Therapy with an implantable cardioverter defibrillator (ICD) in patients with coronary artery disease and dilated cardiomyopathy: benefits and disadvantages.

Contemporary guidelines refer to ICD implantation in patients who experienced ventricular tachycardia or fibrillation as secondary prevention, and in well-defined high risk groups as primary prevention. Randomised studies were performed in patients with coronary artery disease and in non-ischaemic cardiopathies, chiefly dilated cardiomyopathy. After four years' follow-up the absolute risk reduction was some 10% in secondary prevention and 8-20% in primary prevention, depending on the patient population. As only approx. 50% of ICD patients will receive appropriate therapies during long-term follow-up, reasonable risk stratification is crucial. However, apart from ejection fraction of <35%, all other echo- or electrocardiographic factors studied have thus far failed to have significant impact to determine risk in advance. In a retrospective analysis comorbidities such as advanced age, renal failure and atrial fibrillation have been shown to influence the effect of an ICD. During long term follow-up inappropriate shocks, lead complications, premature battery depletion and anxiety are some of the most significant problems for an ICD patient.