Implantable cardioverter defibrillator deactivation

The epidemic of heart failure occurring in westernized societies accounts for a significant proportion of healthcare resource utilization and expenditure. This challenging problem affects all sectors of the health economy and stems in part from a true rise in incidence, particularly evident in ageing individuals with several comorbidities who often exhibit typical clinical features of heart failure despite a preserved left ventricular ejection fraction. However, there is also a significant increase in the prevalence of heart failure reflecting the improved survival of those affected by conditions resulting in a reduced left ventricular ejection fraction (HFrEF) who are diagnosed earlier, prescribed appropriate therapy, and now live with heart failure as a chronic, progressive life limiting condition. Those living with chronic congestive heart failure endure a multidimensional malaise equivalent to that associated with common cancers [1,2]. This includes not only a heavy symptom burden such as that from dyspnoea, some of the mechanisms of which are described by Johnson and Clark in this issue, but also the impact of increasing dependency and a loss of economic stability if the primary breadwinner is directly affected or has to assume the role of an informal carer. There is also significant psychological morbidity including overt clinical depression or anxiety often linked to awareness of the associated mortality risk. Despite our best efforts, heart failure remains a leading cause of death with mortality 1 and 5 years from diagnosis being about 30 and 50%, respectively [3]. Although challenges remain in the elucidation of specific therapy for those with heart failure despite a preserved left ventricular ejection fraction, over the last 20 years or so, comprehensive treatment protocols have gradually evolved for those with HFrEF. These are incorporated in current therapeutic guidelines which also recognize the potential contribution of palliative care [4]. Guideline-directed therapy for chronic HFrEF has been widely adopted, but is relatively complex including multiple prescription drug therapies, implantable electronic devices, and cardiac surgical intervention which may involve the placement of a left ventricular assist device either as destination therapy or as a bridge to transplantation. Such heart failure management is generally accepted as effective but is of itself burdensome. This requires the patient to adhere to polypharmacy, to self-monitor their condition, and to be subject to frequent clinical or laboratory assessment in community or hospital-based heart failure clinics [5]. Heart failure is prognostically uncertain and the disease trajectory is unique to each affected individual [6]. Typically, this clinical cohort exhibit a roller coaster configuration of progressive functional deterioration interspersed with medical crises, the rate and complexity of which increase toward the end of life [7]. The treatment paradigm for those with HFrEF is founded on evidence-based medicine, but central to the ethical application of such practice, it is incumbent on us to weigh up the benefits and burdens of all elements of therapy throughout the course of the illness. In recent years, we have seen a rapid escalation in the use of implantable cardioverter defibrillators (ICDs) to reduce the risk of potentially lethal arrhythmias and sudden death in those with HFrEF. Although offering protection, these devices offer no intrinsic symptomatic benefit unless combined with cardiac resynchronization therapy but rather may affect patient wellbeing in the delivery of uncomfortable shocks, or fear related to that possibility, as well as other device-related complications [8]. Although most patients will accept such trade-offs in favour of survivorship, given the progressive nature of heart failure, maintaining ICD therapy as patients decline may ultimately determine a rather protracted mode of death through congestion and progressive multiorgan failure. Moribund patients often exhibit significant metabolic and biochemical derangement which may trigger arrhythmias and device activity. Kaufman has coined the term ’ironic technology’ in relation these electronic devices, arguing that the effects of such therapy might ultimately be at odds with evolving patients’ preferences in advanced stages of heart failure or in the face of the development of other life-limiting diseases [9]. Discussion about ICD deactivation, if broached at all, often occurs very late in the course of illness, frequently close to the point of death [10]. Certainly, the negative impact of clinically futile shocks at the end of life is well recognized and constitutes a potentially avoidable harm [11]. Uncertainty is writ large here, as it no doubt is in many medical decisions, particularly at the end of life [12]. The precautionary principle offers one way of responding to uncertainty. The principle suggests ‘that when there are uncertainties about the future risks of certain policies or actions, one should refrain from such actions or policies’ [13]. Here, the burden of proof shifts to those who would support such actions or policies to make their case. This principle has been formulated in several settings and has gained most prominence in consideration of environmental issues such as climate change when there is a perception of impending risk from industrial processes or population wide activity. From a normative standpoint, the principle has also been examined as an ethical basis for medical decision-making, which requires us to be aware of the possible consequences of our actions [14]. Given the often inexorable progression of heart failure and an awareness that some previously considered protective treatment modalities could ultimately present harm, should the precautionary principle apply and these potentially hazardous elements of therapy be withdrawn? Although intuitively attractive in terms of ICD management in advanced heart failure states and consistent with the maxim of primum non nocere, this approach has been perceived as too simplistic and overly risk averse, potentially disadvantaging some patients [14,15]. Yet, the application and interpretation of the principle must be determined by reference to (subjective) values [13]. Decisions on the question of device deactivation therefore need to be deliberated in the broader perspective of risk–benefit assessment, physician experience, reasonableness, and, importantly, through the prism of patient values and beliefs. Certainly, we must guard against paternalistic assumptions of patient preferences for survival when subject to the burdens of living with progressive heart failure [16]. Survival scoring systems for heart failure have been developed including the recent MAGGIC model based on the clinical features of 39 372 patients from 30 studies collated and examined by the Meta-Analysis Global Group in Chronic Heart Failure [17]. The well established Seattle Heart Failure Model is also useful and may offer some insight into the mode of death which might be helpful in initiating discussion on preferences for end of life care and device management [18,19]. Although such modelling systems may offer some insight, prognostication on an individual basis remains ambiguous. Accepting that each person with heart failure exhibits a distinctive fluctuating disease trajectory, how do we discern the possible transition point between therapeutic beneficence and maleficence with respect to their ICD therapy? Expected utility theory favours the clinical benefit of ICDs in the earlier phases of heart failure when sudden cardiac death is more likely [7,20], but later one can sense that a phase of therapeutic equipoise comes in when device efficacy becomes much less certain. Recognizing the shift to equipoise with regards to ICD therapy and introducing this notion of uncertainty in discussion with the patient may facilitate review of their expectations and choices for future care and promote advance care planning. Indeed acknowledging such equipoise has been proposed as a means of promoting shared decision-making, a central tenet of advanced heart failure care [21,22]. As suggested in current guidelines, ideally the possibility of later ICD deactivation should first be discussed as part of the informed consent process and revisited at intervals, perhaps triggered by markers of decline or so called ‘inflection points’ along the heart failure disease trajectory, or when considering device replacement because of battery depletion [23–25]. Such sequential discussion should generate incremental value although it must be conceded that many ICD recipients have poor health literacy, unrealistic impressions of device-related benefits, and little concept of the possible clinical and ethical dilemmas these implants might pose close to the end of life [26,27]. Undoubtedly the development and use of ICDs have improved the clinical outlook for many patients with cardiovascular disease, particularly those with heart failure. Celebration of this success needs to be tempered with the knowledge that this intervention may confer risk as well as benefit [28,29]. A precautionary approach to risk management may be justified but needs to be nuanced to accommodate the needs, interests and values of individual patients. The continued utility of such devices needs to be reassessed along each disease trajectory and, if deemed questionable, it would be judicious to review whether maintenance of this treatment option is still in the best interests of the patient. Some patients may be disinclined to participate in these sometimes difficult conversations and the tenor and content of such discussions needs to be calibrated to accommodate variation in their receptiveness, resilience, and intellectual capacity. Work is underway to explore better ways of communication between clinicians and ICD patients with advanced heart failure [30]. Acknowledgements None. Financial support and funding None. Conflicts of interest There are no conflicts of interest.