By Patrick Wingrove SAN FRANCISCO (Reuters) – Germany’s Bayer will continue its expansion into the U.S. despite its November announcement that its promising blood thinner candidate failed to demonstrate superiority over a competing medicine, the drugmaker’s pharmaceuticals head Stefan Oelrich said on Monday. Bayer’s experimental anticoagulant asundexian could still be a blockbuster if its second trial for stroke prevention reads out positively, Oelrich told Reuters at the JPMorgan health conference in San Francisco. He said there is also strong opportunity in the U.S. for the company’s cardiov…