Early Outcome of Atrial Fibrillation Program at Methodist Medical Center of Illinois

ABSTRACT: Purpose. Our objective was to evaluate the early efficacy of a new atrial fibrillation (AF) program in Peoria, Illinois. Methods. This was a retrospective analysis of patients who had undergone AF ablation at the Methodist Medical Center of Illinois between February 19, 2010 and February 25, 2011. Information was obtained through patient medical records from hospital procedures as well as from office visits. Results. Twelve patients underwent AF ablation during this time; 75% of patients had paroxysmal AF, and 25% had chronic AF. As of May 2011, our follow-up showed 0% recurrence for paroxysmal AF and 0% recurrence for chronic AF. There was 1 major complication (delayed cardiac tamponade) and 1 minor complication (elevated LFTs). Twenty-five percent of patients experienced a reduction in antiarrhythmic medication, 50% of patients were able to discontinue antiarrhythmic medication, and in 25% there was no change of antiarrhythmic medication. Three patients required a second ablation. Average fluoro time was 22.4 minutes. Mean age was 62.2 years. Mean follow-up time for patients was 7.4 months. Conclusion. Early results of atrial fibrillation ablation at the Methodist Medical Center of Illinois are promising. Further data and follow-up are needed to evaluate long-term efficacy.

Atrial fibrillation presents both an economic and physical burden on patients. Approximately 16.6% of strokes originate from atrial fibrillation due to embolic phenomena.¹ Adjusted mortality based on the Framingham Heart Study is increased in patients with atrial fibrillation.² Furthermore, symptoms of atrial fibrillation can simply be quite bothersome to patients. Rate-controlling medications as well as antiarrhythmics may also contribute to a patient’s symptoms and interfere with their quality of life.

Atrial fibrillation ablation is an alternative treatment for patients who are symptomatic and who have failed or are intolerant to at least one antiarrhythmic medication. Methodist Medical Center is the first center in Peoria to start a specialized atrial fibrillation ablation program. Initiation of this program required special consideration in terms of staff training, equipment updates, and other logistics such as implementing protocols and strict patient follow-up for such detailed procedures. For example, before initiating the program we presented specialized training seminars to nursing and EP lab personnel on the procedure, post care and early detection of any complications. We also upgraded our EnSite system (St. Jude Medical, St. Paul, MN) to the newer version of Velocity, which is capable of segmentation and fusion. Staff training on transseptal puncture techniques was given. Finally, we implemented a special CT protocol for atrial fibrillation in collaboration with radiology.

It is of note to mention that we have also been able to minimize the use of fluoroscopy during our ablation procedures and have already performed cases (e.g., atrial fibrillation, atrial flutter, SVT, WPW, and ICD insertion) without fluoroscopy. The use of EnSite 3D mapping and intracardiac echo has been utilized, and has helped us minimize x-ray exposure to patients and staff. We are looking forward to eventually eliminating fluoroscopy use.

Our atrial fibrillation program started in January 2010, and along with electrophysiologist Dr. Adel Mina, it is supported by 5 cardiologists from Methodist Medical Group (Dr. Alexander Adler, Dr. Frank Gold, Dr. Tahir Ilahi, Dr. Joel Kupfer, Dr. Shahid Wazir, and our cardiovascular surgeon Dr. James Locher), 5 EP lab staff personnel, and 3 supportive mid-level personnel with strong collaborations with anesthesia, nursing and administrative staff.

The first atrial fibrillation procedure at the Methodist Medical Group was performed on February 20, 2010. Patients who underwent atrial fibrillation ablation between February 20, 2010 and February 25, 2011 were analyzed via chart and procedural reviews.

Methods

The following is an overview of the procedures used for atrial fibrillation ablation, as well as specifics for the twelve patients reviewed, including some information about hospital stay, follow-up and clinical outcomes.

After informed consent with detailed information was given to patients about the procedure, patients were brought into the EP lab.

Standard venous access using three 8 French sheaths were inserted into the right common femoral vein using ultrasound guidance. Likewise, 9 French sheaths were inserted into the left common femoral vein and 7 French sheaths were inserted into the right internal jugular vein.

Transesophageal echocardiogram was done prior to the procedure as well as a 64-slice CAT scan. Anatomy obtained from both modalities were integrated with electroanatomical mapping anatomy obtained from the EnSite Velocity System (St. Jude Medical).

Anticoagulation was done by keeping patients on coumadin. Target INR was between 2 and 3 before the procedure as well as after the procedure, for at least three months. Periodic INRs were done before and after the procedure.

General anesthesia with hemodynamic monitoring was done by the anesthesia team on all patients. Arterial lines were inserted through the femoral arteries to confirm hemodynamic stability.

An 8 French ACUSON AcuNav intracardiac echo catheter (Siemens Medical USA, Malvern, PA) was inserted into the left common femoral vein and placed into the right atrium. It was used to monitor transseptal puncture as well as confirm catheter stability and position, and was also used to evaluate catheter contact during ablation and provide safety guards for early detection of complications.

