Syncope: Previous history of syncope predicted recurrence

Clinical bottom line (level 4)

  1. Patients with a history of >1 episode of syncope were likely to have a recurrence (NNF = 2 for unknown)
  2. Patients with a history of syncope and positive response to head-up tilt testing may have more recurrences (NNF = 8 for unknown)
Grimm et al: European Heart Journal 1997; 18: 1465-1469
Expires February 2004

The study

Prospective cohort study with objective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: cardiology outpatients, Germany

80 patients (aged mean 40y (SD 16y), 51% female) suspected neurally medicated syncope

Excluded if
  • aged <16 or >70
  • structural heart disease
  • any known condition which predisposes to syncope



    • Factors studied:
  • age, gender, previous episodes, response to head-up tilt testing
  • positive baseline tilt test (syncope or presyncopal feelings on the 'Westminster Tilt Protocol' with cardiovascular response)
  • history of >1 previous syncope


    • no specific anti-syncope therapies given

    100% followed for ? duration
    Outcomes studied:
  • recurrence of syncope defined as transient loss of consciousness and muscle tone that by history was not suggestive of other altered states of consciousness

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    recurrence of syncope ? duration 26/80 33%
    (22% to 43%)

    prognostic factor for
    recurrence of syncope     		time to outcome unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    positive baseline tilt test ? duration 1.41
    (0.7 to 2.9)     		8
    (-11 to 2)
    history of >1 previous syncope ? duration 5.2
    (2.0 to 14)     		2
    (1 to 10)

    prognostic factor outcome present outcome absent unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    positive baseline tilt test 6 8 1.41
    (0.7 to 2.9)     		8
    (-11 to 2)
    no positive baseline tilt test 20 46

    prognostic factor outcome present outcome absent unadjusted RR
    (95% CI)    		 NNF+
    (95% CI)
    history of >1 previous syncope 22 19 5.2
    (2.0 to 14)     		2
    (1 to 10)
    no history of >1 previous syncope 4 35

    Comments

    1. No attempt to control for other factors

    Citation

    1. Grimm W, Degenhardt M, Hoffman J, et al: Syncope recurrence can better be predicted by history than by head-up tilt testing in untreated patients with suspected neurally mediated syncope. European Heart Journal 1997; 18: 1465-1469
    Contributor: Bob Phillips and Clare Wotton, February 2000
    Reviewer: Wouter Wieling

    Clinical Question.
    Patient patient with syncope of ?cause; neurally medicated
    Intervention or Exposure head up tilt testing
    Comparison clinical findings
    Outcome recurrence