By Dr Benjamin King, Cardiologist, Perth
Physicians implanting defibrillators have a well-prepared spiel about whether to implant an Implantable Cardioverter Defibrillator (ICD). The discussion includes procedurals risks, inappropriate shocks, quality vs. quantity of life, probability of sudden cardiac death (SCD), and evidence of survival benefit. But when the hardware goes in it is permanent. Do we have a routine for turning off defibrillator programming?
Relativity is changing
The major trials (SCD-HEFT, MADIT-2, DANISH) investigating primary prevention of SCD in patient with impaired LV ejection fraction did not include octogenarians (historically excluded from clinical practice). In 2018, we need to mention to patients what we do not know about defibrillators in their age group. Furthermore, heart disease survival is improving so those implanted as younger patients are now getting older and developing expected comorbidities. Even more older patients appear in the secondary prevention group as age is less of an implant contraindication for patients surviving ventricular arrhythmia.
The 2017 Heart Rhythm Society Guidelines for ICD implantation only recommends withholding ICD implantation to patients if survival with “reasonable quality of life and functional status” is estimated at under one year. Curiously, this same definition for withholding some treatments was used 2000 years ago in the Talmud. Therefore, the doctor should consider disabling the defibrillator in patients who arrive at the same sad landmark, or perhaps before this if patients request this.
In contradistinction to pacing and resynchronisation, which offers significant symptomatic gains and withdrawal may have immediate deleterious effects (some legally and ethically problematic), turning off tachycardia therapies can be a progressive discussion.
ICD patients should know that the ICD is only an insurance policy against SCD. Therefore, if a very quick ‘exit’ from this world becomes more attractive than enduring additional unpleasant ICD shocks, device function can be withdrawn simply by the programmer. While not conceding imminent death, it can still be anxiety-provoking, for which the decision can be easily reversed.
Reprogramming doesn’t have to be in the setting of terminal illness, pain or dementia. More ICD patients die of heart failure than die of VT/VF. All-cause mortality is roughly double cardiovascular death, such that as diagnoses other than VT/VF are made, it is reasonable to discuss with patients where their ICD therapy fits in.
My personal approach
My approach is to insist a final decision not be made at the first discussion. Time to consider and discuss with loved ones is valuable. Indeed, annual ICD tests in stable patients presents opportunities to review patients’ health aspirations. The discussion should be composed and well documented, involving relevant stakeholders in the patients’ health like other matters in Advanced Directives.
It’s probably less traumatic to turn off shocks pre-emptively than during terminal arrhythmia, so if arrhythmia does come, it can gracefully escort the life to its close.
Key Points
- VT/VF therapy (shocks) affects quantity not quality of life and can be simply electronically turned on and off.
- There are not extensive robust survival data set of older patients with ICD.
- ICD patients more commonly die of non-cardiovascular death.
- Discussing timing of turning off shock therapy is best done prospectively during reasonable health and mentation.
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