Clinical outcomes in patients with acute myocardial infarction treated with primary percutaneous coronary intervention stratified according to duration of pain-to-balloon time and type of myocardial infarction.

Background: Based on the clinical outcomes of patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI), treated with primary percutaneous coronary intervention (pPCI), this study intended to assess mortality and major adverse cardiac and cerebrovascular event (MACCE) rates according to duration of pain-to-balloon (PTB) time and type of MI.

Methods: This is a retrospective cohort study based on the prospectively collected ORPKI registry which covers PCIs performed in Poland chosen between January 2014 and December 2017. Under assessment were 1,994 STEMI and 923 NSTEMI patients. Study endpoints included mortality and MACCE rates (in-hospital, 30-day, 12- and 36-month). Predictors of all-cause mortality in the overall group, STEMI and NSTEMI were assessed by multivariable analysis.

Results: Kaplan-Meier survival curve analysis did not reveal significant differences between the STEMI and NSTEMI group for all-cause mortality or MACCE at the 36-month follow-up. While in the long PTB time group, MACCE rate was significantly greater in STEMI patients when compared to NSTEMI (p = 0.004). Among STEMI patients, the short, medium and long PTB time groups differed significantly in the rate of all-cause mortality (p = 0.006) and MACCE (p = 0.04) at 1,095 days of follow-up, which were the greatest in the long PTB time group.

Conclusions: Before considering the length of PTB time, there were no statistically significant differences in mortality or MACCE frequency between the STEMI and NSTEMI group at 36-month follow-up. Longer PTB times are related to significantly greater mortality at the 36-month follow-up in the STEMI, but not in the NSTEMI group.