BackgroundThe recently published 4-level Pulmonary Embolism Clinical Probability Score (4PEPS) integrates different aspects from currently available diagnostic strategies to further reduce imaging... Show moreBackgroundThe recently published 4-level Pulmonary Embolism Clinical Probability Score (4PEPS) integrates different aspects from currently available diagnostic strategies to further reduce imaging testing in patients with clinically suspected pulmonary embolism (PE).AimTo externally validate the performance of 4PEPS in an independent cohort.MethodsIn this post-hoc analysis of the prospective diagnostic management YEARS study, the primary outcome measures were discrimination, calibration, efficiency (proportion of imaging tests potentially avoided), and failure rate (venous thromboembolism (VTE) diagnosis at baseline or follow-up in patients with a negative 4PEPS algorithm). Multiple imputation was used for missing 4PEPS items. Based on 4PEPS, PE was considered ruled out in patients with a very low clinical pre-test probability (CPTP) without D-dimer testing, in patients with a low CPTP and D-dimer <1000 μg/L, and in patients with a moderate CPP and D-dimer below the age-adjusted threshold.ResultsOf the 3465 patients, 474 (14 %) were diagnosed with VTE at baseline or during 3-month follow-up. Discriminatory performance of the 4PEPS items was good (area under ROC-curve, 0.82; 95%CI, 0.80–0.84) as was calibration. Based on 4PEPS, PE could be considered ruled out without imaging in 58 % (95%CI 57–60) of patients (efficiency), for an overall failure rate of 1.3 % (95%CI 0.86–1.9).ConclusionIn this retrospective external validation, 4PEPS appeared to safely rule out PE with a high efficiency. Nevertheless, although not exceeding the failure rate margin by ISTH standards, the observed failure rate in our analysis appeared to be higher than in the original 4PEPS derivation and validation study. This highlights the importance of a prospective outcome study. Show less
Venous thromboembolism (VTE) encompasses pulmonary embolism (PE) and deep vein thrombosis (DVT). DVT most commonly occurs in the deep veins of the lower extremity but can also occur in the veins of... Show moreVenous thromboembolism (VTE) encompasses pulmonary embolism (PE) and deep vein thrombosis (DVT). DVT most commonly occurs in the deep veins of the lower extremity but can also occur in the veins of upper extremity, abdomen and cerebrum. As symptoms of VTE are nonspecific, the diagnosis of VTE is based on diagnostic tests, including clinical decision rules (CDR), D-dimer tests and imaging. Although the diagnostic management of VTE has greatly advanced in recent years with the introduction of novel CDRs and high-sensitive D-dimer tests, the diagnosis may still be challenging in certain settings. The latter is mainly caused by the indirect way of thrombus visualisation by current imaging tests, such as by showing incompressibility with compression ultrasonography (CUS) or a filling defect on contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI).This thesis focuses on challenging settings for diagnosing VTE, including suspected recurrent ipsilateral DVT, upper extremity DVT, cerebral vein thrombosis and portal vein thrombosis. We studied a novel imaging technique called Magnetic Resonance Non-Contrast Thrombus Imaging (MR-NCTI) and its application in these different VTE settings. Show less
Venous thromboembolism is a common disease that can lead to potential fatal complications. The diagnosis and treatment of a first venous thromboembolism has been well studied, however the... Show moreVenous thromboembolism is a common disease that can lead to potential fatal complications. The diagnosis and treatment of a first venous thromboembolism has been well studied, however the diagnostic management and therapy of recurrent venous thromboembolism still have limitations. This thesis discusses a new imaging technique for recurrent deep venous thrombosis and the duration of treatment after a recurrent venous thromboembolism. It shows that Magnetic Resonance Direct Thrombus Imaging might be a potential diagnostic tool for the diagnostic management of recurrent venous thromboembolism. Furthermore the prognosis after a first deep vein thrombosis is discussed by means of recurrence and bleeding risks. Show less
The objectives of this thesis are to simplify, to validate and compare diagnostic strategies in patients with clinical suspicion of acute pulmonary embolism (PE). The revised Geneva score was... Show moreThe objectives of this thesis are to simplify, to validate and compare diagnostic strategies in patients with clinical suspicion of acute pulmonary embolism (PE). The revised Geneva score was simplified and validated. Furthermore, four widely used clinical decision rules (CDRs) were directly compared in excluding PE. It was concluded that the four CDRs in combination with a D-dimer test performed similarly in the exclusion of acute PE. And we confirmed that a normal CT-scan alone can safely exclude PE in patients in whom CTPA is required to rule out VTE in these patients. We showed that the algorithm consisting of a CRD, D-dimer test and CT-scan is also effective in the management of patients with clinically suspected recurrent acute PE. In addition, the role of NT-pro-BNP has been evaluated for the risk assessment for adverse clinical outcome for patients with proven acute PE and we showed the ability to distinguish an increased risk with elevated NT-pro-BNP values for complications during the hospital stay and 30-day mortality. Finally, it is concluded that home treatment with anticoagulant seems effective and safe in patients with acute PE, when selected according to pre defined criteria. Show less
