Acute pulmonary embolism with and without hemodynamic instability (2003-2022): A Swiss nationwide epidemiological study

BACKGROUND: Data on the epidemiological burden of acute pulmonary embolism (PE) in Switzerland is unavailable. Knowledge gaps remain on trends in PE-related comorbidities, PE severity, and length of in-hospital stay (LOS) at a nationwide level. METHODS: We used nationwide, patient-level data including all patients aged 15 years or older hospitalized for PE in Switzerland from 2003 to 2022, amounting to N=180,600. Additionally, we analyzed the Swiss Death Registry for the same period. We estimated the disease-specific age-standardized incidence rates, mortality rates, in-hospital case fatality rates, proportional mortality rates, and LOS. Analyses were stratified by sex and the presence of features of high-risk PE. FINDINGS: During the study period, the PE-related incidence rate increased from 0.87 (95%CI: 0.82;0.92) per 1,000 population in 2003 to 1.19 (95%CI: 1.15;1.24) in 2022. In contrast, a decreasing trend was found for mortality rates (18.7 [95%CI: 16.8;20.6] per 100,000 population in 2003, 13 [95%CI: 11.7;14.2] in 2022), in-hospital case fatality rate (9.8 [95%CI: 9.1;10.5] deaths per 100 hospitalized PE patients in 2003, 7.9 [95%CI: 7.4;8.5] in 2019, subsequent increase during COVID-19 pandemic), and LOS (11 [Q1-Q3: 7-18] days in 2003, 8 [Q1-Q3: 4-16] in 2022). No major sex-differences in trends were present. Except for LOS reduction, patients with high-risk features presented with similar trends. CONCLUSION: The incidence of acute PE in Switzerland increased over the last 20 years. Despite increasing trends in the median age at PE diagnosis, in-hospital case fatality and mortality rate decreased, particularly among patients with high-risk features, and the LOS progressively declined.