Preoperative predictors of new-onset prolonged atrial fibrillation after surgical aortic valve replacement

Randomized feasibility trial of prophylactic radiofrequency ablation to prevent atrial fibrillation after cardiac surgery

OBJECTIVE

To evaluate the feasibility of prophylactic radiofrequency isolation of the pulmonary veins, with left atrial appendage amputation, to reduce the incidence of postoperative atrial fibrillation after cardiac surgery in patients aged 70 years and older.

METHODS

The Federal Food and Drug Administration granted an investigational device exemption to utilize a bipolar radiofrequency clamp for prophylactic pulmonary vein isolation in a limited feasibility trial. Sixty-two patients without prior dysrhythmias were prospectively randomized to undergo either their index cardiac surgical procedure or bilateral pulmonary vein isolation and left atrial appendage amputation during their cardiac operation. The primary outcome was occurrence of in-hospital postoperative atrial fibrillation. Subjects were on 24-hour telemetry until discharge. Dysrhythmias, any episode of atrial fibrillation >30 seconds, were confirmed by electrophysiologists blinded to the study.

RESULTS

Sixty patients, mean age 75 years and mean Congestive heart failure, Hypertension, Age (>65 = 1, >75 = 2 points), Diabetes, previous Stroke/Transient ischemic attack (2 points), Vascular disease, Gender (female) score of 4, were analyzed. Thirty-one patients randomized to control and 29 to the treatment group. The majority of patients in each group underwent isolated coronary artery bypass grafting. No perioperative complications related to the treatment procedure, need for permanent pacemaker, or mortality occurred. The in-hospital incidence of postoperative atrial fibrillation was 55% (17 out of 31) in the control group and 7% (2 out of 29) in the treatment group (P < .001) The control group had a significantly higher requirement for antiarrhythmic medications at discharge: 45% (14 out of 31) versus 7% (2 out of 29) in the treatment group (P < .001).

CONCLUSIONS

Prophylactic radiofrequency isolation of the pulmonary veins with left atrial appendage amputation during the primary cardiac surgical operation reduced the incidence of postoperative atrial fibrillation in patients aged 70 years and older with no history of atrial arrhythmias.

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.

Diagnosis and Treatment of New-Onset Perioperative Atrial Fibrillation

This article reviews medical and surgical risk factors for developing atrial fibrillation (AF), the most common sustained dysrhythmia in the United States. Evidence for assessment and management of patients with AF, including AF newly identified in the preoperative clinic, immediately preoperatively, intraoperatively, and unstable AF, is presented. A stepwise approach to guide anesthetic decision-making in the assessment of newly identified preoperative AF is proposed. Anesthetic considerations, including the potential impacts of anesthetic and vasopressor selection, and current evidence related to rate control and rhythm control via pharmacologic or electrical cardioversion as well as anticoagulation strategies are discussed.

New-onset postoperative atrial fibrillation after mitral valve surgery: Determinants and the effect on survival

Objective

Mitral valve surgery (MVS) carries substantial risk of postoperative atrial fibrillation (PAF). Identifying patients who benefit from prophylactic left atrial appendage amputation (LAAA) or maze is ill-defined. To guide such interventions, we determined preoperative predictors of PAF and investigated 3-year survival of patients with PAF.

Methods

We performed a retrospective analysis of patients undergoing isolated MVS (N = 670) between 2011 and 2021. Patients with preoperative atrial fibrillation, LAAA or pulmonary vein isolation were excluded. Patient characteristics were compared between those without PAF and those who developed transient or prolonged PAF. Predictors of any PAF and prolonged PAF were identified using multivariable regression analysis.

Results

In total, 504 patients without preoperative atrial fibrillation underwent isolated MVS. Of them, 303 patients (60.2%) developed PAF; 138 (27.3%) developed transient and 165 (32.7%) developed prolonged (beyond 30 days) PAF. Patients with PAF were older (65.7 vs 54.3 years, P < .001), with larger left atria (4.8 vs 4.3 cm, P < .001), greater prevalence of hypertension (60% vs 47.8%, P < .05), and were New York Heart Association class III/IV (36% vs 8.5%, P < .001). Independent predictors of PAF included left atria volume index (odds ratio [OR], 1.02; P < .003), older age (OR, 1.04; P < .001), heart failure (OR, 6.73; P < .001), and sternotomy (OR, 2.19; P < .002). Age, heart failure, and sternotomy were independent predictors of prolonged PAF. Patients with PAF had greater mortality at 3 years compared with those without PAF (5.3% vs 0.5%, P < .005). On multivariable analysis, PAF was associated with increased mortality (hazard ratio, 7.81; P < .046).

