Clinical benefit of atrio-ventricular delay optimization in patients with a dual-chamber pacemaker: a pilot study. The CBRAVO trial (NCT01998256)

Abstract

Objective Outcome data on exercise capacity following atrio-ventricular (AV) optimization of dual-chamber pacing are sparse. Pacemaker settings are often left at manufacturers' nominal values upon implantation. We studied the short-term effect of AV optimization on exercise capacity in patients with a dual-chamber pacemaker. Methods and resultsTwenty-eight patients (mean age 73 ± 14 y) with a dual-chamber pacemaker, were randomized towards either nominal AV settings (group 1) or echo-guided AV optimization using the iterative mitral inflow VTI (velocity time integral) method (group 2) at baseline. At 4 weeks, patients were crossed-over to AV optimization in group 1 and returned to nominal AV settings in group 2 for another period of 4 weeks.Oxygen uptake efficiency slope improved significantly after AV optimization (by 126.7 mL/logL ± 190.7 mL/logL; P = 0.003).Conclusions AV optimization in dual-chamber pacing significantly improved functional capacity after 4 weeks. These data provide the background for further validation studies. Keywords AV optimization -interatrial conduction delay -interatrial mechanical delay -dual-chamber pacemaker.contraction of the left atrium can compromise left ventricular filling, leading to an early increase in atrial filling pressures and a limitation in functional exercise capacity 2 . Oxygen uptake efficiency slope (OUES) is a validated marker of exercise capacity in healthy subjects and in patients with heart failure 3 .Resolution of left AV asynchrony in DDD pacing can be obtained by AV delay optimization and has been shown to improve acute haemodynamics in patients with an important IACD 4,5 . Several validated methods for AV optimization exist 6 . However, data on the effects of this intervention on short-and long-term clinical end points as exercise capacity, morbidity and mortality, are sparse.The aim of this pilot study was to investigate the short-term effect of AV optimization on functional [ Original article ]