Predicting Hospital Survival in Patients Admitted to ICU with Pulmonary Embolism

Abstract

Objective The Pulmonary Embolism Severity Index (PESI) and simplified PESI (sPESI) predict mortality for patients with PE. We compared PESI/sPESI to the Acute Physiology and Chronic Health Evaluation IV (APACHE-IV) in predicting mortality in patients with PE admitted to the intensive care unit (ICU). Additionally, we assessed the performance of a novel ICU-sPESI score created by adding three clinical variables associated with acuity of PE presentation (intubation, confusion [altered mental status], use of vasoactive infusions) to sPESI. Materials and Methods Using the eICU Collaborative Research Database from 2014 to 2015, we conducted a large retrospective cohort study of adult patients admitted to the ICU with a primary diagnosis of PE. We calculated APACHE-IV, PESI, sPESI, and ICU-sPESI scores and compared their performance for predicting in-hospital mortality using area under the receiver operating characteristic (AUROC) curve. Score thresholds for >99% negative predictive values (NPV) were calculated for each score. Survival was estimated using the Kaplan–Meier method. Results We included 1424 PE cases. In-hospital mortality was 6.3% [95% CI: 5.1%-7.6%]. AUROC for APACHE-IV, PESI, and sPESI were 0.870, 0.848, and 0.777, respectively. APACHE-IV and PESI outperformed sPESI (P < 0.01 for both comparisons), while APACHE-IV and PESI demonstrated similar performance (P = 0.322). The ICU-sPESI performance was similar to APACHE-IV and PESI (AUROC = 0.847; AUROC comparison: APACHE-IV vs ICU-sPESI: P = 0.396; PESI vs ICU-sPESI: P = 0.945). Hospital mortality for ICU-sPESI scores 0-2 was 1.1%, and for scores 3, 4, 5, 6, and ≥7 was 8.6%, 11.7%, 29.2%, 37.5%, and 76.9%, respectively. Score thresholds for >99% NPV were ≤48 for APACHE-IV, ≤115 for PESI, and 0 points for sPESI and ICU-sPESI. Conclusions By accounting for severity of PE presentation, our newly proposed ICU-sPESI score provided improved PE mortality prediction compared to the original sPESI score and offered excellent discrimination of mortality risk.

Validity of mortality risk prediction scores in critically ill patients with secondary pulmonary embolism

“…APACHE-IV scores are calculated and reported in the eICU-CRD. Variables included in the calculation of PE mortality scores were detailed in our earlier report [ 10 ]. Briefly, to calculate the PESI score, different characteristics are each assigned a number of points as follows: 10 points ═ male sex, history of heart failure, history of chronic lung disease; 20 points ═ heart rate ≥110/min, respiratory rate ≥30/min, temperature <36 ∘ C, oxyhemoglobin saturation <90%; 30 points ═ history of cancer, systolic blood pressure <100 mmHg; 60 points ═ altered mental status; in addition, one point was added for each year of age (e.g., 75 years ═ 75 points).…”

“…To calculate the sPESI score, the presence of the following characteristics was assigned 1 score point each (maximum score of 6 points): age >80 years, history of cancer, chronic cardiopulmonary disease, heart rate ≥110/min, systolic blood pressure <100 mmHg, oxyhemoglobin saturation <90%. Finally, for ICU-sPESI score calculation, in addition to the original 6 sPESI points, three additional binary characteristics were included (maximum score of 9 points): intubation status; altered mental status; and the use of vasoactive drug infusions [ 10 ]. Across the 9 ICU-sPESI points, we identified four classes that provided excellent discrimination of the mortality risk: ≤2 points ≜ Class I (low risk); 3–4 points ≜ Class II (intermediate risk); 5–6 points ≜ Class III (high risk); ≥7 points ≜ Class IV (very high risk) [ 10 ].…”

“…Two commonly used systems are the Pulmonary Embolism Severity Index (PESI) [ 2 ] and the simplified PESI score (sPESI) [ 9 ]. We recently proposed a modified sPESI score (ICU-sPESI) by adding three equally weighted binary variables that denote the severity of PE on presentation: 1) intubation status; 2) altered mental status; and 3) use of vasopressors [ 10 ]. Across the nine ICU-sPESI points, we identified four classes that provide good discrimination of the mortality risk [ 10 ].…”

“…We recently proposed a modified sPESI score (ICU-sPESI) by adding three equally weighted binary variables that denote the severity of PE on presentation: 1) intubation status; 2) altered mental status; and 3) use of vasopressors [ 10 ]. Across the nine ICU-sPESI points, we identified four classes that provide good discrimination of the mortality risk [ 10 ]. Clinical components used to construct PESI, sPESI, and ICU-sPESI are detailed in our earlier report [ 10 ].…”

“…Across the nine ICU-sPESI points, we identified four classes that provide good discrimination of the mortality risk [ 10 ]. Clinical components used to construct PESI, sPESI, and ICU-sPESI are detailed in our earlier report [ 10 ]. It is not known whether PE-specific scores, designed for primary PE, could be used as predictive mortality tools in patients with secondary PE.…”