Conclusions

PAF is common after MVS and associated with late mortality. Older age, advanced heart failure, and sternotomy are associated with prolonged PAF. These factors may identify patients who would benefit from prophylactic LAAA or ablation during MVS.

Minimally Invasive Isolated Aortic Valve Replacement in a Potential TAVI Cohort of Patients Aged ≥ 75 Years: A Propensity-Matched Analysis

(1) Background and Objectives: Transcatheter aortic valve implantation is guideline-recommended from the age of 75. However, this European guideline recommendation is based on limited evidence, since no interaction between age and primary outcome has been found in guideline-stated references. This study aimed to compare the short-term outcomes of minimally invasive isolated aortic valve replacement in patients aged ≥ 75 with those of younger patients; (2) Patients and Methods: This retrospective cohort study included 1339 patients who underwent minimally invasive isolated aortic valve replacement at our facility between 2014 and 2022. This cohort was divided into two age-based groups: <75 and ≥75 years. Operative morbidity and mortality were compared between groups. Further analysis was performed using propensity score matching; (3) Results: After matching, 347 pairs of patients were included and analyzed. Despite the higher EuroSCORE II in the ≥75 group (2.2 ± 1.3% vs. 1.80 ± 1.34%, p ≤ 0.001), the 30-day mortality (1.4% vs. 1.2%; p = 0.90) and major adverse cardiac and cerebrovascular events, such as perioperative myocardial infarction (0.0% vs. 1.2%, p = 0.12) and stroke (1.4% vs. 2.6%, p = 0.06), were comparable between both treatment groups; (4) Conclusions: Minimally invasive aortic valve replacement is a safe treatment method for patients aged ≥ 75. Our results indicate that the unilateral cut-off of 75 years is not a limiting factor for performing minimally invasive aortic valve replacement.

Machine Learning Models of Postoperative Atrial Fibrillation Prediction After Cardiac Surgery

OBJECTIVES

This study aimed to use machine learning algorithms to build an efficient forecasting model of atrial fibrillation after cardiac surgery, and to compare the predictive performance of machine learning to traditional logistic regression.

DESIGN

A retrospective study.

SETTING

Second Affiliated Hospital of Zhejiang University School of Medicine.

PARTICIPANTS

The study comprised 1,400 patients who underwent valve and/or coronary artery bypass grafting surgery with cardiopulmonary bypass from September 1, 2013 to December 31, 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two machine learning approaches (gradient-boosting decision tree and support-vector machine) and logistic regression were used to build predictive models. The performance was compared by the area under the curve (AUC). The clinical practicability was assessed using decision curve analysis. Postoperative atrial fibrillation occurred in 519 patients (37.1%). The AUCs of the support-vector machine, logistic regression, and gradient boosting decision tree were 0.777 (95% CI: 0.772-0.781), 0.767 (95% CI: 0.762-0.772), and 0.765 (95% CI: 0.761-0.770), respectively. As decision curve analysis manifested, these models had achieved appropriate net benefit.

CONCLUSION

In the authors' study, the support-vector machine model was the best predictor; it may be an effective tool for predicting atrial fibrillation after cardiac surgery.

Similar clinical outcomes with transcatheter aortic valve implantation and surgical aortic valve replacement in octogenarians with aortic stenosis

Background

Transcatheter aortic valve implantation (TAVI) is the preferred treatment option for severe aortic stenosis in the elderly and in patients with comorbidities. We sought to compare outcomes after TAVI and surgical aortic valve replacement (SAVR) in octogenarians.

Methods

In this retrospective cohort study conducted at our tertiary center, clinical data were gathered before and after TAVI and SAVR procedures performed from January 2013 to May 2019; follow-up completed in March 2021. The primary outcome was 1-year mortality. Patients were stratified according to Society of Thoracic Surgeons (STS) score and procedure type. Propensity score-based matching was also performed.

