POTENTIAL OVERUSE OF DIAGNOSTIC TESTS FOR EVALUATION OF PULMONARY EMBOLISM

ABSTRACT

SESSION TITLE All About the CLOT VTE SESSION TYPE Original Investigations PRESENTED ON 10/16/2022 1030 am - 1130 am PURPOSE: Pulmonary embolism (PE) is a disorder of coagulation that results in significant morbidity, mortality and emergency department visits. The usage of advanced imaging for the diagnosis of PE has increased greatly, almost 400% from 1998 to 2008. The Well’s Criteria for PE uses historical features, clinician gestalt, and heart rate to risk stratify patients for PE. The score ranges from 0-12.5 and is broken down into low risk 0-2, intermediate risk 3-6, and high risk 7+. The current American College of Emergency Physician guidelines advise that a patient suspected to be at risk for PE with a low or intermediate risk can undergo age adjusted D-Dimer testing. A further addition was the PERC rule. This rule applies 8 questions to the low risk PE patient and 8 negative responses mean the clinician can forgo D-Dimer testing. How well are we adhering to this guidance, and are deviations leading to unnecessary testing which could expose our patients to harm? METHODS: 280 sequential patients receiving diagnostic testing for PE were evaluated and 156 were excluded due to known, suspected, or history of COVID-19 infection. The work-up for the included patients was reviewed and Well’s criteria and the PERC rule were applied by retrospective review. Descriptive statistics were used to describe the proportion of patients evaluated with tests not suggested for their risk strata. RESULTS: Of the 124 patients evaluated, 31/124 (25%) had potentially unnecessary testing. 18 low risk patients underwent advanced imaging—17 CTAs and 1 VQ scan– without being tested by D-Dimer. 11 low risk, PERC rule negative patients still received D-Dimers–all negative, and 1 underwent CTA. One negative age-adjusted D-Dimer still lead to a CTA. One patient with a negative D-Dimer received CTA. These 18 CTAs and 1 VQ scan were all interpreted negative for PE. CONCLUSIONS: Patients undergoing evaluation in emergency departments in the United States may be undergoing unnecessary diagnostic testing based on current guidelines and the summation of the highest quality evidence available for directing the choice of how best to evaluate this patient population. CLINICAL IMPLICATIONS The utilization of CTA for the diagnosis of PE is not without risk. Some estimate 20 additional breast cancers per 100,000 women undergoing the test. CTA studies for PE also pose the risk of unnecessary anticoagulation. A meta-analysis of imaging for PE showed an over diagnosis rate as high as 60% for subsegmental PE when these studies were re-reviewed by a panel of expert chest radiologists. This is quite high, but even more modest meta-analyses have shown a 10% false positive rate. Patients placed on anticoagulation have an annual bleeding risk attributed to anticoagulation of 7% and mortality attributed to anticoagulation of 0.4%. Creative strategies aimed at reducing unnecessary testing can help mitigate some of this risk and protect our patients. DISCLOSURES No relevant relationships by Parth Gandhi research support relationship with Bristol Myers Squibb Please note 2021-2022 Added 03/31/2022 by Jason Nomura, value=Grant/Research Consultant relationship with Philips Please note 2020-2022 Added 03/31/2022 by Jason Nomura, value=Consulting fee No relevant relationships by Dustin Slagle