What we have learned from the family of multicenter automatic defibrillator implantation trials

Electrical device therapy began 50 years ago with the external defibrillator, and was followed subsequently with the introduction of implantable cardiac pacemakers, defibrillators, and resynchronization devices to prevent bradycardia, sudden arrhythmic death, and heart failure. During the past 20 years the Multicenter Automatic Defibrillator Implantation Trial (MADIT) research group has carried out a series of trials, including the MADIT-I, MADIT-II, and MADIT-III (MADIT-CRT), that have focused on improving the outcomes for patients with ischemic and nonischemic cardiac disease. The most recent MADIT-CRT trial showed that a cardiac resynchronization therapy device with defibrillator (CRT-D) was effective in reducing the risk of heart failure or death, whichever came first, in cardiac patients who were asymptomatic or minimally symptomatic (New York Heart Association class I or II) with reduced ejection fraction < or =0.30 and wide QRS complex > or =130 ms when compared with an implantable cardiac defibrillator (ICD) device. The family of MADIT ICD and CRT-D trials have provided a firm foundation for improving the clinical management of at-risk cardiac patients as the second decade of the 21(st) century begins.