Long-term Thromboembolic Risk in Patients With Postoperative Atrial Fibrillation After Left-Sided Heart Valve Surgery

Increased IL-12p70 Levels in Intraoperative Pericardial Fluid Are Predictive of Postoperative Atrial Fibrillation Onset after Coronary Artery Bypass Surgery

Background

Postoperative atrial fibrillation (POAF) is a frequent complication of heart surgery, prolonging hospital stays, as well as increasing morbidity and mortality rates. While previous studies have investigated the determinants influencing atrial fibrillation (AF) following heart surgery, the specific risk factors contributing to POAF occurrence after coronary artery bypass graft surgery (CABG) are not well understood. Here we used the human magnetic Luminex assay to assess whether biomarkers, particularly cytokines, within intraoperative pericardial fluid could serve as predictive markers for POAF onset among CABG individuals.

Methods

In this study we identified 180 patients who underwent CABG with no atrial arrhythmia history. The human magnetic Luminex assay was used to quantify the levels of 36 cytokines in pericardial fluid samples collected during the surgery. The occurrence of POAF was continuously monitored, using both postoperative electrocardiograms and telemetry strips, until the time of discharge.

Results

In our cohort of 124 patients, POAF was observed in 30 patients, accounting for 24.19% of the study population. These patients exhibited significantly higher levels of interleukin (IL)-12p70 in their intraoperative pericardial fluids compared to those with normal sinus rhythms (SR, p < 0.001). Subsequently, IL-12p70 was found to be an independent risk factor for POAF, and receiver operating characteristic (ROC) analysis established a cut-off threshold for predicting POAF onset of 116.435 pg/mL, based on the maximum Youden index (area under the curve: 0.816).

Conclusions

this study establishes a significant association between elevated IL-12p70 levels in intraoperative pericardial fluid and the risk of POAF, particularly when IL-12p70 concentrations exceed the identified cut-off value of 116.435 pg/mL. These findings suggest that IL-12p70 levels could potentially be utilized as a predictive biomarker for the onset of POAF in patients undergoing CABG. This marker may aid in the early identification and management of patients at heightened risk for this complication.

Left atrial dysfunction in bicuspid aortic valve patients with severe aortic stenosis is associated with post-operative atrial fibrillation following aortic valve replacement

Aims

To investigate (i) the association between pre-operative left atrial (LA) reservoir strain and post-operative atrial fibrillation (AF) and (ii) the incidence of post-operative ischaemic stroke events separately in bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) patients after surgical aortic valve replacement for isolated severe aortic stenosis (AS).

Methods and results

We prospectively enrolled 227 patients (n = 133 BAV and n = 94 TAV) with isolated severe AS scheduled for aortic valve replacement. A comprehensive intra- and inter-observer validated pre-operative echocardiogram with an analysis of LA reservoir strain was performed. Post-operative AF was defined as a sustained (>30 s) episode of AF or atrial flutter. The timing of neurological events was defined in accordance with the Valve Academic Research Consortium-3 criteria for stroke. Post-operative AF occurred in 114 of 227 patients (50.2%), with no difference between BAV and TAV patients (48.1 vs. 53.1%, P = 0.452). Persisting post-operative AF at discharge was more frequent in BAV patients (29.7 vs. 8.0%, P = 0.005). Pre-operative LA reservoir strain was independently associated with post-operative AF (odds ratio = 1.064, 95% confidence interval 1.032-1.095, P < 0.001), with a significant interaction between LA reservoir strain and aortic valve morphology (Pinteraction = 0.002). The cumulative transient ischemic attack (TIA)/stroke incidence during follow-up was significantly higher in BAV patients (19.1 vs. 5.8% at 5 years).

Conclusion

Pre-operative LA function was associated with post-operative AF after aortic valve replacement in BAV AS patients, while post-operative AF in TAV AS patients likely depends on transient post-operative alterations and traditional cardiovascular risk factors. TIA/stroke during follow-up was more common in BAV AS patients.

Association Between Serum Levels of Nicotinamide-Adenine Dinucleotide Phosphate Oxidase 2 and the Development of Atrial Fibrillation After Isolated Coronary Artery Bypass Grafting: A Prospective Pilot Study

INTRODUCTION

To investigate the levels of nicotinamide-adenine dinucleotide phosphate oxidase 2 (NOX2) in serum and pericardial drainage samples in the early stage after coronary artery bypass grafting (CABG) and determine whether NOX2 is predictive of postoperative atrial fibrillation (POAF).

