High Probability Of Pulmonary Embolism Research Articles

Clinical results of high probability ventilation/perfusion scintigraphy in the diagnosis of pulmonary embolism

PurposeWhile computed tomography pulmonary angiography plays an effective role in the diagnosis and prognosis of pulmonary embolism (PE), there are not enough studies regarding ventilation/perfusion (V/Q) scintigraphy. We aimed to evaluate the clinical outcomes of PE patients whose V/Q scintigraphy was reported as high probability for PE. MethodDemographic data, Simplified Pulmonary Embolism Severity Index (SPESI), radiological findings, V/Q scintigraphy and echocardiographic (ECHO) findings, laboratory data, treatment information and comorbidities of 43 patients whose V/Q scintigraphy was reported as high probability for PE between January 2020 and January 2023 was recorded. Perfusion scintigraphy defects were classified as subsegmental, multiple subsegmental, segmental, and multiple segmental. Those with subsegmental, multiple subsegmental, and segmental perfusion defects were classified as Group 1, and those with multiple segmental defects as Group 2. ResultsThe mean age of the patients was 74 years (31–94), being 27 women (62.8 %) and 16 men (37.2 %), and there was no significant difference between the two groups. Multisegmental perfusion defect was detected in 23 (53.5 %) patients. 25 % of patients reported as high-probability PE had a SPESI score of ≥2. There was no significant difference between Groups 1 and 2 in terms of SPESI scoring. Perfusion defect had no significant correlation with SPESI score, D-Dimer, Troponin, pulmonary artery systolic pressure, right ventricular dilatation, and length of hospital stay. The presence of comorbidity was significantly positively correlated only with the SPESI score. There was no difference between the two groups regarding laboratory, radiological, echocardiographic findings, presence of comorbidity, unit of treatment, and duration of hospitalization. ConclusionParameters predicting clinical severity and providing treatment benefits are required in PE patients diagnosed with V/Q scintigraphy.

Clinicians' interpretation of ventilation/perfusion lung scan reports: Where are we today?

Clinicians' interpretation of lung scan reports will determine which further management decisions are taken when potentially fatal pulmonary embolism (PE) is suspected. To assess current referring clinicians' interpretation of the terminology used in ventilation/perfusion (V/Q) scan reports, whether this interpretation is affected by experience level, and how it affects clinical management decisions. This was a questionnaire-based cross-sectional study. Between September 2020 and May 2021, 300 questionnaires were distributed among clinicians who refer patients for V/Q scans. Of the 162 clinicians who responded, 94% thought that there is >85% likelihood of PE or definitely PE present when a scan is reported as 'high probability of PE'; 87% interpreted 'low probability of PE' as <10% likelihood of PE or definitely no PE present. Overall, >70% of clinicians across all experience levels correctly interpreted the intended meaning of probability categories according to the Modified Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) II criteria. Of the respondents, 77% agreed that clinically significant PE is ruled out by a normal scan. Further investigation for inconclusive findings, features of parenchymal lung disease and cardiomegaly were selected by 72%, 93% and 98% of clinicians, respectively. The findings of this study regarding high-probability scan results were in line with existing literature on lung scan report interpretation. However, our findings regarding low-probability scan results and negative V/Q scan specificity contrasted with the findings in these articles, suggesting that clinicians are now more familiar with lung scan interpretation guidelines. Experience level did not significantly affect interpretation of reports. Although most clinicians agreed that a negative scan excludes clinically significant PE, two-thirds of them would still subject the patient to further unnecessary investigations to exclude PE. What the study adds. Our findings regarding a low-probability ventilation/perfusion (V/Q) scan and the specificity of a negative V/Q scan contrasted with previous articles on lung scan interpretation, suggesting that clinicians are now more familiar with lung scan interpretation guidelines.Implications of the findings. Although most clinicians understood the negative predictive value of a V/Q scan, 20% would still investigate further with computed tomography pulmonary angiography or treat as confirmed pulmonary embolism. Education of clinicians about the negative predictive value of V/Q scans is important to avoid unnecessary radiation or anticoagulation.

