The Surgical Treatment of Atrial Fibrillation Via Median Sternotomy

Surgical ablation for atrial fibrillation is efficacious in patients with giant left atria

OBJECTIVE

The Cox-Maze IV procedure (CMP-IV) is the most effective treatment for atrial fibrillation. Increased left atrial (LA) size has been identified as a risk factor for failure to restore sinus rhythm. This has biased many surgeons against ablation in patients with giant left atrium (GLA), defined as LA diameter >6.5 cm. In this study we aimed to define the efficacy of the CMP-IV in patients with GLA.

METHODS

From April 2004 through March 2020, 786 patients with a documented LA diameter underwent elective CMP-IV, 72 of whom had GLA. Median follow-up duration was 4 years (interquartile range, 1-7 years). Recurrence was defined as any documented atrial tachyarrhythmia (ATA) lasting 30 seconds. ATA recurrence and survival were analyzed across GLA versus non-GLA groups.

RESULTS

Median age at surgery was 65 (interquartile range, 56-73) years. Median LA diameter within the GLA group was 7.0 (range, 6.6-10.0) cm. There were no differences in rates of postoperative complications for the 2 groups, including rate of postoperative stroke and pacemaker placement (GLA 14%; non-GLA 12%; P = .682). A trend toward increased 30-day mortality in the GLA group did not reach statistical significance (GLA 6%; non-GLA 2%; P = .051). Freedom from ATAs at 5 years postoperatively was comparable for the 2 groups (GLA 82%; non-GLA 84%).

CONCLUSIONS

The CMP-IV had good efficacy in patients with GLA. Our results suggest that LA diameter >6.5 cm should not preclude a patient from undergoing surgical ablation for atrial fibrillation.

Minimally Invasive Mitral Valve Surgery With Concomitant Cox Maze Procedure Is as Effective as a Median Sternotomy With Decreased Morbidity

OBJECTIVE

A right minithoracotomy (RMT) is a minimally invasive surgical approach that has been increasingly performed for the concomitant Cox maze IV procedure (CMP) and mitral valve surgery (MVS). Little is known regarding whether long-term rhythm and survival outcomes are affected by the RMT as compared with the traditional median sternotomy (MS) approach.

METHODS

Between April 2004 and April 2021, 377 patients underwent the concomitant CMP and MVS, of whom 38% had RMT. Propensity score matching yielded 116 pairs. Freedom from atrial tachyarrhythmias (ATA) was assessed with prolonged monitoring annually for 8 years. Survival, rhythm, and perioperative outcomes were compared.

RESULTS

The unmatched RMT cohort had a greater freedom from ATA recurrence at 1 year (99% vs 90%, P = 0.001) and 3 years (94% vs 86%, P = 0.045). The matched RMT cohort had longer cardiopulmonary bypass (median: 215 [199 to 253] vs 170 [136 to 198] min, P < 0.001) and aortic cross-clamp (110 [98 to 124] vs 86 [71 to 102] min, P < 0.001) times but shorter intensive care time (48 [24 to 95] vs 71 [26 to 144] h, P = 0.001) and length of stay (8 [6 to 11] vs 10 [7 to 14] h, P < 0.001). More pacemakers (18% vs 4%, P < 0.001) and postoperative transfusions (57% vs 41%, P = 0.014) occurred in the MS cohort. The 30-day mortality (P = 0.651) and 8-year survival (P = 0.072) was not significantly different between the cohorts.

CONCLUSIONS

Early 1-year and 3-year freedom from ATA recurrence was better in the RMT cohort compared with the MS cohort. Despite longer operative times, the RMT cohort had shorter lengths of stay, fewer postoperative transfusions, and fewer pacemakers placed.

Impact of Obesity on Atrial Fibrillation Recurrence Following Stand-Alone Cox Maze IV Procedure

OBJECTIVE

Obesity is a strong and independent factor for the development of atrial fibrillation (AF), and adversely impacts the success of catheter ablation procedures for AF. This study evaluated the impact of body mass index (BMI) on the outcomes following surgical ablation of AF.

METHODS

Between 2003 and 2019, 236 patients underwent a stand-alone biatrial Cox maze IV procedure (CMP-IV) for refractory AF. Obesity was defined as BMI ≥30 kg/m². Patients were divided into two groups: BMI <30 kg/m² (n = 100) and BMI ≥30 kg/m² (n = 136). Freedom from atrial tachyarrhythmia (ATA) was determined using electrocardiography, Holter, or pacemaker interrogation at 1 year and annually thereafter. Recurrence was defined as any documented ATA lasting ≥30 s. Predictors of recurrence were determined using multivariable logistic regression. Preoperative and procedural outcomes were compared between groups.

