New indications for implantable defibrillator therapy.

Implantable cardioverter defibrillator (ICD) therapy has been extensively evaluated in patients at high risk of sudden cardiac death. Most recently, the Sudden Cardiac Death in Heart Failure Trial found that patients with moderate symptoms of congestive heart failure, whether due to an ischemic or a nonischemic cause, have reduced mortality compared with patients treated only with conventional medical therapy for heart failure. The results of this trial confirm those of earlier trials finding a benefit of ICD therapy in patients with coronary artery disease and reduced left ventricular systolic function, and extend the indications for ICD therapy to those without coronary artery disease.