Prognostic Significance of Asymptomatic Pulmonary Embolism on Routine Ventilation-Perfusion Scans after Lung Transplantation

<h3>Purpose</h3> Asymptomatic pulmonary embolism (PE) is a challenging clinical entity with unclear treatment implications. This is also true of PE detected on routine studies after lung transplant were clot may be donor derived. Our program performs routine ventilation-perfusion (VQ) scans at 3-months post-transplant to establish baseline airway and vascular function but in some cases, these are positive for PE. We hypothesized that asymptomatic PE in this context would carry a benign prognosis irrespective of therapy. <h3>Methods</h3> We studied VQ scans obtained routinely at 3-months post-transplant from double lung transplant recipients in our program between 2004-2016. The risk group was patients whose studies were interpreted as high probability for PE. We used chi square testing for the relationship between PE with 1-year survival. We also used Kaplan Meier analysis with log rank testing and t-tests for the association with overall survival and peak forced expiratory volume in 1 second (FEV1) percent predicted. <h3>Results</h3> 373 patients met inclusion criteria, of whom 35 (9%) had VQ scans interpreted as high probability for PE. The PE group were less likely to have had severe primary graft dysfunction (3% vs. 19%; p=0.03) but were otherwise similar to patients without PE. 7 patients in the PE group (20%) were treated with therapeutic anticoagulation and the remainder treated expectantly. Patients with PE had similar 1-year survival (100% vs. 98%, p=1.00), overall survival (log rank p=0.90) and peak FEV1% predicted (94% [SD 20%] vs. 92% [SD 21%]; p=0.58). We observed no differences between treated and untreated PE. <h3>Conclusion</h3> Asymptomatic PE diagnosed on routine post-transplant VQ scan was not associated with a difference in survival or lung function, irrespective of therapy. This may suggest these changes are donor derived and not reflective of recipient hypercoagulability.

Derivation and Validation of a 4-Level Clinical Pretest Probability Score for Suspected Pulmonary Embolism to Safely Decrease Imaging Testing

In patients with suspected pulmonary embolism (PE), overuse of diagnostic imaging is an important point of concern. To derive and validate a 4-level pretest probability rule (4-Level Pulmonary Embolism Clinical Probability Score [4PEPS]) that makes it possible to rule out PE solely on clinical criteria and optimized D-dimer measurement to safely decrease imaging testing for suspected PE. This study included consecutive outpatients suspected of having PE from US and European emergency departments. Individual data from 3 merged management studies (n = 11 114; overall prevalence of PE, 11%) were used for the derivation cohort and internal validation cohort. The external validation cohorts were taken from 2 independent studies, the first with a high PE prevalence (n = 1548; prevalence, 21.5%) and the second with a moderate PE prevalence (n = 1669; prevalence, 11.7%). A prior definition of pretest probability target values to achieve a posttest probability less than 2% was used on the basis of the negative likelihood ratios of D-dimer. Data were collected from January 2003 to April 2016, and data were analyzed from June 2018 to August 2019. The rate of PE diagnosed during the initial workup or during follow-up and the rate of imaging testing. Of the 5588 patients in the derivation cohort, 3441 (61.8%) were female, and the mean (SD) age was 52 (18.5) years. The 4PEPS comprises 13 clinical variables scored from -2 to 5. It results in the following strategy: (1) very low probability of PE if 4PEPS is less than 0: PE ruled out without testing; (2) low probability of PE if 4PEPS is 0 to 5: PE ruled out if D-dimer level is less than 1.0 μg/mL; (3) moderate probability of PE if 4PEPS is 6 to 12: PE ruled out if D-dimer level is less than the age-adjusted cutoff value; (4) high probability of PE if 4PEPS is greater than 12: PE ruled out by imaging without preceding D-dimer test. In the first and the second external validation cohorts, the area under the receiver operator characteristic curves were 0.79 (95% CI, 0.76 to 0.82) and 0.78 (95% CI, 0.74 to 0.81), respectively. The false-negative testing rates if the 4PEPS strategy had been applied were 0.71% (95% CI, 0.37 to 1.23) and 0.89% (95% CI, 0.53 to 1.49), respectively. The absolute reductions in imaging testing were -22% (95% CI, -26 to -19) and -19% (95% CI, -22 to -16) in the first and second external validation cohorts, respectively. The 4PEPS strategy compared favorably with all recent strategies in terms of imaging testing. The 4PEPS strategy may lead to a substantial and safe reduction in imaging testing for patients with suspected PE. It should now be tested in a formal outcome study.

