Pulmonary embolism in Bujumbura

Relevance . Pulmonary embolism constitutes a diagnostic and therapeutic emergency. In Africa, data are still difficult to obtain. Thus, the objectives of this work is to describe epidemiological, clinical, therapeutic aspects and short-term outcomes of pulmonary embolism confirmed by thoracic angioscan at Kira hospital in Bujumbura, the biggest city of Burundi with population about 375 000. Patients and Methods . This was a descriptive study of 18 patients who had a pulmonary embolism confirmed by thoracic angioscan in Bujumbura from January 1st, 2015 to December 31st, 2018. We included in our study any patient with pulmonary embolism consenting to participate and processing personal data after some clarified explanations in accordance with the World Medical Associations Declaration of Helsinki. For each registered patient, we collected socio-demographic, past history of cardiac disease and factors risk, clinical, echocardiographic and scannographic findings with Wells score. Variables were presented as means and percentages. Results and Discussion. The average age was 53.5 12.3 years with a sex ratio of 1.25 in favor of women. The modal class was the 50 to 59 age group (33.3%). The clinical probability pre-test by simplified Wells score was high in 66.6% and medium in 33.3% of cases. A history of venous thromboembolic disease was the most common risk factor. Dyspnea was the most reason of consultation with 94.4% of cases. One patient died (5.6%) during hospitalization. Six months after discharge from the hospital, we recorded 3 cases (16.7%) of death, 6 cases (33.3%) of pulmonary heart, 3 cases (16.7%) of recurrent pulmonary embolism and one case of vitamin K antagonist overdose with minor bleeding. Conclusion. Pulmonary embolism is common in relatively young population with a predominance of females and chronic no communicable diseases as risk factors. Examination of a patient with an angioscanner is a sensitive and specific clinical study of pulmonary embolism. The outcome is favorable under appropriate treatment in short term.

Elderly Population with COVID-19 and the Accuracy of Clinical Scales and D-Dimer for Pulmonary Embolism: The OCTA-COVID Study

Background: Elderly COVID-19 patients have a high risk of pulmonary embolism (PE), but factors that predict PE are unknown in this population. This study assessed the Wells and revised Geneva scoring systems as predictors of PE and their relationships with D-dimer (DD) in this population. Methods: This was a longitudinal, observational study that included patients ≥75 years old with COVID-19 and suspected PE. The performances of the Wells score, revised Geneva score and DD levels were assessed. The combinations of the DD level and the clinical scales were evaluated using positive rules for higher specificity. Results: Among 305 patients included in the OCTA-COVID study cohort, 50 had suspected PE based on computed tomography pulmonary arteriography (CTPA), and the prevalence was 5.6%. The frequencies of PE in the low-, intermediate- and high-probability categories were 5.9%, 88.2% and 5.9% for the Geneva model and 35.3%, 58.8% and 5.9% for the Wells model, respectively. The DD median was higher in the PE group (4.33 mg/L; interquartile range (IQR) 2.40–7.17) than in the no PE group (1.39 mg/L; IQR 1.01–2.75) (p < 0.001). The area under the curve (AUC) for DD was 0.789 (0.652–0.927). After changing the cutoff point for DD to 4.33 mg/L, the specificity increased from 42.5% to 93.9%. Conclusions: The cutoff point DD > 4.33 mg/L has an increased specificity, which can discriminate false positives. The addition of the DD and the clinical probability scales increases the specificity and negative predictive value, which helps to avoid unnecessary invasive tests in this population.

