The use of the iHealth Core scale, like any other device that makes the weakest electrical signal pass through the body, is not recommended for people with a pacemaker or any other electronic medical implant.
People with non-electronic medical implant can use the iHealth Core balance safely.
Metal implants can affect the accuracy of body fat mass measurement, giving slightly underestimated results. However, if these implants are present in your body at every measurement, you can follow just as effectively the evolution of your fat mass over time.
*credit to Sylvain of iHealth Labs EU
https://helpcenter.ihealthlabs.eu/hc/en-gb/articles/208801405-iHealth-Core-HS6-Can-I-use-the-scale-if-I-have-a-pacemaker-