A simple score to identify the sickest normotensive patients with acute pulmonary embolism

Background: Emerging evidence suggests that various prognostic factors should be combined to identify normotensive patients with pulmonary embolism (PE) at intermediate-high risk for a short-term complicated course. We proposed and externally validated a pragmatic score to identify those patients. Methods: The SIMpLe risk score contained vital Signs, IMaging testing and Laboratory tests. For the primary outcome of 30-day all-cause mortality and the secondary outcome composed of clinical deterioration or PE-related mortality, three independent cohorts from sites in Europe were used to assess overall score performance, discrimination, calibration and prediction. Results: The participants had a median (interquartile range) age of 72 (59-80) years in the PROTECT derivation cohort, 73 (66-82) years in TELOS and 69 (59-81) years in the Ramón y Cajal external validation cohorts. Women comprised 51-58% of each cohort. The SIMpLe score had areas under the curve of 0.69, 0.78 and 0.71 in the PROTECT, TELOS and Ramón y Cajal cohorts for the primary outcome, respectively. The score had good calibration. Using a threshold of a 15% probability of 30-day all-cause mortality, the risk score created a binary test with a positive predictive value of 23.5% in PROTECT, 26.7% in TELOS and 27.0% in Ramón y Cajal. For the composite secondary outcome, the risk score created a binary test with a positive predictive value of 23.5% in PROTECT, 26.7% in TELOS and 28.6% in Ramón y Cajal. Conclusions: The SIMpLe score can be applied to identify the sickest normotensive patients with acute PE and to support shared decision-making.