Management of Pulmonary Thromboembolism

Pulmonary thrombo-embolism (PTE) is a major cause of cardiovascular morbidity and mortality. Incidence of PTE and its associated mortality is affected by the Prescence of associated risk factors, comorbid conditions and advancement in the treatment options. Clinical probability, D-Dimer, echocardiography and CT pulmonary angiography are used in the diagnosis. Management starts with stratification, with high-risk category being benefited from the thrombolytic therapy. Catheter directed therapy may be used in ineligible or failed cases with surgical embolectomy being used as final salvage therapy. Patients with persistent hemodynamic stability can be started on anticoagulation alone. Supportive therapy with fluid expansion and inhalational Nitric oxide may provide benefit in few. Patients with PTE should receive secondary preventive anticoagulation to prevent recurrences. High risk patients with sub-segmental PTE may benefit from anticoagulation. For early detection of long-term complications of PTE a patient cantered follow-up is needed. Chronic thrombo-embolic pulmonary hypertension (CTEPH) is a dreaded complication with pulmonary end-arterectomy being a gold standard management option in eligible patients with non-surgical therapy (balloon pulmonary angioplasty and pulmonary vasodilators) also being used in many cases.

Testing for Heparin Induced Thrombocytopenia in Hospitalized Patients: In Line with Evidence?

Background: Heparin-induced thrombocytopenia (HIT) is an immune complication of heparin therapy caused by antibodies to complexes of platelet factor 4 (PF4) and heparin. Both clinical probability and laboratory testing are needed for establishing a diagnosis of HIT. The 4Ts clinical scoring system, due to a very high negative predictive value when low, offers a robust means to exclude a diagnosis of HIT. However, these strategies are under-employed in clinical practice and limited evidence indicates a high prevalence of over-testing for HIT. Methods: This retrospective analysis was conducted to identify patients who underwent heparin/PF4 antibody testing over a period of 12 months. The testing was performed using an ELISA-based IgG anti-heparin/PF4 antibody assay and an optical density (OD) of 0.4 was used as a cut-off for a positive value. Electronic medical records were reviewed for 4T score documentation, anti-PF4 results, SRA testing and 4T scores were retrospectively calculated for all the patients. SAS v9.4 (Cary, NC) was used for statistical analysis. Results: A total of 105 patients who underwent anti-PF4 antibody testing were included for analysis. Majority of the patients in our cohort were admitted in an intensive care unit setting (75/105,71.4%). On chart review, only 17 patients (16.2%) were noted to have documentation of 4T score. Based on the retrospectively calculated 4T scores, 60 patients (57.1%) had low pre-test probability, 41 (39%) had intermediate pre-test probability and 4 (3.8%) patients were noted to have high pre-test probability. Anti-PF4/heparin antibodies were positive in 9 patients, of which 5 (55.5%) patients did not undergo concomitant SRA testing. Out of 9, 4 (44.4%) had weakly positive (0.4-1.0 OD units), 2 (21.1%) had strongly positive (1.0-2.0 OD units) and 2 (21.1%) patients had very strongly positive (&gt;2 OD units) anti-PF4 antibody titers. Out of 105 patients, SRA was tested in 11 patients (10.5%) and was noted to be positive in 1 (0.95%). Overall, 2 patients were diagnosed and treated for HIT, out of which the diagnosis was not confirmed with SRA in 1 patient (due to high pre-test probability and very strong anti-PF4 titers). In the remaining patients, sepsis (48, 46.6%) and drug-induced thrombocytopenia (29, 28.2%) emerged as the most common possible causes of thrombocytopenia. Conclusion: Among hospitalized patients, over-testing for HIT is common. Practices to promote 4T score documentation and evidence-based anti-PF4 testing may help prevent unnecessary costs associated with serological testing and costly alternate anticoagulants. To improve overall outcomes, clinicians should also attempt to identify and treat other more likely causes of thrombocytopenia, especially in patients with low pre-test probability for HIT. Disclosures No relevant conflicts of interest to declare.

