Background Several factors have been associated with mortality in the months after PE. Factors associated with short-term clinical deterioration or need for hospital-based intervention are less well known.

Methods We prospectively enrolled consecutive emergency department patients with PE and recorded clinical, biomarker and radiographic data. We assessed hospitalised patients daily to identify clinical deterioration or need for hospital-based intervention for 5 days after PE. We captured postdischarge events via 5-day and 30-day interviews. We used univariate and multivariable models to assess associations with clinical deterioration, severe clinical deterioration and 30-day all-cause mortality. We also assessed the test characteristics of three published clinical decision rules.

Results We enrolled 298 patients with PE: mean age 59 (SD±17) years; 152 (51%) male and 268 (90%) white race. 101 (34%) patients clinically deteriorated or required a hospital-based intervention within 5 days, and 197 (66%) did not. 27 (9%) patients suffered severe clinical deterioration and 12 died within 30 days. Factors independently associated with clinical deterioration were hypotension (p=0.001), hypoxia (p<0.001), coronary disease (p=0.004), residual deep vein thrombosis (p=0.006) and right heart strain on echocardiogram (p<0.001). In contrast, factors associated with 30-day all-cause mortality were active malignancy (p<0.001) and congestive heart failure (p=0.009). The sensitivity of clinical decision rules was moderate (39–80%) for 5-day clinical deterioration but higher (67–100%) for 30-day mortality.

Conclusions Most patients do not clinically deteriorate after PE diagnosis. Several factors are associated with short-term clinical deterioration, but these factors differ from those associated with 30-day mortality.