Key result
Active dual-chamber pacing reduced syncope recurrence compared to backup pacing in patients with unexplained syncope and positive ATP tests (21% vs 66%; HR 0.25; 95% CI 0.12-0.56).
Why the study?
Does active dual-chamber pacing reduce syncope recurrence in elderly patients with unexplained syncope and a positive ATP test?
RCT (n=80)
patient-blinded
randomized
Yes
Does active dual-chamber pacing reduce syncope recurrence in elderly patients with unexplained syncope and a positive ATP test?
Hazard Ratio: 0.25 (95% CI 0.12–0.56)
Absolute Event Rate: 21% vs 66%
In elderly patients with unexplained syncope and a positive ATP test, active dual-chamber pacing significantly reduces the risk of syncope recurrence compared to backup pacing.
Supports active dual-chamber pacing in elderly patients with unexplained syncope and positive ATP tests; confirms benefit versus backup pacing in this group.
BACKGROUND: The origin of 40% of syncope cases remains unknown even after a complete diagnostic workup. Previous studies have suggested that ATP testing has value in selecting successful therapy. This patient-blinded, multicenter, randomized superiority trial tested whether, in patients with syncope of unknown origin, selecting cardiac pacing in those with a positive ATP test leads to fewer recurrences than those who do not receive pacing. METHODS AND RESULTS: From 2000 to 2005, 80 consenting patients (mean age, 75.9±7.7 years; 81% women; 56% without diagnosed structural heart disease) with syncope of unknown origin and atrioventricular or sinoatrial block lasting >10 seconds (average, 17.9±6.8 seconds) under ATP administration (20-mg IV bolus) were recruited from 10 hospitals, implanted with programmable pacemakers, and randomized to either active pacing (dual-chamber pacing at 70 bpm) or backup pacing (atrial pacing at 30 bpm). Patients were followed up regularly for up to 5 years for any syncope recurrence, the primary outcome. Mean follow-up was 16 months. Syncope recurred in 8 of 39 patients (21%) randomized to active pacing and in 27 of 41 (66%) randomized to backup pacing (control), yielding a hazard ratio of 0.25 (95% confidence interval, 0.12-0.56). After recurrence, the 27 recurrent control patients were reprogrammed to active pacing, and only 1 reported subsequent syncope. CONCLUSION: This study suggests that, in elderly patients with syncope of unknown origin and positive ATP tests, active dual-chamber pacing reduces syncope recurrence risk by 75% (95% confidence interval, 44-88). CLINICAL TRIAL REGISTRATION: URL: http://www.controlled-trials.com/ISRCTN00029383. Unique identifier: ISRCTN00029383.
No takes yet. Share an insight, caveat, or question.
Flammang et al. (2011) conducted an RCT in syncope of unknown origin (n=80). active pacing (dual-chamber pacing) vs. backup pacing (atrial pacing at 30 bpm) was evaluated on any syncope recurrence (HR 0.25, 95% CI 0.12-0.56). Active dual-chamber pacing reduced syncope recurrence compared to backup pacing in patients with unexplained syncope and positive ATP tests (21% vs 66%; HR 0.25; 95% CI 0.12-0.56).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: