S-ICD screening failure is low in HCM, provided that patients with severe hypertrophy are carefully evaluated. Exercise test should be performed and right parasternal leads tested. Pacemaker patients display lower eligibility rate.

Aims The traditional technique for subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation involves three incisions and a subcutaneous pocket. Recently, a two-incision and intermuscular (IM) technique has been adopted. The PRAETORIAN score is a chest radiograph-based tool that predicts S-ICD conversion testing. We assessed whether the S-ICD implantation technique affects optimal position of the defibrillation system according to the PRAETORIAN score. Methods and results We analysed consecutive patients undergoing S-ICD implantation. The χ2 test and regression analysis were used to determine the association between the PRAETORIAN score and implantation technique. Two hundred and thirteen patients were enrolled. The S-ICD generator was positioned in an IM pocket in 174 patients (81.7%) and the two-incision approach was adopted in 199 (93.4%). According to the PRAETORIAN score, the risk of conversion failure was classified as low in 198 patients (93.0%), intermediate in 13 (6.1%), and high in 2 (0.9%). Patients undergoing the two-incision and IM technique were more likely to have a low (<90) PRAETORIAN score than those undergoing the three-incision and subcutaneous technique (two-incision: 94.0% vs. three-incision: 78.6%; P = 0.004 and IM: 96.0% vs. subcutaneous: 79.5%; P = 0.001). Intermuscular plus two-incision technique was associated with a low-risk PRAETORIAN score (hazard ratio 3.76; 95% confidence interval 1.01–14.02; P = 0.04). Shock impedance was lower in PRAETORIAN low-risk patients than in intermediate-/high-risk categories (66 vs. 96 Ohm; P = 0.001). The PRAETORIAN score did not predict shock failure at 65 J. Conclusion In this cohort of S-ICD recipients, combining the two-incision technique and IM generator implantation yielded the lowest PRAETORIAN score values, indicating optimal defibrillation system position. Clinical trial registration http://clinicaltrials.gov/ Identifier: NCT02275637.

The AST is associated with higher pass rate than the standard MST. It seems more tolerant of high-amplitude T-waves. Consequently, the agreement between MST and AST findings was only moderate.

Long-lasting and rapid NSVT recorded during continuous rhythm monitoring predict appropriate ICD intervention in high-risk HCM patients. Further studies should assess whether prolonged rhythm monitoring may assist in evaluating patients at intermediate risk of SD, in which the decision to implant an ICD needs to be individualized.

Plasma OPN and Gal-3 predict sustained VT/VF in HF patients at high risk for SCD. Larger prospective studies should outline the role of these biomarkers in predicting SCD on top of conventional risk stratification.