Recurrence of syncope is a common event, but the influence of recurrent syncope on the risk of death has not previously been investigated on a large scale. We 'examined the prognostic impact of recurrent syncope in a nationwide cohort of patients with syncope. All patients (n = 70,819) hospitalized from 2001 to 2009 in Denmark with a first-time diagnosis of syncope aged from 15 to 90 years were identified from national registries. Recurrence of syncope was incorporated as a time-dependent variable in multivariable-adjusted Cox models on the outcomes of 30-day, 1-year, and long-term all-cause mortality and cardiovascular death. During a mean follow-up of 3.9 +/- 2.6 years, a total of 11,621 patients (16.4%) had at least 1 hospitalization for recurrent syncope, with a median time to recurrence of 251 days (33 to 364). A total of 14,270 patients died, and 3,204 deaths were preceded by a hospitalization for recurrent syncope. The long-term risk of all-cause death was significantly associated with recurrent syncope (hazard ratio 2.64, 95% confidence interval 2.54 to 2.75) compared with those with no recurrence. On 1-year mortality, recurrent syncope was associated with a 3.2-fold increase in risk and on 30-day mortality associated with a threefold increase. The increased mortality risk was consistent over age groups 15 to 39, 40 to 59, and 60 to 89 years, and a similar pattern of increase in both long-term and short-term risk of cardiovascular death was evident. In conclusion, recurrent syncope is independently associated with all-cause and cardiovascular mortality across all age groups exhibiting a high prognostic influence. Increased awareness on high short-and longterm risk of adverse events in subjects with recurrent syncope is warranted for future risk stratification. (C) 2014 Elsevier Inc. All rights reserved.
American Journal of Cardiology, 2014, Vol 113, Issue 10, p. 1744-1750
Journal Article; Research Support, Non-U.S. Gov't; Adolescent; Adult; Aged; Aged, 80 and over; Cause of Death; Defibrillators, Implantable; Denmark; Electrocardiography; Female; Follow-Up Studies; Hospitalization; Humans; Incidence; Male; Middle Aged; Prognosis; Proportional Hazards Models; Recurrence; Registries; Risk Factors; Survival Rate; Syncope; Time Factors; Young Adult