of patients, respectively, but neither were significantly correlated with postoperative hemoglobin.

Prediction of atrial fibrillation and stroke using machine learning models in UK Biobank

Objective

Atrial fibrillation (AF) is the most common cardiac arrythmia, and it is associated with increased risk for ischemic stroke, which is underestimated, as AF can be asymptomatic. The aim of this study was to develop optimal ML models for prediction of AF in the population, and secondly for ischemic stroke in AF patients.

Methods

To develop ML models for prediction of 1) AF in the general population and 2) ischemic stroke in patients with AF we constructed XGBoost, LightGBM, Random Forest, Deep Neural Network, Support Vector Machine and Lasso penalised logistic regression models using UK-Biobank's extensive real-world clinical data, questionnaires, as well as biochemical and genetic data, and their predictive performances were compared. Ranking and contribution of the different features was assessed by SHapley Additive exPlanations (SHAP) analysis. The clinical tool CHA2DS2-VASc for prediction of ischemic stroke among AF patients, was used for comparison to the best performing ML model.

Findings

The best performing model for AF prediction was LightGBM, with an area-under-the-roc-curve (AUROC) of 0.729 (95% confidence intervals (CI): 0.719, 0.738). The best performing model for ischemic stroke prediction in AF patients was XGBoost with AUROC of 0.631 (95% CI: 0.604, 0.657). The improved AUROC in the XGBoost model compared to CHA2DS2-VASc was statistically significant based on DeLong's test (p-value = 2.20E-06). In addition, the SHAP analysis showed that several peripheral blood biomarkers (e.g. creatinine, glycated haemoglobin, monocytes) were associated with ischemic stroke, which are not considered by CHA2DS2-VASc.

Implications

The best performing ML models presented have the potential for clinical use, but further validation in independent studies is required. Our results endorse the incorporation of some routinely measured blood biomarkers for ischemic stroke prediction in AF patients.

Predictors and mortality of new onset postoperative atrial fibrillation after STAAD surgery: a retrospective cohort study

BACKGROUND

Data on new onset postoperative atrial fibrillation (POAF) after Stanford type A dissection (STAAD) surgery was limited. This study aimed to detect the risk factors for developing POAF after STAAD procedures and the association between POAF and in-hospital mortality.

METHODS

A total of 1354 patients who underwent surgical treatment for STAAD in Beijing Anzhen hospital were enrolled in this single-center retrospective study from January 2015 to October 2020. POAF were defined as atrial fibrillation/flutter requiring treatment after surgery procedure. Logistic model was conducted to detect the predictors of POAF, and inverse probability of treatment weighting (IPTW) and subgroup analysis were used to compare the mortality of POAF and non-POAF groups.

RESULTS

There were 176 patients (13.0%) diagnosed with POAF according to the definition. Multivariate logistics analyses revealed that advanced age [odds ratio (OR), 1.07; 95% CI: 1.05-1.08; P <0.001)], creatinine (OR, 1.00; 95% CI: 1.00-1.01; P =0.001) and cross-clamp time (OR, 1.00; 95% CI: 1.00-1.01; P =0.021) were independent risk factors of developing POAF in STAAD patients. POAF patients were associated with significantly higher in-hospital mortality compared with non-POAF patients (6.5 vs. 19.9%, OR, 3.60; 95% CI: 2.30-5.54; P <0.001), IPTW and subgroup analysis had reached consistent conclusions.

CONCLUSIONS

The incidence of POAF was 13.0% after STAAD surgery, advanced age, creatinine, and cross-clamp time were independent risk factors of developing POAF in STAAD patients. POAF is associated with increased mortality after STAAD procedures.

A new biomarker to predict atrial fibrillation and its adverse events after coronary artery bypass surgery: red blood cell distribution volume

OBJECTIVE

Recent studies suggest that increased red blood cell distribution width may be associated with increased risk of atrial fibrillation. This study aimed to evaluate the relationship between pre-operative and postoperative erythrocyte distribution volume, postoperative atrial fibrillation and related adverse events in patients undergoing isolated coronary artery bypass surgery.

