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Pulmonary perfusion by iodine subtraction maps CT angiography in acute pulmonary embolism: comparison with pulmonary perfusion SPECT (PASEP trial).
Dissaux, B, Le Floch, PY, Robin, P, Bourhis, D, Couturaud, F, Salaun, PY, Nonent, M, Le Roux, PY
European radiology. 2020;(9):4857-4864
Abstract
OBJECTIVE To assess the diagnostic accuracy of iodine map computed tomography pulmonary angiography (CTPA), for segment-based evaluation of lung perfusion in patients with acute pulmonary embolism (PE), using perfusion single-photon emission CT (SPECT) imaging as a reference standard. METHODS Thirty participants who have been diagnosed with acute pulmonary embolism on CTPA underwent perfusion SPECT/CT within 24 h. Perfusion SPECT and iodine map were independently interpreted by 2 nuclear medicine physicians and 2 radiologists. For both modalities, each segment was classified as normoperfused or hypoperfused, as defined by a perfusion defect of more than 25% of a segment. The primary end point was the diagnostic accuracy (sensitivity and specificity) of iodine map for segment-based evaluation of lung perfusion, using perfusion SPECT imaging as a reference standard. Following blinded interpretation, a retrospective explanatory analysis was performed to determine potential causes of misinterpretation. RESULTS The median time between CTPA with iodine maps and perfusion SPECT was 14 h (range 2-23 h). A total of 597 segments were analyzed. Sensitivity and specificity of iodine maps with CTPA for the detection of segmental perfusion defects were 231/284 = 81.3% (95% CI 76.4 to 85.4%) and 247/313 = 78.9% (95% CI 74.1 to 83.1%), respectively. In retrospect, false results were explained in 48.7%. CONCLUSION Iodine map CTPA showed promising results for the assessment of pulmonary perfusion in patients with acute PE, with sensitivity of 81.3% and specificity of 78.9%, respectively. Recognition of typical pitfalls such as atelectasis, fissures, or beam-hardening artifacts may further improve the accuracy of the test. KEY POINTS • Sensitivity and specificity of iodine subtraction maps for the detection of segmental perfusion defects were 81.3% (95% CI 76.4 to 85.4%) and 78.9% (95% CI 74.1 to 83.1%), respectively. • Recognition of typical pitfalls such as atelectasis, fissures, or beam-hardening artifacts may further improve the diagnostic accuracy of the test.
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Minimizing contrast media dose in CT pulmonary angiography with high-pitch technique.
Alobeidi, H, Alshamari, M, Widell, J, Eriksson, T, Lidén, M
The British journal of radiology. 2020;(1111):20190995
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Abstract
OBJECTIVES To perform CT pulmonary angiography (CTPA) using a minimal amount of iodinated contrast media. METHODS 47 patients (25 females) with mean age 69 years (range 41-82 years) referred for contrast-enhanced chest CT were prospectively included in this Phase IV clinical drug trial. All participants underwent a study specific CTPA in addition to the chest CT. The participants received 80 mg I/kg body weight Iohexol contrast media using a preparatory saline bolus, a dual flow contrast/saline bolus and a saline flush, and a scanner protocol with 80 kVp dual source high-pitch mode. Three readers independently assessed the image quality on the 3-point scale non-diagnostic, adequate or good-excellent image quality. Additionally, the pulmonary arterial contrast opacification was measured. RESULTS On average, the patients received 16.8 ml Iohexol 350 mg I/mL (range 12-20 ml). Mean patient weight was 71 kg (range 50-85 kg). Identically for all readers, pulmonary embolism (PE) was detected in 1/47 participants. The median number of examinations visually scored concerning pulmonary embolism as good-excellent was 47/47 (range 44-47); adequate 0/47 (0-3) and non-diagnostic 0/47 (range 0-0). The proportion adequate or better examinations was for all readers 47/47, 100% [95% confidence interval 92-100%]. The mean attenuation ± standard deviation in the pulmonary trunk was 325 ± 72 Hounsfield unit (range 165-531 Hounsfield unit). CONCLUSIONS Diagnostic CTPA with 17 ml contrast media is possible in non-obese patients using low kVp, high pitch and carefully designed contrast media administration. ADVANCES IN KNOWLEDGE By combining several procedures in a CTPA protocol, the contrast media dose can be minimized.
