Using a previously published computer modelling study describing the major determinants of the defibrillation threshold in S-ICD patients, a score model was developed including sub-coil fat, sub-can fat and anterior positioning of the S-ICD can. The PRAETORIAN score estimates the risk of conversion failure:

  • score between ≥30 and <90 = low risk
  • score between ≥90 – <150 = intermediate risk
  • score is ≥150 = high risk

The positive predictive value of the PRAETORIAN score for failure to convert is 98% and the negative predictive value is 51% (HRS 2018). Our article on the PRAETORIAN Score with instructions to check the chest X-ray requirements and to calculate the score can be found here: The PRAETORIAN Score