METHODS

A total of 790 patients (611 males, mean age 58.3 ± 6.2 years) in pre-operative sinus rhythm, who underwent isolated coronary artery bypass grafting with cardiopulmonary bypass at the same centre and by the same surgical team between January 2015 and December 2021, were enrolled retrospectively. Two groups were created, group 1 (n = 183) and group 2 (n = 607), with regard to the occurrence of atrial fibrillation in the early postoperative period or not, respectively. Clinical and demographic data, biochemical and complete blood count parameters, and intra-operative and postoperative data of the patients were recorded. Univariate and subsequent multivariate logistic regression analysis was done to determine significant clinical factors and independent predictors of postoperative atrial fibrillation.

RESULTS

Among the patients, 182 (23.2%) developed atrial fibrillation during the 72 hours postoperatively. Pre-operative and postoperative first-, third- and seventh-day red blood cell distribution volume (p = 0.0001), C-reactive protein (p = 0.0001) and erythrocyte sedimentation rate (p = 0.0001) were significantly increased in group 1. Multivariate logistic regression analysis showed elevated pre-operative and postoperative first-, thirdand seventh-day red blood cell distribution volume, erythrocyte sedimentation rate and C-reactive protein as independent predictors of early postoperative atrial fibrillation.

CONCLUSIONS

Pre-operative and postoperative red blood cell distribution volume was found to be an independent predictor of atrial fibrillation and associated adverse events in the early postoperative period of isolated coronary artery bypass grafting.

Patterns of cytokine release and association with new onset of post-cardiac surgery atrial fibrillation

Introduction

Postoperative Atrial Fibrillation (POAF) is a common complication of cardiac surgery, associated with increased mortality, stroke risk, cardiac failure and prolonged hospital stay. Our study aimed to assess the patterns of release of systemic cytokines in patients with and without POAF.

Methods

A post-hoc analysis of the Remote Ischemic Preconditioning (RIPC) trial, including 121 patients (93 males and 28 females, mean age of 68 years old) who underwent isolated coronary artery bypass grafting (CABG) and aortic valve replacement (AVR). Mixed-effect models were used to analyze patterns of release of cytokines in POAF and non-AF patients. A logistic regression model was used to assess the effect of peak cytokine concentration (6 h after the aortic cross-clamp release) alongside other clinical predictors on the development of POAF.

Results

We found no significant difference in the patterns of release of IL-6 (p = 0.52), IL-10 (p = 0.39), IL-8 (p = 0.20) and TNF-α (p = 0.55) between POAF and non-AF patients. Also, we found no significant predictive value in peak concentrations of IL-6 (p = 0.2), IL-8 (p = >0.9), IL-10 (p = >0.9) and Tumour Necrosis Factor Alpha (TNF-α)(p = 0.6), however age and aortic cross-clamp time were significant predictors of POAF development across all models.

Conclusions

Our study suggests no significant association exists between cytokine release patterns and the development of POAF. Age and Aortic Cross-clamp time were found to be significant predictors of POAF.

Association of LDL to HDL ratio with new-onset atrial fibrillation after on-pump coronary artery bypass graft surgery

OBJECTIVE

This study aims to analyze the association between preoperative LDL/HDL ratio and new-onset atrial fibrillation (AF) after on-pump coronary artery bypass grafting (on-pump CABG), evaluate the clinic value of preoperative LDL/HDL ratio to identify postoperative rhythm.

METHODS

A retrospective study of consecutive patients (n = 2052) who underwent on-pump CABG at TEDA International Cardiovascular Hospital (Tianjin, China), from June 1, 2020, to December 30, 2021, was conducted. The association between preoperative LDL/HDL and new-onset POAF was analyzed by Lowess curve and univariate logistic regression. The receiver operating characteristic curve (ROC) and area under the curve (AUC) were used to evaluate the identification capacity of preoperative LDL/HDL level for new-onset POAF.

RESULTS

In studied populations, the incidence of new-onset POAF was about 29.24%. The lowess curve showed that the association between preoperative LDL/HDL ratio and POAF after on-pump CABG was similar to a linear relationship. With the increasement of preoperative LDL/HDL ratio, the incidence of POAF increased simultaneously. ROC analysis showed that preoperative LDL/HDL ratio could identify postoperative arrhythmia after on-pump CABG (AUC = 0.569,95% CI = 0.529-0.608, P = 0.006) among female patients, the best preoperative LDL/HDL ratio cutoff of 2.11, which was considered a predictive factor of incident POAF, showed a sensitivity of 83.60% (95% CI = 0.775-0.886) and a specificity of 30.02% (95% CI = 0.257-0.346).

