Safety of the pulmonary embolism rule-out criteria rule: Findings from the Registro Informatizado de la Enfermedad TromboEmbolica venosa (RIETE) registry

Background: The diagnostic strategy for pulmonary embolism (PE) includes a D-dimer test when PE probability is low or intermediate, but false-positive D-dimer results are frequent and can result in an unnecessary computed tomography pulmonary angiogram. The PE rule-out criteria (PERC) rule excludes PE without D-dimer testing when pretest probability is <15%. The aim of this study was to assess the safety of the PERC rule strategy in patients included in the Registro Informatizado de la Enfermedad TromboEmbolica venosa (RIETE) registry. Methods: This retrospective cohort study used data from the RIETE registry, an ongoing, international prospective registry of patients with objectively confirmed venous thromboembolism. The primary outcome was the failure rate of the PERC strategy, represented by the proportion of PERC-negative (PERC-N) patients with a PE included in the registry. Secondary outcomes were a comparison of the clinical characteristics, treatment strategy, and outcome of PERC-N versus PERC-positive (PERC-P) patients at 3 months. Results: From 2001 to 2021, a total of 49,793 patients with acute PE were enrolled in the RIETE registry. We included 48,903 in the final analysis after exclusion of 890 patients with an undetermined PERC status. Only 346 patients were PERC-N with a failure rate of 0.7% (95% confidence interval 0.6%–0.8%). PERC-N patients presented more frequently with chest pain but less often with dyspnea, syncope, or hypotension. They also had subsegmental or segmental PE more frequently, were more often treated with direct oral anticoagulants, and received mechanical or pharmacological thrombolysis less often. In addition, PERC-N patients had a lower incidence of recurrent deep vein thrombosis, major bleeding, and death attributed to PE during the 3-month follow-up. Conclusions: A low failure rate of the PERC rule was observed in the RIETE registry, thus supporting its use to safely identify patients with an unlikely probability of PE.