When you leave your current practice, you will not have access to your patients. There is likely a non-solicitation clause in your employment agreement. You do not want to get caught up in a legal battle over patient solicitation.
Patients, however, have free will to see whoever they want for their care. There is nothing tying them to your old practice after you leave.
To skirt this issue, I suggest starting a patient newsletter or blog where they can sign up to receive information you provide. This is an opportunity to connect with your patients, offer them education while also giving them a place to find you if you do leave your current practice.
In full transparency, I did this, I collected email addresses, but I got so nervous about getting sued for solicitation that I deleted the file with all my patient email addresses. This was idiotic and emotional – I wish I still had that file today. However, if this makes you too nervous (it shouldn’t), you can still thrive without this. Like I’ve said, conversion is low, so not all of your direct care patients will come from your previous practice.