Oxygen saturation or respiratory rate to improve risk stratification in hemodynamically stable patients with acute pulmonary embolism

Abstract

Essentials In acute pulmonary embolism (PE), risk stratification is essential to drive clinical management. Improving the 2014-ESC risk stratification strategy is crucial in hemodynamically stable patients. Oxygen saturation and respiratory rate improve risk stratification in hemodynamically stable PE. Simple and routine tests improve risk stratification of hemodynamically stable PE. SUMMARY: Background In patients with acute pulmonary embolism (PE), risk stratification for short-term death is recommended to drive clinical management. A risk stratification strategy combining the simplified Pulmonary Embolism Severity Index (PESI), echocardiography and troponin was proposed by the European Society of Cardiology (ESC) in 2014. The identification of hemodynamically stable patients at increased risk of death by this strategy needs improvement. Objective To assess whether further stratification by serial cut-off values of oxygen saturation or respiratory rate improves the accuracy of the ESC risk stratification strategy in hemodynamically stable PE patients. Methods Prospective cohorts of hemodynamically stable patients with PE were merged in a collaborative database. The accuracy of risk stratification for 30-day mortality by the original and a modified 2014 ESC strategy was assessed. Results Overall, 255 patients (27%) were categorized as low, 510 (54%) as intermediate-low and 181 (19%) as intermediate-high risk according to the original 2014 ESC strategy. Thirty-day mortality was 1.2% in low, 10% in intermediate-low and 11% in intermediate-high-risk patients. By adding oxygen saturation in air of < 88%, the discriminatory power of the 2014 ESC model improved for 30-day mortality (c-statistics, 0.71; 95% confidence interval [CI], 0.65-0.77 vs. 0.63, 95% CI, 0.56-0.69) and for PE-related death (c-statistics, 0.75; 95% CI, 0.69-0.81 vs. 0.63, 95% CI 0.56-0.69). Conclusions Simple and routine tests, such as oxygen saturation or respiratory rate, could be added to the 2014 ESC strategy for risk stratification to identify hemodynamically stable PE patients at increased risk of death who are potentially candidates for more aggressive treatment.

Keywords: anticoagulants; mortality; pulmonary embolism; risk stratification; venous thromboembolism.