MATERIALS AND METHODS

This prospective pilot study involved 152 adults without history of atrial fibrillation who underwent first-time elective isolated CABG. Serum and pericardial fluid samples were simultaneously obtained from patients at baseline and 4, 12, and 24 h post operation. NOX2 levels were determined using enzyme-linked immunosorbent assays. The heart rhythm of patients was continuously monitored through a Holter monitor until discharge. Logistic regression and receiver-operating characteristic (ROC) curve analyses were performed, as appropriate.

RESULTS

Fifty-one patients (33.6%) experienced in-hospital POAF. NOX2 concentration in serum and pericardial drainage samples was increased after surgery, reached its peak at 12 h, and gradually declined thereafter toward the baseline levels by 24 h. At 12 h, patients with POAF had higher levels of serum NOX2 than those without (3.96 ± 0.35 vs. 3.70 ± 0.75 μg/mL, respectively, p = 0.004). There were no discernible differences in pericardial NOX2 between the 2 groups. Multivariate analysis revealed that serum NOX2 at 12 h post operation was the strongest independent predictor of POAF (odds ratio: 2.179, 95% confidence interval: 1.084-4.377). The area under the ROC curve of the POAF predictive model was 0.732 (95% confidence interval: 0.654-0.801).

CONCLUSION

Serum NOX2 may be useful in the identification of POAF. Larger studies are warranted to substantiate these findings.

Clinical Significance of Postoperative Atrial Fibrillation in Hypertrophic Cardiomyopathy Patients Undergoing Septal Myectomy

BACKGROUND

The optimal management of hypertrophic cardiomyopathy (HCM) patients with postoperative atrial fibrillation (POAF) after surgical myectomy remains unknown. We sought to investigate the association between POAF and atrial fibrillation (AF) or cardioembolic events during follow-up to bridge this gap.

METHODS

Patients undergoing surgical myectomy at 2 HCM referral centres in North America from 2002 to 2020 were included in this study. Patients with preoperative AF were excluded. POAF was defined as any episode of AF within 30 days after surgery.

RESULTS

Of 1176 patients, 375 (31.9%) had POAF. Age (adjusted hazard ratio [HR] 1.05, 95% confidence interval [CI] 1.03-1.06; P < 0.001), premyectomy left atrial diameter (LAD; adjusted HR 1.6, 95% CI 1.32-2.02; P < 0.001), and smoking (adjusted HR 1.60, 95% CI 1.17-2.20; P = 0.001) were associated with POAF on multivariable analysis. Of 934 patients with follow-up data, of duration 4.3 ± 4.1 years, AF was detected in 86 (9.2%). Only POAF (HR 4.20, 95% CI 2.44-7.23; P < 0.001), previous history of stroke (HR 4.81, 95% CI 1.63-14.17; P = 0.01), and postmyectomy LAD (HR 1.80, 95% CI 1.21-2.70; P = 0.004) were associated with AF incidence during follow-up. Cardioembolic events occurred in only 15 patients (1.6%). POAF was not associated with increased cardioembolic risk, with only 3 patients with POAF suffering such an event, all more than 4 years after surgery.

CONCLUSIONS

POAF is common in HCM patients undergoing myectomy and is a predictor of AF during follow-up. Over long-term follow-up, cardioembolic events are uncommon. These findings suggest that routine long-term anticoagulation for all HCM patients with postmyectomy AF is not justified after the initial postoperative period.

Prevention of postoperative atrial fibrillation in cardiac surgery: a quality improvement project

PURPOSE

Postoperative atrial fibrillation (POAF) has an incidence of 20-60% in cardiac surgery. The Society of Cardiovascular Anesthesiologists and the European Association of Cardiothoracic Anaesthesiology Practice Advisory have recommended postoperative beta blockers and amiodarone for the prevention of POAF. By employing quality improvement (QI) strategies, we sought to increase the use of these agents and to reduce the incidence of POAF among our patients undergoing cardiac surgery.