Results

Of 542 patients who matched the inclusion criteria, 273 underwent TAVI and 269 SAVR. TAVI patients were older (85.8 ± 3.0 vs. 82.2 ± 2.2 years; P &lt; 0.001) and had a higher mean STS score (5.0 ± 4.0 vs. 2.8 ± 1.3; P &lt; 0.001) and EuroSCORE II (5.3 ± 4.1 vs. 2.8 ± 6.0; P &lt; 0.001). Rates of postoperative permanent pacemaker insertion (15.0% vs. 9.3%; P = 0.040) and paravalvular leak (9.9% vs. 0.8%; P &lt; 0.001) were higher and acute kidney injury lower (8.8% vs. 32.7%; P &lt; 0.001) after TAVI, with no difference between treatment groups for major bleeding (11.0% vs. 6.7%; P = 0.130) or 30-day mortality (5.5% vs. 3.7%; P = 0.315). A statistically significant difference was found between TAVI and SAVR in low- and intermediate-risk groups when it came to occurrence of paravalvular leak, acute kidney injury, and new onset AF (all P &lt; 0.001).

Conclusion

This analysis of an octogenarian “real-life” population undergoing TAVI or SAVR (with a biological valve) showed similar outcomes regarding clinical endpoints in low- and medium-risk (STS score) groups.

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.

Routine left atrial appendage occlusion in patients undergoing cardiac surgery: a narrative review

PURPOSE OF REVIEW

New evidence suggests a greater prevalence of protracted postoperative atrial fibrillation (POAF) than previously recognized. The left atrial appendage (LAA) is the most common source of embolism in patients with nonvalvular atrial fibrillation. In this review, we ask whether there is evidence to support routine LAA occlusion (LAAO) in patients without preexisting atrial fibrillation undergoing cardiac surgery.

RECENT FINDINGS

Overall, available studies are small, inconsistent and have varying proportions of patients with and without preexisting atrial fibrillation. There is considerable discrepancy with respect to the efficacy of LAAO in reducing the risk of POAF-related stroke. Only one study reported a lower rate of stroke in the LAAO group compared with no LAAO. Two studies included a subgroup analysis of patients that developed POAF and report a significantly higher rate of stroke in patients that developed POAF and did not undergo LAAO. There are three clinical trials ongoing that are investigating prophylactic LAAO in patients undergoing cardiac surgery: ATLAS, LAA-CLOSURE and LAACS-2.

SUMMARY

There is currently insufficient evidence to recommend routine addition of LAAO to lower the risk of postoperative stroke. Ongoing clinical trials will provide important insight into the role of routine LAAO in all patients undergoing cardiac surgery.

Late onset atrial fibrillation in patients undergoing surgical aortic valve replacement

OBJECTIVE

Aortic valve disease is a risk factor for atrial fibrillation (AF), and AF is associated with increased late mortality and morbidity after cardiac surgery. The evolution of alternative approaches to AF prophylaxis, including less invasive technologies and medical therapies, has altered the balance between risk and potential benefit for prophylactic intervention at the time of surgical aortic valve replacement (SAVR). Such interventions impose incremental risk, however, making an understanding of predictors of new onset AF that persists beyond the perioperative episode relevant.

METHODS

We conducted a retrospective single-institution cohort analysis of patients undergoing SAVR with no history of preoperative AF (n = 1014). These patients were cross-referenced against an institutional electrocardiogram (ECG) database to identify those with ECGs 3-12 months after surgery. Logistic regression was used to identify predictors of late AF.

RESULTS

Among the 401 patients (40%), who had ECGs in our institution 3-12 months after surgery, 16 (4%) had late AF. Patients with late AF were older than patients without late AF (73 vs. 65, p = .025), and underwent procedures that were more urgent/emergent (38% vs. 15%, p = .015), with higher predicted risk of mortality (2.2% vs. 1.3%, p = .012). Predictors associated with the development of late AF were advanced age, higher preoperative creatinine level and urgent/emergent surgery.

CONCLUSIONS

The incidence of late AF 3-12 months after SAVR, is low. Prophylactic AF interventions at the time of SAVR may not be warranted.

