The efficacy of implantable cardioverter-defibrillators in the prevention of sudden cardiac death: a survey of the current knowledge

The paper offers a review of the results published from randomized studies evaluating the efficacy of therapy with ICD in patients with structural heart disease at high risk of sudden arrythmogenic death. The conclusions from the secondary prevention trials („post-event“ trials) AVID, CIDS and CASH, are consistent in showing a relative risk reduction of the 2-year mortality of 30 % in the group treated with ICD as compared to the conventional medical therapy group. The most impressive benefit observed was in the group of patients with a previous myocardial infarction and moderate to severe left ventricular dysfunction with ejection fraction reduced below 35 %. This trend in patients with coronary artery disease can also be discerned from the results of the primary prevention trials („pre-event“ trials) MADIT, MUSTT and, most recently, MADIT II. However, the therapy with ICD in patients with non-ischemic cardiomyopathy as the modality of primary prevention does not seem to be warranted. In the meantime some indications for treatment with ICD due to secondary prevention are expected to be partially reduced, while others are being shown to be fully justified.

Keywords: implantable cardioverter-defibrillator, sudden cardiac death, ventricular tachycardia, ventricular fibrillation.