Patients’ Perspectives Regarding Generator Exchanges of Implantable Cardioverter-Defibrillators

Abstract

Background:

Shared decision-making is mandated for patients receiving primary prevention implantable cardioverter-defibrillators (ICD). Less attention has been paid to generator exchange decisions, even though, at the time of generator exchange, patients’ risk of sudden cardiac death (SCD), risk of procedural complications, quality of life, or prognosis may have changed. This study was designed to explore how patients make ICD generator exchange decisions.

Methods:

Emory Healthcare patients with primary prevention ICDs implanted from 2013–2021 were recruited to complete in-depth interviews exploring perspectives regarding generator exchanges. Interviews were conducted in 2021. Transcribed interviews were qualitatively coded using multilevel template analytic methods. To investigate benefit thresholds for pursuing generator exchanges, patients were presented “standard gamble” type hypothetical scenarios where their ICD battery was depleted but their 5-year risk of SCD at that time varied (10%, 5%, 1%).

Results:

Fifty patients were interviewed; 18 had a prior generator exchange, 16 had received ICD therapy, and 17 had improved left ventricular ejection fraction. As SCD risk decreased from 10% to 5% to 1%, the number of participants willing to undergo a generator exchange decreased from 48 to 42 to 33 respectively. Responses suggest that doctor’s recommendations are likely to substantially impact patients’ decision-making. Other drivers of decision-making included past experiences with ICD therapy and device implantation, as well as risk aversion. Therapeutic inertia and misconceptions about ICD therapy were common and represent substantive barriers to effective shared decision-making in this context.

Conclusions:

Strong defaults may exist to “continue therapy” and exchange ICD generators. Updated risk stratification may facilitate shared decision-making and reduce generator exchanges in very low-risk patients, especially if these interventions are directed towards clinicians. Interventions targeting phenomena such as therapeutic inertia may be more impactful and warrant exploration in randomized trials.

Introduction

Clinical trials have demonstrated that implantable cardioverter-defibrillators (ICD) reduce mortality in patients with heart failure with reduced ejection fraction (HFrEF) by preventing sudden cardiac death (SCD) from ventricular arrhythmias.^{1, 2} However, ICD implantation is recognized as a preference-sensitive decision, as individuals may differently prioritize longevity, quality of life, and risks associated with invasive procedures. A shared decision-making encounter is now required prior to implantation of a primary prevention ICD.³ While there remains uncertainty regarding the impact of shared decision-making processes on patients’ decisions in this context, tools such as decision aids have been developed and implemented.^{4, 5} Though efforts have been made to improve ICD decisions, there has been far less attention given to decision-making about generator exchange when an ICD battery is depleted.

Of the 100,000 ICDs implanted annually in the United States, 25% are generator exchanges, resulting in healthcare costs of about $370 million.⁶ Often, generator exchanges may be scheduled by default when ICD batteries reach the elective replacement indicator. Substantive discussions with patients prior to generator exchanges do not appear to be the norm,⁷ and the shared decision-making mandate does not extend to generator exchanges. In addition, guidelines have stopped short of providing specific recommendations on how to make generator exchange decisions more patient-centered.

Though generator exchanges may be seen as a continuation of a therapy, patients may undergo significant changes in the time between the initial ICD implant and battery depletion. First, patients’ heart failure may have worsened to the point where their goals of care are different. Second, as patients age and accumulate comorbidities, the relative risk of arrhythmic SCD decreases while the risk of procedural complications increases.⁸ Third, some patients may have experienced an improvement in left ventricular ejection fraction (LVEF), and many of these patients may never have had prior therapies delivered, both of which decrease the risk of arrhythmic SCD and reduce the value proposition of an ICD generator exchange. Thus, ICD generator exchange represents a discrete decision that generally warrants a discussion about a patient’s goals of care, values, and a risk-benefit analysis.^{7, 9} However, these discussions appear to be rare.¹⁰ In one study, 51.9% of patients were unaware they even had the option to decline a generator exchange.¹¹

Understanding how patients approach generator exchange decisions and their perspectives on what might make them want to decline a generator exchange are important first steps to developing a shared decision-making strategy for this decision. We conducted an interview study to explore patients’ decision-making processes and perspectives regarding ICD generator exchange.

