Worldwide data analysis of BIOTRONIK ICD and CRT-D battery longevity

Abstract

Background

Battery longevity is a key consideration in the selection of implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-Ds), with implications for both clinical outcomes and healthcare costs. A recent study suggested shorter-than-expected battery life for BIOTRONIK devices, prompting a comprehensive internal analysis. This analysis aimed to evaluate the real-world battery longevity of BIOTRONIK high-voltage devices (ICDs and CRT-Ds) across three generations, using global remote monitoring data.

Methods

A total of 215,471 BIOTRONIK devices implanted between 2006 and 2024 were analyzed using data from the BIOTRONIK Home Monitoring Service Center. Devices were grouped into three generations (BIO 2000, 2010, 2020) and stratified by type: single-chamber ICD (VR), dual-chamber ICD (DR), CRT-D, and single-lead ICD with an atrial floating dipole (DX). Kaplan–Meier survival analysis was used to estimate median service times, with extrapolation applied to censored data.

Results

Median service times increased substantially across generations (p < 0.001): VR devices improved from 92 (interquartile range 72–106) to 175 (169–182) months (+89%), DR from 73 (63–93) to 155 (132–168) months (+108%), CRT-D from 72 (62–79) to 111 (95–126) months (+52%), and DX from 97 (92–101) to 170 (163–175) months (+74%). DX devices demonstrated superior longevity compared to DR devices.

Conclusion

Battery longevity of BIOTRONIK ICDs and CRT-Ds has improved markedly with each generation. Newer devices demonstrate service times at or above industry standards, supporting their clinical and economic value.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10840-025-02141-5.

Introduction

Implantable cardioverter-defibrillators (ICD) and cardiac resynchronization therapy defibrillators (CRT-D) have become a mainstay of therapy for patients at risk for life-threatening ventricular arrhythmias. Multiple factors influence the specific device chosen for a specific patient. One of the factors that often plays a prominent role when choosing any cardiac implantable electronic device is the projected battery longevity or “service time” [1]. An expert review paper from the European Heart Rhythm Association (EHRA) concludes that given both the clinical and economic value of extended battery life of an implantable device, it should be a determining factor for those involved in choosing what device(s) is used [2]. Especially, a mismatch between patient survival and device longevity may result in significant clinical and economic burden [3].

The energy available from a battery depends not only on its capacity (total amount of electric charge) but also on its internal architecture (stacked plate, folded plate, and spiral wound) and chemistry (anode, cathode, and electrolyte) [4]. Each manufacturer projects estimated battery longevity for each type of device based on usable battery capacity, programmed parameters, specific features, or algorithms that demand regular current consumption, and device activity, e.g., pacing percentages, frequency of defibrillation, frequency of remote transmission and amount of transmitted data, frequency and duration of radiofrequency communications.

Sources of information regarding ICD and CRT-D battery longevity include product performance reports which are prepared by a standardized approach [ISO 5841-2:2014 (E)] by each manufacturer, post-market registries, and single- and multi-center observational reports. All have merits, and all have limitations. Product performance results, despite defined standardized reporting, base product survival on products returned for analysis and complaints/issues reported by clinicians [5].

Prior studies of cardiac implantable electronic device longevity have disparate results depending on multiple factors including when the analysis was performed, and the generation of devices included [6–12].

Given advances in device design and manufacturing, and battery design and architecture, device service times have improved with each successive generation. Also, battery capacity is greater, despite the smaller form factor.

A recent study by Freeman et al. included data from multiple institutions with the data aggregated and analyzed through PaceMate, a cardiac remote monitoring service [13]. The study concluded that battery longevity for ICDs and CRT-Ds varied substantially between device type and manufacturer. They also confirmed that battery longevity has improved over time. Although the specific models analyzed in the study were not disclosed, the battery longevity representation for BIOTRONIK devices was substantially less than prior internal data indicated. Data reflecting service time by manufacturer and by device type of this study is shown in Table 1.

Table 1.

