OBJECTIVES: The VIP registry investigated the efficacy of preventive pacing algorithm
selection in reducing
atrial fibrillation (AF) burden. BACKGROUND: There are few data identifying which patients might benefit most from which preventive pacing algorithms. METHODS: Patients, with at least one documented AF episode and a conventional antibradycardia indication for
pacemaker therapy, were enrolled. They received
pacemakers with AF diagnostics and four preventive algorithms (
Selection and PreventAF series, Vitatron). A 3-month Diagnostic Phase with conventional pacing identified a
Substrate Group (>70% of AF episodes with <2
premature atrial contractions [PACs] before AF onset) and a Trigger Group (< or =70% of AF episodes with <2 PACs before AF onset). This was followed by a 3-month Therapeutic Phase where in the Trigger Group algorithms were enabled aimed at avoiding or preventing a PAC and in the
Substrate Group continuous
atrial overdrive pacing was enabled. RESULTS: One hundred and twenty-six patients were evaluated. In the Trigger Group (n = 73), there was a
statistically significant 28% improvement in AF burden (
median AF burden: 2.06 hours/day, Diagnostic Phase vs 1.49 hours/day, Therapy Phase; P = 0.03304 signed-rank test), and reduced PAC activity. There was no significant improvement in AF burden in the
Substrate Group (
median AF burden: 1.82 hours/day, Diagnostic Phase vs 2.38 hours/day, Therapy Phase; P = 0.12095 signed-rank test), and little change in PAC activity. CONCLUSIONS: We identified a subgroup of patients for whom the
selection of appropriate pacing algorithms, based on individual diagnostic data, translated into a reduced AF burden. Trigger AF patients were more likely responders to preventive pacing algorithms as a result of PAC suppression.