A DIAGNOSTIC DILEMMA: NORMAL D-DIMER IN A PATIENT WITH EXTENSIVE PULMONARY EMBOLISM

SESSION TITLE: Medical Student/Resident Pulmonary Vascular Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: The presentation of pulmonary embolism (PE) is very non-specific and carries a significant morbidity and mortality. Typically, D-dimer assay has a very high sensitivity and a negative predictive value of 99-100% in both low and moderate risk groups. We present a unique case of diagnosing extensive PE with deep vein thrombosis (DVT) in presence of a normal D-dimer. CASE PRESENTATION: A 69-year-old female with significant history of hypertension and diabetes presented with dry cough and worsening of dyspnea on exertion for four days. Patient denied chest pain, palpitations, fever, chills, diaphoresis, leg pain or swelling. Vitals showed a T 98.6, BP 112/64 mmHg, HR 56, RR 16, oxygen saturation of 90% on 3LPM of nasal canula. Physical exam, especially the pulmonary exam, was largely unremarkable. No swelling or pain in the lower extremities was noted. Laboratory findings including the metabolic panel, blood count, and a set of troponins were within normal limits. ECG showed a normal sinus rhythm, and a follow-up chest radiograph and a non-contrast CT scan of chest did not demonstrate any significant findings. Acute PE was ruled out since the D-dimer assay was normal and the pretest probability was low-moderate. Preliminary diagnosis of pulmonary hypertension was suspected and worked up. An echocardiogram showed severe pulmonary hypertension with elevated right ventricular systolic pressure in the setting of a normal LV ejection fraction. A ventilation perfusion scan was subsequently done to evaluate for CTEPH, and was overwhelmingly positive with a high probability of PE. A CT angiogram revealed extensive bilateral central and segmental PE. Doppler ultrasound of lower extremities revealed an acute non-occlusive DVT involving the left popliteal vein. Patient was subsequently started on anti-coagulants and the supplemental oxygen was continued prior to safe discharge. DISCUSSION: D-dimer assay is a highly sensitive test used in the evaluation of PE. It is a measure of monoclonal antibody to D-Dimer produced during the process of fibrinolysis. D-dimer has a half-life of 4-6 hours and stays elevated for about seven days. Once the clot organization and adherence begins, levels of D-dimer drop. As such, D-dimer levels correlate with the presence of fibrin clots. The assay can be falsely negative if the specimen is collected very early or later than 7 days of clot formation. Regardless, a negative assay should be able to safely rule out a large PE in low and moderate risk patients. A low d-dimer assay on presentation in light of an extensive PE/DVT makes our case unique. CONCLUSIONS: D-dimer assay usually provides excellent diagnostic yield while ruling out a PE/DVT. However, it remains prudent to consider the overall clinical presentation and go through a step by step approach to not miss a disease with a fatal potential such as a PE in our case. Reference #1: Dagkiran H, Atas R, Tomic I, Plachtzik C, Geisler T, Gawaz MP, Oberhoff M, Anger T. Severe Pulmonary Embolism with Negative D-Dimer-Testing. Journal of Cardiology and Therapy 2015; 2(1): 265-268 Available from: URL: http://www.ghrnet.org/index.php/jct/article/view/1033 Reference #2: Gupta RT, Kakarla RK, Kirshenbaum KJ, Tapson VF. D-dimers and efficacy of clinical risk estimation algorithms: sensitivity in evaluation of acute pulmonary embolism. AJR Am J Roentgenol. 2009;193(2):425-430 Reference #3: Le Gal G, Righini M, Roy P, et al. Value of D-Dimer Testing for the Exclusion of Pulmonary Embolism in Patients With Previous Venous Thromboembolism. Arch Intern Med. 2006;166(2):176 -180. doi:http://dx.doi.org/10.1001/archinte.166.2.176 DISCLOSURES: No relevant relationships by Richard Miller, source=Web Response No relevant relationships by Kinjal Patel, source=Web Response No relevant relationships by Rutwik Patel, source=Web Response No relevant relationships by Krunal Trivedi, source=Web Response

New evidence in diagnosis of pulmonary embolism during pregnancy.

