Richard Briers' health deteriorated after being diagnosed with emphysema five years ago.
In an interview at the end of January, he told how he blamed his years of smoking for the condition.
"It's totally my fault. So, I get very breathless, which is a pain in the backside. Trying to get upstairs... oh God, it's ridiculous.
"Of course, when you're bloody nearly 80 it's depressing, because you've had it anyway."
More top news
Scotland finally injected some momentum into their World Cup preparations as they beat Italy 48-7 triumph at Murrayfield.
Labour leadership candidate says Britain playing its role in the migrant crisis would help Cameron secure the promised reforms in Brussels.
Ten people have been taken to hospital and another two treated for injuries after a bus crashed into a tree in east London.