Time-to-treatment significantly affects the extent of ST-segment resolution and myocardial blush in patients with acute myocardial infarction treated by primary angioplasty.

Aims: The prognostic role of time-to-treatment in primary angioplasty is still a matter of debate. The aim of our study was to evaluate the relationship between time-to-treatment and myocardial perfusion in patients with ST-segment-elevation myocardial infarction (STEMI) treated by primary angioplasty.

Methods And Results: Our study population consisted of 1072 patients with STEMI treated by primary angioplasty from 1997 to 2001. Myocardial perfusion was evaluated by using ST-segment resolution and myocardial blush grade. Time-to-treatment was defined as the time from symptom-onset to the first balloon inflation. Time-to-treatment was significantly associated with the extent of ST-segment resolution, myocardial blush grade, enzymatic infarct size, and 1-year mortality. After adjustment for baseline confounding factors, time-to-treatment was still associated with impaired ST-segment resolution (adjusted OR [95% CI]=1.01 [1.01-1.02], p<0.001) and myocardial blush (adjusted OR [95% CI]=1.01 [1.01-1.02], p<0.0001).

Conclusions: This study shows that in patients with STEMI treated by primary angioplasty prolonged ischaemic time is associated with impaired myocardial perfusion, larger infarct size, and higher 1-year mortality. Therefore, all efforts should be made to shorten ischaemic time as much as possible to achieve better myocardial perfusion and myocardial salvage in primary angioplasty for STEMI.