Methods

Study Design

We conducted a cross-sectional interview study using a structured interview guide with both open- and closed-ended questions. We also incorporated a standard-gamble choice experiment to explore risk/benefit thresholds for pursuing generator exchange. Interviews were conducted in HFrEF patients with active primary prevention ICDs. All interviews were conducted via telephone, and participants were given a $25 gift card for participating. Oral informed consent was obtained, and the study was approved by the Emory University Institutional Review Board. Data supporting the findings of this study are available from the corresponding author upon reasonable request for purposes of reproduction of results.

Setting and Participants

Using convenience sampling, participants were screened and recruited from the Emory Healthcare Arrythmia Clinic database, which monitors over 3000 patients with active ICDs. Eligibility criteria included: age ≥18, history of HFrEF, active ICD implanted for the primary prevention of sudden cardiac death, and ability to provide informed consent. To ensure appropriate representation of the temporal evolution of patients’ experiences and values and to account for the proximity of the actual ICD generator exchange decision, patients were sampled from 3 groups: those who had an initial ICD implanted less than 3 years ago, an initial ICD implanted more than 5 years ago (needing a generator exchange decision within 1–3 years), or an ICD generator exchange 1–2 years ago. Patients with a history of heart transplant, inotrope dependence, or mechanical circulatory support were excluded. Patients with cardiac resynchronization therapy devices or those with frequent pacing needs were also excluded. Non–English‐speaking patients were excluded because of the interactive nature of the interviews and English‐speaking interviewers. The planned sample size was 50 participants, which is consistent with the hypothesis‐generating goals of this study and was designed primarily to provide thematic saturation. It also allowed for reasonable point estimates of the prevalence of risk/benefit thresholds in the standard-gamble experiments.

Interview Guide

A structured, interactive interview guide was developed by the investigators. It was cognitively pretested with two patients who had primary prevention ICDs implanted at Emory University to ensure adequate communication about the ICD generator exchange procedure and the purpose of ICD therapy and the comprehension of questions.

The interview guide contained both open- and closed-ended questions with interactive probes. The major domains explored were patients’ experiences with their initial ICD implant decision, self-reported therapeutic history, patients’ subjective understanding of the ICD generator exchange procedure, drivers of decision-making for ICD generator exchanges, and patients’ willingness to forgo an ICD generator exchange if their cardiac function recovered and their clinician recommended against the procedure (see Supplemental Methods). Subsequently, to address misconceptions, all participants were told that “out of 100 people with defibrillators, about 7 people’s lives will be saved over a 5-year period because of the defibrillator”, based on data from the SCD-HeFT trial.¹ A description of how a generator exchange procedure would occur and possible procedural risks was also provided at this time. After providing this information, all participants were given the opportunity to change or elaborate on their previous views regarding drivers of generator exchange decisions.

Following the qualitative portion of the interview, we presented participants with a standard-gamble choice experiment to assess how different hypothetical risks of SCD impact participants’ ICD generator exchange decisions. Participants were provided a hypothetical scenario where their clinician told them their individualized risk of SCD was 10% over 5 years and their risk of complication such as infection or bleeding from generator exchange was 3%.¹² Participants were asked whether they would undergo an ICD generator exchange at this level of risk. Depending on their answer, participants were given follow-up scenarios where the risk of SCD was either increased (20% then 40%) or decreased (5% then 1%) while procedural risk stayed constant, to determine a threshold for deferring the generator exchange procedure (Figure 1). Additional data collected from the electronic medical record included demographic data, most recent LVEF, history of ischemic or nonischemic cardiomyopathy, and ICD implant date.

