Introduction Previous research shows that patients with an implanted cardioverter defibrillator (ICD) have a fourfold increased mortality risk when suffering from anxiety compared with ICD patients without anxiety. This research supports the screening of ICD patients for anxiety with the purpose of starting relevant intervention.

Methods and analysis Screen-ICD consists of 3 parts: (1) screening of all hospitalised and outpatient patients at two university hospitals using the Hospital Anxiety and Depression Scale (HADS), scores ≥8 are invited to participate. (2) Assessment of type of anxiety by Structured Clinical Interview for DSM Disorders (SCID). (3) Investigator-initiated randomised clinical superiority trial with blinded outcome assessment, with 1:1 randomisation to cognitive–behavioural therapy (CBT) performed by a cardiac nurse with CBT training, plus usual care or usual care alone. The primary outcome is HADS-A measured at 16 weeks. Secondary outcomes include Becks Anxiety Inventory, HeartQoL, Hamilton Anxiety Scale, heart rate variability, ICD shock, time to first shock and antitachycardia pacing. A total of 88 participants will be included. The primary analyses are based on the intention-to-treat principle and we use a mixed model with repeated measurements for continuous outcomes. For binary outcomes (HADS-A score <8), we use a generalised mixed model with repeated measurements.

Ethics and dissemination The trial is performed in accordance with the Declaration of Helsinki. All patients must give informed consent prior to participation and the trial is initiated after approval by the Danish Data Protection Agency (RH-2015-282) and the regional ethics committee (H-16018868). Positive, neutral and negative results of the trial will be published.

Trial registration number NCT02713360.