Impact of Clinical Presentation and Surgeon Experience on the Decision to Perform Surgical Ablation

The Society of Thoracic Surgeons 2023 Clinical Practice Guidelines for the Surgical Treatment of Atrial Fibrillation

The Society of Thoracic Surgeons 2023 Clinical Practice Guidelines for the Surgical Treatment of Atrial Fibrillation incorporate the most recent evidence for surgical ablation and left atrial appendage occlusion in different clinical scenarios. Substantial new evidence regarding the risks and benefits of surgical left atrial appendage occlusion and the long-term benefits of surgical ablation has been produced in the last 5 years. Compared with the 2017 clinical practice guideline, the current update has an emphasis on surgical ablation in first-time, nonemergent cardiac surgery and its long-term benefits, an extension of the recommendation to perform surgical ablation in all patients with atrial fibrillation undergoing first-time, nonemergent cardiac surgery, and a new class I recommendation for left atrial appendage occlusion in all patients with atrial fibrillation undergoing first-time, nonemergent cardiac surgery. Further guidance is provided for patients with structural heart disease and atrial fibrillation being considered for transcatheter valve repair or replacement, as well as patients in need of isolated left atrial appendage management who are not candidates for surgical ablation. The importance of a multidisciplinary team assessment, treatment planning, and long-term follow-up are reiterated in this clinical practice guideline with a class I recommendation, along with the other recommendations from the 2017 guidelines that remained unchanged in their class of recommendation and level of evidence.

Statewide data on surgical ablation for atrial fibrillation: The data provide a path forward

OBJECTIVE

Atrial fibrillation (AF), if left untreated, is associated with increased intermediate and long-term morbidity/mortality. Surgical treatment for AF is lacking standardization in patient selection and lesion set, despite clear support from multi-society guidelines. The aim of this study was to analyze a statewide cardiac surgery registry to establish whether or not there is an association between center volume and type of index procedure with performance of surgical ablation (SA) for AF, the lesion set chosen, and ablation technology used.

METHODS

Adult, first-time, nonemergency patients with preoperative AF between 2014 and 2022 excluding standalone SA procedures from a statewide registry of Society of Thoracic Surgeons data were included (N = 4320). AF treatment variability by hospital volume (ordered from smallest to largest) and surgery type were examined with χ2 analyses. Hospital-level Spearman correlations compared hospital volume with proportion of AF patients treated with SA.

RESULTS

Overall, 37% of patients with AF were ablated at the time of surgery (63% of mitral procedures, 26% of non-mitrals) and 15% had left atrial appendage management only. There was a significant temporal trend of increasing performance of SA for AF over time (Cochran-Armitage = 27.8; P < .001). Hospital cardiac surgery volume did not correlate with the proportion of AF patients treated with SA (rs = 0.19; P = .603) with a rate of SA below the state average for academic centers. Of cases with SA (n = 1582), only 43% had a biatrial lesion set. Procedures that involved mitral surgery were more likely to include a biatrial lesion set (χ2 = 392.3; P < .001) for both paroxysmal and persistent AF. Similarly, ablation technology use was variable by type of concomitant operation (χ2 = 219.0; P < .001) such that radiofrequency energy was more likely to be used in non-mitral procedures.

CONCLUSIONS

These results indicate an increase in adoption of SA for AF over time. No association between greater hospital volume or academic status and performance of SA for AF was established. Similar to national data, the type of index procedure remains the most consistent factor in the decision to perform SA with a disconnect between AF pathophysiology and decision making on the type of SA performed. This analysis demonstrates a gap between evidence-based guidelines and real-world practice, highlighting an opportunity to confer the benefits of concomitant SA to more patients.

Temporal trends and predictors of surgical ablation for atrial fibrillation across a multistate healthcare system

Background

Multiple class I and class IIa recommendations exist related to surgical ablation (SA) of atrial fibrillation (AF) in patients undergoing cardiac surgery.

Objective

Examine temporal trends and predictors of SA for AF in a large US healthcare system.

Methods

We retrospectively analyzed data from the Society for Thoracic Surgery (STS) Adult Cardiac Surgery Database for 21 hospitals in the Providence St. Joseph Health system. All patients with preoperative AF who underwent isolated coronary artery bypass graft (CABG) surgery, isolated aortic valve replacement (AVR), AVR with CABG surgery (AVR+CABG), isolated mitral valve repair or replacement (MVRr), and MVRr with CABG surgery (MVRr+CABG) from July 1, 2014, to March 31, 2020 were included. Temporal trends in SA were evaluated using the Cochran-Armitage trends test. A multilevel logistic regression model was used to examine patient-, hospital-, and surgeon-level predictors of SA.

Results

Among 3124 patients with preoperative AF, 910 (29.1%) underwent SA. This was performed most often in those undergoing isolated MVRr (n = 324, 44.8%) or MVRr+CABG (n = 75, 35.2%). Rates of SA increased over time and were highly variable between hospitals. Years since graduation from medical school for the primary operator was one of the few predictors of SA: odds ratio (95% confidence interval) = 0.71 (0.56–0.90) for every 10-year increase. Annual surgical (both hospital and operator) and AF catheter ablation volumes were not predictive of SA.