Figure 1.

Flowchart for standard gamble experiment. SCD (sudden cardiac death).

Data Management

Interviews were audio recorded and transcribed verbatim. Questions with predefined response categories and demographic data were entered into Microsoft Excel. Data entry was verified during transcription review.

Data Analysis

Quantitative data were analyzed using SAS 9.4 (Cary, NC) and Microsoft Excel (Redford, CA). Descriptive statistics were tabulated for patient characteristics, responses to closed-ended questions, and responses to the choice experiment.

Transcripts of the interviews were analyzed using MAXQDA, a qualitative analysis software. The primary analytic aim was qualitative description, providing a rich description of reasons why patients answered in a particular way, and understanding the range of views and reasons for views in key domains.¹³ A multi-level template analytic method was used.¹⁴ SRQR reporting guidelines were used for this manuscript. The preliminary codebook was developed by the research team a priori based on the domains of the interview guide. This codebook was expanded, refined inductively as themes emerged during transcript review using constant comparison, and then finalized after review. Transcripts were double-coded by B.R. and S.M. using the final codebook, and discrepancies were reviewed with N.D. and resolved by consensus. To further enhance trustworthiness, all instances of codes of primary analytic interest were reviewed by the research team to ensure they represented a coherent theme.

Results

Participant Characteristics

A convenience sample of 182 patients were identified as potentially eligible. Thirty-eight were excluded due to invalid contact information, 2 were physically unable to complete the interview, and 2 were deceased (Figure 2). Fifty participants completed the interview, 18 declined, and 72 did not respond (response rate 36%). Mean age was 66 years (SD 13), 50% were female, and 54% were African American (Table 1). Baseline demographics for those who declined the interview were generally the same as those who participated, however, only 28% of decliners were female. Participants’ average LVEF (most recent) was 35% (SD 13.5%), 32% had a self-reported history of ICD shocks (75% of whom had experienced appropriate ICD shocks), and 38% had a history of ischemic cardiomyopathy. Thirty-six percent of participants had a prior ICD generator exchange, and 32% were expected to need to consider a generator exchange within the next 3 years.

Figure 2.

Study Schema. ICD (implantable cardioverter-defibrillator).

Table 1.

Demographic information (n=50)

Characteristics	Overall n (%)
Age
≥ 65 years	31 (62)
< 65 years	19 (38)
Sex
Female	25 (50)
Male	25 (50)
Race
White	20 (40)
African-American	27 (54)
Missing	3 (6)
Time Since Implant/Generator Exchange
<7 years	35 (70)
≥7 years	15 (30)
Left Ventricular Ejection Fraction
≤35%	33 (66)
>35%	17 (34)
Etiology of cardiomyopathy
Ischemic	19 (38)
Non-ischemic	31 (62)
Has your ICD ever shocked you?
No	34 (68)
Yes	16 (32)
Appropriate Shock	12 (75)
Inappropriate Shock	4 (25)
Prior Generator Exchange?
Yes	18 (36)
No	32 (64)

Risk Thresholds for Declining Generator Exchanges

Forty-nine out of 50 participants completed the standard-gamble choice experiment to determine willingness to undergo generator exchange at varying levels of SCD risk with a constant 3% risk of procedural complication “such as infection or bleeding” (Figure 3). Of these 49 participants, 48 were willing to undergo a generator exchange at a 10% 5-year risk of SCD. Of these 48 participants, 42 were still willing to undergo generator exchange at 5% 5-year risk of SCD. All of those who were unwilling to undergo generator exchange at this risk level were females. Of the 42 participants still willing to undergo generator exchange at 5% 5-year risk of SCD, 33 were still willing to undergo generator exchange at 1% 5-year risk of SCD. 39% of the group who were still willing to undergo generator exchange at 1% 5-year risk of SCD had experienced prior shocks from the device. Only one participant was unwilling to undergo a generator exchange at a 10% 5-year risk of SCD, and this participant declined again at 20% 5-year risk of SCD. This participant was willing to undergo the generator exchange at 40% 5-year risk of SCD. Patients’ responses to these questions did not appreciably vary based on prior history of appropriate ICD shocks.