METHODS

This single-centre QI initiative followed the traditional Plan, Do, Study, Act (PDSA) cycle scientific methodology. A POAF risk score was developed to categorize all patients undergoing cardiac surgery as either normal or elevated risk. Risk stratification was incorporated into a preprinted prescribing guide, which recommended postoperative beta blockade for all patients and a postoperative amiodarone protocol for patients with elevated risk starting on postoperative day one (POD1). A longitudinal audit of all patients undergoing cardiac surgery was conducted over 11 months to track the use of prophylactic medications and the incidence of POAF.

RESULTS

Five hundred and sixty patients undergoing surgery were included in the QI initiative from 1 December 2020 to 1 November 2021. The baseline rate of POAF across all surgical subtypes was 39% (198/560). The use of prophylactic amiodarone in high-risk patients increased from 13% (1/8) at the start of the project to 41% (48/116) at the end of the audit period. The percentage of patients receiving a beta blocker on POD1 did fluctuate, but remained essentially unchanged throughout the audit (34.8% in December 2020 vs 46.7% in October 2021). After 11 months, the overall incidence of POAF was 29% (24.9% relative reduction). Notable reductions in the incidence of POAF were observed in more complex surgical subtypes by the end of the audit, including multiple valve replacement (89% vs 56%), aortic repair (50% vs 33%), and mitral valve surgery (45% vs 33%).

CONCLUSIONS

This single-centre QI intervention increased the use of prophylactic amiodarone by 28% for patients at elevated risk of POAF, with no change in the early postoperative initiation of beta blockers (46.7% of patients by POD1). There was a notable reduction in the incidence of POAF in patients at elevated risk undergoing surgery.

Perioperative Atrial Fibrillation and One-year Clinical Outcomes in Patients Following Major Emergency Abdominal Surgery

The prevalence and impact of perioperative atrial fibrillation (AF) during an admission for major emergency abdominal surgery are sparsely examined. Therefore, this study aimed to compare the 30-day and 1-year outcomes (AF-related hospitalization, stroke, and all-cause mortality) in patients with and without perioperative AF to their major emergency abdominal surgery. All patients without a history of AF who underwent major emergency abdominal surgery from 2000 to 2019 and discharged alive were identified using Danish nationwide registries. Patients with and without perioperative AF (defined as new-onset AF during the index hospitalization) were matched 1:4 on age, gender, year of surgery, and type of surgery. The cumulative incidences and hazard ratios of outcomes were assessed using a multivariable Cox regression analysis comparing patients with and without perioperative AF. A total of 2% of patients were diagnosed with perioperative AF. The matched cohort comprised 792 and 3,168 patients with and without perioperative AF, respectively (median age 78 years [twenty-fifth to seventy-fifth percentile 70 to 83 years]; 43% men). Cumulative incidences of AF-related hospitalizations, stroke, and mortality 1 year after discharge were 30% versus 3.4%, 3.4% versus 2.7%, and 35% versus 22% in patients with and without perioperative AF, respectively. The 30-day outcomes were similarly elevated among patients with perioperative AF. Perioperative AF during an admission for major emergency abdominal surgery was associated with higher 30-day and 1-year rates of AF-related hospitalization and mortality and similar rates of stroke. These findings suggest that perioperative AF is a prognostic marker of increased morbidity and mortality in relation to major emergency abdominal surgery and warrants further investigation.

Patients with Artificial Heart Valves

BACKGROUND

In Germany, a total of 38 547 heart valve procedures were performed in 2022. With a growing number of patients undergoing the surgical and interventional implantation of heart valves, the incidence of prosthetic endocarditis is also rising.

METHODS

We summarize the current state of the prophylaxis, diagnosis, and treatment of prosthetic endocarditis in a selective review of the literature.

RESULTS

Prosthetic endocarditis accounts for 10-30% of all cases of endocarditis. As its echocardiographic and microbiologic findings are often less specific than those of native endocarditis, its diagnosis now increasingly relies on alternative imaging modalities such as F-18-FDG PET-CT. Anti-infective and surgical treatment are made more difficult by biofilm formation on the prosthetic valve and the frequent formation of perivalvular abscesses.

