Jan Freeman: What to do when an adjective loses weight
Massive attack: What to do when an adjective loses weight. «Is it really OK to call things “massive†if - like malicious software or a fire or a heart attack - their mass is negligible or irrelevant? »

Of course any word can be overutilized. Massive heart attack, as the author points out, has become a figure of speech, so much so that it would sound strange to use another expression, unless you just want to say someone has had a heart attack without indicating if it was big or small. But I don't have any problem with applying massive to massless objects. You can also apply massless adjectives to objects with mass, such as air head. 😆
Anybody who feels a heart attack can't be "massive" fails to appreciate the gravity of the situation.

Now that is a weighty argument. Weight is defined by physics, roughly, as gravity times mass. So if the heart attack is massive, and there is great gravity to the situation, the weight of the discussion might break the scales.

That's really heavy, Glenn.