Median service time in months by device type and manufacturer per Freeman et al. [13]

	ICD VR	ICD DR	CRT-D
MDT (n = 789)	107.4 (96.1, 115.7)	91.7 (84.4, 101.0)	78.2 (67.4, 88.2)
ABT (n = 577)	129.5 (115.0, 141.4)	108.6 (100.7, 118.8)	83.1 (71.6, 91.8)
BSX (n = 408)	151.3 (136.6, 163.8)	134.1 (118.3, 143.4)	110.6 (96.9, 123.1)
BIO (n = 143)	84.0 (64.6, 100.9)	92.9 (80.5, 100.7)	76.0 (61.5, 85.7)

Data are reported as median (interquartile range)

Abbreviations: ICD VR single-chamber implantable cardioverter-defibrillator, DR dual-chamber implantable cardioverter-defibrillator, CRT-D cardiac resynchronization therapy defibrillator

The purpose of this analysis was to determine in a large-scale global analysis the battery longevity of high-voltage cardiac implantable devices, i.e., ICDs and CRT-Ds from a single manufacturer (BIOTRONIK) from 2006 to present day and to determine the battery performance from one generation of devices to the next.

Methods

All BIOTRONIK high-voltage devices can be remotely monitored through the BIOTRONIK Home Monitoring system. Home Monitoring is the only cardiac device remote monitoring system with automatic daily transmissions of data. In a large, randomized trial [14], it was shown that Home Monitoring demonstrated robust transmission reliability while battery longevity was conserved despite high frequency transmission load [15]. The Home Monitoring Service Center (HMSC) was the data source used to assess the longevity of these devices. Home Monitoring data from 2006 to present day was utilized for the analysis.

To accurately assess the longevity of multiple families of devices, it was necessary to first sort them into groups/families with shared characteristics (i.e., electromechanical platform, battery capacity, architecture, etc.). To that end, we grouped the 215,471 devices into three generations. For simplicity, these generations will be referred to as 2000, 2010, and 2020, roughly corresponding to their introduction timeframe into the market (Table 2).

Table 2.

BIOTRONIK ICD/CRT-D device generations and initial manufacturing dates

	Model	Model variations	Initial manufacturing date
BIO 2000	Lumax	300/340/500/540	March 2006
BIO 2010
	Tach 50	Lumax 600/640/700/740	September 2011
	TachNXT	Idova, Iforia, Ilesto	November 2012
	Tach70	Inlexa 1, Inventra, Iperia, Itrevia	May 2014
	TachNT2	Ilivia, Inlexa 3/7, Intica	November 2015
BIO 2020	iShock	Acticor/Rivacor, Ilivia/Intica Neo	May 2018

Each group’s total device numbers were further subdivided into individual device types (i.e., VR for single-chamber, DR for dual-chamber, DX for single-lead ICD with atrial floating dipole, and CRT-D for cardiac resynchronization therapy defibrillator) given the known variations that exist in therapeutic features, housekeeping current, number of leads present, and other factors with measurable current drain on the battery (Table 3).

Table 3.

Number of BIOTRONIK high-voltage devices by device type and generation

	Generation BIO 2000	Generation BIO 2010	Generation BIO 2020	Total
ICD VR	12,613	18,356	8256	39,495
ICD DR	14,475	29,883	16,444	60,802
CRT-D	13,933	36,486	25,858	75,737
DX ICD	2,001	22,718	14,718	39,437
Total	42,482	107,443	65,546	215,471

Abbreviations: ICD VR single-chamber implantable cardioverter-defibrillator, DR dual-chamber implantable cardioverter-defibrillator, CRT-D cardiac resynchronization therapy defibrillator, DX ICD single-lead implantable cardioverter with floating atrial dipole

Defining service time as a linear extrapolation of battery capacity starting at device manufacturing, i.e., before implantation, would be a simplistic approach given that there is no pacing before implantation. The resulting battery capacity use rate was underestimated, that is service time overestimated. This would be especially true for CRT devices. Therefore, the following formulas were utilized to truly reflect service time. For devices that have already reached the elective replacement indicator (ERI) (i.e., uncensored), service time was from the date of implantation to the date of the most recent HMSC message. For devices that have not reached ERI in their most recent HMSC message (i.e., censored), battery capacity for service time was defined as the battery capacity, minus the battery capacity used at the time of the first HMSC message, minus reserve battery capacity from ERI to end of service (EOS). The battery use rate was defined as the battery capacity at the time of the most recent message in HMSC, minus the battery capacity at the first message, divided by days between the most recent and first message. Finally, utilizing these definitions, the “expected” service time has been calculated as battery capacity for service time divided by battery use rate.

To demonstrate meaningful data in the formulas used for censored devices as defined above, the available HMSC data was filtered to assure that the implant date as documented in the HMSC was within 31 days of the first HMSC message. In addition, at least 10% of total battery capacity had to have been used between the first and most recent HMSC message.

