Syncope in paced patients with sick sinus syndrome from the DANPACE trial: incidence, predictors and prognostic implication.
OBJECTIVE
Syncope is a cause of significant morbidity in sick sinus syndrome (SSS) which may not be resolved with permanent pacemaker therapy. We aimed to determine the incidence, predictors and prognostic implication of syncope in paced patients with SSS.


METHODS
We studied 1415 patients (mean age 72.9 years, SD 11.1) with SSS who were randomised in the DANPACE study to either rate-responsive single chamber pacing (n=707) or rate-responsive dual chamber pacing (n=708). Main outcome measures were patient-reported syncope after pacemaker implantation and mortality.


RESULTS
Mean follow-up was 5.4 years (SD 2.6). A total of 247 (17.5%) patients experienced syncope after pacemaker implantation (135 (19%) from the rate-responsive single chamber pacing group, and 112 (15.8%) from the rate-responsive dual chamber pacing group. Predictors of syncope post pacemaker implantation included: age 0-39 years (HR 2.9, 95% CI 1.4 to 6.3, p=0.01; reference range 60-79 years), age ≥80 years (HR 1.4, 95% CI 1.0 to 1.8, p=0.03), syncope prior to pacemaker implant (HR 1.8, 95% CI 1.4 to 2.3, p<0.001), previous myocardial infarction (HR 1.5, 95% CI 1.1 to 2.1, p=0.03), heart failure (HR 1.4, 95% CI 1.0 to 1.9, p=0.046), and high Charlson comorbidity index (HR 1.6, 95% CI 1.1 to 2.2, p=0.01). Patients who experienced syncope post pacemaker implant had higher mortality compared with patients who did not (adjusted HR 1.6, 95% CI 1.3 to 2.1, p<0.001).


CONCLUSIONS
Syncope in paced patients with SSS is common, and is associated with higher mortality. The predictors identified in this study suggest a multifactorial aetiology of syncope.
Department of Cardiology, Nottingham University Hospitals NHS Trust, , Nottingham, UK.
Marie Jennyfer
MJ
Ng Kam Chuen
Rikke Esberg
RE
Kirkfeldt
Henning Rud
HR
Andersen
Jens Cosedis
JC
Nielsen
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009017:Morbidity / Q000639:trends; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012804:Sick Sinus Syndrome / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D013575:Syncope / Q000150:complications / Q000453:epidemiology* / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult
Arrhythmias