Objectives: There are different variables related to urgent angioplasty (UA) success in patients admitted with ST elevation myocardial infarction (STEMI). This study aims to determine them analyzing popoulation characteristics and time to treatment.

Methods and Results:An observational study was conducted in patients (p) with STEMI and UA between 2014 and 2023 at a Buenos Aires public hospital.Study group was divided in two regarding angioplasty success, analyzing demographics, medical history, and delay from symptoms onset to treatment (in means and quartiles, shown in minutes): total ischaemic time (TIT,time from chest pain to successful opening of the artery or final TIMI ), time to diagnostic (TTD, first medical contact until interventional cardiologis is contact ) and time from first medical contact until flow restauration(TCB). Chi square test for qualitative data, T test or Kruskal-Wallis in quantitative. p< 0,05 for statistical significance. 

In 1251 p with STEMI,UA was successfully achieved in 1128 of them (90,1%)- G1,defined as TIMI flow II/III after procedure. Failed angioplasty was evidenced in 9,9% (123 p, G2). Comparing both , there was a prevalence of arterial hypertension (55% vs. 69.1%; p=0,0002) and dyslipidemia (30% vs 39,6%; p=0,02), without difference in other cardiovascular risk factors, gender or age. Prior coronary events did not differ (10,6% vs 15,4%; p=0,1); neither did presence of multivessel disease (47% vs 54,4%, p 0,06).  Delays on attending primary care and time to revascularization where significantly higher in Group 2: TIT: 251min(172-382) vs 301min(196;573); p< 0,005 and TCB: 142 min(109-210) vs 195 min(129-255);p= 0,02. Patients in Group 2, tend to show heart failure symptoms at presentation(Presentation Killip Kimbal not A  G1 21,5% vs G2 37,4%; p< 0,001).

Conclusion: UA success rates in p with STEMI diagnosis is related with shorter TIT and TTD , more than the preexistence of coronary history, compared with those that don´t achieve optimal revascularization.