Septal Pacing for Atrial Fibrillation Suppression Evaluation - SAFE

Aug 14, 2013
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Author/Summarized by Author:
Anthony A. Bavry, MD, MPH, FACC
Summary Reviewer:
Deepak L. Bhatt, MD, MPH, MBA, FACC
Trial Sponsor:
St. Jude Medical
Date Published:
01/01/2013
Date Updated:
08/14/2013
Original Posted Date:
08/14/2013
References

Description:

The goal of the trial was to evaluate the impact of site and rate of atrial pacing among patients with paroxysmal atrial fibrillation and sick sinus syndrome.

Hypothesis:

Pacing from the atrial septum with continuous overdrive pacing will prevent the development of persistent atrial fibrillation.

Study Design

  • Randomized
  • Parallel

Patient Populations:

  • Patients ≥18 years of age with paroxysmal atrial fibrillation and sick sinus syndrome undergoing permanent pacer implantation

    Number of enrollees: 385
    Duration of follow-up: 3.1 years
    Mean patient age: 70 years
    Percentage female: 57%
    Mean ejection fraction: 65%

Exclusions:

  • Prior permanent pacer or defibrillator
  • Anticipated heart surgery within the next 6 months
  • Angina (class III or IV)
  • Expected not to tolerate high rate pacing
  • Limited life expectancy
  • Awaiting cardiac transplant
  • Reversible etiology for atrial fibrillation

Primary Endpoints:

  • Persistent atrial fibrillation

Drug/Procedures Used:

Patients from Asia and Europe with paroxysmal atrial fibrillation and sick sinus syndrome were randomized to right atrial appendage pacing with a continuous overdrive pacing algorithm (n = 98), right atrial appendage pacing with no continuous overdrive pacing algorithm (n = 99), right atrial septum pacing with a continuous overdrive pacing algorithm (n = 92), or right atrial septum pacing with no continuous overdrive pacing algorithm (n = 96).

The continuous atrial overdrive pacing algorithm was constructed to ensure a high percentage of pacing from the right atrium.

Concomitant Medications:

  • Beta-blockers: 20%
  • Sotolol: 3%
  • Amiodarone: 12%
  • Aspirin: 37%
  • Warfarin: 11%

Principal Findings:

Overall, 385 patients were randomized. The mean age was 70 years, 57% were women, 54% had hypertension, 16% had diabetes, mean left ventricular ejection fraction was 65%, and mean left atrial size was 39 mm.

At a mean follow-up of 3.1 years, the primary outcome of persistent atrial fibrillation occurred in 26% of patients.

Pacing from the right atrial septum compared with the right atrial appendage did not prevent the occurrence of persistent atrial fibrillation (hazard ratio [HR], 1.18; 95% confidence interval [CI], 0.79-1.75; p = 0.65).

Continuous atrial overdrive pacing algorithm compared with no continuous atrial overdrive pacing algorithm also did not prevent the occurrence of persistent atrial fibrillation (HR, 1.17; 95% CI, 0.79-1.74; p = 0.69).

There was no difference in findings according to tested subgroups.

Interpretation:

Among patients with paroxysmal atrial fibrillation and sick sinus syndrome, pacing from an alternative site (right atrial septum) or pacing with a continuous atrial overdrive algorithm did not prevent the occurrence of persistent atrial fibrillation. While this study was negative, it does not negate prior studies, which revealed that atrial pacing compared with ventricular pacing prevents the occurrence of atrial fibrillation.

References:

Lau CP, Tachapong N, Wang CC, et al. Prospective Randomized Study to Assess the Efficacy of Site and Rate of Atrial Pacing on Long-Term Progression of Atrial Fibrillation in Sick Sinus Syndrome: Septal Pacing for Atrial Fibrillation Suppression Evaluation (SAFE) Study. Circulation 2013;Jul 18:[Epub ahead of print].

Keywords: Heart Atria, Follow-Up Studies, Atrial Appendage, Cardiac Pacing, Artificial, Sick Sinus Syndrome, Stroke Volume, Confidence Intervals, Heart Ventricles, Hypertension, Diabetes Mellitus, Atrial Septum


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