LAUSR

BACKGROUND Atrial fibrillation (AF) remains the most relevant arrhythmia with a prevalence of 2%. The treatment options are either highly invasive and cost-intensive or limited by potential side effects or insufficient efficacy. However, no direct means of prevention that could reduce the burden of AF have been tested. OBJECTIVE To determine whether remote ischemic preconditioning (RIPC) has an impact on inducibility and sustainability of AF. METHODS 146 patients with paroxysmal AF undergoing electrophysiological study were randomized to receive either RIPC, performed by short episodes of forearm ischemia, or sham intervention (NCT02779660). Effective refractory periods, conduction times, velocities, and conduction delays measured were analyzed by pacing from CS-catheter. Endpoints of the study were the inducibility and sustainability of AF after pre-specified rapid pacing sequences. RESULTS RIPC significantly reduces the inducibility (OR: 0.35, 95%CI 0.17-0.71, p=0.003) and sustainability (OR: 0.36, 95%CI 0.16-0.81, p=0.01) of AF. Furthermore, it decreased dispersion of atrial refractory periods (16.0±14.0ms vs. 22.7±19.0ms, p=0.021) as well as atrial conduction delays (49.2±19.6ms vs. 56.2±22.5ms, p=0.049 for proximal CS, 42.4±16.6ms vs. 49.8±22.2ms, p=0.029 for distal CS). In the whole cohort, longer atrial conduction delay (57.6±22.2ms vs. 50.0±20.5ms, p=0.044) and slower conduction velocity (1.74±0.3mm/ms vs. 1.93±0.5mm/ms, p=0.006) were associated with inducibility of AF, whereas a wider dispersion of effective refractory periods (25.9±18.3ms vs. 15.7±11.6ms, p=0.028) maintain AF episodes. CONCLUSION RIPC reduces the inducibility and sustainability of AF which is possibly mediated by changes in electrophysiological properties of atria. It may be used as a simple, non-invasive procedure to reduce AF burden.