Sinus Rhythm Off Research Articles

Abstract 15976: Results of the Full Cox-Maze Procedure: EKG vs 24-Hour Holter vs One-Week Long-Term Holter Monitoring

Introduction: Much of work published on Cox-Maze procedure results has utilized EKGs or 24-hour Holter without information on anti-arrhythmic drugs (AAD). The purpose of this study was to explore results at 6 and 24 months following the Cox-Maze procedure using various rhythm monitoring techniques. Hypothesis: It was hypothesized that long-term monitoring (LTM) would identify more patients who experienced atrial arrhythmia (AA) at each time point than other monitoring techniques. Methods: Cox-Maze III/IV patients off AAD were offered 1-week LTM with n=220 at 6 and n=94 at 24 months. EKG, 24-hour Holter, and LTM were ascertained at the same time. The HRS definition (AA >30 seconds) was used for ablation failure. Results: At 6 months EKG found n=216 returned to sinus rhythm (SR), 24-hr Holter found n=211 returned to SR, while n=203 were in SR by LTM (FIGURE). Of patients experiencing AA at 6 months, duration <1 hour was documented in 56% by 24-hr Holter and 59% by LTM (FIGURE). At 24 months, EKG found n=89 returned to SR, 24-hr Holter found n=88 returned to SR, while n=85 were in SR by LTM. Of patients experiencing AA at 24 months, duration <1 hour was documented in 50% by 24-hr Holter and 67% by LTM. At 6 months, percent in SR differed for EKG vs LTM (p<0.001) and 24-hr Holter vs LTM (p=0.02). At 24 months, monitoring methods did not differ. Conclusions: The Cox-Maze procedure demonstrated high return to SR off AAD, regardless of monitoring technique. However, LTM provides more accuracy earlier in postoperative period and should be used when discussing discontinuation of anticoagulation. Due to clinical and financial challenges in applying LTM, patients in which LTM has most value should be identified.

A39 Session 11: Cardiovascular Disease Intervention: Afib cryo-ablation as a concomitant procedure to aneurysm repair

Since the development of cryo-energy for surgical ablation of atrial fibrillation, the procedure has become safer and more effective as concomitant to coronary or valve surgery. However, it is still only performed in a fraction these cases when indicated, and less often in patients undergoing aneurysm surgery. We describe our experience in patients undergoing ascending aneurysm repair and concomitant surgical cryoablative atrial fibrillation MAZE. From January 2004 until November 2011, 40 patients underwent ascending aneurysm repair and surgical cryo-ablation at our institution and were retrospectively analyzed. Average age was 67.6 years (43–85) and nine (23%) patients were female. Preoperative, intraoperative, and postoperative variables including complications, rhythm success, and survival were analyzed. Aortic root replacement was performed in 23 (57.5%) and arch replacement with circulatory arrest in 18 (45%). An average of 5 lesions were performed. Each was performed for 60 s. All lesions achieved temperatures of −120 °C. At an average of 41.8 months, 81% of patients were in sinus rhythm, and 63% were in sinus rhythm off antiarrhythmic medications. Operative survival was 100%, with actuarial one and five year survivals of 97.5% and 93.1%, respectively. Kaplan–Meier analysis revealed improved overall survival in patients with rhythm success (log-rank test p = 0.037). Aortic aneurysm repair with concomitant Cryo-ablative MAZE is safe and efficacious despite the requirement for an already extensive procedure. Excellent short and long term survival can be achieved as can rhythm success rates similar to those quoted in the setting of other procedures. Successful restoration of sinus rhythm improves long term survival and should be considered in patients presenting with aortic aneurysm and atrial fibrillation.