Conclusion

Wide variability in rates of SA for AF exist, underscoring the need for greater preoperative collaboration between cardiologists, electrophysiologists, and cardiac surgeons.

Surgical Ablation of Permanent Atrial Fibrillation: Age, LV Dilatation, Obesity

OBJECTIVES

 Although concomitant surgical ablation can help to reach freedom from atrial fibrillation (FREEAF) even in patients with permanent atrial fibrillation (AF), some cardiac surgeons hesitate to perform concomitant ablation to avoid perioperative risk escalation. Here, we investigated outcome and predicators of therapeutic success of concomitant surgical ablation in an all-comers study.

METHODS

 Ablation-naïve patients with formerly accepted permanent AF (FAP, n = 41) or paroxysmal AF (parAF, n = 24) underwent concomitant epicardial bipolar radio frequency ablation and implantable loop recorder (ILR) at two surgical departments. Follow-up examination for 24 months included electrocardiogram, ILR readout, 24h Holter monitoring, echocardiography, and blood sampling.

RESULTS

 Eighty-six percent of parAF and 70% of FAP patients reached FREEAF (month 24). Mortality was low (parAF/FAP: 5.3 ± 0.2%/4.1 ± 0.3%; p < 0.05; EuroScoreII; 6.1 ± 0.7%/6.4 ± 0.4%, p = ns) and no strokes occurred. FREEAF induced atrial reverse remodeling (left atrial [LA] diameter: -6.7 ± 2.2 mm) and improved cardiac function (left ventricular ejection fraction [LVEF]: +7.3 ± 2.8%), while AF resulted in further atrial dilation (+8.0 ± 1.0 mm, p < 0.05) and LVEF reduction (-7.0 ± 1.3%, p < 0.05). Higher LV (odds ratio [OR]: 1.164) and LA diameter (OR: 1.218), age (OR: 1.180) and body mass index (BMI) (OR: 1.503) increased the risk factors of AF recurrence. Patients remaining in sinus rhythm (SR) demonstrated a decrease in BMI, while AF recurrence was associated with stable overweight. Further aging did not reduce FREEAF.

CONCLUSIONS

 Long-term SR is achievable by concomitant surgical ablation even in FAP patients. Therefore, it should be offered routinely. Obesity influences therapeutic long-term success but may also offer addressable therapeutic targets to reach higher FREEAF rates.

Is It Conceivable to Still Perform the Cut and Sew Cox Maze III Procedure in the Current Era?

To determine whether cut and sew Cox maze III procedure is still associated with adequate safety endpoints when performed in conjunction with other open-heart procedures. Between January 2008 and January 2015, 113 consecutive adult patients were submitted to cut and sew Cox maze III procedure in association with other operations for structural heart disease. Mean age was 49 years and 80 (70.8%) were females. Longstanding or persistent atrial fibrillation has occurred in 87.6% and rheumatic heart disease in 80.7%. Valve surgery was performed in 98.2%. The number of associated procedures was correlated with morbidity and hospital mortality. Overall mean cardiopulmonary bypass and aortic cross-clamping times were 129 ± 26 and 105 ± 23 minutes, respectively. Hospital mortality was 1.77%, re-exploration for bleeding 0.9%, cerebrovascular accident 1.8%, and acute renal failure requiring hemodialysis 2.6%. The greater number of associated procedures did not correlate with poorer safety outcomes. Permanent pacemaker was required in 18.2% of those with three associated procedures, as opposed to 4% with two procedures and no requirement with one procedure (P = .01). Frequency of sinus rhythm was 88%, 88%, and 85% at 6, 12, and 24 months, respectively. In a contemporary single-center cohort of predominantly rheumatic patients, the surgical treatment of atrial fibrillation associated with structural heart disease by means of cut and sew Cox maze III procedure is safe, with low morbidity and mortality rates. Surgical complexity, defined by number of associated procedures, did not translate into poorer safety endpoints, except for greater need of permanent pacemaker.

Long-term outcome following concomitant mitral valve surgery and Cox maze procedure for atrial fibrillation

OBJECTIVE

Atrial fibrillation (AF) is associated with increased early and long-term morbidity/mortality following valve surgery. This study examined long-term influence of concomitant full Cox maze (CM) and mitral valve procedures on freedom from atrial arrhythmia and stroke.

METHODS

This sample comprised patients who underwent CM with a mitral valve procedure (N = 473). Data on rhythm, medication status, and clinical events captured according to Heart Rhythm Society guidelines at 6, 9, 12, 18, and 24 months and yearly thereafter up to 7 years.

