Risk Factors of Recurrence of Atrial Fibrillation (AF) After AF Surgery in Patients With AF and Mitral Valve Disease

An effective prediction model based on XGBoost for the 12-month recurrence of AF patients after RFA

BACKGROUND

Atrial fibrillation (AF) is a common heart rhythm disorder that can lead to complications such as stroke and heart failure. Radiofrequency ablation (RFA) is a procedure used to treat AF, but it is not always successful in maintaining a normal heart rhythm. This study aimed to construct a clinical prediction model based on extreme gradient boosting (XGBoost) for AF recurrence 12 months after ablation.

METHODS

The 27-dimensional data of 359 patients with AF undergoing RFA in the First Affiliated Hospital of Soochow University from October 2018 to November 2021 were retrospectively analysed. We adopted the logistic regression, support vector machine (SVM), random forest (RF) and XGBoost methods to conduct the experiment. To evaluate the performance of the prediction, we used the area under the receiver operating characteristic curve (AUC), the area under the precision-recall curve (AP), and calibration curves of both the training and testing sets. Finally, Shapley additive explanations (SHAP) were utilized to explain the significance of the variables.

RESULTS

Of the 27-dimensional variables, ejection fraction (EF) of the left atrial appendage (LAA), N-terminal probrain natriuretic peptide (NT-proBNP), global peak longitudinal strain of the LAA (LAAGPLS), left atrial diameter (LAD), diabetes mellitus (DM) history, and female sex had a significant role in the predictive model. The experimental results demonstrated that XGBoost exhibited the best performance among these methods, and the accuracy, specificity, sensitivity, precision and F1 score (a measure of test accuracy) of XGBoost were 86.1%, 89.7%, 71.4%, 62.5% and 0.67, respectively. In addition, SHAP analysis also proved that the 6 parameters were decisive for the effect of the XGBoost-based prediction model.

CONCLUSIONS

We proposed an effective model based on XGBoost that can be used to predict the recurrence of AF patients after RFA. This prediction result can guide treatment decisions and help to optimize the management of AF.

Clinical factors associated with arrhythmia and short-term prognosis following mitral valve repair: a retrospective cohort study

BACKGROUND

Postoperative arrhythmia (POA) is one of the common and serious postoperative complications. This retrospective study was conducted to investigate the clinical factors associated with POA and its short-term prognosis following mitral valve repair.

METHODS

A total of 618 patients receiving mitral valve repair between January 2015 and November 2020 in our hospital were included in this retrospective study, including 318 males and 300 females and aged 53.9±9.3 years. The patients were grouped into arrhythmia and non-arrhythmia groups and investigated for risk factors associated with the prognosis of POA using multivariate logistic regression based on their clinical data.

RESULTS

POA was observed in 314 (50.8%) patients and atrial fibrillation (AF) was the most frequent (43.3%) type of POA. Compared with non-arrhythmia patients, arrhythmia patients had significantly longer time to use vasoactive drug use, longer intensive care unit (ICU) stay and longer hospital stay. In addition, the incidence of postoperative heart failure was significantly higher (P<0.05). Logistic regression analysis showed that preoperative arrhythmia [odds ratio (OR) =9.17; 95% confident interval (CI): 4.49-18.10], postoperative pain (OR =4.70; 95% CI: 1.55-6.12) and postoperative hypoxemia (OR =3.25; 95% CI: 1.04-6.28) were independently associated with POA.

CONCLUSIONS

This study demonstrates that the incidence of arrhythmia is relatively high after mitral valve repair and is associated with preoperative arrhythmia, postoperative pain and postoperative hypoxemia.

Left Atrial Appendage Exclusion in Atrial Fibrillation Radiofrequency Ablation during Mitral Valve Surgery: A Single-Center Experience

Background

Atrial fibrillation surgical radiofrequency ablation (AFSA) during mitral valve surgery (MVS) has almost completely superseded the Cox-Maze procedure for the treatment of atrial fibrillation.

Methods

We retrospectively analyzed 100 patients who underwent MVS + AFSA in our institution from January 2008 to June 2017. We compared the effectiveness of AFSA in patients who underwent LAA exclusion to those who did not. Moreover, we analyzed the role of preoperative AF duration (≤ or >1 year) and medial-lateral left atrial dimensions (ML-LAD) (≤ or >6 cm). The efficacy endpoint was freedom from AF at discharge and at 2-year follow-up. The safety endpoints were need of a permanent pacemaker (PMK), surgical re-exploration, occurrence of stroke, and left circumflex artery or esophageal lesions.