The effect of the Cox-maze procedure for atrial fibrillation concomitant to mitral and tricuspid valve surgery

Atrial fibrillation (AF) is associated with less favorable outcomes in patients undergoing mitral valve and tricuspid valve surgery. Despite growing evidence on the potential benefits of surgical ablation for AF there is significant variability among surgeons in treatment of AF. The purpose of our study was to assess the effect of the Cox-maze procedure on operative and follow-up outcomes. In our prospective study, patients who underwent isolated mitral valve or mitral valve+tricuspid valve surgery without history of AF (n=506), with untreated AF (n=75), or with Cox-maze procedure (n=236) were included (N=817). Sinus rhythm was captured according to Heart Rhythm Society guidelines. Patientswho underwent the Cox-maze procedure were propensity score matched to patients without history of AF resulting in 208 pairs of patients. Operative outcomes were comparable after propensity score matching (Cox-maze procedure vs no AF) stroke/transient ischemic attack (0.5% vs 0.5%; P=1.00), renal failure (2.9% vs 1.4%; P=.34), and operative mortality (1.4% vs 1.4%; P=1.00). High return to sinus rhythm was documented at 6, 12, and 24 months (92%,91%, and 86%, respectively) as well as sinus rhythm off antiarrhythmic drugs (79%, 84%, and 82%, respectively). Incidence of embolic stroke in patients who underwent Cox-maze procedure was 1.7% (4 out of 232 patients) and 5.1 cases per 1000 person-years. No difference in 4-year cumulative survival between propensity score-matched groups (91.9% vs 86.9%; log rank, 1.67; P=.20), but higher for patients who underwent Cox-maze procedure versus patients with untreated AF (hazard ratio, 2.47; P=.048). Higher additive European System for Cardiac Operative Risk Evaluation (odds ratio, 1.40; P<.001) and limited surgeon experience with Cox-maze procedure (odds ratio, 3.60; P<.001) were significant predictors for failure to perform Cox-maze procedure. In our center, 76% of patients undergoing mitral valve or mitral valve+tricuspid valve surgery experiencing AF underwent concomitant Cox-maze procedure, which is considerably higher than the national average. No increased morbidity was associated with the Cox-maze procedure with the benefit of very low thromboembolic rate. These results suggest the need for performance-based education for AF surgical ablation to achieve optimal outcomes.

Ganglionated plexi ablation vs linear ablation in patients undergoing pulmonary vein isolation for persistent/longstanding persistent atrial fibrillation: a randomized comparison

Introduction: The optimal ablation technique for persistent and longstanding persistent Atrial Fibrillation (AF) is unclear. Both Linear Lesions (LL) and Ganglionated Plexi (GP) ablation have been used, in addition to Pulmonary Vein Isolation (PVI), but no direct comparison of the two methods exists. Methods: Two hundred sixty four consecutive patients with persistent/longstanding persistent AF were randomly assigned to 2 different ablation schemes: PVI+LL (n=132) and PVI+GP ablation (n=132). Consistent Sinus Rhythm (SR) off antiarrhythmic drug was assessed after follow-up of at least 3 years with the use of an implanted monitoring device (IMD). Results: All procedural endpoints were acutely achieved. At 12 months following a single procedure, 47% of patients treated with PVI+LL were in SR compared to 54% of patients treated with PVI+GP (p=0.29). At 3 years, 34% of patients with PVI+LL and 49% of patients with PVI+GP maintained SR (p=0.035). Atrial flutter was more frequent in PVI+LL than in PVI+GP ablation group (18% versus 6%, P=0.002). After a second procedure in 78 patients of the PVI+LL group and 55 patients of the PVI+GP group, the long-term overall success rate was 52% and 68%, respectively (p=0.006). Conclusions: PVI+GP ablation confers superior clinical results with less ablation-related left atrial flutter and reduced AF recurrence compared to PVI+LL at 3 years of follow-up.

A Prospective Randomized Study Comparing Isolation of the Arrhythmogenic Vein Versus All Veins in Paroxysmal Atrial Fibrillation

