Refining risk in normotensive acute pulmonary embolism

Introduction: Normotensive acute pulmonary embolism (aPE) has a wide spectrum of outcomes. The best method to identify patients at higher-risk remains unclear. Aims and Objectives: 1) develop a unique prognostic model for adverse outcomes in normotensive aPE, 2) validate the Bova score in a North American population. Methods: This was a multi-centre retrospective cohort of all aPE admitted from emergency departments in Calgary, Canada between 2012-2017. Logistic regression models with bootstrapping for internal validation were used to predict the composite primary outcome of in-hospital death or hemodynamic decompensation. Results: 2067 patients with normotensive aPE were assessed. A primary outcome occurred in 32 patients (1.5%). Stratified by simplified pulmonary embolism severity index (sPESI), 21.2% were low-risk (0% event rate) and 78.8% were high-risk (2.0% event rate). The multivariable model in sPESI high-risk patients (n=1179) retained high-sensitivity troponin ≥50 pg/ml, CT right-left ventricular diameter ratio ≥1.5, systolic blood pressure Conclusions: Our novel risk score discriminated normotensive aPE patients at high risk of in-hospital adverse events better than the Bova score. Further validation of our score is warranted.