RESULTS

Obese patients had a higher rate of diabetes (16% vs 7%, P = 0.044) and larger left atrial diameter (4.9 ± 1.1 cm vs 4.6 ± 1.0 cm, P = 0.021) when compared to non-obese patients. There was no difference in major complication rate between the groups (4% vs 7%, P = 0.389). There was no operative mortality in either group. During 4.1 ± 2.4 years of follow-up, there was no significant difference in freedom from ATA with or without antiarrhythmic drugs in obese patients when compared to the non-obese group (P > 0.05). Absence of sinus rhythm at discharge predicted AF recurrence up to 7 years postoperatively.

CONCLUSIONS

As opposed to catheter ablation, obesity did not adversely impact the short and long-term outcomes of stand-alone surgical ablation with CMP-IV, and BMI was not a predictor of AF recurrence. Additionally, there was no significant increase in major complications in obese patients.

Efficacy of the stand-alone Cox-Maze IV procedure in patients with longstanding persistent atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and results in significant morbidity and mortality. The Cox-Maze IV procedure (CMP-IV) has been shown to have excellent efficacy in returning patients to sinus rhythm, but there have been few reports of late follow-up in sizable cohorts of patients with longstanding persistent AF, the most difficult type of AF to treat.

METHODS AND RESULTS

Between May 2003 and March 2020, 174 consecutive patients underwent a stand-alone CMP-IV for longstanding persistent AF. Rhythm outcome was assessed postoperatively for up to 10 years, primarily via prolonged monitoring (Holter monitor, pacemaker interrogation, or implantable loop recorder). Fine-Gray regression was used to investigate factors associated with atrial tachyarrhythmia (ATA) recurrence, with death as a competing risk. Median duration of preoperative AF was 7.8 years (interquartile range: 4.0-12.0 years), with 71% (124/174) having failed at least one prior catheter-based ablation. There were no 30-day mortalities. Freedom from ATAs was 94% (120/128), 83% (53/64), and 88% (35/40) at 1, 5, and 7 years, respectively. On regression analysis, preoperative AF duration and early postoperative ATAs were associated with late ATAs recurrence.

CONCLUSION

Despite the majority of patients having a long-duration of preoperative AF and having failed at least one catheter-based ablation, the stand-alone CMP-IV had excellent late efficacy in patients with longstanding persistent AF, with low morbidity and no mortality. We recommend consideration of stand-alone CMP-IV for patients with longstanding persistent AF who have failed or are poor candidates for catheter ablation.

Late results after stand-alone surgical ablation for atrial fibrillation

OBJECTIVES

Stand-alone surgical ablation of atrial fibrillation is indicated in patients with refractory atrial fibrillation who have failed medical or catheter-based ablation. Few reports of late outcomes after stand-alone surgical ablation exist using comprehensive follow-up with strict definitions of success. This study examined our late outcomes of the stand-alone Cox-Maze IV procedure.

METHODS

Between January 2003 and December 2019, 236 patients underwent a stand-alone Cox-Maze IV for refractory atrial fibrillation. Freedom from atrial tachyarrhythmias was assessed by electrocardiography, Holter, or pacemaker interrogation for up to 10 years, with a mean follow-up of 4.8 ± 3.5 years. Rhythm outcomes were compared in multiple subgroups. Factors associated with recurrence were determined using Fine-Gray regression, allowing for death as the competing risk.

RESULTS

The majority of patients (176/236, 75%) had nonparoxysmal atrial fibrillation. Median duration of preoperative atrial fibrillation was 6.2 years (interquartile range, 3-11). Fifty-nine percent of patients (140/236) failed 1 or more prior catheter-based ablation. Thirteen patients (6%) experienced a major complication. There was no 30-day mortality. Freedom from atrial tachyarrhythmias was 94% (187/199), 89% (81/91), and 77% (24/31) at 1, 5, and 10 years, respectively. There was no difference in freedom from atrial tachyarrhythmias between patients with paroxysmal atrial fibrillation versus nonparoxysmal atrial fibrillation (P > .05) or those undergoing sternotomy versus a minimally invasive approach (P > .05). Increased left atrial size and number of catheter ablations were associated with late atrial fibrillation recurrence. For patients who experienced any atrial tachyarrhythmia recurrence, the median number of recurrences was 1.5 (1.0-3.0).

CONCLUSIONS

The stand-alone Cox-Maze IV had excellent late efficacy at maintaining sinus rhythm in patients with symptomatic, refractory atrial fibrillation, with low morbidity and no mortality. The Cox-Maze IV, in contrast to catheter-based ablation, was equally effective in patients with paroxysmal and nonparoxysmal atrial fibrillation.