CONCLUSION

Increased awareness of this clinical entity in the outpatient setting will promote the earlier initiation of appropriate diagnostic studies. Proper diagnostic evaluation is an essential prerequisite for the early detection and timely treatment of prosthetic endocarditis, with the goal of preventing progressive destruction and thus improving the outcome. Preventive and educative measures should be intensified, and certified, multidisciplinary endocarditis teams should be established. Antibiotic prophylaxis is now given much more restrictively than in earlier years; the risk of infection must be weighed against the potential development of both individual and collective resistance to antibiotic drugs.

Anticoagulation use in perioperative atrial fibrillation after noncardiac surgery: a systematic review and meta-analysis

BACKGROUND

Perioperative atrial fibrillation is associated with an increased risk of stroke, myocardial infarction, and death after noncardiac surgery. Anticoagulation therapy is effective for stroke prevention in nonsurgical atrial fibrillation, but its efficacy and safety in perioperative atrial fibrillation are unknown.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL from database inception until January 2022. We included studies comparing anticoagulation versus no anticoagulation use in patients with perioperative atrial fibrillation after noncardiac surgery. Our study outcomes included stroke ± systemic embolism, bleeding, mortality, myocardial infarction, and venous thromboembolism. We pooled studies using fixed-effects models. We reported summary risk ratios (RRs) for studies reporting multivariable-adjusted results.

RESULTS

Seven observational studies but no randomised trials were included. Of the 27,822 patients, 29.1% were prescribed therapeutic anticoagulation. Anticoagulation use was associated with a lower risk of stroke ± systemic embolism (RR 0.73; 95% CI, 0.62-0.85; I2 = 81%; 3 studies) but a higher risk of bleeding (RR 1.14; 95% CI, 1.04-1.25; 1 study). There was a lower risk of mortality associated with anticoagulation use (RR 0.45; 95% CI, 0.40-0.51; I2 = 80%; 2 studies). There was no difference in the risk of myocardial infarction (RR 2.19; 95% CI, 0.97-4.96; 1 study). The certainty of the evidence was very low across all outcomes.

CONCLUSION

Anticoagulation is associated with a reduced risk of stroke and death but an increased risk of bleeding. The quality of the evidence is very poor. Randomised trials are needed to better determine the effects of anticoagulation use in this population.

Prediction model for postoperative atrial fibrillation in non-cardiac surgery using machine learning

Some patients with postoperative atrial fibrillation (POAF) after non-cardiac surgery need treatment, and a predictive model for these patients is clinically useful. Here, we developed a predictive model for POAF in non-cardiac surgery based on machine learning techniques. In a total of 201,864 patients who underwent non-cardiac surgery between January 2011 and June 2019 at our institution, 5,725 (2.8%) were treated for POAF. We used machine learning with an extreme gradient boosting algorithm to evaluate the effects of variables on POAF. Using the top five variables from this algorithm, we generated a predictive model for POAF and conducted an external validation. The top five variables selected for the POAF model were age, lung operation, operation duration, history of coronary artery disease, and hypertension. The optimal threshold of probability in this model was estimated to be 0.1, and the area under the receiver operating characteristic (AUROC) curve was 0.80 with a 95% confidence interval of 0.78-0.81. Accuracy of the model using the estimated threshold was 0.95, with sensitivity and specificity values of 0.28 and 0.97, respectively. In an external validation, the AUROC was 0.80 (0.78-0.81). The working predictive model for POAF requiring treatment in non-cardiac surgery based on machine learning techniques is provided online (https://sjshin.shinyapps.io/afib_predictor_0913/). The model needs further verification among other populations.

Myeloperoxidase Levels in Pericardial Fluid Is Independently Associated with Postoperative Atrial Fibrillation after Isolated Coronary Artery Bypass Surgery

BACKGROUND

Postoperative atrial fibrillation (POAF) is the most common complication after surgery for atherosclerotic cardiovascular disease (ASCVD) and leads to extended hospital stays and increased mortality. Myeloperoxidase (MPO) in postoperative pericardial drainage fluid is associated with an increased risk of POAF; however, the correlations between MPO in intraoperative pericardial fluid and POAF remain largely unknown. The aim of the study was to evaluate whether MPO is associated with POAF.

