Background
New treatment regimens have been introduced in the past 20 years, which may influence the short‐ and long‐term prognosis for patients with and without a cancer diagnosis following pulmonary embolism. However, newer studies investigating these trends are lacking. Therefore, we aimed to investigate the 30‐ and 31‐ to 365‐day mortality following pulmonary embolism.

Methods and Results
Using the Danish nationwide registries, patients with a diagnosis of pulmonary embolism between 2000 and 2020 were included. Age‐ and sex‐standardized 30‐ and 31‐ to 365‐day mortality was calculated and stratified by cancer status. In total, 60 614 patients (29.6% with recent cancer; mean age, 68.2 years) were included. The 30‐day mortality for patients with no recent cancer decreased from 19.1% (95% CI, 17.9%–20.4%) in 2000 to 7.3% (95% CI, 6.7%–8.0%) in 2018 to 2020 (hazard ratio [HR], 0.36 [95% CI, 0.32–0.40]; P<0.001). The 30‐day mortality for patients with recent cancer decreased from 32.2% (95% CI, 28.8%–36.6%) to 14.1% (95% CI, 12.7%–15.5%) (HR, 0.38 [95% CI, 0.33–0.44]; P<0.001). The 31‐ to 365‐day mortality for patients with no recent cancer decreased from 12.5% (95% CI, 11.4%–13.6%) to 9.4% (95% CI, 8.6%–10.2%) (HR, 0.73 [95% CI, 0.64–0.83]; P<0.001).The 31‐ to 365‐day mortality for patients with recent cancer remained stable: 39.4% (95% CI, 35.1%–43.7%) to 38.3% (95% CI, 35.9%–40.6%) (HR, 0.97 [95% CI, 0.84–1.12]; P=0.69).

Conclusions
From 2000 to 2020, improvements were observed in 30‐day mortality following pulmonary embolism regardless of cancer status. For patients with recent cancer, 31‐ to 365‐day mortality did not improve, whereas a minor improvement was observed for patients without recent cancer.