RESULTS

Mean age was 65 years, mean left atrium size was 5.3 cm, and 15% had paroxysmal AF. Perioperative stroke occurred in 2 patients (0.4%) and operative mortality was 2.7% (n = 13). Return to sinus rhythm regardless of antiarrhythmic drugs at 1, 5, and 7 years was 90%, 80%, and 66%. Sinus rhythm off antiarrhythmic drugs at 1, 5, and 7 years was 83%, 69%, and 55%. Freedom from embolic stroke at 7 years was 96.6% (0.4 strokes per 100 patient-years) with a majority of patients off anticoagulation medication. Greater odds of atrial arrhythmia recurrence during 7 years was associated with longer AF duration (odds ratio [OR], 1.07; P = .001), whereas lower odds were associated with cryothermal energy only (OR, 0.64; P = .045) and greater surgeon experience (OR, 0.98; P = .025).

CONCLUSIONS

This study suggests that the addition of CM to mitral valve procedures, even with a high degree of complexity, did not increase operative risk. In long-term follow-up, the CM procedure demonstrated acceptable rhythm success, reduced AF burden, and remarkably low stroke rate. Individual surgeon experience and training may notably influence long-term surgical ablation for AF success.

The Society of Thoracic Surgeons 2017 Clinical Practice Guidelines for the Surgical Treatment of Atrial Fibrillation

EXECUTIVE SUMMARY

Surgical ablation for atrial fibrillation (AF) can be performed without additional risk of operative mortality or major morbidity, and is recommended at the time of concomitant mitral operations to restore sinus rhythm. (Class I, Level A) Surgical ablation for AF can be performed without additional operative risk of mortality or major morbidity, and is recommended at the time of concomitant isolated aortic valve replacement, isolated coronary artery bypass graft surgery, and aortic valve replacement plus coronary artery bypass graft operations to restore sinus rhythm. (Class I, Level B nonrandomized) Surgical ablation for symptomatic AF in the absence of structural heart disease that is refractory to class I/III antiarrhythmic drugs or catheter-based therapy or both is reasonable as a primary stand-alone procedure, to restore sinus rhythm. (Class IIA, Level B randomized) Surgical ablation for symptomatic persistent or longstanding persistent AF in the absence of structural heart disease is reasonable, as a stand-alone procedure using the Cox-Maze III/IV lesion set compared with pulmonary vein isolation alone. (Class IIA, Level B nonrandomized) Surgical ablation for symptomatic AF in the setting of left atrial enlargement (≥4.5 cm) or more than moderate mitral regurgitation by pulmonary vein isolation alone is not recommended. (Class III no benefit, Level C expert opinion) It is reasonable to perform left atrial appendage excision or exclusion in conjunction with surgical ablation for AF for longitudinal thromboembolic morbidity prevention. (Class IIA, Level C limited data) At the time of concomitant cardiac operations in patients with AF, it is reasonable to surgically manage the left atrial appendage for longitudinal thromboembolic morbidity prevention. (Class IIA, Level C expert opinion) In the treatment of AF, multidisciplinary heart team assessment, treatment planning, and long-term follow-up can be useful and beneficial to optimize patient outcomes. (Class I, Level C expert opinion).

Should We Ablate Atrial Fibrillation During Coronary Artery Bypass Grafting and Aortic Valve Replacement?

BACKGROUND

This study evaluates the safety and efficacy of concomitant atrial fibrillation (AF) ablation in patients with AF undergoing coronary artery bypass grafting (CABG) or aortic valve replacement (AVR) or both.

METHODS

This is a single-center retrospective study of patients with AF presenting for CABG or AVR or both between 2009 and 2013. They were divided into an ablation group that underwent concomitant AF ablation and a control group that did not. Follow-up data were obtained using telephone interviews. The data were 100% complete with a median follow-up of 30 months.

RESULTS

A total of 375 patients with AF presented for CABG (44%), AVR (27%), or CABG and AVR (29%). The ablation (129 patients) and control (246 patients) groups had similar baseline characteristics. The ablation group had significantly longer cardiopulmonary bypass and cross-clamp times, adding a mean of 31 ± 3 and 22 ± 3 minutes (p < 0.01 for both), respectively. There were similar unadjusted rates of hospital mortality (4.7% versus 5.3%, p = 0.79), stroke (3.1% versus 3.3%, p = 0.94), and reopening (4.7% versus 6.5%, p = 0.46) between the groups. The intensive care and hospital length of stays were similar. The ablation group had a lower incidence of postoperative AF (27% versus 78%, p < 0.01). Adjusted operative mortality was similar, but the intervention group had significantly lower odds of postoperative AF (odds ratio 0.11, p < 0.01). Although there was no difference in mid-term survival, the ablation group had higher mid-term AF-free survival (p < 0.01) and a trend toward higher anticoagulation-free (p = 0.09) and stroke-free survival (p = 0.08).

CONCLUSIONS

Concomitant AF ablation in patients with AF undergoing CABG or AVR or both does not increase perioperative rates of mortality or morbidity. Moreover, concomitant AF ablation is effective at reducing postoperative AF burden and increases mid-term AF-free survival.