METHODS

A total of 97 patients with no history of atrial arrhythmia who had undergone coronary artery bypass surgery (CABG) were identified. We prospectively measured the levels of MPO in intraoperative pericardial fluid and blood using the human magnetic Luminex assay. Then, the occurrence of atrial fibrillation was continuously observed by postoperative ECG and telemetry strips until discharge.

RESULTS

Our data showed that POAF occurred in 24 of 97 patients (24.74%). MPO levels in blood were higher in the POAF group than the SR group (p = 0.064). Patients with POAF had significantly higher intraoperative pericardial fluid MPO levels than patients who remained in SR (p = 0.021). There was no significant correlation between pericardial fluid MPO levels and blood MPO levels (r = -0.47, p = 0.770). In a multivariable logistic regression model, pericardial fluid MPO levels were significantly associated with a higher risk of POAF (odds ratio = 1.016, 95% confidence interval, 1.001-1.031; p = 0.031).

CONCLUSIONS

Higher intraoperative pericardial fluid MPO levels are linked with POAF in patients undergoing CABG. This finding provides insight into a possible mechanism of MPO in pericardial fluid increase susceptibility to developing POAF in patients undergoing CABG.

A novel predictive model for new-onset atrial fibrillation in patients after isolated cardiac valve surgery

Background

Postoperative atrial fibrillation (POAF) is a severe complication after cardiac surgery and is associated with an increased risk of ischemic stroke and mortality. The main aim of this study was to identify the independent predictors associated with POAF after isolated valve operation and to develop a risk prediction model.

Methods

This retrospective observational study involved patients without previous AF who underwent isolated valve surgery from November 2018 to October 2021. Patients were stratified into two groups according to the development of new-onset POAF. Baseline characteristics and perioperative data were collected from the two groups of patients. Univariate and multivariate logistic regression analyses were applied to identify independent risk factors for the occurrence of POAF, and the results of the multivariate analysis were used to create a predictive nomogram.

Results

A total of 422 patients were included in the study, of which 163 (38.6%) developed POAF. The Multivariate logistic regression analysis indicated that cardiac function (odds ratio [OR] = 2.881, 95% confidence interval [CI] = 1.595–5.206; P &lt; 0.001), Left atrial diameter index (OR = 1.071, 95%CI = 1.028–1.117; P = 0.001), Operative time (OR = 1.532, 95%CI = 1.095–2.141; P = 0.013), Neutrophil count (OR = 1.042, 95%CI = 1.006–1.08; P = 0.021) and the magnitude of fever (OR = 3.414, 95%CI = 2.454–4.751; P &lt; 0.001) were independent predictors of POAF. The above Variables were incorporated, and a nomogram was successfully constructed with a C-index of 0.810. The area under the receiver operating characteristic curve was 0.817.

Conclusion

Cardiac function, left atrial diameter index, operative time, neutrophil count, and fever were independent predictors of POAF in patients with isolated valve surgery. Establishing a nomogram model based on the above predictors helps predict the risk of POAF and may have potential clinical utility in preventive interventions.

Derivation and Validation of a Clinical Score for Predicting Postoperative Atrial Fibrillation in Noncardiac Elective Surgery (the HART Score)

Postoperative atrial fibrillation (POAF) represents the most frequent cardiac arrhythmia in the surgical setting. It affects almost 3% of all patients over 45 years old who underwent noncardiovascular surgery and is associated with a higher risk of stroke, heart failure, myocardial infarction, and cardiac arrest. The study aimed to assess independent predictors of POAF and derive and validate a score for risk prediction in clinical practice. This was a retrospective cohort study including all consecutive candidates to all types of noncardiac elective surgery attending a cardiological preoperative assessment from 2016 to 2019. Exclusion criteria were a previous diagnosis of AF and the cancelation of the planned surgery. A total of 2,048 patients were enrolled (1350 men, aged 72 ± 12 years). A total of 44 patients experienced POAF (2.1%) - median 3 days (first to third quartile 2 to 4 days). Age (odds ratio [OR] 1.03 for each year, 95% confidence interval [CI] 1.01 to 1.07), hypertension (OR 3.43, 95% CI 1.22 to 9.63), thyroid dysfunction (OR 2.47, 95% CI 1.22 to 5.01), and intermediate or high-risk surgery (OR 18.28, 95% CI 2.51 to 33.09) resulted as independent predictors of POAF (all p <0.05). The Hypertension, Age, surgery Risk, and Thyroid dysfunction score (OR 2.59 for each point, 95% CI 1.79 to 3.75, p <0.001) was then created based on those 4 items. A cut-off score ≥6 had a 70% sensitivity and a 72% specificity in detecting POAF (area under the curve 0.76). Bootstrapping for internal validation confirmed the overall results (area under the curve 0.72). In conclusion, POAF complicates around 2% of all noncardiac surgery. A 4-item risk score, such as the Hypertension, Age, surgery Risk, and Thyroid dysfunction score, could be effective in implementing POAF screening and improving management.

