The usefulness of minimal ventricular pacing and preventive AF algorithms in the treatment of PAF: the 'MinVPace' study

The beneficial effects of atrial pacing on the incidence, duration and symptomatology of paroxysmal atrial fibrillation (PAF) may be negated by increased ventricular pacing. This prospective randomised study evaluates the effect of pacing algorithms that minimise ventricular pacing (MinVP) with and without anti-AF algorithms, on AF burden (AFB) in patients with symptomatic PAF. Patients implanted with pacemakers with MinVP capability with AFB 1-70% were enrolled. Three different DDDRP devices were assessed. Following a 1-month induction phase, patients were randomised to MinVP with and without preventive AF algorithms or dual chamber rate adaptive pacemaker (DDDR) (AV delay (AVD) 150 ms) for 2 months per study phase. The primary outcome measure was AFB. One hundred and ten patients were enrolled; of these, 66 (mean age 74.3 +/- 7.9, 56% males) had an AFB of 1-70% during the induction phase and completed all study phases. There was no significant difference in AFB between the control phase DDDR, 13.8% (95% CI 8.7 to 18.8), and MinVP, 14.4% (95% CI 9.4 to 19.4), or MinVP with AF algorithms enabled, 14.7% (95% CI 9.7 to 19.7), (p = 0.65 and p = 0.49, respectively). Median ventricular pacing was significantly higher during the control phase, 86.0% (IQR 72.8, 97.3), than in MinVP 2.0% (IQR 0.0, 14.1) and MinVP + algorithms 3.0% (IQR 0.4, 15.6), p = <0.001. MinVP algorithms are effective in reducing ventricular pacing. However, there is no significant reduction in AFB with minimal ventricular pacing algorithms in the short term. No additional benefit or adverse outcome was found with preventative anti-AF algorithms in combination with MinVP algorithms.