Direct Admission of STEMI Patients to the Catheterization Lab Shortens Pain-to-Balloon and Door-to-Balloon Time Intervals but Only the Pain-to-Balloon Interval Impacted Long-term Mortality

Shortening the pain-to-balloon time (P2B) in ST-elevation myocardial infarction (STEMI) patients treated by primary percutaneous coronary intervention (PPCI) is essential in order to limit myocardial damage and improve prognosis. We aimed to examine whether direct admission of PPCI-treated STEMI patients to the catheterization lab, thus bypassing the emergency department, expedites reperfusion and improves long-term prognosis.

Consecutive PPCI-treated STEMI patients included in the ACSIS prospective nationwide multicenter registry were divided into two groups: patients admitted directly to the catheterization lab and those admitted via the emergency department. The P2B and door-to-balloon (D2B) intervals were measured and their impact on mortality compared in study groups by both logistic regression and propensity score matching.

Of 11,370 patients admitted for an acute coronary syndrome included in six bimonthly nationwide ACSIS registries (2004-2016), 4839 patients (age 61.7±13 years, 80% men) were admitted urgently due to STEMI and treated by PPCI. These comprised the study population, with 1174 admitted directly to the catheterization lab and 3665 via the emergency department. The respective median P2B and D2B were significantly shorter in the directly admitted STEMI patients (median 160 and 35 minutes) compared with those admitted via the emergency department (median 210 and 75 minutes, p<0.001). Decreased mortality was observed with direct admission at 1-year, 2-years and at the end of follow-up (median 6.4 years, all p<0.001), and these survival differences persisted after adjustment. However, only P2B, but not D2B, decreased short- and long-term survival (p<0.001). Direct admission of PPCI-treated STEMI patients to the catheterization lab decreased short- and long-term mortality by shortening P2B, and facilitated the attainment of guideline-dictated D2B constraint. To our surprise only P2B interval, but not the D2B interval, impacted mortality. These findings make one wonder whether the D2B has reached its limit of effect in the last decade.