Review
Implantable Cardioverter Defibrillators (ICDs) in Octogenarians

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Octogenarians are a growing section of the community. Implantable cardioverter defibrillator (ICD) implantations and replacements in this age group are becoming frequent. There are no randomised control trials or large observational studies of octogenarians and indications for ICD implantations are extrapolated from published primary and secondary prevention trials, where the age group has been in its sixties. About 75% of ICDs are implanted for primary prevention guided by patient's ejection fraction.

Most patients who have ICDs do not have a clear idea about the function and limitation of ICDs. Patient education about ICDs is an important aspect which deserves consideration, particularly in this age group.

The use of ICDs in octogenarians should be individualised and carefully scrutinised. It should take into consideration overall health status, symptom severity, co-morbidities and intermediate and long-term prognosis. There should be detailed discussion about patient preference and expectations. Physicians must provide a realistic appraisal of potential benefits and risks and address device management issues at end of life. This discussion should also take place when ICD replacement is considered.

Introduction

There are only limited options in treatment of life threatening ventricular arrhythmias.

  • 1.

    Antiarrhythmic drugs: which do not prolong life and have significant side effects.

  • 2.

    Radiofrequency ablation: which has a limited role in patients who already have an ICD.

  • 3.

    Implantable Cardioverter Defibrillators (ICDs): provide complete treatment for ventricular tachycardia/fibrillation and bradyarrhythmia including, where indicated, biventricular pacing. ICDs have also been shown to improve survival in many primary and secondary prevention trials; however, ICDs have their own limitations.

With increasing life expectancy, octogenarians are a growing sector of the population.

One in eight ICD implants in the USA are in patients aged 80 years or more, according to a paper published in 2009, and is currently estimated to be one in five [1], [2]. While Australian figures of ICD implants in octogenarians are not available, the number of ICD implants is certainly increasing. This article is an attempt to analyse the available data and attempt to rationalise the use of ICD in octogenarians.

ICDs are implanted for primary and secondary prophylaxis against sudden cardiac deaths. At present, a greater number of ICDs are implanted for primary rather than secondary prophylaxis. In the ACT (Advancement in ICD) trial, 75% of implants were for primary prophylaxis [1].

Currently, the only criterion for ICD implantation for primary prevention is a low ejection fraction. In an editorial on ICDs for primary prevention of sudden death, Dr. Alfred Buxton [3] cites a case of an 83 year-old with EF of 20%, functional class 3 with co-morbidities, referred for primary prevention ICD. There are many such examples in the literature of octogenarians receiving ICDs just because of an EF  35%. In addition to new implants, another important consideration is ICD replacements in this age group. ICD replacements receive less stringent scrutiny than new implants because of the perception that ICDs are for life.

ACC, AHA and HRS 2008 guidelines for ICD implantation [4] do not specify an age criterion for ICD implantation. These guidelines state that ‘ICD therapy is not indicated for patients who do not have a reasonable expectation of survival with an acceptable functional status for at least one year, even if they meet ICD implantation criteria specified in the Class I, IIa and IIb recommendations’. This statement is frequently used as an endorsement for ICD implantation in octogenarians.

Section snippets

Age Limit in Published Primary and Secondary ICD Trials

Table 1 lists secondary and primary prevention ICD trials. In all these trials the age range of patients was much lower than 80 years. Only a small number of octogenarians are represented in these major trials and there is no randomised trial data of ICDs in this age group. Low number of elderly patients in these trials has led to the use of variable age cut off for subgroup analysis. Age limits of 65, 70 and 75 years have been used as ‘elderly’ for the purpose of subgroup analysis. This

Subgroup Analysis of the ICDs in the Elderly

  • (1)

    Healy et al. [5] reported on the role of secondary prevention in patients ≥75 years. This was a subgroup analysis of secondary prevention ICD trials, AVID, CASH and CIDS amongst elderly patients aged 75 years and over. They compared 1614 patients under the age of 75 and 252 patients 75 and over. In under the age of 75, survival for ICD patients was much better compared to medical therapy (<0.0001) while there was no statistical difference between the two arms in patients aged 75 and over (P = 

Trials Supporting ICD Implantation in the Elderly

  • (1)

    Strimmel et al. [11] report on 84 patients with a mean age of 82.68 years who had primary and secondary prevention ICDs. They report ‘low complication’ rate of 9.4% with serious complications in 4.8% but no mortality. Half of the patients received CRT-D implants. Survival during the follow-up period was good, 60% at five years but the benefit was mainly in the CRT-D group.

