PERFORM: Pulmonary embolism risk score for mortality in computed tomographic pulmonary angiography-confirmed patients

BACKGROUND: Current prognostic scores for pulmonary embolism (PE) were partly based on patients without PE confirmation via computed tomographic pulmonary angiography (CTPA), involving subjective parameters and complicated scoring methods. Therefore, we sought to develop an objective, accurate, and simple prognostic model in CTPA-confirmed patients to predict the risk of 30-day mortality. METHODS: We retrospectively evaluated 509 patients with objectively confirmed PE by CTPA from 2010 to 2017 in the Minhang Hospital, which is affiliated to Fudan University. Patients were randomly divided into the training and validation cohorts. The primary end point was 30-day mortality. The secondary end points were the time to recovery in 30 days and mortality in 15 days. We compared the predictive performance of Pulmonary Embolism Severity Index (PESI), simplified PESI (sPESI), and the PE risk score we developed, called PERFORM. FINDINGS: PERFORM (ranging from 0 to 12 score) is based on the patient's age, heart rate, and partial pressure of arterial oxygen. The area under the curve was 0.718 (95% confidence interval CI, 0.627-0.809) for the training cohort and 0.906 (95% CI, 0.846-0.966) for the validation cohort. PERFORM was as good as PESI and sPESI in predicting mortality. Patients in the low-risk group (PERFORM score < 5) had a shorter time to recovery, whereas those in the high-risk group (PERFORM score ≥ 5) had a high mortality. INTERPRETATION: PERFORM in CTPA-confirmed patients is an objective, accurate, and simple tool to predict the risk of 30-day mortality. FUNDING: Research Project of Shanghai Municipal Commission of Health and Family Planning (201740127), Shanghai Medical Key Subject Construction Project (ZK2019B08).