Although the rate of latecomer among patients with ST-segment elevation myocardial infarction (STEMI) appears to have decreased over the last years, the optimal management of these patients is still debated. The aim of this study was to describe characteristics, temporal trends and impact of revascularization on in-hospital mortality of patients with STEMI presenting later than 12 hours after symptom onset.

All STEMI patients admittedto Cardiology B department of FattoumaBourguiba University Hospital (Monastir, Tunisia) between January 1998 and December 2017 were retrospectively enrolled in a registry. Studypopulation was divided into patients presenting later than 12 hoursafter symptom onset (latecomer) and patients presenting within 12 hours(early-comer).

Out of 1734 patients, 224 (12.9 %) were latecomers. Prevalence of late presentation decreased from 17.6 % to 8.3 % (p < 0.001) throughout the study period. Compared to early-comers, latecomers tended to be older (63.9 ± 12 vs 59.2 ± 12 years, p < 0.001) and were more commonly male (p < 0.001). Diabetes, hypertension and chronic kidney disease were more prevalent in latecomers. Latecomer STEMI patients were more likely to present with cardiogenic shock (23.2 % vs 12.7 %, p = 0.001) compared with early comers. In the latecomer group, there was a marked increase in the use of percutaneous coronary intervention (PCI) over time from 7 % to 46.9 %(p < 0.001).  All cause in-hospital mortality in latecomers was reduced from 23.2 % to 10.9 % (p < 0.001). In multivariate analysis, primary PCI had an independent protective effect onin-hospital mortality in latecomer STEMI patients (OR = 0.65; 95 % CI, 0.50 - 0.84,p = 0.001).

According to the present study, there was a progressive decrease in latecomers prevalence in STEMI patients along with a reduction in in-hospital mortality rate. This reduction was concomitant with an increase in primary PCI implementation in this setting.