The Syncope-Stopper study: comparison of the effectiveness and complications of upfront pacing with standard care for high-risk adult patients with unexplained syncope

Syncope-Stopper

Paciente / Población Intervención / Exposición Comparación Desenlace

In 200 older adults with high-risk unexplained syncope, upfront pacemaker implantation reduced cardiovascular death, recurrent syncope, bradycardia or device complications at 12 months compared with standard monitoring.

N

200pacientes

Diseño

Australian (Victoria) multicentre, prospective, open-label, 1:1 randomised controlled trial across six recruiting hospitals in metropolitan Melbourne; investigator-initiated, sponsored by Alfred Health with funding from Monash University and the National Heart Foundation, no commercial sponsor; age 55 years or older, at least one unexplained syncope in the preceding 12 months and a DROP score of 2 or more (distal conduction disease, no related historical precipitant, older age over 65, PR prolongation); excluded were an existing Class I device indication, likely neurocardiogenic/vasovagal aetiology (postural systolic fall over 30 mmHg, carotid sinus hypersensitivity, situational syncope), LVEF under 40%, prior pacemaker/ICD/loop recorder, contraindication to transvenous pacing and comorbidity precluding follow-up; upfront permanent pacemaker implanted by a cardiologist with pacing expertise versus standard care as directed by the treating team (Holter or implantable loop recorder); 12 months of follow-up.

Desenlace

12-month composite of recurrent syncope, bradycardia requiring pacemaker implantation, cardiovascular death, or device-related complication requiring re-intervention

Relevancia

2Importante — uno de varios pilares.

ResultadoThe composite occurred in 17.2% with upfront pacing and 31.7% with standard care (HR 0.49, 95% CI 0.27–0.87; P = 0.014). Recurrent syncope fell from 21.8% to 11.1% (11 of 99 vs 22 of 101; HR 0.47, 95% CI 0.23–0.97; P = 0.037, NNT 9.3), and bradycardia leading to a pacemaker occurred in 0% versus 18.8% (P < 0.001). Cardiovascular death was 3.0% in both arms and all-cause mortality 4.0% versus 3.0%. Major device complications were 3.0% versus 1.0% and minor complications 9.1% versus none. Emergency presentations were 24.2% versus 40.6% (P = 0.016), admissions 36.4% versus 63.4% (P < 0.001), and median admission days 0 versus 3.

William JB, Voskoboinik A, et al. Presented at ESC Congress 2026, Hot Line 10, 31 August.

Discusión y crítica

Two of the four components of the composite are decided by the assignment itself: bradycardia leading to a pacemaker cannot occur in patients who already have one, and it supplied 19 of the standard-care events. Read the composite with that in mind and the trial still holds, because recurrent syncope halved on its own — 11.1% against 21.8%, with an NNT of 9 in patients averaging 80 years, two thirds of whom faint without warning and nearly half of whom had already been injured. The strategy is unblinded and small, mortality is unchanged, and 9% paid a minor device complication; what the DROP score buys is a pretest probability of bradyarrhythmia high enough that waiting to document it costs more than pacing without proof.