Safe exclusion of pulmonary embolism using the Wells rule and qualitative D-dimer testing in primary care: prospective cohort study

Abstract

Objective To validate the use of the Wells clinical decision rule combined with a point of care D-dimer test to safely exclude pulmonary embolism in primary care.Design Prospective cohort study. Setting Primary care across three different regions of the Netherlands (Amsterdam, Maastricht, and Utrecht).Participants 598 adults with suspected pulmonary embolism in primary care.Interventions Doctors scored patients according to the seven variables of the Wells rule and carried out a qualitative point of care D-dimer test. All patients were referred to secondary care and diagnosed according to local protocols. Pulmonary embolism was confirmed or refuted on the basis of a composite reference standard, including spiral computed tomography and three months' follow-up.Main outcome measures Diagnostic accuracy (sensitivity and specificity), proportion of patients at low risk (efficiency), number of missed patients with pulmonary embolism in low risk category (false negative rate), and the presence of symptomatic venous thromboembolism, based on the composite reference standard, including events during the follow-up period of three months. ResultsPulmonary embolism was present in 73 patients (prevalence 12.2%). On the basis of a threshold Wells score of ≤4 and a negative qualitative D-dimer test result, 272 of 598 patients were classified as low risk (efficiency 45.5%). Four cases of pulmonary embolism were observed in these 272 patients (false negative rate 1.5%, 95% confidence interval 0.4% to 3.7%). The sensitivity and specificity of this combined diagnostic approach was 94.5% (86.6% to 98.5%) and 51.0% (46.7% to 55.4%), respectively.Conclusion A Wells score of ≤4 combined with a negative qualitative D-dimer test result can safely and efficiently exclude pulmonary embolism in primary care. IntroductionFor many doctors, patients with unexplained shortness of breath or pleuritic chest pain pose a diagnostic dilemma. In particular doctors in primary care, who in many countries are the first to be consulted when patients have these symptoms, have to differentiate between common self limiting diseases, such as myalgia or respiratory tract infections, and the rarer life threatening diseases such as pulmonary embolism. As the symptoms of pulmonary embolism may be relatively mild, it can be easily missed, 1 2 and because pulmonary embolism has a high mortality doctors do not always get another chance if it is misdiagnosed.3 As a result, most doctors in primary care have a low threshold for referring patients with suspected pulmonary To stratify patients with suspected pulmonary embolism between a high probability (need for referral) of having the condition compared with a low probability, clinical decision rules (combining the different characteristics of patients and the disease into a score) have been developed. The clinical decision rule developed by Wells and colleagues is the most widely known, validated, and implemented tool for the detection of pulmonary embolism in secondary care. The Wells clinical decision rul...

The role of computed tomography in the diagnosis of acute and chronic pulmonary embolism

“…They concluded that patients with high Wells score (>4), or low Wells score (≤4) but positive D-dimer test should undergo CTPA. In such cases, a negative CTPA was shown to safely exclude PE, with a low incidence of DVT (0.6%), nonfatal PE (0.2%), and fatal PE (42)(43)(44). Of note, among patients with a high pretest probability for PE but normal D-dimer, the CTPA showed PE in 19%-28% of patients when using quantitative rapid ELISA technique for determining D-dimers or even 24%-36% when using a semiquantitative latex agglutination technique (45,46).…”

Tema 6-2015: Tromboembolismo Pulmonar: Fisiopatología Y Diagnóstico

“…La medición de marcadores de laboratorio como el dímero D de alta sensibilidad se recomienda para pacientes con baja probabilidad de TEP en las escalas de validación clínica con sensibilidad de 85% y valor predictivo negativo de 99% (65)(66)(67)(68)(69)(70) .…”

Pulmonary embolism: clinical guidelines of European Society of Cardiology (2014).The Task Force of the European Society of Cardiology for diagnosis and management of pulmonary embolism

“…В связи с этим предложены различные комбинации клинической оценки, измерения D димера плазмы крови и визуа лизационных методов диагностики. Эти алгоритмы были апробированы у больных с подозрением на ТЭЛА, обратившихся за неотложной помощью [99,113,114,116,197] либо госпитализированных по то му же поводу, и совсем недавно -в условиях первич ной медицинской помощи [118,126]. При недостат ке доказательной базы для отмены антикоагулянтов значительно возросло число эпизодов ВТЭ и внезап ных кардиологических смертей в течение 3 мес.…”

“…При помощи данных методов в исследованиях безопасно исключается ТЭЛА у больных с низкой клинической вероятностью этого заболевания [99,100,105], однако у больных со средней клинической вероятностью безопасность исключения ТЭЛА с по мощью этих методов не изучалась. Использование данных тестов «у постели больного» обладает уме ренной чувствительностью, но соответствующих клинических исследований не проводилось за ис ключением недавнего исследования в первичном звене медицинской помощи, в котором использова но упрощенное измерение D димера [118], а 3 ме сячный тромбоэмболический риск у больных с ма ловероятным диагнозом ТЭЛА и отрицательным D димером составил 1,5 %.Специфичность D димера при подозрении на ТЭЛА у больных старше 80 лет снижается примерно до 10 % [119]. Недавно получены доказательства о не обходимости коррекции порогового значения D ди мера соответственно возрасту больного [120,121].…”