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Indirect comparison and cost-utility of dabigatran etexilate and rivaroxaban in the treatment and extended anticoagulation of venous thromboembolism in a UK setting.
Jugrin, AV, Hösel, V, Ustyugova, A, De Francesco, M, Lamotte, M, Sunderland, T
Journal of medical economics. 2016;(1):1-10
Abstract
BACKGROUND Acute venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is traditionally managed with a short course of parenteral anticoagulation followed by 3-6 months of a vitamin-K antagonist. Non-vitamin K oral anticoagulants (NOACs) do not require routine monitoring and dose adjustment, thus potentially provide an alternative treatment option. METHODS AND RESULTS Because of the lack of head-to-head clinical studies, an indirect comparison was conducted of dabigatran etexilate and rivaroxaban based on the respective phase III clinical trial. The derived relative safety and efficacy estimates were used to evaluate the cost-utility of dabigatran compared with rivaroxaban in the treatment and secondary prevention of VTE. The results of the indirect comparison showed no significant difference between dabigatran and rivaroxaban in avoiding recurrent VTE following index PE, index DVT, or DVT/PE combined, in treatment and extended anticoagulation. Dabigatran has significantly less major or clinically relevant bleeds (MCRBE) compared to rivaroxaban in treatment after index DVT and treatment after DVT or PE combined, but was not significantly different from rivaroxaban after index PE or in extended anticoagulation. In cost-utility deterministic analyses, dabigatran was projected dominant in all analyzed settings, given its marginally lower total cost and marginally higher QALYs gained compared to rivaroxaban. Probabilistic analyses results showed a high likelihood of dabigatran being considered good value for money in the UK, in treatment and in secondary prevention of VTE. CONCLUSION The cost-effectiveness evaluations showed that dabigatran can be considered the dominant treatment strategy compared to rivaroxaban in the patients' sub-groups considered, given the projected marginally higher clinical benefits and lower treatment costs.
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Reduction in the length of stay with rivaroxaban as a single-drug regimen for the treatment of deep vein thrombosis and pulmonary embolism.
van Bellen, B, Bamber, L, Correa de Carvalho, F, Prins, M, Wang, M, Lensing, AW
Current medical research and opinion. 2014;(5):829-37
Abstract
OBJECTIVE The phase III EINSTEIN DVT and EINSTEIN PE trials demonstrated the potential of oral rivaroxaban for the treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE). The length of initial hospitalization in patients presenting with either symptomatic DVT or PE was assessed using hospitalization records from these trials. METHODS Analyses were carried out in the intention-to-treat population, using non-parametric and parametric statistical methods. RESULTS Overall, 52% (1781/3434) of EINSTEIN DVT patients and 90% (4328/4821) of EINSTEIN PE patients were admitted to hospital. The proportion of hospitalized patients with a length of stay of five or fewer days receiving rivaroxaban was 54% compared with 31% for enoxaparin/vitamin K antagonist (VKA) in patients with DVT. For patients with PE, the corresponding values were 45% and 33%. Stays of 6-10 days were observed in 29% of rivaroxaban-treated patients compared with 45% of enoxaparin/VKA-treated patients for DVT. For patients with PE, these values were 39% and 46% in the rivaroxaban and enoxaparin/VKA groups, respectively. Overall, length of stay was significantly shorter in the rivaroxaban group, compared with the enoxaparin/VKA group across all analyses performed (p < 0.0001). Across regions, the observed admission rates and length of stay duration varied greatly: Asia had the longest overall hospitalization rates, whereas the lowest rates were reported in North America, Australia and New Zealand. Nevertheless, a consistent trend was observed: length of hospital stay in patients with DVT or PE receiving rivaroxaban was shorter than, or at least similar to, patients receiving enoxaparin/VKA. CONCLUSION A single-drug regimen with rivaroxaban may reduce the burden on healthcare systems and patients, and provides effective and well tolerated treatment. The studies shared an open-label design that allowed comparison of initial hospitalization, but limitations include the well monitored clinical trial setting in which decisions on admission and discharge could vary from real-world management.
