Profitability Trial in Primary Preventive Implantable Cardioverter-defibrillator Recipients (HAPPIER)

Current criteria for risk stratification of patients in risk of sudden cardiac death are mainly based on left ventricular ejection fraction and NYHA class. This criteria are too robust, approximately 2/3 of ICD recipients do not profit from this treatment in the following 5 years, especially those with non-ischaemic cardiomyopathy. We plan to sub-stratify this group of patients with both ischaemic and non-ischaemic cardiomyopathy by: non-linear heart rate variability analysis, microvolt T-wave alternans, QRT-T angle and character and amount of left ventricular scarring assessed by magnetic resonance imaging. Pre-implantation values will be correlated with numbers and character of ICD therapy (both anti-tachycardial pacing and ICD discharge). The results may allow to decrease the number of patients, who do not profit from ICD treatment.