Carotid sinus syndrome, should we pace? A multicentre, randomised control trial (Safepace 2).

BACKGROUND: Cardioinhibitory carotid sinus hypersensitivity (CICSH) is highly prevalent among older people with falls.

OBJECTIVE: To assess the efficacy of dual-chamber pacing in older patients with CICSH and unexplained falls.

DESIGN: A multicentre, double blind, randomised controlled trial.

SETTING: Selection from emergency room, geriatric medicine and orthopaedic departments.

PATIENTS: Patients aged >50 years, with two unexplained falls and/or one syncopal event in the previous 12 months for which no other cause is evident apart from CICSH.

INTERVENTIONS: Patients randomised to either a 700/400 kappa, rate responsive pacemaker or implantable loop recorder (Medtronic Reveal thera RDR, Medtronic, Minneapolis, Minnesota, USA).

MAIN OUTCOME MEASURES: The primary outcome was the number falls after implantation. Secondary outcomes were time to fall event, presyncope, quality of life and cognitive function.

RESULTS: 141 patients were recruited from 22 centres. Mean age was 78 years and mean follow-up 24 months. The overall relative risk of falling after device implantation compared with before was 0.23 (0.15 to 0.32). No significant reduction in falls was seen between paced and loop recorder groups (RR=0.79; 95% CI 0.41 to 1.50). Data were also consistent in both groups for syncope, quality of life and cognitive function. Conclusions These results question the use of pacing in CICSH. However, the study was underpowered and also patient characteristics differed from those in Safepace 1-participants were physically and cognitively frailer. Further work is necessary to assess cardiac pacing in this setting.