Ablation procedures in patients with paroxysmal atrial fibrillation (PAF) includes isolation of all pulmonary veins (PVs). We hypothesized that an approach using an algorithm to detect arrhythmogenic PVs (aPVs) might lead to shorter procedure duration (PD) and fewer proarrhythmic effects (PE). Isolation of the aPVs only leads to a reduced PD, reduced PEs, and fewer adverse events, with a success rate comparable to the standard all-PV approach. In this prospective trial, 207 patients with PAF were randomized to undergo isolation of the aPV (AG group, n = 105) or isolation of all PVs (VG group, n = 102). The aPV was identified by atrial fibrillation (AF) induction, focal discharge, or short local PV decremental conduction during PV pacing. Patients were followed with repetitive 7-day Holter electrocardiograms (ECGs) after 3, 6, and 12 months in our arrhythmia clinic. In 97% of patients, at least 1 aPV was identified (mean, 2.1). PD did not differ significantly (152.3 ± 57.1 minutes vs 162 ± 68 minutes, P = 0.27) between the groups, but the number of radiofrequency (RF) applications and fluoroscopy time (FT) and dose were significantly lower in the AG group than in the VG group. The occurrence of PE (new-onset atrial tachycardia) and adverse events (AE) did not differ between the 2 groups (P = 0.1). Sinus rhythm off antiarrhythmic medication (documented on 7-day Holter ECGs) 12 months after a single procedure was achieved in 53% in the AG group and 59% in the VG group (P = 0.51). Isolation of the aPVs detected by a straightforward algorithm leads to similar success rates compared to a standard all-PV approach with regard to PD, AE, or PE and is associated with less RF and a shorter FT.

Are There Gender Differences in Outcomes after the Cox-Maze Procedure for Atrial Fibrillation?

Atrial fibrillation (AF) management suggests that women do not tolerate medication rhythm control strategies as well as men do; however, AF percutaneous catheter ablation has been found to be favorable. The study purpose was to compare the sex-based outcomes for patients who undergo the Cox-Maze procedure for AF. Data were collected through our AF surgical ablation registry. Rhythm was verified by electrocardiogram and 24-hour holter at 6 and 12 months. General health-related quality of life (Short-Form 12) and specific AF symptom burden (Atrial Fibrillation Symptom Checklist: Frequency and Severity, version 3) were obtained at baseline and 12 months. Since 2005, a total of 540 patients have undergone a Cox-Maze procedure (34% were women). The women presented with higher operative risk [additive European System for Cardiac Operative Risk Evaluation (EuroSCORE), 6.71 ± 2.61 vs 5.25 ± 2.80, t = 5.85, P < 0.001], higher rates of congestive heart failure (49% vs 32%, P < 0.001), and more concomitant mitral valve procedures (32% vs 19%, P = 0.001). Perioperative outcomes were similar. Return to sinus rhythm off antiarrhythmics were not different at 6 and 12 months (78% vs 75%, P = 0.53, and 81% vs 80%, P = 1.00, respectively). Cumulative 2-year survival (93.9% for the men and 89.3% for the women) was not different for all-cause mortality (hazard ratio, 1.47; confidence interval, 0.68-3.21; P = 0.33) and cardiac-related mortality [women: 10/14 (71%) vs men 7/11 (64%), P = 1.00]. Health-related quality of life showed significant improvement; AF symptoms significantly decreased across the sexes. Outcomes after the Cox-Maze procedure are similar across sex. Atrial fibrillation surgical ablation should be considered a treatment option for women-it is safe and effective, improves general health-related quality of life, and reduces AF symptom burden.

Ganglionated plexus ablation vs linear ablation in patients undergoing pulmonary vein isolation for persistent/long-standing persistent atrial fibrillation: A randomized comparison

The optimal ablation technique for persistent and long-standing persistent atrial fibrillation (AF) is unclear. Both linear lesion (LL) and ganglionated plexus (GP) ablation have been used in addition to pulmonary vein isolation (PVI), but no direct comparison of the 2 methods exists. The aim of this study is to assess the comparative safety and efficacy of 2 different ablation strategies-PVI+LL vs PVI+GP ablation -in patients with persistent or long-standing persistent AF. Two hundred sixty-four consecutive patients with persistent/long-standing persistent AF were randomly assigned to 2 different ablation schemes: PVI+LL (n = 132) and PVI+GP (n = 132) ablation. Consistent sinus rhythm (SR) off antiarrhythmic drug was assessed after follow-up of at least 3 years with the use of an implanted monitoring device. All procedural end points were acutely achieved. At 12 months after a single procedure, 47% of the patients treated with PVI+LL were in SR compared to 54% of the patients treated with PVI+GP (P = .29). At 3 years, 34% of the patients with PVI+LL and 49% of the patients with PVI+GP maintained SR (P = .035). Atrial flutter was more frequent in the PVI+LL group than in PVI+GP group (18% vs 6%; P = .002). After a second procedure in 78 patients of the PVI+LL group and 55 patients of the PVI+GP group, the long-term overall success rate was 52% and 68%, respectively (P = .006). PVI+GP ablation confers superior clinical results with less ablation-related left atrial flutter and reduced AF recurrence compared to PVI+LL ablation at 3 years of follow-up.