Diagnosis of pulmonary embolism (PE) in pregnancy is notoriously difficult and lacking high quality evidence. Three studies (DiPEP, ARTEMIS and CT-PE-Pregnancy) evaluating a systematic approach to PE diagnosis have recently been published. DiPEP is a retrospective case-control study that found a poor utility of clinical decision rules or D-dimer testing for PE diagnosis in pregnancy. ARTEMIS and CT-PE-Pregnancy are well conducted prospective management studies that proposed two algorithms with different clinical decision rules and D-dimer criteria for the diagnosis of PE in pregnancy. They included few events in high risk patients, which makes difficult the assessment of both algorithm's safety in women with a high probability of PE. Considering this new evidence, D-dimer testing might be useful to avoid radiation imaging in pregnant women considered at low risk for PE. In contrast, a negative D-dimer cannot be considered sufficiently safe to rule out PE when clinicians estimate that PE is the most likely diagnosis.

Referral Patterns and Diagnostic Yield of Lung Scintigraphy in the Diagnosis of Acute Pulmonary Embolism.

Introduction. The purpose of this study is to assess referral patterns and the yield of ventilation-perfusion (V/Q) scintigraphy in patients referred for acute pulmonary embolism (PE). Methods. We retrospectively reviewed the charts of all patients who underwent V/Q studies between April 1, 2008, and March 31, 2010. Patients were subdivided into 4 groups based on their referral source: emergency department (ED), hospital inpatient ward, outpatient thrombosis clinic, and all other outpatient sources. Results. A total of 1008 patients underwent V/Q scintigraphy to exclude acute PE. The number of ED, inpatient, thrombosis clinic, and outpatient studies was 43 (4.3%), 288 (28.6%), 351 (34.8%), and 326 (32.3%). Proportion of patients with contrast contraindication varied significantly among the different groups. Of the 1,008 studies, 331 (32.8%) were interpreted as normal, 408 (40.5%) as low, 158 (15.7%) as intermediate, and 111 (11.0%) as high probability for PE. 68 (6.7%) patients underwent CTPA within 2 weeks following V/Q. Conclusion. The rate of nondiagnostic studies is lower than that reported in previously published data, with a relatively low rate of intermediate probability studies. Only a small fraction of patients undergoing a V/Q scan will require a CTPA.

Is stand‐alone D‐dimer testing safe to rule out acute pulmonary embolism?

Background Recently, stand-alone D-dimer testing at a positivity threshold of 750 μg L-1 has been proposed as a safe and efficient approach to rule out acute pulmonary embolism (PE), without additional imaging, but this approach needs validation. Objectives To evaluate stand-alone D-dimer testing at a positivity threshold of 750 μg L-1 to rule out PE. Methods Individual data from 7268 patients with suspected PE previously enrolled in six prospective management studies were used. Patients were assessed by the Wells rule followed by quantitative D-dimer testing in those with a 'PE unlikely' score. Patients were classified post hoc as having a negative (< 750 μg L-1 ) or positive (≥ 750 μg L-1 ) D-dimer. Using a one-stage meta-analytic approach, the negative predictive value (NPV) of stand-alone D-dimer testing was evaluated overall and in different risk subgroups. Results The pooled incidence of PE was 23% (range, 13-42%). Overall, 44% of patients had a D-dimer < 750 μg L-1 , of whom 2.8% were diagnosed with PE at baseline or during 3-month follow-up (NPV, 97.2%; 95% confidence interval [CI], 94.9-98.5). The NPV was highest in patients with a low probability of PE according to the Wells rule (99.2%; 95% CI, 98.6-99.5%) and lowest in those with a high probability of PE (79.3%; 95% CI, 53.0-92.8%). The NPVs in patients with active cancer, patients with previous venous thromboembolism and inpatients were 96.2% (95% CI, 85.6-99.1%), 94.7% (95% CI, 88.6-97.6%) and 92.7% (95% CI, 79.3-97.7%), respectively. Conclusions Our findings suggest that stand-alone D-dimer testing at a positivity threshold of 750 μg L-1 is not safe to rule out acute PE.

