Implantable pacemaker devices are available with specific atrial pacing algorithms designed to prevent atrial arrhythmias (Preventive stimulation). These algorithms work by increasing the atrial pacing rate to achieve continuous overdrive pacing or by responding to triggers such as premature atrial complexes.

Different investigation’s showed that preventive atrial pacing was associated with a 30 to 50 % reduction in the risk of recurrence of AF, compared with no pacing. But a complete recurrence-free long-term effect is not reached.

A hybrid therapy consisting of a combination of preventive atrial stimulation and pharmacologic therapy maybe useful in restoring sinus rhythm. The HOPE-(Heart Outcomes Prevention Evaluation)-Trial showed a overwhelming evidence that, in a broad range of high-risk patients, an ACE-Inhibitor (Ramipril) prevents cardiovascular death, stroke, and heart failure. AF leads to an activation of the renin-angiotensin system (RAS), which seems to play an important role in atrial remodelling. Both experimental and clinical data have confirmed the pro-arrhythmic role of the RAS and demonstrated an anti-arrhythmic effect of ACE- and AT-I-Inhibtors. Madrid et al. showed that a combination of the AT-I-Inhibitor irbesartan plus amiodarone decreased the rate of AF recurrences, with a dose-dependent effect, in AF patients. ACE- and AT-I-Inhibitors represent new and efficient therapeutical options to contrast the nearly inevitable progression of this arrhythmia towards its permanent form. Beta-Blockers are a common pharmacologic therapy in AF patients.

The aim of the BACE-PACE-Trial is to investigate preventive pacing stimulation (PS) vs. standard DDD[R]-60-Stimulation (ST) in combination with antiarrhythmic Beta-Blocker or ACE-inhibitor therapy on the recurrence of atrial fibrillation in patients with dual-chamber pacemakers

The Responder (patients without AF recurrence, respectively with a significant reduction in AF burden) are compared to the standardstimulation. A clinically relevance meant a reduction in AF burden of more than 25 % (experts consensus).