The Kaplan-Meier survival analysis was used to estimate the service times by calculating median longevity for each curve where first occurrences of ERI battery status were considered events. Comparisons across generations were performed using the log-rank test. Management of non-censored events is described above. Resulting data was compared to the Freeman et al. [13] data to determine battery longevity more accurately for BIOTRONIK ICDs and CRT-Ds.

Results

A total of 215,471 devices implanted in 6,526 clinics across 79 countries were included in the analysis, representing a total already reported service time of 977,314 years. Overall, the proportion of devices that reached ERI in their most recent HMSC message was 26.1%, 7.4%, and 0.2% for device generation 2000, 2010, and 2020, respectively. The number of BIOTRONIK devices by type (VR, DR, CRT-D, DX) and by generation is shown in Table 3.

Median service time in months between implant and ERI is shown in Table 4 and represented as bar graphs in Fig. 1. Note the progressive improvement between generation 2000, 2010, and 2020 which is significant regardless of the type of device analyzed (p < 0.001). For VR devices, there was an 89% improvement in service time between generation 2000 and 2020; 108% improvement for DR devices, 52% improvement for CRT-D devices, and 69% improvement for DX devices. DX devices which allow atrial sensing in the absence of a dedicated atrial lead had better battery longevity, 170 months (interquartile range 163–175), than DR devices, 155 months (132–168), and almost equivalent to VR devices, 175 months (169–182). DX service time improved 74% between BIO 2000 and BIO 2020. The Kaplan–Meier survival curves to ERI by device type and generation are shown in Fig. 2. Survival curves for individual device models are available in the Supplementary Material (Fig. S1).

Table 4.

Median service time in months by high-voltage device type and generation

	Generation BIO 2000	Generation BIO 2010	Generation BIO 2020	Improvement (%) *
ICD VR	91.8 (71.6, 105.6)	137.0 (127.2, 149.6)	175.3 (168.9, 181.9)	89
ICD DR	73.4 (63.0, 93.4)	117.5 (100.6, 129.0)	155.1 (131.8, 167.7)	108
CRT-D	71.8 (62, 79.1)	89.7 (75.9, 103.2)	110.8 (95, 125.6)	52
DX ICD	97.3 (91.8, 100.6)	128.6 (119.9, 137.4)	170.0 (163.4, 175.1)	74

*Percentage improvement service time between generations 2000 and 2020

Data are reported as median (interquartile range)

Abbreviations: ICD VR single-chamber implantable cardioverter-defibrillator, DR dual-chamber implantable cardioverter-defibrillator, CRT-D cardiac resynchronization therapy defibrillator, DX ICD single-lead implantable cardioverter with floating atrial dipole

Fig. 1.

Median Service Time in days grouped by device type and generation for BIOTRONIK devices

Fig. 2.

The Kaplan–Meier survival curves with 95% confidence intervals to the elective replacement interval (ERI) for BIOTRONIK implantable cardioverter-defibrillators (ICDs), stratified by device generation: A single-chamber (VR), B dual-chamber (DR), C cardiac resynchronization therapy defibrillator (CRT-D), and D DX system

When the median service times provided by Freeman et al. [13] are compared with the median service times from this analysis, as shown in Fig. 3, BIO 2000 service time appears very similar to the BIOTRONIK service time estimates, suggesting that the majority of BIOTRONIK devices included in the analysis were older generation devices.

Fig. 3.

Median service time estimates reported by Freeman et al. [13] for BIOTRONIK (BIO), Boston Scientific (BSX), Medtronic (MDT), and Abbott (ABT) implantable cardioverter-defibrillator, compared with those observed in our analysis stratified by BIOTRONIK device generation. Abbreviations: VR, single-chamber implantable cardioverter-defibrillator; DR, dual-chamber implantable cardioverter-defibrillator; CRT, cardiac resynchronization therapy defibrillator; DX, single-lead implantable cardioverter with floating atrial dipole

In the Kaplan-Meier curves comparing BIO 2000, 2010, and 2020 service times to the Kaplan-Meier curves provided by Freeman et al., there are also observations of note. For single-chamber ICDs, Fig. 4A, the KM curve from Freeman et al., does not reach the median KM survival time, and any comparison to the BIO curves is not valid. For dual-chamber ICDs, Fig. 4 B, and CRT-Ds, Fig. 4 C, the curves from the study are very similar to the BIO 2010 KM curves, again suggesting that older devices were included in the BIOTRONIK cohort in the Freeman publication.

Fig. 4.