Outcome of Concomitant Cox-Maze III Procedure Using an Argon-Based Cryosurgical System: A Single-Center Experience With 250 Patients

The Cox-Maze procedure (CM) for atrial fibrillation (AF) is associated with a high rate of sinus restoration. This study assessed the safety and efficacy of concomitant CM using an argon-based cryosurgical platform only. Data were collected prospectively for 250 consecutive patients undergoing concomitant cryosurgical CM. We examined baseline characteristics, perioperative and postoperative outcomes, health-related quality of life (Medical Outcomes Trust SF-12 Health Survey and AF Symptom Checklist) and Kaplan-Meier survival analysis. Mean age was 64.3 ± 12.1 years, AF duration was 35.7 ± 54.2 months, left atrial size was 5.2 cm (range, 3.1 to 11.0 cm; 16.8% > 6 cm), 86% had nonparoxysmal AF, with history of cardioversion in 32% and catheter ablation in 8%. Concomitant procedures were mitral valve operation in 69.6%, coronary artery bypass graft in 29.2%, aortic valve replacement in 22.0%, with 46% multiple concomitant procedures and 16% with a previous cardiac operation. Perioperative outcomes were 5 deaths (2%), 3 strokes (1%), 1 transient ischemic attack (<1%), and 4 pacemakers for sinus node dysfunction (2%). There were no late thromboembolic events (mean follow-up, 28.2 ± 23.7 months), and 11% were taking warfarin for atrial arrhythmia at 1 year. Significant improvement in health-related quality of life (p < 0.001) was noted. At24months, 92.4% of patients were in sinus rhythm; with 82.8% in sinus rhythm off antiarrhythmic drugs. Two-year cumulative survival was 91%. The cryosurgical CM procedure can be performed safely and effectively as defined by the low number of postoperative morbidities, high return to sinus rhythm off antiarrhythmic drugs, and low rate of thromboembolic events, with most patients off anticoagulation by 2 years.

Catheter Ablation for Persistent Atrial Fibrillation

A new era of atrial fibrillation (AF) treatment began in 1997–1998 with the discovery that triggers within the pulmonary veins initiate AF and reports that elimination of these triggers is successful in treating AF in its paroxysmal form.1–3 However, in patients with persistent AF, the success rate of exclusive pulmonary vein isolation is substantially lower.4,5 To improve the outcome of persistent AF ablation, different ablation strategies have been explored, but to date the optimal strategy has not been defined. Although some groups argue that limited ablation, including pulmonary vein isolation and, if present, ablation of nonpulmonary vein triggers, is sufficient for persistent AF ablation, other groups, including ours, favor more extensive, substrate-based ablation in addition to pulmonary vein isolation. In this review, we will discuss the rationale for a substrate-based ablation strategy to treat persistent AF and show why elimination of triggers is not sufficient in most patients with persistent AF. Response by Roten et al on p 1232 In a simple model, an electric impulse in AF can form because of abnormalities in impulse generation (triggers) or can result from abnormal impulse propagation (reentry). By a strict definition, a trigger is a focal source of new impulse generation. The mechanism by which a new impulse can form is either abnormal automaticity or triggered activity. Trigger-ablation protocols target these sources of new impulse generation. Abnormal impulse propagation, on the other hand, depends on altered substrate properties causing nonuniform or slowed conduction. This in turn causes multiple forms of wave reentry thought to be responsible for AF perpetuation: random reentry (multiple wavelets), macro- and microreentry, or functional reentry (rotors). Substrate-based ablation strategies aim to abate abnormal impulse propagation and interrupt any form of atrial reentry. Triggers of paroxysmal AF are mainly located in the pulmonary …

POSTER PRESENTATIONS

POSTER PRESENTATIONS

The Outcome of the Cox Maze Procedure in Patients With Previous Percutaneous Catheter Ablation to Treat Atrial Fibrillation

