Assessment of the Bova score for risk stratification of acute normotensive pulmonary embolism: A systematic review and meta-analysis

Background: Identification of normotensive pulmonary embolism (PE) at high risk of early adverse outcome is crucial for guiding treatment. Studies showed the Bova score had promising performance in stratifying normotensive PE. Methods: We conducted a systematic review and meta-analysis to evaluate the prognostic performance of the Bova score for normotensive PE. Results: Nine studies involving 8342 acute normotensive PE patients were enrolled. Overall, 71.4%, 20.2% and 8.4% patients were stratified as risk class I, II and III. Pooled incidence of short-term PE related composite adverse outcome of each group were 3.8%, 10.8% and 19.9%, respectively, exhibiting a significant rising trend. Increasing trends of 30-day and in-hospital composite adverse outcome rates, as well as PE related mortality, were also observed with upper risk classes. Compared with risk class I and II, high risk group (class III) was significantly associated with short-term PE related composite adverse outcome (OR: 5.45, 95% CI, 3.70-8.02) and PE related death (OR: 5.09, 95% CI, 3.54-7.30). Pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of the score for predicting short-term composite adverse outcome were 0.25 (95% CI, 0.22-0.29), 0.93 (95% CI, 0.92-0.93), 4.05 (95% CI, 2.90-5.67) and 0.81 (95% CI, 0.74-0.88), respectively. The weighted area under the summarized receiver characteristics operation curve for predicting composite adverse outcome was 0.73 +/- 0.09. Conclusion: The Bova score could effectively discriminate normotensive PE with different short-term prognosis and has good performance in identifying patients at higher risk of short-term adverse events.