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PROOF trial: protection from pulmonary embolism with the OptEase filter.
Ziegler, JW, Dietrich, GJ, Cohen, SA, Sterling, K, Duncan, J, Samotowka, M
Journal of vascular and interventional radiology : JVIR. 2008;(8):1165-70
Abstract
PURPOSE A postmarketing surveillance registry was conducted to monitor the safety and effectiveness of the OptEase vena cava filter when used as a permanent filter. MATERIALS AND METHODS This study was a nonrandomized, multicenter prospective trial with all patients receiving the OptEase vena cava filter for the prevention of pulmonary embolism (PE). A total of 11 clinical sites in the United States enrolled patients. A 1-month postimplantation follow-up examination was performed to determine potential filter migration and the presence of symptomatic thrombosis of the inferior vena cava (IVC) or lower extremities. At 6-month postimplantation follow-up, patients were again assessed for the safety and stability of the filter and any clinical evidence of symptomatic thrombosis. RESULTS One hundred fifty patients were enrolled in this study. Fifty-five patients (36.6%) were unable to complete all of the necessary follow-up at 6 months. At 1 month, filter migration and filter-related symptomatic deep vein thrombosis was observed in one patient each (0.9% and 0.8%, respectively). At 6 months, no new cases of filter migration or filter-related symptomatic thrombosis were observed. Filter tilting (> or = 15 degrees off the IVC axis) was observed in one patient at baseline (0.7%), four patients at 1-month follow-up (3.6%), and three patients (11.4%) at 6-month follow-up. Incidental findings on follow-up radiographs included filter fracture in two patients (1.8%) at 1 month and in one additional patient (4.3%) at 6 months. There were no clinical sequelae associated with the filter fracture. CONCLUSIONS The co-primary endpoints of filter migration and symptomatic thrombus formation at 1 month had an observed frequency of 0.9% and 0.8%, respectively. These co-primary endpoints were stable and unchanged at 6 months.
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Prospective evaluation of the negative predictive value of V/Q SPECT using 99mTc-Technegas.
Leblanc, M, Leveillée, F, Turcotte, E
Nuclear medicine communications. 2007;(8):667-72
Abstract
OBJECTIVE To verify the negative predictive value of pulmonary ventilation/perfusion scintigraphy with single photon emission computed tomography (V/Q SPECT) in ruling out pulmonary thromboembolism. METHODS V/Q SPECT using 99mTc-Technegas was performed on 584 patients to rule out pulmonary thromboembolism between October 2004 and July 2005. Pulmonary thromboembolism was defined as any clear-cut vascular mismatch, regardless of size. Indeterminate scans were defined as cases having matching vascular type defects with a corresponding X-ray abnormality, or cases with equivocal mismatches. Other patterns were considered negative for pulmonary thromboembolism. Outcome data was gathered >3 months after the scan. Absence of pulmonary thromboembolism was defined as any patient still alive at least 3 months after the scan, with no anticoagulation treatment and no proof of pulmonary thromboembolism by other techniques, either at the time of the scan or during follow-up, or death by other causes. RESULTS One hundred and eight patients (19%) had a positive pulmonary thromboembolism reading, 18 (3%) an indeterminate study, and 458 (78%) patients had a negative reading for pulmonary thromboembolism. There were 189 patients with an abnormal chest X-ray. The mean follow-up time was 165 days. Of the 458 patients classified as negative for pulmonary thromboembolism, patients receiving chronic anticoagulation for other causes were excluded from follow-up (n=53), which left 405 patients for final analysis. There were no pulmonary thromboembolism-related deaths in the negative group. Six patients were identified as false negatives. The negative predictive value is estimated at 98.5%. CONCLUSION SPECT pulmonary scintigraphy using 99mTc-Technegas demonstrates a high negative predictive value and a low indeterminate rate.
