The shock index and the simplified PESI for identification of low-risk patients with acute pulmonary embolism

Abstract

We compared the test characteristics of the shock index (SI) and the simplified pulmonary embolism severity index (sPESI) for predicting 30-day outcomes in a cohort of 1,206 patients with objectively confirmed pulmonary embolism (PE). The primary outcome of the study was all-cause mortality. The secondary outcome was nonfatal symptomatic recurrent venous thromboembolism (VTE) or nonfatal major bleeding. Overall, 119 (9.9%) out of 1,206 patients died (95% CI 8.2–11.5%) during the first month of follow-up. The sPESI classified fewer patients as low-risk (369 (31%) out of 1,206 patients, 95% CI 28–33%) compared to the SI (1,024 (85%) out of 1,206 patients, 95% CI 83–87%) (pversus 8.3% (95% CI 6.6–10.0%)), while the 30-day rate of nonfatal recurrent VTE or major bleeding was similar (2.2% (95%CI 0.7–3.6%) versus 3.3% (95%CI 2.2–4.4%)). The net reclassification improvement with the sPESI was 13.4% (p = 0.07). The integrated discrimination improvement was estimated as 1.8% (p<0.001). The sPESI quantified the prognosis of patients with PE better than the SI.