Multidetector computed tomographic pulmonary angiography in patients with a high clinical probability of pulmonary embolism

ESSENTIALS: When high probability of pulmonary embolism (PE), sensitivity of computed tomography (CT) is unclear. We investigated the sensitivity of multidetector CT among 134 patients with a high probability of PE. A normal CT alone may not safely exclude PE in patients with a high clinical pretest probability. In patients with no clear alternative diagnosis after CTPA, further testing should be strongly considered. Whether patients with a negative multidetector computed tomographic pulmonary angiography (CTPA) result and a high clinical pretest probability of pulmonary embolism (PE) should be further investigated is controversial. This was a prospective investigation of the sensitivity of multidetector CTPA among patients with a priori clinical assessment of a high probability of PE according to the Wells criteria. Among patients with a negative CTPA result, the diagnosis of PE required at least one of the following conditions: ventilation/perfusion lung scan showing a high probability of PE in a patient with no history of PE, abnormal findings on venous ultrasonography in a patient without previous deep vein thrombosis at that site, or the occurrence of venous thromboembolism (VTE) in a 3-month follow-up period after anticoagulation was withheld because of a negative multidetector CTPA result. We identified 498 patients with a priori clinical assessment of a high probability of PE and a completed CTPA study. CTPA excluded PE in 134 patients; in these patients, the pooled incidence of VTE was 5.2% (seven of 134 patients; 95% confidence interval [CI] 1.5-9.0). Five patients had VTEs that were confirmed by an additional imaging test despite a negative CTPA result (five of 48 patients; 10.4%; 95% CI 1.8-19.1), and two patients had objectively confirmed VTEs that occurred during clinical follow-up of at least 3 months (two of 86 patients; 2.3%; 95% CI 0-5.5). None of the patients had a fatal PE during follow-up. A normal multidetector CTPA result alone may not safely exclude PE in patients with a high clinical pretest probability.

Importance of risk factors for the evaluation of patients with a suspected pulmonary embolism.

The reliable exclusion of a pulmonary embolism (PE) in hemodynamically stable patients remains a challenge. The European Society of Cardiology guidelines for PE diagnosis published in 2008 and updated in 2014 recommend a low-threshold computed tomography (CT) indication for patients with a high probability of pulmonary embolism or those with elevated levels of D-dimers. Certain elements of the recommendations are controversial, while others, including the evaluation of the risk factors for PE, are considered only in individual cases. In the present study, various risk factors, including obesity, smoking, contraceptive use, immobility level, history of malignant disease and thrombophilia and the factors of familial predisposition, deep vein thrombosis (DVT)/PE-history, long-distance flying <1 week and surgery <4 weeks previously, were retrospectively examined in 492 patients with a suspected PE. The data demonstrated a significant risk of PE with contraceptive use, a history of DVT/PE and thrombophilia. The immobility level, surgery <4 weeks and long-distance flying <1 week previously, as well as family history, malignant disease, obesity and smoking, were not observed to be associated with a significantly higher risk of PE. Contraceptive use and thrombophilia, in addition to a history of DVT/PE, each appear to have a significant predictive value in the context of PE risk stratification. Therefore, patients with a suspected PE, who additionally present with at least one of the aforementioned risk factors, should undergo further diagnostic steps for PE risk stratification, including a low-threshold CT examination, even in the absence of elevated D-dimers.

ST-elevation myocardial infarction secondary to paradoxical coronary emboli in a patient with massive pulmonary embolism and essential thrombocytosis: A case report

Introduction: Essential thrombocytosis (Et) is a myeloproliferative disorder with higher incidence of thrombotic events. to our knowledge, we present the first case of st-segment elevation myocardial infarction (stEMI) secondary to paradoxical right coronary artery (rcA) embolus through a patent foramen ovale (PFO) in a patient with essential thrombocytosis and pulmonary embolus. case report: A 67-year old female with a history of Et presented to the emergency room with dyspnea. Physical examination revealed an elevated JVP, an s1Q3t3 pattern on her presenting EcG, and an elevated D-dimer. V/Q scan showed a high probability for pulmonary embolism as well as unusual evidence of right-to-left cardiac shunting. After starting low molecular weight heparin, she developed new-onset chest

Prognostic value of brain natriuretic peptide in acute pulmonary embolism

BackgroundPlasma levels of brain natriuretic peptide (BNP) correlate closely with the pressure and mural tension of the right ventricle and with pulmonary arterial pressure. The relationship between brain natriuretic peptide increase in acute pulmonary embolism (APE) and the increase in mortality and morbidity has frequently been suggested in small studies but its global prognostic performance remains largely undefined. MethodsBNP levels were determined among the 30 consecutive patients arriving at the emergency department with shortness of breath and moderate to high probability of pulmonary embolism. All patients were subjected to a thorough clinical and physical examination, 12 lead electrocardiography, chest X-ray, echocardiography, laboratory tests including complete blood count, coagulation profile, renal and liver functions, brain natriuretic peptide and multiline computed tomography. Results20 patients were diagnosed with APE. Among them, 7 were diagnosed with massive embolism (group 1) and 13 had mild to moderate embolism (group 2). Among the first group 6 patients died while only 2 patients from the second group died. BNP levels were significantly higher in group 1 (130±15pg/ml) compared to group 2 (91±7pg/ml) (P<0.05) and this was associated also with an increased mortality in group 1. ConclusionBNP levels can help predict the severity and possible outcome in patients with pulmonary embolism.

