Implantable cardioverter defibrillators work — so why aren't we using them?

Economics and rationing

The uptake of new technologies into the Canadian health care system is generally slower than in the United States. As monopolies, provincial governments are able to tightly regulate the roll-out of a new technology, by placing caps on the volumes covered by government insurance and by other indirect disincentives for procedures such as defibrillator implantation. Thus, provincial and territorial Ministries of Health are able to force rationing decisions downstream to the physician at the bedside simply by placing limits on how many procedures can be performed every year.8 This is less of a concern in the United States, although rationing undoubtedly occurs there as well. During the period of the study (1995–2003), centres in Canada were routinely running out of funding for implantable cardioverter defibrillators well before the end of the fiscal year, which resulted in difficult and inelegant rationing decisions.

Knowledge translation, guideline penetration and access problems

Physician judgment clearly plays a large role in implant decisions. It is unknown whether physicians are not considering implantable defibrillators at all for potentially eligible patients, whether they consider but decide against offering it to their patients, whether they offer it but patients decline it, or whether the resources are unavailable or difficult to obtain. Although the greater use of the therapy among patients who came to an academic teaching institute (as opposed to a smaller or community-based institution) strongly supports the existence of inadequate knowledge translation and guideline penetration, it may also reflect a relative unavailability of the resource at smaller community hospitals. One key infrastructural difference between this country and the United States is that defibrillator implantations in Canada are performed almost exclusively in large teaching institutions with full electrophysiology programs, whereas in the United States they are carried out in many medium-sized and small community facilities as well. Certainly, then, Canada's geographic scale and the resulting remoteness of implant facilities for many patients may well factor prominently into decision-making. Patients from regions of Canada with no nearby implant centre have previously been shown to have lower implant rates for these devices.9

Cultural values, social factors and reduced rates of death

A decision to implant an implantable cardioverter defibrillator is fundamentally different from a decision to begin drug therapy for, say, hypercholesterolemia. We use drugs for hypercholesterolemia to reduce not only deaths but also illness and disability, and when we introduce a drug to a patient, there is an expectation by both physician and patient that the individual in question will derive benefit.

However, when we implant a cardioverter defibrillator, we know that when it fires, it does only one thing: it prevents sudden cardiac death. It accomplishes nothing else. We also know that most patients implanted with a cardioverter defibrillator will eventually die from something else, never having had their life “saved” by the device. Thus, the implantable cardioverter defibrillator will be truly life-saving for only a small percentage of those in whom we implant the device, whereas drugs that we prescribe for common conditions like hypercholesterolemia will slightly extend the lives and marginally reduce illness in a greater proportion of treated patients. Patients and physicians thereby perceive these therapies differently. There is no doubt that this weighs into the decision-making process and probably contributes to differences in the general acceptance of drugs versus the general acceptance of implantable cardioverter defibrillators. For example: given the choice, would you prefer to take a statin for 6.1 years and extend your life by a statistical average of 34 days,10 or have an implantable cardioverter defibrillator that has, say, a one-in-ten chance of truly saving your life sometime over the next 3 years? The risk reductions and p values of these options may be comparable, but the way the benefit is perceived and presented is very different.

Finally, patients who have survived an episode of sudden cardiac death are arguably compelled to consider their own mortality in a much more thorough and philosophical way than many other patients do. Many begin thinking about mode of death, and the fact that a reduction in the probability of sudden death (regarded by most as a painless or even “pleasant” way to die) necessarily means that death, when it does come, is more likely to be nonsudden, or less pleasant. Is living longer, only to eventually die in a less palatable way, the preferred course? Clearly, the right answer differs for different people.

Reasons for the relative underuse of implantable cardioverter defibrillators in Canada and the United States for secondary prevention of sudden death are undoubtedly multifactorial. More investigation is required to examine the reasons for the difference between Canada and the United States. In the interim, efforts should be made to ensure that all physicians are aware of this option for survivors of sudden cardiac death. Paternalism and bedside rationing should be discouraged; physicians should instead engage their patients in a discussion about the benefits versus the potential downsides of implantable cardioverter defibrillator therapy and advocate for their patients to secure this treatment when appropriate. Patients who are eligible according to guidelines deserve to be offered the therapy; but they also must be empowered to refuse it if, after being fully informed, they determine that it is not the right choice for them.

@ See related article page 41