I,ve Had Trauma Induced Stroke My Left Carotid Arterie Is

i,ve had trauma induced stroke my left carotid arterie is now 100% blocked however other arteries is reduced by 15% i,am 60 year old male its been 3 years since stroke , when my blood goes to left blocked
arterie it stops and then what happens to blood does it have to flow against the flow so to speak? is this bad for heart? or anything else?