Was she still the size of a large, drug-addled horse, or had she dropped any of that weight? As I recall, a big loss in weight over a short time can cause great havoc for your heart. And if the heart is already weakened by drugs and such...
Don't know if it's true or not but news reports say she was recently hospitalized with a collapsed lung, and was recently running a fever with other health issues.
Everybody's quick to assume foul play, but though she looked good for her age, I'd bet she had the heart of an eighty year old woman. Yes, Virginia, drugs & alcohol really do kill. No conspiracies necessary at all.
Anyone who's ever seen Anna Nicole Smith in person or on camera anytime over the last twenty years could easily see that she was committing slow-motion suicide, while all of her parasitic 'friends' and that repulsive leech of an unemployed lawyer who calls himself her 'husband' averted their eyes & did nothing except pick her pockets while she was still here. Pigs. Every last one of them.