Beyond squabbling on numbers (COVID was actively fought in most developed countries, otherwise it would have killed many more), the difference is control.

Heart disease is well-understood, and largely avoidable with education; hence, it's not a problem as far as the ruling classes are concerned.

COVID and other infectious diseases, on the other hand, can hit literally anybody with a social life. They are fundamentally uncontrollable at the individual level, and have the potential to upset the social order if the numbers get out of control (as they did, shortly, last year). Until that continues to be the case, COVID will continue to be addressed as a significant problem.