I filled a claim years ago for hypertension and was denied. If VA put hypertension on the agent oranges list would I be able to use that as a start date or would I have to start a new claim?
Maybe. In Nehmer it was ruled that many veterans who had filed claims for heart disease caused by agent orange were awarded significant retroactive benefits.
However, I have to comment that although there may be some small chance of retroactive benefits, I personally believe that VA won't be awarding any more agent orange benefits. If hypertension were awarded it would be interesting to see what happened since many hypertension claims are service connected but rated at 0% since hypertension isn't in and of itself a disabling condition. Because of a familial pattern I've been hypertensive for most of my life, I take a couple of pills, I'm not at all disabled by it.
To get a rating for a disabling condition the condition actually has to be disabling in some way. Unless your hypertension is wildly out of control you could get 25 years of retro at 0% service connected and that would net you...$00.00.