Rhythm outcomes after aortic valve surgery: Treatment and evolution of new-onset atrial fibrillation

BACKGROUND

The impact of new-onset atrial fibrillation (AF) after aortic valve (AV) surgery on mid- and long-term outcomes is under debate. Here, we sought to follow up heart rhythms after AV surgery, and to evaluate the mid-term prognosis and effectiveness of treatment for patients with new-onset AF.

METHODS

This single-center cohort study included 978 consecutive patients (median age, 59 years; male, 68.5%) who underwent surgical AV procedures between 2017 and 2018. All patients with postoperative new-onset AF were treated with Class III antiarrhythmic drugs with or without electrical cardioversion (rhythm control). Status of survival, stroke, and rhythm outcomes were collected and compared between patients with and without new-onset AF.

RESULTS

New-onset AF was detected in 256 (26.2%) patients. For them, postoperative survival was comparable with those without new-onset AF (1-year: 96.1% vs. 99.3%; adjusted P = .30), but rate of stroke was significantly higher (1-year: 4.0% vs. 2.2%; adjusted P = .020). With rhythm control management, the 3-month and 1-year rates of paroxysmal or persistent AF between patients with and without new-onset AF were 5.1% versus 1.3% and 7.5% versus 2.1%, respectively (both P < .001). Multivariate models showed that advanced age, impaired ejection fraction, new-onset AF and discontinuation of beta-blockers were predictors of AF at 1 year.

CONCLUSIONS

In most cases, new-onset AF after AV surgery could be effectively converted and suppressed by rhythm control therapy. Nevertheless, new-onset AF predisposed patients to higher risks of stroke and AF within 1 year, for whom prophylactic procedures and continuous beta-blockers could be beneficial.

Effect of Continuous Electrocardiogram Monitoring on Detection of Undiagnosed Atrial Fibrillation After Hospitalization for Cardiac Surgery: A Randomized Clinical Trial

IMPORTANCE

Postoperative atrial fibrillation (POAF) occurring after cardiac surgery is associated with adverse outcomes. Whether POAF persists beyond discharge is not well defined.

OBJECTIVE

To determine whether continuous cardiac rhythm monitoring enhances detection of POAF among cardiac surgical patients during the first 30 days after hospital discharge compared with usual care.

DESIGN, SETTING, AND PARTICIPANTS

This study is an investigator-initiated, open-label, multicenter, randomized clinical trial conducted at 10 Canadian centers. Enrollment spanned from March 2017 to March 2020, with follow-up through September 11, 2020. As a result of the COVID-19 pandemic, enrollment stopped on July 17, 2020, at which point 85% of the proposed sample size was enrolled. Cardiac surgical patients with CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes, prior stroke or transient ischemic attack, vascular disease, age 65-74 years, female sex) score greater than or equal to 4 or greater than or equal to 2 with risk factors for POAF, no history of preoperative AF, and POAF lasting less than 24 hours during hospitalization were enrolled.

INTERVENTIONS

The intervention group underwent continuous cardiac rhythm monitoring with wearable, patch-based monitors for 30 days after randomization. Monitoring was not mandated in the usual care group within 30 days after randomization.

MAIN OUTCOMES AND MEASURES

The primary outcome was cumulative AF and/or atrial flutter lasting 6 minutes or longer detected by continuous cardiac rhythm monitoring or by a 12-lead electrocardiogram within 30 days of randomization. Prespecified secondary outcomes included cumulative AF lasting 6 hours or longer and 24 hours or longer within 30 days of randomization, death, myocardial infarction, ischemic stroke, non-central nervous system thromboembolism, major bleeding, and oral anticoagulation prescription.

RESULTS

Of the 336 patients randomized (163 patients in the intervention group and 173 patients in the usual care group; mean [SD] age, 67.4 [8.1] years; 73 women [21.7%]; median [interquartile range] CHA2DS2-VASc score, 4.0 [3.0-4.0] points), 307 (91.4%) completed the trial. In the intent-to-treat analysis, the primary end point occurred in 32 patients (19.6%) in the intervention group vs 3 patients (1.7%) in the usual care group (absolute difference, 17.9%; 95% CI, 11.5%-24.3%; P < .001). AF lasting 6 hours or longer was detected in 14 patients (8.6%) in the intervention group vs 0 patients in the usual care group (absolute difference, 8.6%; 95% CI, 4.3%-12.9%; P < .001).