Figure 3.

Patients’ willingness to defer ICD (implantable cardioverter-defibrillator) generator exchange based on risk of SCD (sudden cardiac death) or their doctor’s recommendation.

Participants were also asked whether they would decline a generator exchange if their doctor recommended against it due to improved heart function and decreased risk of SCD. Of the 45 participants who responded to this question, 17 said they would still want a generator exchange in this scenario (Figure 3). Of 33 participants who said they would get a generator exchange at 1% 5-year risk of SCD in the standard-gamble part of the interview, only 16 said that they would want a generator exchange if their doctor recommended against it due to improved heart function and decreased risk of SCD.

Quantitative Data as a Driver of Decision-Making

There was general enthusiasm for learning “the numbers” related to risks of procedural complications or risk of arrhythmic SCD before deciding about a generator exchange. Some participants clearly wanted quantitative estimates of personalized risk of SCD and risk of procedural complications. A subset of this group even noted that they wanted the SCD risk estimates to account for age and comorbidities. For others, the most important statistics were those about personal health, such as LVEF and how many years they had gone without arrhythmia or need for ICD therapy.

There was considerable heterogeneity in how patients used quantitative data. When presented with probabilistic data, some participants simply compared the percentages of risk and benefit. “Of course, ‘cause 10 is higher than 3…10 percent chance of savin’ my life is better than 3 percent of a risk that it’s gonna cause an infection” (Table 2). Others weighed probabilistic risks and benefits differently. For instance, even when the risk of procedural complications was higher than the risk of SCD, some participants were more willing to accept the risk of procedural complications because living with complications was better than SCD. Other participants focused on benefit data but ignored risk data. These participants felt they were “different than those statistics” or that “those statistics don’t apply” to them. Others claimed they wanted risk/benefit data, but it was clear that their decision-making was not anchored in quantitative data. For example, one participant claimed, “I like the data, so I would wanna know the numbers,” (Table 2) however, he revealed that even though he would decline a generator exchange at a 20% 5-year risk of SCD based on his interpretation of the data, his family’s and the doctor’s recommendations would likely drive his decision to get a generator exchange in that circumstance. “Me personally, [I would] probably not [get a generator exchange], then again…my family would have to weigh in…” and “if the doctor recommended it, then that’s gonna hold sway with me”.

Table 2.

Drivers of ICD generator decision-making

Driver	Sub-Category	Quote
Quantitative Data	Different Uses of Data	“Of course, ‘cause 10 is higher than 3…10 percent chance of savin’ my life is better than 3 percent of a risk that it’s gonna cause an infection.”
	Enthusiasm for Numbers	“I like the data, so I would wanna know the numbers.”
Doctor’s Recommendation		“Not being a cardiologist…I’m not a man who’s gonna take a chance of losing my life because I thought I was—I had gone to med school. I realize I haven’t.”
Prior Experiences with the Device	Previous Appropriate Shocks	“…it’s already saved my life once. The good outweighs the bad, no question in my mind.”
	Never Needed Device	“If I went 12 years without needing any therapy, I might think, geez, maybe I don’t need this after all.”
	Misattribution of Clinical Stability	“I just think that I wanna get it replaced because…I haven’t had any problems since [the initial implant]. My [ejection fraction] keeps going up.”
Prior Implant Experiences	Availability Heuristic	“That would be the fourth operation with zero complications, and I think it would be sufficient data that I wouldn’t have anything to worry about for the [next] time.”
Risk Aversion		“I’d rather have it and it not havin’ to work…The doctor don’t know. He knows the signs are improving, but you still could…[need] a defibrillation.”
Therapeutic Inertia	Extension of the Initial Implant Decision	“I knew that [a generator exchange] was part of the process of having a defibrillator…I already knew that, and I agreed to get it done. Once you agree to get somethin’ done, you certainly have to agree to the maintenance—in my mind, anyway.”
	Loss Aversion/Comfort with the Device	“…I still want it in me. I don’t know. It’s not a habit. I’m attached to it mentally. It’ll be hard to lose it.”
	Default Choice	“…I wasn’t given an option or anything. It was more so, this is what’s coming up, this is what you have to do, and when do you want to schedule?”
Misconceptions	Purpose of the Device	“I be afraid if they able to take [the generator] off and remove it, what would happen? What would my heart do without it for so long? Would it put me back to square one, or would it keep on progressin’ bein’ good?”
	Need the ICD to Live	“It was either [get the generator exchange] or not live, so it was easy [to decide].”
	Nature of the Procedure	“I was just going off of what [the clinician] said, so because they never said a new device, that never registered until I got to the hospital. It was more so of, I’m thinking batteries are like you put in a remote control, like a watch or whatever, so I’m thinking replacing the battery’s not necessarily removing the device.”

