changes in functional capacity will be recorded using the established 6-minute walk test. The unit of measurement for the distance covered in 6 minutes will be meters.

The outcome is based on a published RCT in Circulation by Blumenthal et al. . A global stress measure (mean rank), was the primary outcome combining the following components at baseline and following treatment: Beck Depression Inventory II, Spielberger Anxiety Inventory-State, General Health Questionnaire, PROMIS Anger Questionnaire, and Perceived Stress Scale. A range from 1 to 147 was present with higher scores suggestive of better function. The change in each individual scaled score is presented in secondary outcome. (see also NCT00981253)

The investigators will apply the Short Form-36 health questionnaire [36,37]. The SF-36 is an eight-dimensional scale consisting of 36 items. It assesses health-related quality of life based on physical, social, and psychological functioning, role behavior due to physical and psychological functional impairment, physical pain, general health perception, and vitality.

The investigators will apply the European Quality of Life 5 Dimensions 5 Level survey (EQ-5D-5L) [36,37]. The EQ-5D-5L consists of five health-related dimensions that can be assessed at five levels.

The questionnaire contains a visual analog scale for assessing general health. It consists of a straight line from 0 to 100, with endpoints representing extreme values-such as "worst imaginable health" on one side and "best imaginable health" on the other. The participants mark a position on the line. The position of the mark provides a numerical value.

The BDI-II is a self-report questionnaire comprising 21 items that assess depression severity. Its reliability and validity have been established through various studies among diverse populations and cultural backgrounds. Higher scores indicates increased depression symptoms

The STAI is the most authoritative tool for assessing anxiety in adults, precisely distinguishing between transient "state anxiety" and persistent "trait anxiety". The STAI measures anxiety with 20 items and has a range of 20 to 80. A higher score indicates more pronounced anxiety

The PROMIS Anger scale comprises eight items that evaluate various aspects of anger. Scores on the scale range from 8 to 40, with higher scores indicating greater levels of anger

The GHQ assesses general distress and consists of 12 items. Respondents' scores range from 0 to 36, where higher scores correspond to increased distress

The Perceived Stress Scale-10 item version is a short tool for the assessment of how individuals perceive stress in their lives. The values range from 0 to 40. Higher values indicate higher perceived stress.

All ICD shock events occurring during the follow-up period will be classified as either appropriate or inappropriate, based on predefined criteria.

Appropriate shocks will be defined as those delivered in response to documented, life-threatening ventricular arrhythmias, including:

• Ventricular tachycardia (VT)
• Ventricular fibrillation (VF),

Inappropriate shocks will be defined as those delivered in the absence of a qualifying ventricular arrhythmia. For example:

-Supraventricular tachycardias (e.g., atrial fibrillation or flutter) misclassified as VT/VF or Oversensing due to lead malfunction, signal noise, or double counting.

All shock events will be reviewed using intracardiac electrograms and device event logs retrieved from the ICD or CRT-D memory. When available, surface ECG data will be used to support rhythm interpretation.

A shock will only be classified as appropriate if there is clear evidence of a ventricular arrythmia

IL-6 is measured in pg/ml. Standard value is under 4.4 pg/ml. Higher values indicate an increased stress level

C-reactive protein (CRP) is measured in mg/dl. Standard value is under 0.5 mg/dl. Higher values indicate an increased stress level.

Procalcitonin is measured in ng/ml. Standard value is under 0.5 ng/ml. Higher values correlate with systemic inflammatory reaction and indicate bacterial infections.