668 two catheters (ddd) or one (vdd) for atrio-ventricular block? complication rates over a more than 20 years experience

Abstract Background in patients with atrio-ventricular block and spared sinus node function dual chamber (DDD) pacing or ventricular (VDD) pacing are considered as an alternative in clinical practice. Literature lacks validated data on the best treatment choice in this situation. Decision should be made balancing risk and benefit ratio of a single or dual lead procedure. Aims to compare complication rates of DDD and VDD implants in a single center experience. Methods data from consecutive patients who underwent DDD or VDD implantation in our institution between January 2000 and December 2021 were included in the analysis. Complications consisted of catheter dislodgements (i.e. dislodgements needing a repositioning procedure), catheter related problems (i.e. lead problems needing a substitution) and infections (i.e. pocket infections or lead infections needing antibiotic therapy or extraction). The need of an upgrading procedure in VDD recipients was not considered as a complication but as a further procedure. The rate of generator replacement and its longevity was also recorded. Results we performed 2499 pacemaker implantations, among them 1435 (57,4%) were DDD and 1064 (42,6%) were VDD. The majority of DDD and VDD recipients were male (836 patients, 58,3% and 609 patients, 57,2% respectively). The VDD population was significantly older (77,7 years old vs 75,5 years old, p<0,01) at the time of implant. Complications occurred more often in the DDD than in the VDD group, without reaching statistical significance (7,3% vs 5,7% p=0,13). No statistical difference was found in catheter displacement rate between DDD and VDD cohorts (4,9% vs 3,8%, p=0,21). In the first group, dislodgements were more frequent for the atrial catheter (41) than the ventricular (29). Catheter-related problems occurred in 25 (1,7%) with a DDD and in 5 (0,5%) patients implanted with a VDD (p<0,01). Infections were also more frequent in patients with dual-chamber pacemakers (1,5%, 22 patients) than in those with single-chamber pacemakers (1,3%, 14 patients) (p=0,67). Twenty (1,9%) VDD recipients needed upgrading to DDD mode during the follow-up due to chronotropic incompetence, whereas a single patient with a DDD underwent a CRT upgrading to relieve the symptoms of heart failure. During the study period, we changed 121 DDD and 140 VDD generators. Mean device duration was similar in both groups: 91,3 months and 93,3 months (p=0,43). Conclusions VDD implantation was the more frequent choice for elderly patients. No significant complications difference occurred in in patients implanted with DDD and with VDD pacemakers, although catheter-related problems occur more frequently in the former population. A small proportion of VDD recipients needed to upgrade the device to DDD. Both pacing choices are equally effective in atrio-ventricular block.