Is Meth So Addictive that Someone Could use It Even if They Are Dying?

I have a family member (50 yo) with late stage heart failure. He was hospitalized twice for fluid building up around the heart and lungs and was released from the hospital 3 weeks ago. He has a history of meth use, but I'm not sure if he still uses it because he hides it. I want to know if it's possible that he's still using it. He's not taking the steps to take care of his heart failure like he should. My mother thinks that he's definitely not on meth because it would've killed him by now. I want to know is meth so addicting that someone would use it, even on their deathbed?