In-hospital mortality of high-risk pulmonary embolism: a nationwide population-based cohort study in Portugal from 2010 to 2018

The mortality associated with high-risk pulmonary embolism (PE) is remarkably high, and reperfusion to unload right ventricle should be a priority. However, several registries report reperfusion underuse. In Portugal, epidemiological data about the incidence, rate of reperfusion and mortality of high-risk PE are not known. Nationwide population-based temporal trend study in the incidence and outcome of high-risk PE, who were admitted to hospitals of the National Health Service in Portugal between 2010 and 2018. High-risk PE was defined as patients with PE who developed cardiogenic shock or cardiac arrest. International Classification of Diseases (ICD), 9th and 10th revision, Clinical Modification codes, were used for data from the period between 2010 and 2016 (ICD-9-CM) and 2017–2018 (ICD-10-CM), respectively. The assessment focused on trends in the use of reperfusion treatment, which was defined by application of thrombolysis or pulmonary embolectomy. A comparison was made between the use or non-use of reperfusion therapy in order to examine trends in in-hospital mortality among high-risk PE cases. From 2010 and 2018, there were 40.311 hospitalization episodes for PE in adult patients at hospitals of the National Health Service in mainland Portugal. There was a significant increase in the annual incidence of PE (41/100.000 inhabitants in 2010 to 46/100.000 in 2018; R2=0.582, p = 0.010). The average annual incidence was 45/100.000 inhabitants/year, with 2,7% of the PE episodes (1104) categorized as high-risk. The mortality rate associated with high-risk PE was high, although it has decreased over the years (74.2% in 2010 to 63.6% in 2018; R2=0.484; p = 0.022). Thrombolytic therapy was underused in high-risk PE, and its usage has not increased in recent years (17.3% in 2010 to 21.1% in 2018, R2=-0.127; p = 0.763). Surgical pulmonary embolectomy was used in 0.27% of cases, and there was no registry of catheter-directed thrombolysis. Patients with high-risk PE undergoing reperfusion therapy had lower in-hospital mortality compared to non-reperfused patients (OR=0.52; IC95% 0.38–0.70). In Portugal, between 2010 and 2018, very few patients with PE developed high-risk forms of the disease, but the mortality rate among those patients was high. The low reperfusion rate could be associated with high in-hospital mortality and highlights the need to implement advanced therapies, as an alternative to systemic thrombolysis.