Other Drivers of Decisions

ICD generator exchange decisions were also impacted by factors other than numerical risks and benefits. Patients identified their doctors’ recommendations, their experiences living with the device, their prior experience with device implantation, and general aversion to risk as important factors in their generator exchange decision.

Doctor’s Recommendations:

A majority of participants cited the importance of their doctor’s input or recommendation in their decision to undergo a generator exchange. Reliance on doctors’ recommendations was based on two types of considerations. One related to expertise; specifically, participants felt that the doctor is the expert in knowing what medical therapies are indicated and most helpful. For example, one participant stated, “Not being a cardiologist…I’m not a man who’s gonna take a chance of losing my life because I thought I was—I had gone to med school. I realize I haven’t” (Table 2). Other participants emphasized trust in the context of an established therapeutic relationship where the doctor knows them.

Prior Experiences with Device Therapy:

Patients’ experiences with ICD therapy impacted their perspectives on generator exchange decisions in three distinct ways. First, some participants experienced necessary, lifesaving shocks. This type of direct experience of the benefit of the device was more salient than the potential risk of procedural complication or lack of benefit from the generator exchange. As one participant said “…it’s already saved my life once. The good outweighs the bad, no question…” (Table 2). Second, some individuals who had never needed device therapy concluded that they may not want a generator exchange. For these participants, having no history of ICD shock was an indication that they did not need the device, or at least that a generator exchange might not be worth the risks of the procedure. “If I went 12 years without needing any therapy, I might think, geez, maybe I don’t need this after all” (Table 2). Third, some people who had never needed therapy from the device misattributed their welfare to the ICD and wanted the generator exchange. “I just think that I wanna get it replaced because…I haven’t had any problems since [the initial implant]. My [ejection fraction] keeps going up” (Table 2). The latter view evinces a misconception of the function of ICDs (see section below on misconceptions).

Prior Implant Experiences:

Some participants believed that an absence of prior complications provided evidence that a future generator exchange would be unlikely to have complications. This is a form of the availability heuristic and is reflected in comments such as, “That would be the fourth operation with zero complications, and I think it would be sufficient data that I wouldn’t have anything to worry about for the [next] time” (Table 2). Others expressed that they would face the decision to get a generator exchange with less trepidation because their prior experiences with ICD implant or exchange made them feel more comfortable with the process.

Risk Aversion:

Some patients described the ICD as sort of a safety net, claiming they wanted a generator exchange even if the absolute risk of SCD was low. These participants had a distinct outlook on risk, emphasizing that risk estimates were predictions, not guarantees. Since their future health was uncertain, they wanted to take all precautionary measures to mitigate the risk of SCD. As one participant stated, “I’d rather have it and it not havin’ to work…The doctor don’t know. He knows the signs are improving, but you still could…[need] a defibrillation” (Table 2). Often, these participants described risk aversiveness in both their initial implant decision and considerations for a generator exchange and explained their thinking with other risk averse behaviors such as wearing a seatbelt, suggesting risk aversiveness may be a general outlook influencing decision-making beyond ICD.