Contribution of V/Q SPECT to planar scintigraphy in the diagnosis of pulmonary embolism

AimTo evaluate the feasibility of V/Q SPECT and analyze its contribution to planar V/Q lung scintigraphy in the diagnosis of pulmonary embolism (PE). Material and methodsA total of 109 patients with suspected PE showing Wells score>2 and elevated D-dimer were studied. The V/Q could not be completed in 7 patients, so they were excluded. Ventilation and perfusion scans were done using Technegas and 99mTc-MAA. Planar study included 8 projections on a 256×256 matrix and 128 projections on a 128×128 matrix were acquired for the SPECT study, applying an iterative method. Planar images were interpreted according to modified PIOPED criteria, and SPECT by the guidelines of the EANMMI. The results with both techniques were compared. ResultsV/Q planar scintigraphy and SPECT could be performed in 102 patients. V/Q planar scintigraphy was considered “diagnostic” in 39 of the 102 patients, and “non-diagnostic” in 63. Of the 39 “diagnostic” studies, 31 were reported as high probability of PE and 8 as normal. Of the 63 “non-diagnostic”, 26 corresponded to intermediate, 29 to low, and 8 to very low probability. The SPECT study was “diagnostic” in 97 and indeterminate in only 5. All patients with a high probability planar scintigraphy had a positive SPECT. In the 8 patients with a normal planar scintigraphy SPECT was negative in 5 and positive in 3. In the 63 patients with a “non-diagnostic” planar scintigraphy SPECT was “diagnostic” in 58 of them, positive in 17 and negative in 41. ConclusionV/Q SPECT is a feasible technique as it was performed in 102 of the 109 patients who were enrolled in the study (94%).The addition of V/Q SPECT to planar V/Q decreases the number of “non-diagnostic” reports from 62% in planar scintigraphy to 4.9% in SPECT. Therefore, V/Q SPECT should be included in the diagnosis approach of PE due to its high diagnostic yield.

Prevalence of Venous Thromboembolic Events and Diagnostic Performance of the Wells Score and Revised Geneva Scores for Pulmonary Embolism in Patients with Interstitial Lung Disease: A Prospective Study

To determine the prevalence of venous thromboembolism (VTE) in patients with connective tissue disease-related interstitial lung diseases (CTD-ILD) and idiopathic interstitial pneumonia (IIP) and to further evaluate associated risk factors. To also examine the diagnostic performance of the Wells score and the revised Geneva scores for diagnosing pulmonary embolism (PE) in ILD patients. Fifty-seven patients with CTD-ILD and IIP were prospectively enrolled. Plasma D-dimer was measured by ELISA. Deep-vein thrombosis (DVT) was examined by venous ultrasonography and PE by computed tomography pulmonary angiography. PE prevalence was further assessed by the Wells score and the revised Geneva score. VTE was diagnosed in 15 (26.3%, 15/57) patients. Bivariate analysis revealed that dyspnoea (OR 3.750, 95%CI 1.095-12.842, P=0.035), lower extremity oedema (OR 8.667, 95%CI1.814-41.408, P=0.007), palpitations (OR 4.75, 95%CI1.073-21.032, P=0.040), and positive D-dimer (OR 5.087, 95%CI 1.015-25.485, P=0.048) were associated with VTE. Using the Wells Score, 46 (80.70%), eight (14.4%) and three (5.26%) patients had a low, intermediate and high probability of PE, respectively, with seven (15.22%), three (37.5%) and two (66.67%) of the respective cases confirmed. By the revised Geneva score, 23 (40.35%), 32 (56.14%) and two (3.51%) patients had a low, intermediate and high probability of PE, respectively, with two (8.70%), nine (28.13%) and one (50.00%) of the respective cases confirmed. The AUC for the Wells score and the revised Geneva score was 0.720±0.083 (CI 0.586 to 0.831) and 0.704± 0.081 (CI 0.568 to 0.817), respectively. VTE can be seen in approximately one fourth of patients with CTD-ILD or IIP and the Wells score and the revised Geneva score can be used for categorising PE risk.