The Kaplan-Meier curves comparing BIO 2000, 2010, and 2020 service times to the Kaplan-Meier curves provided by Freeman et al. [13] for A single-chamber transvenous and subcutaneous ICDs, B dual-chamber ICDs, and C cardiac resynchronization therapy defibrillators. Abbreviations: BIO, BIOTRONIK; BSX, Boston Scientific; MDT, Medtronic; ABT, Abbott

Differences between the large-scale BIOTRONIK high-voltage device analysis and the Freeman data is best appreciated visually when survival curves are superimposed. Figure 4 A overlays BIOTRONIK survival curves by generation for VR devices against the same subset from their manuscript [13]. Figure 4 B does the same for DR devices and Fig. 4 C for CRT-D devices. There was no DX device subset in the study by Freeman et al. for comparison.

Discussion

Battery longevity of cardiac implantable electronic devices remains a critical issue. Longer battery survival times can mean fewer, less frequent invasive procedures for patients and overall lower costs for healthcare systems and higher quality-adjusted life years. Advantages of longer battery service time provide a competitive edge for manufacturers [16, 17].

Just as there has been continued improvement in device design and manufacturing practices since permanent pacemakers were first introduced in 1958, battery technology continues to evolve as well. Today’s ICDs and CRT-Ds operate on lower housekeeping current and offer peak performance with fewer capacitor reformation cycles, despite smaller and more ergonomic form factor, while taking advantage of greater battery capacity. Therefore, it is not surprising that when service time or battery longevity of a very large cohort of high-voltage devices (215,471) is analyzed by generations or “families” of devices, there has been consistent, progressive improvement in battery longevity [8].

In the recent study by Freeman et al. comparing battery longevity from four manufacturers [13], although the models analyzed are not specified, their data suggested that BIOTRONIK service time was markedly shorter than reflected in prior BIOTRONIK internal data. These findings led to the initiation of the massive analysis of BIOTRONIK high-voltage devices described in this manuscript.

As noted in the Section 3, it is highly suggestive that the BIOTRONIK cohort included in the study was predominantly older BIOTRONIK devices. Inclusion by Freeman et al. of predominantly older BIOTRONIK high-voltage devices is also suggested by analyses in prior publications [16, 18].

Beyond BIO 2000, there is progressive improvement in service time for BIO 2010 and BIO 2020, and when curves are overlaid on study outcomes, BIOTRONIK high-voltage devices are at or above industry standards.

Limitations

This study is an observational, retrospective analysis based on real-world data, and is therefore subject to inherent heterogeneity in patient follow-up across sites and countries, which may introduce residual and unmeasured confounding; however, this reflects routine clinical practice.

The proportion of devices that reached ERI was relatively small. In particular, the newest generation of BIOTRONIK high-voltage devices (Rivacor and Acticor), manufactured since May 2018, have not been in service long enough to provide actual ERI data. Consequently, service time estimates for these devices were based on extrapolation rather than observed ERI events. However, the use of a previously validated method [19], combined with the inclusion of devices that had consumed ≥10% of their battery capacity since implantation, should provide reliable estimates that account for most device-specific programming and patient-specific operational features, as major programming changes typically occur early after implantation.

Data was obtained from an internal proprietary database and could be perceived as a limitation of the analysis. It is hoped that any perception of bias is minimized by the uniform methods by which transmitted device data is handled within the HMSC and by the transparency of the longevity limitations of the earliest generation of devices included in this analysis.

Conclusions

Service time or battery longevity is mainly dependent on product generation. Because recent device technologies have lower current consumption due to advanced electronics and newer semiconductors, despite smaller “can” size, larger battery capacity can be accomplished.

The recent study “Variability in Implantable Cardioverter-Defibrillator Battery Longevity” [13] appears to misrepresent current BIOTRONIK ICD and CRT-D service times. BIOTRONIK devices from the 2010 generation of high-voltage devices forward show industry average service times with the newest BIOTRONIK ICD and CRT-D technologies, demonstrating industry leading service times.

Author contribution

D.H. and V.L. contributed to the study design and conception. Material preparation, data extraction, and statistical analysis were performed by C.R. and S.P. The first draft of the manuscript was written by D.H. and B.S. C.R., S.P., D.G., and V.L. critically reviewed the manuscript for important intellectual content. All authors read and approved the final version of the manuscript.

Data availability

The data underlying this article were provided by Biotronik SE & Co. KG and BIOTRONIK Inc. Data are available from the corresponding author upon reasonable request and with permission from BIOTRONIK.

Declarations

Consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

All authors are employees of BIOTRONIK SE & Co. KG or its affiliates.