Long-term outcome of patients with vasovagal syncope.

Background: After abnormal head-up tilt test (HUT), several trials have evaluated treatment strategies for vasovagal syncope (VVS). However, few unequivocal results have been obtained. The aim of the study was to prospectively analyze the natural history of patients with VVS who did not undergo specific treatment but received education for avoiding syncope after an abnormal HUT.

Methods: From 1996, 334 consecutive patients with VVS and an abnormal HUT result were followed. All of them received education for avoiding syncope as first-line therapy.

Results: During 30.4 +/- 21 months, there were no cardiac deaths. However, 101 patients (30.2%) had recurrences (1 recurrence, n = 64; > or =2, n = 37), which were not influenced by the type of response during HUT or by age. Time to first recurrence was correlated with the number of recurrences (r: -0.34, P =.0001). Mean recurrence-free time was 50.1 months (95% CI 46-54) and the cumulative probability of no recurrence was 69.8%. Receiver operator character curve analysis, demonstrated significant differences in the recurrence rate between patients with <5 or > or =5 previous episodes of syncope (25.1% vs 44%; P =.001). In addition, the mean recurrence-free time of patients with <5 episodes was significantly longer (54.1 months) than in patients with > or =5 episodes (39.6 months; P =.0005). Multivariate logistic regression identified the previous number of episodes as an independent risk marker of recurrences (odds ratio 2.34, 95% CI 1.4-3.8, P =.001). Age (at HUT performance) as a continuous variable was not a predictor of outcome.

Conclusions: Survival of patients with VVS presenting after an abnormal HUT is excellent. Although the broad majority of those patients do not suffer recurrences after education, the number of previous syncopal episodes critically influences the recurrence rate.