The study used date from Alzheimer Disease Centers from September 2005 through December 2011 to look at how often cardiac implantable electronic devices are placed among older adults with and without cognitive impairment.
Of the 16,245 participants who had at least one baseline visit and at least 1 follow-up visit in the study period, 45.8% had no cognitive impairment, 21.3% had Mild Cognitive Impairment (MCI), and 33% had dementia. Rates of new pacemaker placement in these folks were as follows:
- 4 per 1000 person-years for participants without cognitive impairment
- 4.7 per 1000 person-years for participants with MCI
- 6.5 per 1000 person-years for participants with dementia
When adjusting for baseline demographics such as age, sex, race, intensity of pacemaker use in the the patients hospital referral region, cardiac comorbidity burden, functional status, and type of dementia, the authors found that:
- Patients were 1.6 times more likely to receive a pacemaker if they had dementia than if they didn't have any cognitive impairment
- Patients were 2.9 more likely to receive a pacemaker if they had severe dementia than if they didn't have any cognitive impairment.
So I guess that was a long answer to a simple question. Now we know a pacemaker is more likely to be placed in someone with dementia (and even more so in someone with severe dementia), our next post will address the issue of what happens when people consider turning them off.
by: Eric Widera (@ewidera)
NOTE: I'll also be reviewing Katy Butler's book "Knocking on Heaven's Door: The Path to a Better Way of Death" this week. Comment on any of the pacemaker posts this week or talk about it on twitter and you'll be entered into a drawing to win one of the paperback versions (for twitter, just make sure you include @geripalblog in the tweet)
Comments
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http://www.ncbi.nlm.nih.gov/pubmed/19433698
2. Cholinesterase inhibitors and incidence of bradycardia in patients with dementia in the veterans affairs new England healthcare system.
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http://www.ncbi.nlm.nih.gov/pubmed/19793162
3. Cholinesterase inhibitors and hospitalization for bradycardia: a population-based study. PLoS Med. 2009 Sep;6(9):e1000157. doi: 10.1371/journal.pmed.1000157. Epub 2009 Sep 29.
http://www.ncbi.nlm.nih.gov/pubmed/19787032
Really interesting phenomenon - but some theory to guide the process of interpreting the results and planning next steps would be very helpful.
One alternative that you suggest is that it is a consequence of the disease and its treatment - therapeutic cascade.
Alternatively, other comments suggest a "vulnerable patient" combined with mercenary health system interpretation.
I could also imagine that the perceived limitations in self-care for people with dementia would lead to preference for treatments like a pacemaker that at least seem to require less patient participation.
A research letter isn't the place for this kind of differentiation, but I do find myself wishing that medical research like this was more sensitive to the very different interpretations and did more to try to figure out why such phenomena might occur.
Another theory is that pacemakers are not thought about in the same category of interventions as CPR and intubation are, and so there are no discussions around pacemakers similar to discussions about code status.
I think that you should strongly consider stopping either of these meds before placing a permanent pacemaker.