On some occasions, the intracardiac echo was advanced through the transseptal puncture into the left atrium to more clearly visualize the venous anatomy as well as give more detailed information about catheter contact.

Duodecapolar catheters were inserted through the right internal jugular vein into the coronary sinus with the proximal poles in the high right atrium. A right ventricular quadripolar catheter was inserted into the right ventricle.

Two transseptal punctures were performed using the ACross™ Transseptal Access System (St. Jude Medical). This was done under intracardiac echo as well as fluoroscopy guidance. Monitoring was also continued with hemodynamic guidance. The SafeSept™ Transseptal Guidewire (Pressure Products, Inc., San Pedro, CA) was used to avoid through and through punctures.

A spiral catheter was used to obtain electroanatomical mapping of the left atrium, which was later merged with CT imaging anatomy.

An esophageal temperature probe was advanced into the esophagus and intermittently repositioned in close proximity to the ablating catheter. It’s important to evaluate change in temperature during ablation; any significant rise of more than 0.5° was enough to consider lowering the wattage output or moving to another area. Power was titrated at 20 watts with an irrigation catheter in areas close to the esophagus.

In total there were nine patients with paroxysmal atrial fibrillation and three patients with persistent atrial fibrillation. We performed pulmonary vein isolation on twelve patients. Seven patients had roof line ablation, three patients had coronary sinus line and three patients had complex fractionated atrial electrogram ablation. Two patients had cavotricuspid isthmus line of block; this was only done for patients who had concomitant atrial flutter.

Substratate modification with roof line, CS-isthmus line and fractionated atrial electrogram ablation were done in persistent atrial fibrillation patients, and were also done in patients with paroxysmal atrial fibrillation who had inducible atrial fibrillation despite pulmonary vein isolation, until patients were rendered no longer inducible with rapid atrial pacing and Isuprel infusion.

Anticoagulation was done with heparin bolus, as well as drip to maintain ACT more than 350 and less than 400; frequent ACTs were checked every 15 minutes, and heparin was readjusted until ACTs remained stable.

Left atrial pressure, as well as patient input and output, were continuously monitored throughout the procedure. Ablation was performed using saline irrigation catheters with power of 35 watts except for areas close to the esophagus or inside the veins, when it was titrated to 20 watts. Care was taken to avoid ablation inside veins and rather to isolate veins just outside the os.

After ablation, if the patient continued to experience atrial fibrillation, DC cardioversion was done in 8.3% patients with paroxysmal AF and in 66.7% patient with persistent AF.

Isuprel was started in all patients with decremental atrial pacing down to a cycle length of 200. Approximately 8.3% of patients had inducible atrial fibrillation.

Protamine 30 to 40 mg was given, and catheters were removed at the end of the procedure. Hemostasis was achieved by manual pressure at venous access sites.

Patients stayed overnight and typically were sent home the second day. The average length of hospital stay was 2.4 days. The most common reason to extend hospital stay was for the patient to achieve therapeutic INR.

All patients were followed up periodically with a periodic Holter monitor done every three months as well as EKGs to evaluate for recurrence if the patient maintained sinus rhythm.

Regarding patient baseline characteristics, average left atrial size was 3.9 cm, and the average number of antiarrhythmics was 2.1. Average CHADS2 score was 1.58, 25% persistent and 75% paroxysmal.

Results

Mean follow-up time for patients was 7.4 months. Follow-up showed 100% of patients stayed in sinus rhythm and 83.3% had symptoms improved. We were able to decrease antiarrhythmic medications in 25% of patients and discontinue antiarrhythmics in 50%; there was no change in antiarrhythmic medications in the other 25% of patients. There was only one major complication due to delayed pericardial effusion twelve days post procedure, probably related to anticoagulation, and was successfully drained with no recurrence.

Conclusion

The atrial fibrillation ablation program at the Methodist Medical Center of Illinois, including the AF protocol described above, appear to be promising, with overall good safety and efficacy thus far. Compared with other studies,³ the patients from Methodist Medical Center of Illinois were a somewhat older population; however, despite the age difference, early outcomes were still favorable. Future data will be needed to evaluate long-term success and efficacy.

For more information, please visit: www.mymethodist.net/services/cardiovascular/

References

1. Fuster V, Ryden LE, Cannom DS, et al. ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation). J Am Coll Cardiol 2006;48:e149-246.
2. Benjamin EJ, Wolf PA, D'Agostino RB, et al. Impact of atrial fibrillation on the risk of death: the Framingham Heart Study. Circulation 1998;98:946-952.
3. Calkins H, Brugada J, Packer DL, et al. Heart Rhythm 2007 HRS/EHRA/ECAS expert Consensus Statement on catheter and surgical ablation of atrial fibrillation: recommendations for personnel, policy, procedures and follow-up. A report of the Heart Rhythm Society (HRS) Task Force on catheter and surgical ablation of atrial fibrillation. Heart Rhythm 2007;4:816-861.