Strokes can cause minimal damage, or catastrophic damage, depending on the type of stroke (and other factors, ie so called brain plasticity)
They can leave you with a tic, or paralyzed.
What is more, their damaged can often be reduced or mitigated if rapid medical treatment is administered to restore blood flow from ruptured or blocked arteries.
So, strokes during arrests will not be recorded as deaths during arrests, as strokes are very often not fatal, even if they cause catastrophic permanent damage (ie loss of speech or paralysis), and what it is more, symptoms may not be visible until hours after the stroke occurs.
For delayed onset and progressive stroke symptoms, it is not likely that a stroke that happened during an arrest would be recorded as a stroke during the arrest from a vascular restraint or any other arrest related situation.
But rather, it would more likely get recorded as, inmate displayed signs of medical distress or non-responsiveness in the holding center, when he or she was ultimately examined by the medical staff, or transferred to the hospital, it was determined that he had a stroke in his cell.
Keep in mind, someone (another inmate or staff) would have to notice that the inmate was displaying stroke symptoms, and give a shit enough about it, to do something about it.
And in that case, the person may not die, but may be permanently paralyzed, and/or have lost speech abilities, etc, etc.