Potential Barriers to Effective Decision-making

As described, there was heterogeneity among participants regarding each of the above bases for decision-making. Several types of decision-making errors, which were barriers to effective decision-making were also observed.

Therapeutic Inertia:

Of the 17 participants who would still want a generator exchange in the scenario that their LVEF improved, their risk of SCD decreased such that ICD therapy was no longer indicated, and their doctor recommended against a generator exchange, 15 (88%) demonstrated therapeutic inertia as a major driver. For these participants, a generator exchange simply represented continuation of their current plan or treatment approach. For some, there was hesitation to discontinue ICD therapy for fear of disrupting their current good health. As one participant said, “if it ain’t broke, don’t fix it”. For others, generator exchange was not viewed as a discrete decision at all, and they considered ICD therapy to be a lifelong commitment after the initial implant, regardless of how their health or values might have changed. “I knew that [a generator exchange] was part of the process of having a defibrillator…Once you agree to get somethin’ done, you certainly have to agree to the maintenance…” (Table 2).

Therapeutic inertia was often reflected in language suggestive of loss. These participants described an emotional attachment to the ICD and did not want to lose their ICD, even if it was no longer necessary. After presenting one participant with the scenario where his doctor recommended against an ICD generator exchange due to improved cardiac function, he said, “I still want it in me…I’m attached to it mentally. It’ll be hard to lose it” (Table 2). Loss aversion was not found to be dependent upon therapeutic history; it was observed in patients with and without prior shocks.

In describing ICD generator exchange experiences, participants also described clinical practices that promoted therapeutic inertia. ICD generator exchanges were often treated as the default and scheduled via nurse phone call when the device triggered an elective replacement indicator alert. Some participants who had had generator exchanges stated that they were never presented the option of declining the generator exchange. One patient stated, “I wasn’t given an option or anything. It was more so, this is what’s coming up, this is what you have to do, and when do you want to schedule?” (Table 2) These responses suggest that healthcare teams sometimes also consider getting the generator exchange as the clear default choice.

Misconceptions:

There were also misconceptions found to drive generator exchange decisions. Even though all participants in this study had ICDs without cardiac resynchronization therapy, some believed their device had improved their LVEF, heart failure symptoms, and quality of life, and that it was responsible for their clinical stability. “I be afraid if they able to take [the generator] off and remove it, what would happen? What would my heart do without it for so long? Would it put me back to square one, or would it keep on progressin’ bein’ good?” (Table 2) For these patients, misunderstandings increased willingness to undergo generator exchange, even in the case of decreased SCD risk. Along similar lines, participants occasionally assumed that their clinical stability was a result of the ICD implant and declining a generator exchange would result in immediate death. These patients quite literally saw the decision to get a generator exchange as choosing life and the decision to decline a generator exchange as choosing death. As one participant said, “It was either [get the generator exchange] or not live, so it was easy [to decide]” (Table 2). For the majority of patients, addressing misconceptions by providing them with background information about the purpose of the ICD did not impact their generator exchange decision.

Some participants did not realize that a generator exchange would require an in-hospital procedure or even any procedure at all. Those who had already undergone a prior generator exchange often attributed this to the language used by their healthcare providers. They claimed that the term “battery exchange” was misleading. To them, even though the leads were remaining in place, they felt that the entire ICD itself had been removed and replaced. “I was just going off of what [the clinician] said, so because they never said a new device, that never registered until I got to the hospital. It was more so of, I’m thinking batteries are like you put in a remote control, like a watch or whatever, so I’m thinking replacing the battery’s not necessarily removing the device” (Table 2).