CONCLUSION

Preoperative LDL/HDL ratio is associated with new-onset POAF, but there is a difference in different sex. Preoperative LDL/HDL level can help to identify postoperative rhythm in females.

Colchicine for prevention of post-operative atrial fibrillation: Meta-analysis of randomized controlled trials

Objective

This study intended to assess the efficacy of colchicine for prevention of post-operative atrial fibrillation (AF).

Background

Post-operative AF is a common complication of surgery operations. Inflammation plays a crucial role in the pathogenesis of post-operative AF. Colchicine, a potent anti-inflammatory drug, may have a role in mitigating the incidence of post-operative AF.

Methods

We searched Cochrane Library, Web of Science, PubMed, China National Knowledge Infrastructure (CNKI), Database of Chinese sci-tech periodicals (COVIP), and Wanfang Database for randomized controlled trials (RCTs) comparing colchicine versus placebo, or usual care for prevention of post-operative AF. The main outcome was the occurrence of AF post operation, which includes cardiac surgery, lung surgery, or pulmonary vein isolation. The estimated risk ratio (RR) for the occurrence of post-operative AF was evaluated using a random-effects model. The safety end point was the development of any side effects.

Results

A total of 12 RCTs with 2274 patients were eventually included in this meta-analysis, where 1141 patients received colchicine and 1133 patients received placebo or usual care. Perioperative colchicine treatment was related to a decreased incidence of post-operative AF (RR: 0.65; 95% confidence interval [CI]: 0.56 to 0.75, p<0.001). Although the incidence of gastrointestinal side effects was increased with colchicine therapy when compared to placebo (RR = 2.49, 95% CI 1.85 to 3.34, p < 0.001), the incidence of major adverse events was not increased (RR = 0.86, 95% CI 0.46 to 1.60, p = 0.64).

Conclusion

In conclusion, the results of our meta-analysis suggest that colchicine treatment could lower the incidence of post-operative AF. Further studies are needed to determine the optimal colchicine treatment regime to minimize the incidence of adverse events.

Incidence and Outcomes of Postoperative Atrial Fibrillation after Coronary Artery Bypass Grafting of a Randomized Controlled Trial: A Blinded End-of-cycle Analysis

Objective

The objective of this study is to analyse the incidence of postoperative atrial fibrillation (POAF), demography, post-operative outcomes including morbidity and mortality, length of Cardiac Intensive Care Unit (CICU) stay, High Dependency Unit (HDU) stay, and total hospital stay in patients undergoing coronary bypass grafting (CABG) at Institut Jantung Negana (IJN).

Methods

We conducted a prospective, randomised, controlled trial. We supplied the treatment group with Tocovid capsules and the control group with placebo containing palm superolein.

Results

Since January 2019, we have recruited the target population of 250 patients. However, the result is still blinded as we are still analysing blood samples for tocotrienol levels. 89.2% of patients completed the study with a 3.6% mortality and a 7.6% attrition rate. 35.2% of the patients developed POAF, the mean time being 46.06 ± 26.96 hours post-CABG. We did not observe any statistically significant difference when we compared left atrial size, New York Heart Association (NYHA) functional class, ejection fraction and premorbid history, besides EuroSCORE II (The European System for Cardiac Operative Risk Evaluation II) status except for older age group, right atrial size, and pleural effusion. There was also no difference in bypass time, cross clamp time or number of anastomoses. However, we noted a significant difference in death (p = 0.01) and renal failure requiring dialysis (p = 0.007) among patients with POAF; those patients also had a longer CICU stay (p = 0.005), HDU stay (p = 0.02), and total hospital stay (p = 0.001).

Conclusions

POAF is associated with a higher incidence of renal failure and death while it increases CICU, HDU, and total hospital stay. It remains to be seen whether Tocovid reduces POAF and its associated sequelae.

Clinical Trial Registration

NCT03807037 (Registered on 16 January 2019).

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.