It might. That would likely be really an individual response. If the person being edged has high blood pressure to start with, I'd approach this with care. Do other sexual situations cause a spike in BP? Has he been edged not in a cage? Could his BP be monitored?
Does he have other heart problems?
This is something I'd discuss with his/your doctor. You don't have to get really specific, but ask about prolonged or intense sexual activity. That should be enough of a description. :)