Discussion

Substantial attention has been directed toward shared decision-making for ICDs; however, generator exchange decisions have received less attention than the initial implant. This study provides novel insights into how patients make ICD generator exchange decisions. These insights provide avenues for development of future interventions- that can be tested in the context of clinical trials- to make the decision-making process more patient-centered.

Efforts to promote shared decision-making often focus on a clear presentation of probabilistic data. These data suggest that individualized presentation of SCD risk, which may differ at the time of exchange from initial implantation, may be useful and valued by patients but that effects on patients’ decisions are likely to be modest. As SCD risk decreased, so did the number of participants who wanted a generator exchange. However, even at a 1% 5-year risk of SCD, where many might not even be offered ICD therapy, 77% of patients in our study still wanted generator exchange. While this may reflect some patients’ genuine preferences, these findings suggest that risk estimates may be difficult for patients to contextualize. Though patients were generally interested in personalized risk and may feel better informed with this information,¹⁵ they may not be equipped to interpret risk data accurately. These challenges are all likely further compounded by varying levels of health literacy and numeracy.¹⁶

In contrast, our findings suggest a particularly important, if not surprising, role for clinicians in decisions in contextualizing risks and benefits regarding ICD generator exchanges. These data suggest that doctor’s recommendations are likely to substantially impact patients’ decision-making. Among the patients who still wanted generator exchange at 1% risk, more than half were willing to decline a generator exchange when suggested by their doctor. Together these results suggest that personalized risk/benefit estimates may be useful to develop and to study primarily as a tool for clinicians to use to communicate with patients and to structure recommendations rather than as a standalone tool such as a decision aid.

Consistent with prior work related to ICD decision-making, this study highlights the presence of significant misconceptions about ICDs among some patients.¹⁰ These misconceptions have driven enthusiasm about decision aids. This study helps to deepen understanding of the nature of some of these misconceptions in the context of generator exchange decisions specifically. For example, it has been previously demonstrated that many patients do not recognize that generator exchange is an elective procedure.⁸ Our study also found that many patients expected generator exchanges to be simple- often expecting essentially no “procedure”- and nearly risk free. Patients’ exaggerated expectations about ICDs, or misunderstandings about the exchange procedure, may make them more inclined to have a generator exchange in circumstances where the benefits are less significant. These findings reinforce the importance of developing and testing strategies to help advance more accurate understanding, and the generator exchange decision may prompt an opportunity for improved communication, as true misconceptions prevent meaningful shared decision-making. However, addressing misconceptions can be challenging. In this study, we attempted to address misconceptions regarding ICD therapy and generator exchange procedures by reading the participants a paragraph of background information. Despite providing patients with accurate information, some misconceptions persisted.

One of the most impactful findings within these data relates to the phenomenon of therapeutic inertia. The pre-existence of a device is one of the key ways in which the decision about a generator exchange is different from initial implantation, and this study suggests it may represent a barrier to effective decisions. This phenomenon has been described as a barrier to medication deprescription and recognized as a critical issue, particularly in the elderly.¹⁷ These data suggest that it plays a significant role in the context of device therapy. Importantly, therapeutic inertia is distinct from risk aversion. Whereas risk aversion may reflect values and preferences, and is indicative of a cautious disposition, therapeutic inertia does not. It represents a psychological decision-making flaw (related to phenomena of loss aversion and “sunk costs”) that, in its most significant form, leads patients not to understand the generator exchange decision as a distinct decision. Loss aversion may also lead a person to view themselves as “worse off” and fail to weigh the benefits of forgoing the procedure such as avoiding potential complications, inappropriate shocks, and discomfort associated with the ICD. As a result, patients may expose themselves to the risks of ICD generator exchange when ICD therapy may not align with their true values and preferences. In addition, clinical practices that promote therapeutic inertia were also described. Importantly, these data are patients’ recollections rather than prospective evaluations of encounters, and practices may vary across institutions.