Autonomic Neuromodulation for Atrial Fibrillation Following Cardiac Surgery: JACC Review Topic of the Week

Autonomic neuromodulation therapies (ANMTs) (ie, ganglionated plexus ablation, epicardial injections for temporary neurotoxicity, low-level vagus nerve stimulation [LL-VNS], stellate ganglion block, baroreceptor stimulation, spinal cord stimulation, and renal nerve denervation) constitute an emerging therapeutic approach for arrhythmias. Very little is known about ANMTs' preventive potential for postoperative atrial fibrillation (POAF) after cardiac surgery. The purpose of this review is to summarize and critically appraise the currently available evidence. Herein, the authors conducted a systematic review of 922 articles that yielded 7 randomized controlled trials. In the meta-analysis, ANMTs reduced POAF incidence (OR: 0.37; 95% CI: 0.25 to 0.55) and burden (mean difference [MD]: -3.51 hours; 95% CI: -6.64 to -0.38 hours), length of stay (MD: -0.82 days; 95% CI: -1.59 to -0.04 days), and interleukin-6 (MD: -79.92 pg/mL; 95% CI: -151.12 to -8.33 pg/mL), mainly attributed to LL-VNS and epicardial injections. Moving forward, these findings establish a base for future larger and comparative trials with ANMTs, to optimize and expand their use.

Long-Term Survival in Patients with Post-Operative Atrial Fibrillation after Cardiac Surgery: Analysis from a Prospective Cohort Study

Background: Post-operative (POP) atrial fibrillation (AF) is frequent in patients who undergo cardiac surgery. However, its prognostic impact in the long term remains unclear. Methods: We followed 1386 patients who underwent cardiac surgery for an average of 10 ± 3 years. According to clinical history of AF before and after surgery, four subgroups were identified: (1) patients with no history of AF and without episodes of AF during the first 30 days after surgery (control or Group 1, n = 726), (2) patients with no history of AF before surgery in whom new-onset POP AF was detected during the first 30 days after surgery (new-onset POP AF or Group 2, n = 452), (3) patients with a history of paroxysmal/persistent AF before cardiac surgery (Group 3, n = 125, including 87 POP AF patients and 38 who did not develop POP AF), and (4) patients with permanent AF at the time of cardiac surgery (Group 4, n = 83). All-cause mortality was the primary outcome of the study. We tested the associations of potential determinants with all-cause mortality using univariable and multivariable statistical analyses. Results: Overall, 473 patients (34%) died during follow-up. After adjustment for multiple confounders, new-onset POP AF (hazard ratio (HR) = 1.31, 95% confidence interval (CI): 0.90–1.89; p = 0.1609), history of paroxysmal/persistent AF before cardiac surgery (HR = 1.33, 95% CI: 0.71–2.49; p = 0.3736), and permanent AF (Group 4) (HR = 1.55, 95% CI 0.82–2.95; p = 0.1803) were not associated with a significantly increased risk of mortality when compared with Group 1 (patients with no history of AF and without episodes of AF during the first 30 days after surgery). In new-onset POP AF patients, oral anticoagulation was not associated with mortality (HR = 1.13, 95% CI: 0.83–1.54; p = 0.4299). Conclusions: In this cohort of patients who underwent different types of heart surgery, POP AF was not associated with an increased risk of mortality. In this setting, the role of long-term anticoagulation remains unclear.

