Primary ventricular fibrillation in the STEMI code era: trends and acute-phase mortality over the last 15 years

Background Primary ventricular fibrillation (PVF) is a serious complication of ST elevation myocardial infarction (STEMI). However, the widespread use of reperfusion therapies and post-resuscitation care may have reduced the prevalence of PVF and improved the prognosis for these patients in recent years. Purpose This study aims to analyze changes in the prevalence, management, reperfusion times, and acute-phase mortality of PVF in STEMI patients over the past 15 years, since the initiation of the STEMI Code program. Method In 2009, the STEMI Code network was officially launched in Catalonia, an autonomous region of Spain. This public network prioritizes primary percutaneous coronary intervention (PPCI) as the reperfusion therapy for STEMI patients. The Ruti-STEMI registry prospectively included all STEMI patients admitted to the Critical Cardiac Care Unit of a University Hospital between January 2009 and December 2023. Patients were classified into three periods based on the year of admission: Period 1 (2009-2013), Period 2 (2014-2018), and Period 3 (2019-2023). We analyzed trends in PVF prevalence, reperfusion times, and in-hospital mortality across these three periods. Results A total of 5,454 STEMI patients were included in the registry, distributed as follows: Period 1 (n=1,808), Period 2 (n=1,674), and Period 3 (n=1,972). The overall prevalence of PVF was 8% (436 patients), with a mean age of 62.6 years (SD 11.7), and 21.7% were women, with no significant differences between periods. The prevalence of PVF in STEMI patients increased from Period 1 to Period 3 (6.3%, 8%, and 9.5%, respectively, p<0.001). The use of reperfusion therapy increased from 90.1% in Period 1 to 92.3% in Period 3 (p=0.002), with all patients receiving PPCI. The reperfusion rate was higher in PVF patients than in non-PVF patients (94.5% vs 91.4%, p=0.023). The median ischemia time (time from pain onset to reperfusion) was shorter in PVF patients (150 minutes, IQR: 113-209) compared to non-PVF patients (190 minutes, IQR: 133-318, p<0.001). In-hospital mortality across all periods was 4.1%, with no significant differences between periods. However, in-hospital mortality was higher in PVF patients compared to non-PVF patients (18.3% vs 2.8%, p<0.001). Despite the increase in PVF prevalence, in-hospital mortality in PVF patients remained stable over the 15 years (14.9%, 18.7%, and 20.2% in Periods 1, 2, and 3, respectively, p=0.260). Main results are presented in Table 1. Conclusions The prevalence of primary ventricular fibrillation in STEMI patients has increased from 6.3% to 9.5% over the past 15 years since the initiation of the STEMI Code program. While the reperfusion rate was higher and ischemia times were shorter in PVF patients, the management of PVF did not lead to a reduction in in-hospital mortality over this period