Together, findings from this study suggest that productive targets to advance shared decision-making for ICD generator exchanges may be directed at: (1) arming clinicians with individual prognostic data to aid in developing recommendations; (2) correcting patient misconceptions; and (3) interrupting therapeutic inertia. For example, individualized risk-benefit information may be less impactful in decision aids, but these data may help clinicians tailor their discussions and recommendations. For this information to be useful, there is a need for better risk prediction models for SCD and generating these models should be a focus of future investigation. Furthermore, more research is needed to explore how best to communicate these risk estimates to patients and integrate these estimates into recommendations to enhance shared decision-making.¹⁸ Decision aids specifically oriented for generator exchange decisions may be useful tools for deepening understanding and addressing misconceptions¹⁹ (and this has been a goal of existing decision aids), though their impact in clinical contexts remains uncertain. Randomized control trials are needed to determine the best strategy for improving patient engagement in the decision-making process and correcting for the types of misconceptions that were found in this study.²⁰

Perhaps the most novel, and potentially productive, avenue to improve generator exchange decision-making is to target therapeutic inertia. One strategy may be to have a shared decision-making discussion in clinic prior to scheduling a generator exchange in which it is emphasized that it is a discrete decision and that a generator exchange is optional. A second strategy- that is not mutually exclusive- would be to use nudge strategies in discussions with patients to help correct cognitive errors. An example of this approach would be to provide case examples to illustrate when and why patients might elect not to have a generator exchange performed. The impact of these approaches or others, of course, is unknown. Empirical investigation is needed- ideally through randomized trials- to understand the efficacy of these approaches and to identify which approach is best at targeting therapeutic inertia.

There are limitations to this study. First, this study used a relatively small sample of patients from a single healthcare system. Other themes could emerge in different populations, and this study was not designed to provide prevalence estimates of views within the population. Second, patients were sampled from three groups in order to account for patients’ proximity to their own ICD generator exchange decision; however, patients who had declined ICD generator exchanges were not represented in this study. This group could provide important further insights. Third, appropriateness of prior ICD therapy was ascertained by patient reports. This was not validated by device interrogations. Finally, this study used hypothetical scenarios and questions to examine decision-making. It is unknown whether patients’ theoretical decision-making would match their actual decision-making in similar scenarios. However, the hypothetical nature of this study is well-suited to direct further exploration of strategies for improving the ICD generator exchange decision-making process.

Conclusion

There are multiple ways in which shared decision-making for ICD generator exchange decisions appears to be suboptimal. This is a significant policy-level issue because these decisions entail significant healthcare costs and can potentially impact patients’ quality of life. Furthermore, there are unique considerations in generator exchange decisions that make them different from initial ICD implant decisions. Personalized quantitative risk/benefit estimates may be useful for patients in making a generator exchange decision, as some patients are sensitive to changes in risk. Doctor’s recommendations, however, which may be driven by changes in risk and benefit, appear likely to be more impactful. In this respect, providing personalized prognostic data to clinicians may enhance conversations and ensure that patients’ evolving circumstances and preferences are appropriately considered. These data also suggest additional barriers, specifically misconceptions about ICDs and therapeutic inertia. Efforts to address misconceptions and, perhaps more importantly, to disrupt therapeutic inertia by highlighting generator exchange as a discrete decision warrant further study, ideally through randomized trials.

What is Known:

• ICD generator exchange decisions are preference sensitive and distinct from the initial implant decision.

• Unlike the initial implant decision, shared decision-making encounters are not mandated for ICD generator exchanges, and they do not appear to be the norm.

What the Study Adds:

• Numeric risk/benefit data may be most useful as a tool for clinicians to communicate with patients and structure recommendations.

• Barriers to effective decision-making- namely therapeutic inertia and misconceptions about ICD therapy or the generator exchange procedure- were found to be common amongst study participants.

• Efforts to address misconceptions about generator exchange and to disrupt therapeutic inertia by highlighting generator exchange as a discrete decision warrant further study, ideally through randomized trials.