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Gadolinium-enhanced pulmonary magnetic resonance angiography in the diagnosis of acute pulmonary embolism: a prospective study on 48 patients.
Pleszewski, B, Chartrand-Lefebvre, C, Qanadli, SD, Déry, R, Perreault, P, Oliva, VL, Prenovault, J, Belblidia, A, Soulez, G
Clinical imaging. 2006;(3):166-72
Abstract
OBJECTIVE Gadolinium-enhanced pulmonary magnetic resonance angiography (MRA) can be an option in patients with a history of previous adverse reaction to iodinated contrast material and renal insufficiency. Radiation is also avoided. The aim of this study is to prospectively compare the diagnostic value of MRA with that of a diagnostic strategy, taking into account catheter angiography, computed tomography angiography (CTA), and lung scintigraphy [ventilation-perfusion (VQ)]. MATERIAL AND METHODS Magnetic resonance angiography was done in 48 patients with clinically suspected pulmonary embolism (PE) using fast gradient echo coronal acquisition with gadolinium. Interpretation was done with native coronal images and multiplanar maximum intensity projection reconstructions. Results were compared to catheter angiography (n=15), CTA (n=34), VQ (n=45), as well as 6-12 months clinical follow-ups, according to a sequenced reference tree. RESULTS The final diagnosis of PE was retained in 11 patients (23%). There were two false negatives and no false positive results with MRA. Computed tomography angiography resulted in no false negatives or false positives. Magnetic resonance angiography had a sensitivity of 82% and a specificity of 100%. CONCLUSION In our study, pulmonary MRA had a sensitivity of 82% and a specificity of 100% for the diagnosis of PE, with slightly less sensitivity than CTA. In the diagnostic algorithm of PE, pulmonary MRA should be considered as an alternative to CTA when iodine contrast injection or radiation is a significant matter.
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A randomized trial comparing 2 low-molecular-weight heparins for the outpatient treatment of deep vein thrombosis and pulmonary embolism.
Wells, PS, Anderson, DR, Rodger, MA, Forgie, MA, Florack, P, Touchie, D, Morrow, B, Gray, L, O'Rourke, K, Wells, G, et al
Archives of internal medicine. 2005;(7):733-8
Abstract
BACKGROUND Low-molecular-weight heparins (LMWHs) are now standard therapy for the treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE). No published trials have compared LMWHs, and few studies have examined outpatient therapy for PE. Only tinzaparin sodium has demonstrated superiority to unfractionated heparin in a clinical trial. METHODS We compared 2 LMWH products, tinzaparin and dalteparin sodium, for the treatment of acute DVT and PE in a randomized, controlled clinical trial of consecutive outpatients presenting to a venous thromboembolism service at 4 tertiary-care hospitals. Patients were treated with subcutaneous tinzaparin sodium, 175 IU/kg every 24 hours, or subcutaneous dalteparin sodium, 200 IU/kg every 24 hours, for at least 5 days. Warfarin sodium therapy was started simultaneously and continued for 90 days. The primary end point was efficacy (recurrence of venous thromboembolism); safety (bleeding) was a composite end point. RESULTS Two hundred fifty-four patients received tinzaparin (39 with PE and 215 with DVT) and 251 received dalteparin (51 with PE and 200 with DVT). Most patients had an active malignancy or idiopathic DVT/PE. The outcome events occurred in 11 (4.4%; 95% confidence interval [CI], 2.2%-7.7%) and 15 patients (5.9%; 95% CI, 3.3%-9.5%) in the dalteparin and tinzaparin groups, respectively, including 9 and 10 recurrences, respectively, and 2 and 5 major hemorrhages, respectively (P = .44). The 95% CI on the difference of -1.5% was -5.3% to 2.4%. CONCLUSIONS Tinzaparin and dalteparin are safe and effective for the outpatient treatment of DVT or PE. Our finding of no differences between the LMWHs based on major clinical end points means that practical issues can be the deciding factor on which drug to use.
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Tomographic imaging in the diagnosis of pulmonary embolism: a comparison between V/Q lung scintigraphy in SPECT technique and multislice spiral CT.
