Temporal trends in primary ventricular fibrillation in the STEMI code era: a 15-year registry. Analysis of prevalence, acute-phase and long-term mortality

Background Primary ventricular fibrillation (PVF) is a life-threatening complication of ST-segment elevation myocardial infarction (STEMI). The widespread implementation of reperfusion strategies and improvements in post-resuscitation care may have modified the prevalence and prognosis of PVF in recent years. Purpose To assess temporal changes over the last 15 years, following the implementation of the STEMI Code network, in the prevalence, management, reperfusion times, and short- and long-term mortality of PVF in patients with STEMI. Methods In 2009, the STEMI Code network was officially launched in Catalonia, Spain, prioritizing primary percutaneous coronary intervention (PPCI) as the reperfusion strategy for STEMI. The Ruti-STEMI registry prospectively included all consecutive STEMI patients admitted to the Cardiac Critical Care Unit of a tertiary university hospital between January 2009 and December 2023. According to year of admission, patients were classified into three 5-year periods: Period 1 (2009–2013), Period 2 (2014–2018), and Period 3 (2019–2023). We analyzed temporal trends in PVF prevalence, reperfusion therapy, ischemia time (symptom onset-to-reperfusion), 30-day case fatality, and 2-year all-cause mortality. Results A total of 5,455 STEMI patients were included: 1,808 in Period 1, 1,674 in Period 2, and 1,973 in Period 3. Overall PVF prevalence was 8% (n=436). Mean age was 62.6±11.7 years, and 21.7% were women, with no differences across periods. PVF prevalence increased significantly over time (6.3%, 8.0%, and 9.5% across Periods 1–3, respectively; p<0.001). Overall reperfusion therapy increased from 90.1% in Period 1 to 92.3% in Period 3 (p=0.002), exclusively with PPCI. Reperfusion rates were higher in PVF compared with non-PVF patients (94.5% vs. 91.4%; p=0.023). Median ischemia time was shorter in PVF patients (150 minutes [IQR 113–209]) than in non-PVF patients (190 minutes [IQR 133–318]; p<0.001). Overall 30-day case fatality was 6.3%, with no significant differences across periods. However, 30-day mortality was significantly higher in PVF versus non-PVF patients (21.1% vs. 5.0%; p<0.001). Two-year mortality was 12.6%, without temporal differences. Among 30-day survivors, long-term mortality was similar between PVF and non-PVF patients (5.3% vs. 5.9%; p=0.693). The main results are shown in Table 1. Conclusions The incidence of PVF in STEMI patients increased from 6.3% to 9.5% over 15 years following STEMI Code implementation. Although reperfusion rates were higher and ischemia times shorter in PVF patients, no reduction in short- or long-term mortality was observed over time.