Abstract 5894: Device Diagnosed New-Onset Atrial Fibrillation Following Cardiac Resynchronization Therapy: Incidence and Patient Characteristics
Data on the occurrence and implications of new-onset atrial fibrillation (AF) following cardiac resynchronization therapy (CRT) are scarce. We studied the incidence of new-onset AF in CRT-defibrillator (CRT-D) recipients. Furthermore, the influence of new-onset AF on echocar-diographic response to CRT and the rate of adverse events was evaluated. The study population consisted of 223 consecutive patients without a history of AF. New-onset AF was defined as atrial high-rate episodes >180 bpm during >10 minutes/day as detected by the device. Echocardiography was performed at baseline and after 6 months of CRT. Long-term events included ICD therapy for ventricular arrhythmias, hospitalization for heart failure and all-cause mortality. Fifty-five patients (25%) developed new-onset AF during a mean follow up of 32±16 months. When compared to the patients that maintained sinus rhythm (SR) during follow-up, patients developing AF showed less left ventricular (LV) reverse remodeling (ΔLV end systolic volume 37±53 vs. 19±37 ml, p<0.05) and less improvement in LV function (ΔLV ejection fraction 6.7±8.9 vs. 3.5±10.3%, p<0.05) as compared to patients without AF. Importantly, patients developing AF experienced more appropriate ICD shocks for ventricular arrhythmias, more inappropriate shocks and more hospitalizations for heart failure (figure). Recipients of CRT-D who develop new-onset AF show less echocardiographic response to CRT and more cardiac events during long-term follow-up.