Results

Overall, the rate of AF freedom was 69% at discharge and 80% at 2-year follow-up. LAA exclusion did not influence AF freedom at 2-year follow-up, and 84.6% of patients who underwent LAA exclusion were in the sinus rythm (SR) at 2 year compared to 75% of those who did not receive LAA exclusion free from AF as well (p=0.230). AF duration ≤1 or >1 year did not influence sinus rhythm (SR) maintenance (85.7% vs. 75.8%; p=0.224), and in these two groups, LAA exclusion did not change the efficacy of AFSA. ML-LAD ≤ 6 cm was associated with better results in terms of SR maintenance. A statistically significant association between LAA exclusion and SR maintenance at 2-year follow-up (p=0.017) was found among patients with ML-LAD ≤ 6 cm. Complications included 7 cases of PMK implantation, 2 cases of surgical re-exploration, and 1 case of stroke. No circumflex artery or esophageal lesions occurred after surgical procedures.

Conclusions

In our experience, AFSA during isolated MVS resulted in good outcomes in terms of SR maintenance and incidence of complications. AF duration ≤ 1 year did not influence results, while patients with ML-LAD ≤ 6 cm had significantly better results regarding SR at follow-up. In patients with ML-LAD ≤ 6 cm, LAA exclusion significantly increased the success rate of SR maintenance at 2-year follow-up.

Does Surgical Ablation of Atrial Fibrillation Benefit Patients Undergoing Bioprosthetic Valve Replacement?

The benefit of avoiding lifelong anticoagulation therapy in patients with bioprosthetic heart valve implantation may potentially be offset by atrial fibrillation (AF); however, clinical impact of surgical AF ablation in such patients remains controversial. We enrolled 426 patients (aged 72.0 ± 7.8 years) with AF who underwent left-side valve replacement with bioprostheses between 2001 and 2018. Of these, 297 underwent concomitant surgical ablation (ablation group) and 129 underwent valve replacement alone (non-ablation group). Clinical outcomes were compared, and mortality was considered as a competing risk factor against valve-related complications. Inverse-probability weighting (IPTW) was adopted to reduce selection bias. The ablation group had lower baseline risk profiles than the non-ablation group. In crude analysis, early mortality rates were 3.4% and 7.0% in the ablation and non-ablation groups, respectively (P = 0.104). During follow-up (1521.9 patient-years), the ablation group showed lower AF-recurrence (P < 0.001) and anticoagulant medication rate (P = 0.021), and lower overall mortality risk (subdistribution hazard ratio [SHR], 0.63; 95% confidence interval [CI], 0.42-0.94), but higher risk of permanent pacemaker implantation (SHR, 4.67; 95% CI, 1.36-16.05). No significant difference in the risk of stroke (SHR, 1.27; 95% CI, 0.55-2.95) was observed between the groups. After baseline IPTW-adjustment, findings of the clinical outcomes were analogous to those from crude analyses. In patients undergoing bioprosthetic valve replacement, the addition of surgical ablation was associated with improved rhythm outcomes and survival but at the expense of a higher risk of pacemaker implantation. The underlying mechanism of improved survival by AF ablation needs further investigation.

Cox-maze III procedure for atrial fibrillation during valve surgery: a single institution experience

Objectives

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in patients with heart valve disease. Our aim was to summarize our experience and evaluate the efficacy and safety of the Cox maze III procedure combined with valve surgery in patients with AF.

Methods

A retrospective, observational analysis was performed for all consecutive patients underwent maze III procedure combined with valve surgery between October 2015 and June 2019. In this trial, we used a monopolar radiofrequency (RF) ablation in addition to cut and sew technique to treat AF.

Results

66 patients (37 female, 56.1%) with persistent or long-lasting persistent AF associated with valve disease were identified. The mean age was 54.2 ± 8.4 years (range, 30 to 73 years). Overall hospital mortality was 3.0%. The duration of cardiopulmonary bypass and aortic cross clamping was 175.4 ± 32.9 and 115.6 ± 22.8 min respectively. The first 24 h drainage was 488.6 ± 293.3 ml. The postoperative hospital stay was 14.8 ± 8.3 days. The postoperative incidence of permanent pacemaker implantation, reoperation for bleeding, renal failure required hemodialysis, and stroke was 4.5, 1.5, 4.5% and 0 respectively. The frequency of sinus rhythm was 91.7, 93.1, 94.7, 93.3 and 89.5% at 1, 3, 6, 12, and 24 months respectively.

Conclusions

The Cox-Maze III procedure is safe in the surgical treatment of AF associated with valve disease, and efficacious for sinus rhythm maintenance, with low morbidity and mortality.