Impact of implantable-cardioverter-defibrillator trials on clinical management of patients with heart failure

Heart failure is a deadly disease. Every year, tens of thousands of patients die from this condition, many of them suddenly. Efforts aimed at reducing mortality centered initially on antagonizing the neurohormonal system, which is maladaptively upregulated in response to myocardial failure. Antagonists of the renin-angiotensin-aldosterone and adrenergic nervous systems have reduced the rates of cardiovascular mortality and sudden cardiac death. Antiarrhythmic drug therapy has not fared as well. Consequently, efforts to reduce the risk of sudden death have focused on the use of implantable cardioverter-defibrillators (ICDs). How best to identify patients who will benefit from this invasive and expensive therapy has yet to be clearly determined. In this review, we discuss the effectiveness of ICDs in primary and secondary prevention of sudden death in heart failure patients, and examine the impact that the use of ICDs has had on clinical decision making.