heart attack vs heart failure

I believe a heart failure is associated with disorders that impair the blood pumping activities of the heart, while a heart attack is related to oxygen starvation of the heart muscle.

In a heart attack, the heart itself is damaged. Heart failure means the heart can't do its job. A heart attack can certainly lead to heart failure.

I would say it's like the difference between a cut to the femoral artery and blood loss. You don't die from the cut, you die from the loss of blood. If the heart attack is severe enough, you can die from the resulting heart failure.

MrPedantic

I would say that when you "die of something", the "something" is the direct cause of death; whereas when you "die from something", the "something" may be the indirect cause of death.

Therefore you usually "die of your wounds", rather than "from your wounds"; but you're as likely to die "from your injuries" as "of your injuries".

However, it's probable that many native speakers use both alike.