Table 2

Baseline probabilities and diagnostic accuracy of conventional testing versus ICM for unexplained syncope

Monthly probability for general populationAge and sex-specificUS Centers for Disease Control16
HR for cardiac vs no syncope2.01Soteriades et al 20022
HR for vasovagal vs no syncope1.08Soteriades et al 20022
Cardiac cause of syncope
Proportion of unexplained syncope patients with arrhythmia60.4%Solbiati et al, 201718; meta-analysis of 4381 patients
Proportion of arrhythmia patients with bradycardia*68.7%
Proportion of arrhythmia patients with ventricular tachycardia and ventricular fibrillation*10.2%
Proportion of arrhythmia patients with supraventricular tachycardia or atrial fibrillation*21.1%
Syncope recurrence
Monthly probability of syncope recurrence5.1%EaSyAS15; monthly risk corresponding to event rate of 0.6 events/year
Injury due to syncope
Probability of major injury per syncope event4.8%Bartoletti et al, 200819
Probability of minor injury per syncope event24.7%Bartoletti et al, 200819
Probability of ECG capture
Conventional testing18.9%Farwell et al, 200643
Reveal LINQ ICMMonth 0=70%
Month 1=82%
Month 2=78%
Month 3=87%
Month 4=90%
Month 5 onward=97%
Musat et al, 201744
Battery life
Reveal LINQ ICM3.0 years
Adverse events
Risk of AE requiring ICM explantFirst cycle=0.00734
Subsequent cycles=0
Pooled data from LINQ ICM usability and registry studies
Probability of ICM removal (explant)
Probability of removal on diagnosis of arrhythmic syncope80%Assumption
Probability of removal on diagnosis of non-arrhythmic syncope100%Assumption
  • *See online supplemental files for a breakdown of how these probabilities were calculated.

  • AE, adverse event; EaSyAS, Eastbourne Syncope Assessment Study; ECG, electrocardiogram; HR, hazard ratio; ICM, insertable cardiac monitor; US, United States.