CONCLUSIONS AND RELEVANCE

In post-cardiac surgical patients at high risk of stroke, no preoperative AF history, and AF lasting less than 24 hours during hospitalization, continuous monitoring revealed a significant increase in the rate of POAF after discharge that would otherwise not be detected by usual care. Studies are needed to examine whether these patients will benefit from oral anticoagulation therapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02793895.

Biochemical predictors of postoperative atrial fibrillation following cardiac surgery

Background

New-onset postoperative atrial fibrillation (POAF) is common after cardiac surgery. Early identification of its risk factors during the preoperative period would help in reducing the associated morbidity, mortality, and healthcare costs.

Aim of the study

This study aimed to identify the predictors of POAF following open cardiac surgery, with emphasis on biochemical parameters.

Methods

A total of 1191 patients with no preoperative atrial fibrillation (AF) and undergoing open cardiac surgery for any reason were included in this retrospective study. Data on clinical and biochemical parameters, the occurrence of new-onset AF, and its clinical course were retrieved from the hospital database.

Results

During the early postoperative period 330 patients (27.7%) developed atrial fibrillation, at median third postoperative day (range 1–6 days) and 217 (65.8%) responded to treatment. Multivariate analysis identified the following as the significant independent predictors of any POAF: EF < 60% (Odds ratio (OR), 2.6), valvular intervention (OR, 2.4), liver failure (OR, 2.4), diabetes (OR, 1.6), low hematocrit (OR, 2.1), low thrombocyte (OR, 5.6), low LDL (OR, 1.6), high direct bilirubin (OR, 2.0), low GFR (OR, 1.6), and high CRP (OR, 2.0). Following parameters emerged as significant independent predictors of persistent AF: EF < 60% (OR, 1.9), diabetes (OR, 2.1), COPD (OR, 1.8), previous cardiac surgery (OR, 3.1), valvular intervention (OR, 2.4), low hematocrit (OR, 1.9), low LDL (OR, 2.1), high HbA1c (OR, 2.0), and high CRP (OR, 2.7).

Conclusions

Certain parameters assessed during preoperative physical and laboratory examinations have the potential to be used as markers of POAF.

The preoperative glomerular filtration rate predicts new-onset postoperative atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy who undergo isolated septal myectomy

Background

Few studies have focused on new-onset postoperative atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy who have undergone septal myectomy. Therefore, we investigated the incidence and prognosis effects of postoperative atrial fibrillation following septal myectomy in patients with hypertensive obstructive cardiomyopathy. Additionally, we investigated the relationship of estimated glomerular filtration rate and postoperative atrial fibrillation.

Methods

Data from 300 patients with hypertrophic obstructive cardiomyopathy who underwent isolated surgical septal myectomy were collected from January 2012 to March 2018.

Results

The overall incidence of postoperative atrial fibrillation during hospitalization was 22.67% (68 of 300 patients). Patients with postoperative atrial fibrillation were older (P<0.001), had lower preoperative estimated glomerular filtration rate (P<0.001), and a larger preoperative left atrial diameter (P=0.038) compared to patients without. The preoperative estimated glomerular filtration rate predicted postoperative atrial fibrillation with sensitivity and specificity of 0.824 and 0.578 (P<0.001), respectively. Multivariate regression analyses showed that age [odds ratio (OR) =1.090, 95% confidence interval (CI): 1.034-1.110], an New York Heart Association functional class ≥ III (OR =2.985, 95% CI: 1.349-6.604), hypertension (OR =2.212, 95% CI: 1.062-4.608), a history of syncope (OR =3.890, 95% CI: 1.741-8.692), and the preoperative estimated glomerular filtration rate (OR =0.981, 95% CI: 0.965-0.996) were independent risk factors associated in the development of postoperative atrial fibrillation. Survival analysis showed that the incidence of long-term cardiovascular events was higher in the patients with postoperative atrial fibrillation than that in the patients without the condition (P<0.001).

Conclusions

The preoperative estimated glomerular filtration rate was a moderate predictor of postoperative atrial fibrillation after septal myectomy. Postoperative atrial fibrillation affected the early recovery and the long-term prognoses of patients with hypertrophic obstructive cardiomyopathy who underwent septal myectomy.