Estimating defibrillator longevity: a need for an objective comparison

Longevity of implantable cardioverter-defibrillators: implications for clinical practice and health care systems

AIMS

Comparative studies on the longevity of implantable cardioverter-defibrillators (ICDs) among different manufacturers have never been reported. Longevity of ICD devices implanted from 1 January 2000 to 31 December 2002 was prospectively investigated according to their type and manufacturer.

METHODS AND RESULTS

Longevity of single-chamber (SC), double-chamber (DC), and biventricular (CRT-D) ICDs from Medtronic (MDT), Guidant (GDT), and St Jude Medical (SJM) was measured in all the patients who required device replacement. The observation follow-up ended on 31 December 2007; patients who died prematurely or were transplanted before battery exhaustion were excluded from the analysis. Factors associated with longevity (number of delivered shocks, pacing activity) were researched. One hundred and fifty-three patients received an ICD in the abovementioned period. Six underwent heart transplantation, and 23 died before device replacement; 80 had an SC device, 59 had DC device, and 14 had CRT-D device. Longevity of MDT was superior to GDT and SJM, replacement rates being, respectively, 42%, 95.3%, and 97.2%. Only MDT manufacturers and SC type were associated with greater ICD longevity. Longevity had an impact on the cost/month of treatment of replaced ICDs.

CONCLUSION

Battery longevity is significantly different among manufacturers. ICD cost is strictly dependent on device longevity, whereas device up-front cost is of limited clinical meaning. Appropriate assessment of cost-effectiveness should be based on ICD longevity in the real-life scenario.

The implantable cardioverter defibrillator

Implantable cardioverter defibrillators (ICDs) have evolved from the treatment of last resort to the gold standard therapy for patients at high risk for ventricular tachyarrhythmias. High-risk patients include those who have survived life-threatening arrhythmias, and individuals with cardiac diseases who are at risk for such arrhythmias, but are symptomless. Use of an ICD will affect the patient's quality of life. Some drugs can substantially affect defibrillator function and efficacy, and possible drug-device interactions should be considered. Patients with ICDs may encounter cell phones, antitheft detectors, and many other sources of potential electromagnetic Interference. In addition to treating ventricular tachyarrhythmias, new defibrillators provide full featured dual chamber pacing, and could treat atrial arrhythmias, and congestive heart failure by means of biventricular pacing.