Runner in Paris witnesses murder/violence

Hello! I'm looking for a book by a male author set in Paris. The male protagonist is a 70-something runner with a heart condition who witnesses a murder/violence and decides to get revenge on the perpetrator by killing him. The runner knows he'll be caught, but decides to keep running after he kills the perp and die of a heart attack instead.

The cover of the (North American edition) of the book has a b&w photo of the Eiffel Tower. Patron read the book about 8-9 years ago and thinks the book was published around 2010.

Any ideas? Thanks for your help.