Cardiac Implantable Electronic Device Reutilization

Battery Life of Explanted Devices at a Tertiary Care Center

Lindsey Gakenheimer, B.S.; Joshua Romero, M.D.; Timir S. Baman, M.D.; Dan Montgomery, B.S.; Cydni A. Smith, B.A.; Hakan Oral, M.D.; Kim A. Eagle, M.D.; Thomas Crawford, M.D.

Disclosures

Pacing Clin Electrophysiol. 2014;37(5):569-575. 

In This Article

Results

Device Data

During the study period, 2,452 device procedures were performed at the University of Michigan. A total of 801 devices were explanted. The manufacturers of the explanted generators were Medtronic (MDT; 454), Boston Scientific/Guidant (BS)/(GDT; 255), St. Jude Medical (SJM; 73 [St. Paul, MN, USA]), and Biotronik (BTK; 15 [Biotronik GmBH, Berlin, Germany]). The name of the manufacturer of four devices could not be identified. Five hundred and forty-one devices were explanted for ERI and 260 for all other indications. Of the 801 devices, 13.2% (41/311) of pacemakers, 21.0% (64/305) of ICDs, and 16.2% (30/185) of cardiac resynchronization therapy and defibrillation devices (CRT-Ds) had sufficient battery life and no evidence of malfunction. After eliminating the 541 devices explanted for ERI, 51.9% of pacemakers (41/79), 54.2% of ICDs (64/118), and 47.6% of CRT-Ds (30/63) met the criteria for reuse. Figure 1 shows the numbers of reusable and nonreusable CIEDs according to the device type and manufacturer among explanted non-ERI devices in the study.

Figure 1.

The number of reusable and nonreusable CIEDs according to the device type and manufacturer among explanted non-ERI devices in the study. BS/GDT = Boston Scientific/Guidant; BTK = Biotronik; CRT-D = cardiac resynchronization therapy—defibrillator; CRT-P = cardiac resynchronization therapy—pacemaker; ERI = elective replacement indicator; ICD = implantable cardioverter-defibrillator; MDT = Medtronic; SJM = St. Jude Medical.

Figure 2 compares the average length of time, in months, that nonreusable and reusable devices remained inside their owner. Devices deemed reusable were, on average, 4.5 years younger than the nonreusable devices (average age of reusable devices: 17.78 ± 1.77 months; average age of nonreusable devices: 72.09 ± 2.26 months, P = 0.003).

Figure 2.

The length of time, in months, from initial CIED implantation to generator removal for non-ERI devices in the study. Abbreviations as in Figure 1.

A measure of the percent pacing found that reusable devices had paced less than 50% of the time (percent atrial pacing: 43.84% ± 6.55%; percent ventricular pacing: 49.43% ± 5.20%). The average pacing thresholds in the reusable devices were fairly low (atrial pacing threshold: 1.01 ± 0.14 V at 0.45 ± 0.02 ms; right ventricular pacing threshold: 1.15 ± 0.10 V, 0.48 ± 0.02 ms; left ventricular pacing threshold: 2.21 ± 0.43 V, 0.66 ± 0.10 ms). Average impedance measurements were 520.9 ± 41.4 V in the atrium, 570.4 ± 34.2 V in the right ventricle, and 569.2 ± 53.0 V in the left ventricle. Table I lists the indications for CIED explantation. Devices that were explanted for infection, upgrade to a high voltage and/or CRT device, lead failure, heart transplant, or left ventricular assist device (LVAD) implantation were more likely to contain sufficient battery life for potential reuse. A logistic regression analysis determined that the following indications for explantation were independent predictors for a device being reusable: infection, an upgrade to an ICD or CRT-D, heart transplant/LVAD implantation, patient request, and lead failure (Table II). SJM or BS/GDT devices were less likely to meet the criteria for reuse, although the finding for BS/GDT devices was not statistically significant.

Patient Demographics

Younger patients were more likely to have a reusable device (56.20 ± 1.49 and 61.21 ± 0.766 years for patients with a reusable and nonreusable device, respectively, P = 0.007). Males were 3.5 times mores likely to have a reusable device than females (75.8% of males vs 24.2% of females, P = 0.027). Table III and Table IV list the indications for ICDs and pacemakers, respectively. Patients who had an ICD for primary prevention of sudden cardiac death (nonischemic cardiomyopathy [NICM] or ischemic cardiomyopathy [ICM]) were more likely to have a reusable device than patients with initial ICD indication of secondary prevention, although this did not reach statistical significance (P = 0.058). There was no difference in the indications for pacemakers in the reusable versus the nonreusable devices.

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