Contribution of V/Q SPECT to planar scintigraphy in the diagnosis of pulmonary embolism

To evaluate the feasibility of V/Q SPECT and analyze its contribution to planar V/Q lung scintigraphy in the diagnosis of pulmonary embolism (PE). A total of 109 patients with suspected PE showing Wells score>2 and elevated D-dimer were studied. The V/Q could not be completed in 7 patients, so they were excluded. Ventilation and perfusion scans were done using Technegas and (99m)Tc-MAA. Planar study included 8 projections on a 256×256 matrix and 128 projections on a 128×128 matrix were acquired for the SPECT study, applying an iterative method. Planar images were interpreted according to modified PIOPED criteria, and SPECT by the guidelines of the EANMMI. The results with both techniques were compared. V/Q planar scintigraphy and SPECT could be performed in 102 patients. V/Q planar scintigraphy was considered "diagnostic" in 39 of the 102 patients, and "non-diagnostic" in 63. Of the 39 "diagnostic" studies, 31 were reported as high probability of PE and 8 as normal. Of the 63 "non-diagnostic", 26 corresponded to intermediate, 29 to low, and 8 to very low probability. The SPECT study was "diagnostic" in 97 and indeterminate in only 5. All patients with a high probability planar scintigraphy had a positive SPECT. In the 8 patients with a normal planar scintigraphy SPECT was negative in 5 and positive in 3. In the 63 patients with a "non-diagnostic" planar scintigraphy SPECT was "diagnostic" in 58 of them, positive in 17 and negative in 41. V/Q SPECT is a feasible technique as it was performed in 102 of the 109 patients who were enrolled in the study (94%). The addition of V/Q SPECT to planar V/Q decreases the number of "non-diagnostic" reports from 62% in planar scintigraphy to 4.9% in SPECT. Therefore, V/Q SPECT should be included in the diagnosis approach of PE due to its high diagnostic yield.

Prevalência e preditores de embolia pulmonar em pacientes com insuficiência cardíaca agudamente descompensada

The prevalence of pulmonary embolism (PE) has not been reported in patients hospitalized due to classical findings of decompensated heart failure (HF). To describe the prevalence of PE and to assess the diagnostic accuracy of the Wells and Geneva scores in patients hospitalized due to HF. Patients hospitalized primarily due to HF underwent systematic ventilation-perfusion lung scan, and PE was defined by a result of high probability. Aiming at interpreting, low clinical probability of PE was defined as prevalence < 5%, according to the literature. When calculating the sample size, 49 patients were required to provide a 95% confidence interval with ±10% accuracy, estimating an a priori prevalence of 15%. Of 51 patients studied, six had a high probability of PE on lung scan, resulting in 12% prevalence (95% CI = 5% - 23%). The Wells and Geneva scores had an area under the ROC curve of 0.53 (95% CI = 0.27 - 0.80; p = 0.80) and 0.43 (95% CI = 0.13 - 0.73; p = 0.56), respectively, indicating lack of accuracy for the diagnosis of PE. Alternatively, variables related to HF showed a tendency towards association with PE, and an exploratory model formed by that type of variable showed diagnostic accuracy for PE (ROC = 0.81; 95% CI = 0.66 - 0.96; p = 0.01). (1) Despite the lack of primary suspicion, patients admitted with HF have intermediate clinical probability of concomitant PE; (2) the scores usually used to estimate the clinical probability of PE do not apply to the population with HF, and future predictive models should consider variables related to that syndrome.

A Review of Electrocardiography in Pulmonary Embolism: Recognizing Pulmonary Embolus Masquerading as ST-Elevation Myocardial Infarction

A 64-year-old woman with hypertension and diabetes presented with acute shortness of breath and left-sides chest discomfort. Electrocardiopgram (ECG) demonstrated Q waves, coved ST-segment elevations, and T-wave inversions in leads V₁-V₄, suggesting acute anterior ST-elevation myocardial infarction (STEMI). catheterization revealed nonocclusive coronary artery disease with elevated pulmonary and right heart pressures, confirmed by echocardiography. Ventilation perfusion scan was deemed high probability for pulmonary embolism (PE). Treatment for a submassive PE was initiated and ECG changes resolved by discharge. This case exemplifies similarities in clinical presentation of PE and acute STEMI. The presence of Q waves in anterior leads wih coved ST-elevation after PE has not been described previously. We review the differential diagnosis of ST elevation and the assorted spectrum of ECG changes seen in PE.

