Adverse reaction reports describe suspected side effects. A report does not mean the drug caused the event — co-medications, underlying disease and coincidence all contribute.
Is estrogen replacement therapy approved in United States?
Yes. FDA has authorised it.
Who is the marketing authorisation holder for estrogen replacement therapy in United States?
National Heart, Lung, and Blood Institute (NHLBI) is the originator. The local marketing authorisation holder may differ — check the official source linked above.