  • (2)

    Ertel et al. [12] reported on 2967 patients with ICD of which 7.6% were above the age of 80 years. Their mean survival was

Influence of Co-morbidities on Survival in ICD Patients

Octogenarian patients have a higher incidence of co-morbidities. Both heart failure and renal impairment are important determinants of survival in this group. A combination of these and other co-morbidities incrementally increases mortality. Bilchick et al. [14] published a risk model based on more than 45,000 primary prevention ICD patients over the age of 75 years. Heart failure, atrial fibrillation, chronic obstructive pulmonary disease, kidney disease, EF  20% and diabetes mellitus were

What are the Real Benefits of ICD Implantation?

It is worth noting the real life benefits of ICD implants. In AVID, the largest secondary prevention trial, ICD was not of clinical benefit if the ejection fraction was >35% or <20% and 11 ICD implants resulted in one life saved. In SCD-HeFT the largest primary prevention trial, 15 ICD implants were required to save one life and there was actually no benefit in the non-ischaemic cardiomyopathy group. Tung et al. [15] have stated that not a single trial has demonstrated a statistically

Device Related Adverse Events

In any consideration of ICD implants, particularly in octogenarians, it is worth considering device related adverse events. van Rees et al. [16] performed a systematic review of randomised 11 ICD and seven CRT trials. Average in-hospital mortality was 0.2 for ICD and 0.3% for CRT-D; pneumothorax incidence was 0.9%. For CRT coronary sinus, complication was 2%. There was a significant incidence of lead dislodgement (ICD 1.8% and CRT 5.7%). Other complications included haematomas and bleeding.

Quality vs. Quantity

The impact of ICD shocks on physical and emotional well-being needs to be considered in this age group. There is a 15–20% incidence of inappropriate shocks in ICD patients and the commonest cause of inappropriate shocks is atrial fibrillation [17]. It is an accepted fact that the incidence of atrial fibrillation rises with increasing age. Shocks, particularly repeated shocks, lead to increased mortality, morbidity and hospital admissions. This aspect is seldom discussed with the patients prior

Economics of ICD Implantation

ICDs are expensive and it is necessary to consider economics of ICD implantation [18]. None of the trials have shown improved survival during the first year of ICD implantation. Cost effectiveness data ($35,000–131,000 per QALY) have shown that ICDs are cost effective if the patient survives at least three years after implant.

Ethical Dilemma of Therapy Termination

Both the Heart Rhythm Society and the European Society of Cardiology [19] recommend candid discussion with the patient about ICD deactivation in an appropriate clinical context. A retrospective study of discussion with the next of kin of 100 patients with ICD revealed that ICD deactivation was discussed in only 27% of cases and eight patients received a shock from ICD minutes before death [20], [21]. Modern generation ICDs are small and are frequently forgotten particularly when the patient is

ICD Replacement in Octogenarians

The question of ICD replacement in octogenarians arises quite frequently. In a recent editorial, Kramer et al. [23] recommend a new approach to ICD replacement or battery depletion, lead fractures or infections.

The authors argue that ICD therapy is not a lifelong treatment commitment and comprehensive medical evaluation should occur before ICD replacement. In octogenarians requiring ICD replacement the following need to be considered: whether appropriate ICD therapy has been delivered; what

Conclusion

Octogenarians are a growing section of the community. Initial implantations and replacements in this age group are becoming frequent. There are no randomised control trials or large observational studies and indications are extrapolated from primary and secondary prevention trials where the age group has been in its sixties.

This review is not an argument against ICD implantation in octogenarians but the use of ICDs in octogenarians should be individualised and carefully scrutinised. It should

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  • Cited by (3)

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