I'm not sure I buy the causal link between a small increase in door to ECG time and an increase in 30 day mortality (AFAIK, there's no other research explicitly

I'm not sure I buy the causal link between a small increase in door to ECG time and an increase in 30 day mortality (AFAIK, there's no other research explicitly linking those two stats). Door to reperfusion (or "door to balloon") time matters a lot, but the article doesn't mention those stats.