We had just received our starters in Business Class when an announcement was made, asking if a doctor was on board, My traveling companion was a doctor and we were taken to the rear of the coach cabin where a gentleman was quite unwell. We spent about two hours with him until he was stable and comfortable. When we returned to our seats, the meal service had concluded, and the cabin lights were dimmed. We asked to be served our meal, and we were told that dinner service was over and everything had been stowed. We were furious; also the flight attendent leader took our names in case there were any questions regarding the sick passanger. We thought that Delta could have at least written a note of appreciation for our efforts, but we never heard one word. Since then, I have made 3 trips on American to LHR and kissed Delta goodbye.