Pacemakers are usually designed to do several things. For the most part, the pacemaker should not need replaced ever (except the battery which will need to be changed about every 10 years). This is because the function they serve will never need to be adjusted. They are not like a cell phone in which a newer version will come out with more features. The only advantage to the newer ones is that they seem to get smaller and smaller every time a new one comes out. Most people leave their original devices in unless something wrong happens. Here are some reasons that a pacemaker and/or internal cardioverter-defibrillator (ICD) would be removed.
1. Malfunction: Every once in a while the pacemaker or or ICD feature of it will malfunction. This almost never means it stops pacing, but extremely rarely they will deliver an inappropriate shock. This is not dangerous, it just hurts a bit and should prompt you to go to the emergency room. Also, sometimes the leads coming from the pacemaker fracture.
2. Infection: Any foreign object in your body has the potential to be infected. It must come out after.
3. Desire by the patient: some patients change their minds about wanting one.
I suggest that you pose this question to your husband's cardiologist
at your next visit. The two of you can discuss this issue in the context of his device and its specific issues. Good luck.