Incidence of Patients with Deep Vein Thrombosis and Pulmonary Embolism in Elevated D-Dimer Levels

Elevated levels of D-dimers with unknown significance often irritate in clinical practice. No detailed information in medical literature exists about the percentage of deep vein thrombosis (dvt) and pulmonary embolism (pe). 236 patients with elevated levels of D-dimers were divided by pretest-probability for deep vein thrombosis and pulmonary embolism (Wells' Score). Subsequently every patient was evaluated by compression ultrasound of deep vein thrombosis of the legs. In cases of medium or high probability of pulmonary embolism an additional lung perfusion scintigraphy was performed. The statistic evaluation of the medians of D-dimers was performed by Wilcoxon-Mann-Whitney-Test for asymptotic significance. 39% of the patients proved to have deep vein thrombosis, 23% proved to have pulmonary embolism. The median of D-dimers in patients without dvt (1356 ng/ml), p = 0.01) was significantly lower in comparison to patients with dvt of pelvic veins (3541 ng/ml), upper legs (2694 ng/ml) and lower legs (1796 ng/ml). In patients with pulmonary embolism the D-dimers median was significantly higher in comparison to patients without pe (1518 ng/ml, p = 0.01). In clinical practice elevated D-dimers correlate in 39% with dvt and 23% with pe. Elevated D-dimer levels should always be correlated with pretest-probability in order to avoid unnecessary compression ultrasound.

Inappropriate Use of D-Dimer Assay and Pulmonary CT Angiography in the Evaluation of Suspected Acute Pulmonary Embolism

The authors question whether the d-dimer assay and pulmonary computed tomography angiography (CTA) are being used appropriately to evaluate suspected acute pulmonary embolism (PE) at their hospital. To answer this question, a retrospective review was performed on all emergency department (ED) patients who underwent d-dimer assay and/or CTA from August 15, 2008, to August 14, 2009. The authors' algorithm for diagnosing PE requires that patients with low or intermediate probability of acute PE undergo a d-dimer assay, followed by CTA if the d-dimer is positive. Patients with high probability of PE should have CTA performed without a d-dimer assay. This result suggests that d-dimer assay and CTA are used inappropriately to evaluate patients with suspected acute PE in our ED. The low threshold for initiating an evaluation for PE decreases the prevalence of PE in this population.

Is a V/Q scan based algorithm correctly used to diagnose acute pulmonary embolism? A daily practice survey

Introduction Diagnostic flow-charts for pulmonary embolism (PE) are widely implemented in the management of PE. A major drawback of a diagnostic PE algorithm is the use of several consecutive tests, which may be challenging in daily clinical practice. Materials and methods Evaluation whether the use of an algorithm, starting with a ventilation/perfusion (V/Q) scan after a normal chest X-ray, is correctly used in daily clinical practice for diagnosing acute PE. Consecutive V/Q scans of patients with suspected acute PE were assessed to evaluate the use of the predefined diagnostic algorithm. Results A chest X-ray had been performed in 101 of the 130 patients who underwent V/Q scanning; 89 patients had a normal chest X-ray. The V/Q scan was normal in 77/130 patients (59%), 30/130 patients (23%) had a non-high probability and 23/130 patients (18%) a high probability for PE. Only 3 of the 30 patients with a non-high V/Q scan (10%) underwent a computed tomographic pulmonary angiography (CTPA) scan, in contrast to the algorithm that required a CTPA scan in every patient with a non-high V/Q scan. Overall, the diagnostic strategy, starting with a V/Q scan as the baseline diagnostic tool with a prior chest X-ray, was appropriately followed in only 75/101 patients (74%). Conclusions A complex diagnostic algorithm for diagnosing PE is often not followed properly. This improper use of an algorithm could lead to a potential delay of establishing or excluding PE, a delay of therapy and/or unnecessary treatment. More simple algorithms could resolve this diagnostic management dilemma.