Title of Trial
The Australian Intervention Randomized Control of Rate in Atrial Fibrillation (AIRCRAFT)

Date and Location of Presentation
This study was presented as an abstract at NASPE 2002

Date and Citation of Primary Publication(s) or References
May 2003, JACC 41:1697-702i

Purpose of the Trial
This multi-center trial compared atrioventricular junction ablation with pharmacologic ventricular rate control in patients with permanent atrial fibrillation and mild to moderate symptoms.

Study Categories
Ablation and Atrial Fibrillation

Patient Population
Patients with permanent atrial fibrillation with mild to moderate symptoms, preserved LV function and a ventricular rate that was controlled with medications

Inclusion Criteria

1. Age > 40
2. Symptomatic permanent atrial fibrillation (>12 months or with failed cardioversion) with uncontrolled ventricular rate in witch a good rate control could be achieved by drugs over a three month period
3. The ability to give informed consent
4. The ability to perform a treadmill test

Exclusion Criteria

1. Clinical indication for ablation or pacing
2. The likelihood of surgery or transcatheter valvuloplasty within 12 months of enrollment
3. Untreated resting mean ventricular rate <80 bpm and <150 bpm during exercise
4. Unstable angina
5. Wolf-Parkinson-White Syndrome
6. Severe tricuspid regurgitation or tricuspid prosthetic valve
7. New York Heart Association Class IV despite medical therapy
8. Unwillingness or inability to cooperate or to give informed consent
9. A serious medical condition that would preclude optimal participation in the study
10. An occupation or hobby that precluded permanent pacing
11. Inability to travel to the study center for follow-up

Study Design

Randomized controlled Trial (Un-blinded). In the pharmacologic treatment arm, drugs were prescribed to obtain optimal heart rate control. Medications used include digoxin, metoprolol, atenolol, verapamil and diltiazem. The choice of rate control agents was that of the treating physician. In the ablation treatment arm, patients underwent ablation of the His bundle that resulted in complete heart block. A Pacesetter Trilogy SR pacemaker was implanted and programmed to VVIR. Ablation patients discontinued use of rate control agents unless these medications were used for other reasons.

All patients underwent treadmill testing, echocardiogram, holter monitoring and a quality of life questionnaire at the end of 6 months and 12 months.

Primary Endpoint

Cardiac function as measured by echo and exercise tolerance

Secondary Endpoints

Ventricular rate control. Quality of Life

Baseline Characteristics

Number of patients: 99

Mean Age:   68 ± 8.7

Gender: % female;    29%

Other characteristics

Ischemic heart disease was noted in 40% of patients. The mean duration of atrial fibrillation was 68 ± 104 months. 77% of patients were taking warfarin. 44% of patients had a diagnosis of hypertension.

Years Follow-up:  One year

Results

49 patients were randomized to the ablation group, while 50 patients were randomized to the medication group. There were no significant baseline differences between groups. No significant change was observed in left ventricular ejection fraction in either group during the study. There was no significant difference in exercise time during treadmill testing in either group during the study. Holter monitoring at 12 months revealed a higher lower and mean heart rate for the ablation group and a lower maximum heart rate for the ablation group. Overall quality of life with the assessment of quality of life questionnaire was not significantly different between the two groups. Using the CAST (developed for use in the cardiac arrhythmia suppression trial) quality of life questionnaire the ablation group had a 6.6 point reduction in the symptom scale (RR 18%, p=0.004). Global assessment of quality of life using the CAST quality of life questionnaire revealed that the ablation group reported a 6% better quality of life (p=0.01)

Sponsor:
Pacesetter INC, Getz Brothers proprietary limited (Sydney Australia)

Trial Status: Completed

Review written by Amin Al-Ahmad, MD