Dual-chamber pacing with closed loop stimulation reduces syncope burden, time to first recurrence
Dual-chamber pacing with closed loop stimulation (DDD-CLS), compared with sham pacing, lessens by sevenfold syncope burden and time to first recurrence, extending time to first syncope recurrence in patients with head-up tilt test-induced vasovagal syncope, a recent study has found.
Canadian and Spanish patients (aged ≥40 years) with high burden syncope (≥5 episodes, ≥2 episodes in the past year) and a cardioinhibitory head-up tilt test (bradycardia <40 beats/min for 10 sec or asystole >3 sec) were randomly assigned to either DDD-CLS pacing for 12 months followed by sham DDI mode pacing at 30 pulses/min for 12 months (group A) or sham DDI mode for 12 months followed by DDD-CLS pacing for 12 months (group B).
Cross-over of patients in both arms occurred after 12 months of follow-up or when a maximum of three syncopal episodes occurred within 1 month.
Overall, 46 patients completed the protocol (mean age 56.30 years; 47.8 percent men), with a mean of 12 (range 9 to 20) previous syncopal episodes. Of the patients, 72 percent (95 percent CI, 47 to 90 percent) in the DDD-CLS had ≥50-percent reduction in the number of syncopal episodes compared with 28 percent (9.7 to 53.5 percent) in the sham DDI mode (p=0.017).
Events occurred in four patients (8.7 percent) during DDD-CLS and in 21 (45.7 percent) during sham DDI (hazard ratio, 6.7; 2.3 to 19.8). There was significantly different Kaplan-Meier curve between groups in the time to first syncope (29.2 months; 15.3 to 29.2 vs 9.3 months; 6.21 to NA; p<0.016; odds ratio, 0.11; 0.03 to 0.37; p<0.0001).