Impact of oral anticoagulation therapy on postoperative atrial fibrillation outcomes: a systematic review and meta-analysis

BACKGROUND

Post-operative atrial fibrillation (POAF) is the most common complication after cardiac surgery. Recent studies had shown this phenomenon is no longer considered transitory and is associated with higher risk of thromboembolic events or death. The aim of this study was to systematically review and analyze previous studies comparing oral anticoagulation therapy with no anticoagulation, regarding these long-term outcomes.

METHODS

PubMed/MEDLINE, EMBASE, Web of Science and Cochrane Database were systematically searched to identify the studies comparing the risk of stroke, or thromboembolic events or mortality of POAF patients who received anticoagulation compared with those who were not anticoagulated. Incidence of stroke, thromboembolic events and all-cause mortality were evaluated up to 10 years after surgery. Time-to-event outcomes were collected through hazard ratio (HR) along with their variance and the early endpoints using frequencies or odds ratio (OR). Random effect models were used to compute statistical combined measures and 95% confidence intervals (CI). Heterogeneity was evaluated through Q statistic-related measures of variance (Tau2, I2, Chi-squared test).

RESULTS

Eight observational cohort studies were selected, including 15,335 patients (3492 on Oral Anticoagulants (OAC) vs 11,429 without OAC) that met the inclusion criteria for qualitative synthesis. Patients had a wide gender distribution (38.6-82.3%), each study with a mean age above 65 years (67.5-85). Vitamin K antagonists were commonly prescribed anticoagulants (74.3-100%). OAC was associated with a protective impact on all-cause mortality at a mean of 5.0 years of follow-up (HR is 0.85 [0.72-1.01]; p = 0.07; I2 = 48%). Thromboembolic events did not differ between the two treatment arms (HR 0.68 [0.40-1.15], p = 0.15).

CONCLUSION

Current literature suggests a possibly protective impact of OAC therapy for all-cause mortality in patients with new-onset atrial fibrillation after cardiac surgery. However, it does not appear to impact thromboembolism rate.

Anticoagulation therapy in patients with post-operative atrial fibrillation: Systematic review with meta-analysis

BACKGROUND

Post-operative atrial fibrillation (POAF) is a relevant complication after surgery. Several studies have shown that POAF has important consequences for long-term morbidity and mortality, by increasing the risk of thromboembolic events. However, the use of oral anticoagulation (OAC) is not well established in this context.

METHODS

We searched MEDLINE, CENTRAL, PsycInfo and Web of Science for clinical trials and observational studies evaluating anticoagulation vs. no anticoagulation in patients with POAF (after cardiac or non-cardiac surgery). Data were screened and extracted by two independent reviewers. We performed a random- effects model to estimate the pooled odds ratio (OR) with 95% Confidence Intervals (CI), and heterogeneity was evaluated by I² statistics. The outcomes of interest were all-cause mortality, thromboembolic events, and bleeding events.

RESULTS

Overall, 10 observational retrospective studies were included: 5 studies with 203,946 cardiac surgery POAF patients, and 5 studies with 29,566 patients with POAF after non-cardiac surgery. In cardiac surgery POAF, the OAC use was associated with lower risk of thromboembolic events (OR 0.68; 95%CI 0.47-0.96, I² = 31%; 4 studies) and the bleeding risk was significantly increased (OR 4.30; 95%CI 3.69 to 5.02, 1 study). In non-cardiac surgery POAF, OAC did not significantly reduce the risk of thromboembolic events (OR 0.71, 95%CI 0.33-1.15; I² = 79%; 5 studies) but was associated with increased risk of bleeding (OR 1.20, 95%CI 1.10-1.32, I² = 0%; 3 studies). Mortality was not significantly reduced in both cardiac and non-cardiac surgery POAF.

CONCLUSION

Oral anticoagulation was associated with a lower risk of thromboembolic events in patients with POAF following cardiac surgery but not in non-cardiac surgery. Bleeding risk was increased in both settings. The confidence on pooled results is at most low, and further data, namely randomized controlled trials are necessary to derive robust conclusions.

Neurological Complications of Cardiac Procedures

Neurological complications after cardiac surgery and percutaneous cardiac interventions are not uncommon. These include periprocedural stroke, postoperative cognitive dysfunction after cardiac surgery, contrast-induced encephalopathy after percutaneous interventions, and seizures. In this article, we review the incidence, pathophysiology, diagnosis, and management of these complications. Improved understanding of these complications could lead to their prevention, faster detection, and facilitation of diagnostic workup and appropriate treatment.