Surgical ablation may be performed on symptomatic patients who failed catheter ablation. We investigated the outcomes of patients who presented for Cox Maze III/IV procedure (CM III/IV) after failing at least one left-sided ablation. Forty patients were identified as having had at least one left-sided ablation (mean 2.3 ablations per patient). Rhythm was verified using electrocardiograms and 24-hour Holter monitoring. Health-related Quality of life (HRQL) (SF-12) and the Symptom Frequency and Severity Checklist were collected before surgery and postoperatively. The majority of patients (N=38) presented with long standing persistent atrial fibrillation (mean, 50.16 months). There was 1 operative death, 1 noncardiac death in late follow-up (mean, 25.5 months), and no embolic strokes. The return to sinus rhythm off class I/III antiarrhythmic drugs at 6, 12, and 24 months was 76% (29/38), 89% (23/26), 93% (13/14), respectively: 7 patients required cardioversion; 4 patients required another ablation. For every additional ablation before surgery, there was almost 4 times greater odds of receiving a follow-up intervention (OR=3.58, p=0.02, CI: 1.21-10.56). Exit block was tested on 96 previously ablated pulmonary veins and 91 (95%) were found to conduct. HRQL and symptom/severity scores improved significantly postoperatively (p=0.02)/(p=0.03), respectively. Surgical ablation following failed catheter ablation is safe and effective. Over 90% of the tested pulmonary veins were not isolated at time of surgery questioning the validity of documented acute conduction block during catheter ablation. Increase in the number of ablations before the surgical ablation may be related to inferior outcomes.

Cryoablation inside the pulmonary vein after failure of radiofrequency antral isolation

Antral pulmonary vein (PV) ablation with radiofrequency (RF) energy has become widely used as a curative approach for the treatment of atrial fibrillation. In some patients, despite antral ablation, PV entry and exit conduction block (BDB) cannot be achieved with RF energy. Cryoablation inside the PV may be an effective method to achieve BDB. This study sought to describe a strategy of cryoablation within the PV to produce BDB in patients in whom antral RF ablation has failed. In 15 of 148 consecutive patients (57 +/- 8.9 years old, 80% male) with atrial fibrillation (14 paroxysmal, 1 chronic) undergoing PV isolation cryoablation (CryoCath Technologies, Inc., Montreal, Canada) was performed 12 +/- 2 mm inside the PV after RF antral isolation failed. Nine patients were undergoing a repeat PV isolation procedure. Procedural and follow-up data were recorded and collected. In these 15 patients, BDB could not be achieved in 23 veins (12 left superior PV) with antral or ostial ablation alone. After cryoablation inside the vein, all patients had documented PV BDB and were in normal sinus rhythm at the end of the procedure. The average PV diameter before and after the procedure was unchanged (1.77 +/- 0.18 vs 1.74 +/- 0.19, P = .641). The average fluoroscopic and procedure times were 57 +/- 16 min and 5.3 + 1.2 hours, respectively. At 1-year follow-up, 75% of patients remained in sinus rhythm off antiarrhythmic medication; 7 of 9 patients undergoing a repeat procedure were in sinus rhythm at 1 year off antiarrhythmics. None of the patients had clinical evidence of PV stenosis after cryoablation. Cryoablation inside the PV after failed antral isolation with RF is a safe and effective method to achieve acute BDB.

Linear Cryoablation of the Left Atrium Versus Pulmonary Vein Cryoisolation in Patients With Permanent Atrial Fibrillation and Valvular Heart Disease

The aim of this study was to clarify the role of pulmonary vein isolation (PVI) alone versus left atrial linear lesions in the treatment of permanent atrial fibrillation (AF) in patients with left atrial dilatation and valvular disease. The primary end point was to assess the persistence of sinus rhythm (SR) off antiarrhythmic drugs (AADs) at 2-year follow-up and to correlate clinical outcome with surgical results validated with electroanatomic mapping (EAM). A total of 105 patients with permanent AF undergoing valve surgery were assigned to 3 different groups: in groups "U" and "7," left atrial linear cryoablation was performed, whereas in group "PV" patients, anatomic cryoisolation of pulmonary veins only was performed. In groups U and 7, SR was achieved in 57% of patients, whereas it was achieved in 20% of PV patients during 2-year follow-up. In the first 51 patients, the ablation schemes were validated with EAM. The EAM showed that the U lesion was never obtained: in 59% of these patients, a complete 7 lesion was achieved instead; in the 7 group, a complete 7 lesion was present in 65% of patients, whereas a complete PVI was obtained in 71% of patients. Considering patients in whom a complete 7 lesion was demonstrated with the EAM, SR without AADs was achieved in 86% of patients, whereas only 25% of patients with complete PVI were in SR without AADs. In patients with permanent AF, left atrial dilatation and valvular heart disease linear lesions in the posterior region of the left atrium are more effective than PVI alone. With cryoablation, the surgical intent is fulfilled in only approximately 65% of the cases. Knowing the real anatomic and electrophysiological effects of surgical ablation is necessary to correctly interpret the clinical outcome.