Reinartz, P, Wildberger, JE, Schaefer, W, Nowak, B, Mahnken, AH, Buell, U
Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2004;(9):1501-8
Abstract
UNLABELLED Although ventilation/perfusion (V/Q) lung scintigraphy is a well-accepted and frequently performed procedure in the diagnosis of pulmonary embolism, there is growing controversy about its relevance, particularly due to the increasing competition between scintigraphy and CT. Even though comparative studies between both modalities have already been performed, their results were highly inconsistent. Remarkably, in most of those studies, conventional planar perfusion scans were compared with tomographic images acquired using state-of-the-art CT scanners-a study design that cannot give impartial results. Hence, the aim of our study was a balanced comparison between V/Q lung scintigraphy and CT angiography using advanced imaging techniques for both modalities. METHODS A total of 83 patients with suspected pulmonary embolism were examined using V/Q lung scintigraphy in SPECT technique as well as 4-slice spiral CT. Ventilation scans were done using an ultrafine aerosol. Additionally, planar images in 8 views were extracted from the V/Q SPECT datasets. Two experienced referees assessed each of the 3 modalities. The final diagnosis was made at a consensus meeting while taking into account all of the imaging modalities, laboratory tests, clinical data, and evaluation of a follow-up period. RESULTS In the course of the consensus conference, pulmonary embolism was diagnosed in 37 of the 83 patients (44.6%). Compared with planar scintigraphy, SPECT raised the number of detectable defects at the segmental level by 12.8% (+11 defects; P = 0.401) and at the subsegmental level by 82.6% (+57 defects; P < 0.01). The sensitivity/specificity/accuracy of planar V/Q scintigraphy and V/Q SPECT was 0.76/0.85/0.81 and 0.97/0.91/0.94, respectively, compared with 0.86/0.98/0.93 for multislice CT. CONCLUSION SPECT and ultrafine aerosols are technical advancements that can substantially improve lung scintigraphy. Using advanced imaging techniques, V/Q scintigraphy and multislice spiral CT both yield an excellent and, in all aspects, comparable diagnostic accuracy, with CT leading in specificity while SPECT shows a superior sensitivity. Even though planar lung scintigraphy yields satisfactory results for a nontomographic modality, it does not compare with tomographic imaging.
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Duration of prophylaxis against venous thromboembolism with fondaparinux after hip fracture surgery: a multicenter, randomized, placebo-controlled, double-blind study.
Eriksson, BI, Lassen, MR, ,
Archives of internal medicine. 2003;(11):1337-42
Abstract
BACKGROUND The benefit of thromboprophylaxis for 1 month has never been evaluated in patients undergoing hip fracture surgery, a setting in the highest risk category for postoperative venous thromboembolism (VTE). METHODS In a double-blind multicenter trial, 656 patients undergoing hip fracture surgery were randomly assigned to receive prophylaxis with a once-daily subcutaneous injection of either 2.5 mg of fondaparinux sodium or placebo for 19 to 23 days. Before randomization, all patients had received fondaparinux for 6 to 8 days. The primary efficacy outcome was VTE occurring during the double-blind period (deep vein thrombosis detected by mandatory bilateral venography or documented symptomatic deep vein thrombosis or pulmonary embolism). The main safety outcome was major bleeding. RESULTS The primary efficacy outcome was assessed in 428 patients. Fondaparinux reduced the incidence of VTE compared with placebo from 35.0% (77/220) to 1.4% (3/208), with a relative reduction in risk of 95.9% (95% confidence interval, 87.2%-99.7%; P<.001). Similarly, the incidence of symptomatic VTE was significantly lower with fondaparinux (1/326; 0.3%) than with placebo (9/330; 2.7%). The relative reduction in risk was 88.8% (P =.02). Although there was a trend toward more major bleeding in the fondaparinux group than in the placebo group (P =.06), there were no differences between the 2 groups in the incidence of clinically relevant bleeding (leading to death, reoperation, or critical organ bleeding). CONCLUSIONS Extended prophylaxis with fondaparinux for 3 weeks after hip fracture surgery reduced the risk of VTE by 96% and was well tolerated.