Novel Combined Antioxidant Strategy against Hypertension, Acute Myocardial Infarction and Postoperative Atrial Fibrillation

Reactive oxygen species (ROS) play a physiological role in the modulation of several functions of the vascular wall; however, increased ROS have detrimental effects. Hence, oxidative stress has pathophysiological impacts on the control of the vascular tone and cardiac functions. Recent experimental studies reported the involvement of increased ROS in the mechanism of hypertension, as this disorder associates with increased production of pro-oxidants and decreased bioavailability of antioxidants. In addition, increased ROS exposure is found in ischemia-reperfusion, occurring in acute myocardial infarction and cardiac surgery with extracorporeal circulation, among other settings. Although these effects cause major heart damage, at present, there is no available treatment. Therefore, it should be expected that antioxidants counteract the oxidative processes, thereby being suitable against cardiovascular disease. Nevertheless, although numerous experimental studies agree with this notion, interventional trials have provided mixed results. A better knowledge of ROS modulation and their specific interaction with the molecular targets should contribute to the development of novel multitarget antioxidant effective therapeutic strategies. The complex multifactorial nature of hypertension, acute myocardial infarction, and postoperative atrial fibrillation needs a multitarget antioxidant strategy, which may give rise to additive or synergic protective effects to achieve optimal cardioprotection.

Postoperative Atrial Fibrillation: Features, Mechanisms, and Clinical Management

Advances in atrial fibrillation (AF) management, perioperative medicine, and surgical techniques have reignited an interest in postoperative AF (POAF). POAF results from the interaction among subclinical atrial substrate, surgery-induced substrate, and transient postoperative factors. Prophylaxis for POAF after cardiac surgery is well established but the indications for preoperative treatment in noncardiac surgery need further investigation. A rate-control strategy is adequate for most asymptomatic patients with POAF and anticoagulation should be initiated for POAF more than 48 to 72 hours postsurgery. Research is needed to improve evidence-based management of POAF and guide long-term management in view of the substantial late recurrence-rate.

Post-Cardiac Surgery Atrial Fibrillation: Risks, Mechanisms, Prevention, and Management

Atrial fibrillation (AF) is the most common complication of cardiac surgery (CS). There are numerous risk factors, proposed mechanisms, and financial/clinical implications of post-CS AF (PCSAF). Management involves 2 arms: prevention and treatment. This review highlights and summarizes previous literature on PCSAF and challenges the standard dogma regarding anticoagulation, particularly in the short term.

Self-monitoring for recurrence of secondary atrial fibrillation following non-cardiac surgery or acute illness: A pilot study

Background

Atrial fibrillation (AF) secondary to non-cardiac surgery and medical illness is common and, although often transient, is associated with an increased risk of stroke and mortality. This pilot study tested the feasibility of self-monitoring to detect recurrent AF in this setting and the frequency with which it occurred.

Methods

Patients with new secondary AF after non-cardiac surgery or medical illness that reverted to sinus rhythm before discharge were recruited in three tertiary hospitals in Australia. Participants performed self-monitoring for AF recurrence using a Handheld single-lead ECG device 3–4 times/day for 4-weeks.

Results

From 16,454 admissions, 224 (1.4%) secondary AF cases were identified. Of these, 94 were eligible, and 29 agreed to participate in self-monitoring (66% male; median age 67 years). Self-monitoring was feasible and acceptable to participants in this setting. Self-monitoring identified AF recurrence in 10 participants (34%; 95% CI, 18% −54%), with recurrence occurring ≤ 9 days following discharge in 9/10 participants. Only 4 participants (40%) reported associated palpitations with recurrence. Six participants (60%) with recurrence had a CHA₂DS₂-VA score ≥ 2, suggesting a potential indication for oral anticoagulation.

Conclusions

Approximately 1 in 3 patients with transient secondary AF will have recurrent AF within nine days of discharge. These recurrent episodes are often asymptomatic but can be detected promptly using patient self-monitoring, which was feasible and acceptable. Future research is warranted to further investigate the incidence of secondary AF, the rate of recurrence after discharge and its prognosis, and whether use of oral anticoagulation can reduce stroke in this setting.