Saving lives and reducing inappropriate device therapy: The MADIT family of implantable cardioverter-defibrillator and cardiac resynchronization therapy trials

Abstract

In 1980, Mirowski et al. [1] reported the first 3 patients treated with an automatic implantable defibrillator (AID). At that time, the AID was implanted with electrodes attached to the epicardium through a surgical thoracotomy with the battery portion of the unit placed undeer the skin in the abdominal wall. The AID detected the onset of ventricular fibrillation through a unique algorithm and the device was considered a “shock box” since shock was the only therapy delivered. The U.S. Food and Drug Administration (FDA) initially provided approval for use of the AID device in high-risk cardiac patients who had been resuscitated from a prior aborted cardiac arrest. Around the same time frame, Medtronic developed a pacing approach (antitachycardia pacing [ATP]) to terminate rapid ventricular tachycardia (VT) by delivering a series of appropriately timed pacing stimuli in the interval between the QRS and T-wave complexes of the tachycardia (review article [2]). This pacing technique was effective in terminating VT in a majority of patients with ventricular tachyarrhythmias. However, this ATP approach produced acceleration of VT and even ventricular fibrillation and sudden death in a small percentage of patients, and ATP therapy was not approved by the FDA as a stand-alone therapy. The AID was initially developed by Drs. Mirowski and Mower in association with Dr. M. Stephen Heilman at the Medrad/Intec Company in Pittsburgh, Pennsylvania, and the implantable defibrillator was subsequently sold to CPI/Guidant Corporation in 1985. Although CPI/Guidant and Medtronic were competitors in the pacemaker field, both companies recognized the need for a device with tiered therapy that would include ATP and defibrillation. Through a cooperative agreement, CPI/Guidant and Medtronic jointly agreed on a device involving ATP and shock therapy, called the automatic implantable cardioverter defibrillator (AICD) for treating patients at risk for life-threatening VT and/or ventricular fibrillation.