Even though the doctor told him smoking was deleterious to his health, he didn't quit until just before he died.
I'd like to know if it means "he died as a result of not giving up smoking".
Sure. Maybe he finally kicked the habit and the next month he was killed crossing the street by a drunk driver. Or trampled at a Who concert. Or shot by a bank robber.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
Thanks.
Actually how he was killed and why doen't matter. The important thing is whether he quit or not before his death.