No one's saying that, nice try. If you die of heart disease and don't test positive for covid, it's not going to be reported as a factor. If you're asymptomatic and it could've exacerbated the heart disease, then it's likely going to be reported as a comorbidity, but not the primary cause, so I wouldn't necessarily report it as a covid death, but I'm also potentially also leaning towards it as such because we've seen it can exacerbate those pre existing conditions.
If you just don't care and die of heart disease by your own inaction, your vaccination status is only relevant if you contracted symptomatic covid in particular, because the vaccine is meant to reduce hospitalizations and deaths from that