Surgery for Atrial Fibrillation: A Worldwide Review

Risk Factors for Atrial Fibrillation Recurrence After Cox Maze IV Performed Without Pre-exclusion

BACKGROUND

New guidelines from The Society of Thoracic Surgeons recommend adding surgical ablation as a concomitant procedure for class I indications. We performed the maze procedure for all patients who experienced atrial fibrillation (AF) before cardiac surgery, without surgeon pre-exclusion.

METHODS

We retrospectively analyzed 83 patients, aged 71 ± 11 years (22% >80 years), who underwent Cox maze IV for persistent AF between 2014 and 2017. The mean AF duration (AFD) was 6.9 ± 8.6 years and European System for Cardiac Operative Risk Evaluation II was 7.2 ± 6.8.

RESULTS

The 30-day mortality was 2.4%. During follow-up (mean, 675 days), the 1-, 2-, and 3-year survival rates were 92%, 86%, and 82%, respectively. No strokes were observed despite a mean CHA₂DS₂-VAS_C (Congestive heart failure, Hypertension, Age [≥65 = 1 point, ≥75 = 2 points], Diabetes, and Stroke/transient ischemic attack [2 points], vascular disease, Sex [female = 1 point]) score of 4.1 (expected stroke rate, 4%/y). Twelve patients required a new pacemaker; 56 of 73 survivors (77%) remained AF free. Multivariate logistic regression identified preoperative AFD, f wave size, and mean heart rate per Holter as important risk factors for AF recurrence, with AFD as the most important: 98% of patients with AFD less than 5 years remained AF free. Although the AF-free rate with the AFD of 5 or more years was only 55%, their symptoms improved without heart failure readmission. Concomitant atrial plication was performed more frequently in the group with AFD for 5 or more years, with greater atrial volume reduction and appreciable increases in stroke volume.

CONCLUSIONS

The Cox maze IV procedure performed without pre-exclusion showed reasonable survival rates. Although AF recurred in patients with longer AFD, they fared well with substantial increases in stroke volume. Concomitant atrial volume reduction may have contributed to these additional benefits.

Modified Maze Procedure for Atrial Fibrillation as an Adjunct to Elective Cardiac Surgery: Predictors of Mid-Term Recurrence and Echocardiographic Follow-Up

The radiofrequency maze procedure achieves sinus rhythm in 45%-95% of patients treated for atrial fibrillation. This retrospective study evaluates mid-term results of the radiofrequency maze-performed concomitant to elective cardiac surgery-to determine sinus-rhythm predictive factors, and describes the evolution of patients' echocardiographic variables. From 2003 through 2011, 247 patients (mean age, 64 ± 9.5 yr) with structural heart disease (79.3% mitral disease) and atrial fibrillation underwent a concomitant radiofrequency modified maze procedure. Patients were monitored by 24-hour Holter at 3, 6, 12, and 24 months, then annually. Eighty-four mitral-valve patients underwent regular echocardiographic follow-up. Univariate and multivariate analysis for risk factors of maze failure were identified. The in-hospital mortality rate was 1.2%. During a median follow-up of 39.4 months, the late mortality rate was 3.6%, and pacemaker insertion was necessary in 26 patients (9.4%). Sinus rhythm was present in 63% of patients at the latest follow-up. Predictive factors for atrial fibrillation recurrence were arrhythmia duration (hazard ratio [HR]=1.296, P=0.045) and atrial fibrillation at hospital discharge (HR=2.03, P=0.019). The monopolar device favored maze success (HR=0.191, P <0.0001). Left atrial area and indexed left ventricular end-diastolic volume showed significant decrease both in sinus rhythm and atrial fibrillation patients. Early sinus rhythm conversion was associated with improved left ventricular ejection fraction. Concomitant radiofrequency maze procedure provided remarkable outcomes. Shorter preoperative atrial fibrillation duration, monopolar device use, and prompt treatment of arrhythmia recurrences increase the midterm success rate. Early sinus rhythm restoration seems to result in better left ventricular ejection fraction recovery.

Radiofrequency ablation for atrial fibrillation during concomitant cardiac surgery. Mid-term results

BACKGROUND

Atrial fibrillation is found in an increasing number of patients undergoing open heart surgery. It is associated with higher mortality rates, risk of stroke and left ventricular dysfunction. Surgical ablation for atrial fibrillation has evolved from the complex"cut and sew" Maze procedure to less invasive techniques, utilizing alternative energy sources. We present our experience with left atrial radiofrequency ablation during cardiac surgery, outlining the technical aspects of the procedure and postoperative outcomes, with emphasis on mid-term freedom from atrial fibrillation.

METHODS

The study included 93 consecutive patients with history of atrial fibrillation scheduled for cardiac surgery between January 2008 and December 2011. Concomitant left atrial radiofrequency ablation was performed using monopolar (endocardial) or bipolar (epicardial) systems, depending on the type of underlying cardiac pathology. Duration of the atrial fibrillation, re-do surgery, low ejection fraction, advanced age, or giant left atria were not considered as contraindications.

RESULTS

Of the included patients, 73.1 % were discharged in stable sinus rhythm. Overall freedom from atrial fibrillation was 69.6 % at late follow-up, which ranged from 12 to 48 months (median, 22 months) and did not differ for the two approaches (epicardial vs. endocardial). The presence of early atrial tachyarrhythmia was a predictor of atrial fibrillation recurrence (p = 0.026). Age was also associated with higher recurrence rates during hospital stay (p = 0.04), but not for late atrial fibrillation.

CONCLUSION

Concomitant left atrial radiofrequency ablation conveyed satisfactory early and mid-term rhythm control, with acceptable postoperative outcomes, given the risk profile of our patient cohort.

Surgical Maze procedure as a treatment for atrial fibrillation: a meta-analysis of randomized controlled trials

Surgical or modified Maze procedures have been promoted to treat atrial fibrillation (AF); however, few randomized controlled clinical trials (RCTs) examine their outcomes. The purpose of this meta-analysis is to compare the efficacy of surgical Maze procedures performed concomitantly with referral cardiac surgery versus pharmacologic therapy for the treatment of AF. We searched MEDLINE, Cochrane database, FDA web-portal, and clinicaltrials.gov for all RCTs comparing surgical Maze procedures with medical therapy for sinus rhythm maintenance. Primary outcomes were either freedom from AF within 12 months postprocedure off antiarrhythmic drug (AAD), or freedom from AF while taking an AAD. Secondary outcomes included operative mortality, all-cause mortality, hospital length of stay, and postoperative complications. Both fixed- and random-effects models were used for a meta-analysis of 9 randomized controlled trials (n = 472, of which 249 underwent a Maze procedure and 213 underwent referral surgery alone). The surgical Maze procedure significantly increased the odds of freedom from AF within 12 months compared with cardiac surgery alone (OR 5.22, 95% CI 1.71-15.88). There was significant heterogeneity among the trials for freedom from AF (chi-square = 15.98 for 4 degrees of freedom, P= 0.003). Among the two studies that fully reported AAD use, there was no evidence of improved survival free from AF and AAD therapy (OR 1.78, 95% CI 0.73-4.34). Among patients with valvular AF, surgical Maze procedures are associated with a decrease in AF one year postprocedure without significant increase in mean length of hospital stay, perioperative complications, operative, or all-cause mortality. Large RCTs defining rates of freedom from AF without AADs postprocedure, are still needed to evaluate outcomes and determine the appropriate role for surgical Maze procedures in the management of AF.