The Pulmonary Embolism Severity Index (PESI) is a validated clinical prognostic model for patients with pulmonary embolism (PE). Recently, a simplified version of the PESI was developed. We sought to compare the prognostic performance of the original and simplified PESI. Using data from 15,531 patients with PE, we compared the proportions of patients classified as low versus higher risk between the original and simplified PESI and estimated 30-day mortality within each risk group. To assess the models' accuracy to predict mortality, we calculated sensitivity, specificity, and predictive values and likelihood ratios for low- versus higher-risk patients. We also compared the models' discriminative power by calculating the area under the receiver-operating characteristic curve. The overall 30-day mortality was 9.3%. The original PESI classified a significantly greater proportion of patients as low-risk than the simplified PESI (40.9% vs. 36.8%; p<0.001). Low-risk patients based on the original and simplified PESI had a mortality of 2.3% and 2.7%, respectively. The original and simplified PESI had similar sensitivities (90% vs. 89%), negative predictive values (98% vs. 97%), and negative likelihood ratios (0.23 vs. 0.28) for predicting mortality. The original PESI had a significantly greater discriminatory power than the simplified PESI (area under the ROC curve 0.78 [95% CI: 0.77-0.79] vs. 0.72 [95% CI: 0.71-0.74]; p<0.001). In conclusion, even though the simplified PESI accurately identified patients at low-risk of adverse outcomes, the original PESI classified a higher proportion of patients as low-risk and had a greater discriminatory power than the simplified PESI.

Although associated with adverse outcomes in other cardiovascular diseases, the prognostic value of an elevated white blood cell (WBC) count, a marker of inflammation and hypercoagulability, is uncertain in patients with pulmonary embolism (PE). We therefore sought to assess the prognostic impact of the WBC in a large, state‐wide retrospective cohort of patients with PE. We evaluated 14,228 patient discharges with a primary diagnosis of PE from 186 hospitals in Pennsylvania. We used random‐intercept logistic regression to assess the independent association between WBC count levels at the time of presentation and mortality and hospital readmission within 30 days, adjusting for patient and hospital characteristics. Patients with an admission WBC count <5.0, 5.0–7.8, 7.9–9.8, 9.9–12.6, and >12.6 × 109/L had a cumulative 30‐day mortality of 10.9%, 6.2%, 5.4%, 8.3%, and 16.3% (P < 0.001), and a readmission rate of 17.6%, 11.9%, 10.9%, 11.5%, and 15.0%, respectively (P < 0.001). Compared with patients with a WBC count 7.9–9.8 × 109/L, adjusted odds of 30‐day mortality were significantly greater for patients with a WBC count <5.0 × 109/L (odds ratio [OR] 1.52, 95% confidence interval [CI] 1.14–2.03), 9.9–12.6 × 109/L (OR 1.55, 95% CI 1.26–1.91), or >12.6 × 109/L (OR 2.22, 95% CI 1.83–2.69), respectively. The adjusted odds of readmission were also significantly increased for patients with a WBC count <5.0 × 109/L (OR 1.34, 95% CI 1.07–1.68) or >12.6 × 109/L (OR 1.29, 95% CI 1.10–1.51). In patients presenting with PE, WBC count is an independent predictor of short‐term mortality and hospital readmission. Am. J. Hematol. 88:677–681, 2013. © 2013 Wiley Periodicals, Inc.