Not really. They can grow old and feeble and indeed that is referenced in several points and stories. Sometimes they can even grow so old they are taken off the front line and put on training and clerical duties. Or they just kill themselves once they are declared unfit for combat duty. It just takes a 1000 years or so for it to happen. 

That's one of the quirks of the blood Angels and their successors. Long effective lifespans, even by space Marine standards.