Empirical pulmonary vein isolation in patients with chronic atrial fibrillation using a three-dimensional nonfluoroscopic mapping system: long-term follow-up.

The purpose of this study was to assess the feasibility and long-term results of empirical isolation of both superior pulmonary veins in patients with chronic AF. Although localizing and ablating the focal triggers of AF has been proven an effective approach, this strategy is time consuming, often requires multiple procedures, and carries the risk of pulmonary vein stenosis. Whether ostial electrical isolation of the superior pulmonary veins, without initial detailed mapping, is a more efficient approach is not known. The study included 71 consecutive patients who had chronic AF. Using a nonfluoroscopic electroanatomic mapping system, the left and right superior pulmonary veins were ablated circumferentially at the venoatrial junction, with the aim of achieving electrical isolation of the veins. Following ablation, if frequent atrial ectopies were present, mapping and ablation were considered. The patients were periodically followed with 48-hour Holter and loop recorder monitoring. After the ablation of the right and left superior pulmonary veins 59 (83%) of 71 patients maintained sinus rhythm without premature atrial beats. The remaining 12 patients underwent further mapping and ablation including 5 patients who required isolation of the left inferior pulmonary veins. True electrical isolation could be achieved only in 45 (31%) of the 147 targeted veins. At the latest follow-up (mean 29 +/- 8 months), 80% of the patients with upper vein isolation remained in sinus rhythm off medications, 62% of the patients maintained sinus rhythm on previously ineffective medications, and 17% continued to be in AF. Fourteen (20%) patients developed intermittent episodes of left atrial flutter, and mapping in these patients revealed large electrically silent areas in the left atrium. Empirical isolation of pulmonary veins appeared to be an effective approach to help maintain sinus rhythm in patients with chronic AF. True electrical isolation of the pulmonary veins was associated with a higher likelihood of long-term success. Left atrial flutter was seen in a significant number of patients at long-term follow-up.

1019-24 Atrial Fibrillation is Strongly Associated with Prolonged Hospital Stay After Open Heart Surgery Even After Correcting for Common Predictors of Morbidity

A trial fibrillation (AF) has been shown to be associated with prolonged hospital stay after open heart surgery. It has been difficult to establish whether AF is causally related to prolonged hospitalization or is simply a marker for more complicated patients. We identified 110 patients in sinus rhythm off antiarrhythmic medications prior to open heart surgery who developed at least 6 hours of AF after surgery and compared them to 96 randomly selected controls who did not develop AF. Patients that developed AF had a longer mean hospital stay after open heart surgery than did patients without postoperative AF (11.7 ± 8.l vs. 7.2 ± 4.4 days, p &lt; 0.0001, 95% CI 2.7 – p6.3 days). Only 15 patients (14%) had AF identified as the sole reason for extending their hospitalization at least one full day 12.5 ± 1.6 days per patient). Nevertheless, after controlling for history of congestive heart failure, myocardial infarction, or diabetes, age, ejection fraction, sex, the type of surgery performed, and bypass pump time. AF remained a highly significant (p &lt; 0.0001) predictor of the duration of hospitalization after surgery. The specific treatment of AF alone probably accounts for only a small portion of the prolonged hospitalization associated with new AF after open heart surgery. Despite this finding. the significantly prolonged hospitalizations of patients that develop AF and the powerful predictive value of AF for explaining prolonged hospital stay even after correcting for other clinical variables suggests that AF is not simply a marker for more complicated patients but in a causal manner contributes to prolonged hospitalization. Effective prevention and treatment of AF should significantly shorten the mean duration of hospitalization after open heart surgery.