Physician and Patient Beliefs and Preferences in Pulmonary Embolism and Deep Vein Thrombosis Testing in People with Cancer

Introduction It is unclear whether evidence-based diagnostic protocols are followed when cancer patients are tested for venous thromboembolism (VTE). Evidence-based protocols reduce unnecessary diagnostic imaging, offer a patient-centered approach, and have the potential to standardize practice across medical specialties and settings. However, anecdote suggests that specialists who test people with cancer for VTE may prefer diagnostic imaging over clinical probability scoring and D-dimer testing. The aim of this study was to identify physician and patient knowledge, beliefs, values and preferences for VTE testing in cancer. This study was part of a program of research to set International Society of Thrombosis and Haemostasis standards for VTE testing in people with cancer. Methods This was an international qualitative interview study following COREQ guidelines. Semi-structured interviews with physicians and cancer patients were conducted via Zoom. We used purposive sampling to ensure inclusion of physicians from all specialties who test people with cancer for VTE, practicing across all continents. We invited people treated for cancer who had and did not have experience of VTE testing. We used grounded theory to create a conceptual framework which explains physician and patient values and preferences for VTE testing. Transcripts were coded by three researchers independently, who met to discuss their findings and agree on common codes. Researchers were a Thrombosis physician and two undergraduate students who ensured reflexivity was incorporated into their analysis. Results A total of 32 physicians and 6 cancer patients were invited to interview. Of those invited, 23 physicians and 6 patients across 6 continents completed an interview. Interviews lasted between 21 and 86 minutes. Our derived conceptual model can be seen in the attached Figure. Physicians reported a low threshold to test for VTE in people with cancer compared to those without cancer, because VTE was considered a fatal disease and highly prevalent in this patient population. Imaging was generally the only test used for VTE testing in cancer patients. Many participants relied on their Gestalt estimation of VTE probability when deciding whether to order imaging for pulmonary embolism or deep vein thrombosis. Most thought that low Wells score in combination with a negative D-dimer was not sufficiently sensitive to exclude VTE and anticipated the Wells score and D-dimer to be elevated. The Wells scores had poor face validity because they do not include cancer-specific variables and participants hoped to see a more nuanced formal score for VTE testing in cancer patients. Participants believed that their colleagues would support their diagnostic approach. Patients reported they were used to having tests and CT scans. Patients felt it was important for their physicians to prioritize testing for VTE. Patients had full trust and confidence in their physicians' testing decisions, particularly in decisions made by their oncologists. Conclusion Physicians have a low threshold to test people with cancer for VTE and tend not to use clinical probability assessment and D-dimer. Patients are comfortable having diagnostic imaging, feel VTE testing is important and have full trust in their physicians. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Diagnostic Accuracy of D-Dimer for Pulmonary Embolism and Lower Limb Deep Vein Thrombosis Testing in People with Cancer: A Meta-Analysis

Introduction There are evidence-based protocols for the diagnosis and exclusion of pulmonary embolism (PE) and deep vein thrombosis (DVT) which include clinical probability scoring along with selective D-dimer testing and diagnostic imaging. D-dimer assessment in VTE (venous thromboembolism) testing tends to be omitted in patients with cancer, partly because of perceived D-dimer lack of sensitivity and specificity. The aim of this systematic review and meta-analysis was to report the diagnostic accuracy of D-dimer for PE and lower limb DVT in patients with cancer. This study was part of a research program to set International Society of Thrombosis and Haemostasis standards for VTE testing in patients with cancer. Methods This systematic review and meta-analysis followed the MOOSE guidelines and was registered in PROSPERO, CRD42020181007. We searched Medline via OVID from conception to 12 th March 2020 for diagnostic PE and DVT studies reporting on people with cancer, or a subgroup of people with cancer. Researchers in the field were contacted for information on unpublished studies. All languages were included. Two researchers screened the titles and abstracts. Four researchers reviewed the selected full texts to determine which studies fulfilled inclusion criteria. Two researchers assessed risk of bias using QUADAS-2, extracted data on the true positive, false positive, true negative and false negative results for D-dimer alone, and D-dimer combined with clinical probability estimation. We used the bivariate random effects method to meta-analyze sensitivity and specificity values. We used a random effects model to estimate pooled false negative rates and efficiency for combining a negative D-dimer (manufacturer recommended cutoff) with a low clinical probability to exclude PE or DVT in patients with cancer. Results were displayed on a Forest plot. Heterogeneity was assessed using I 2. Results From 7947 titles and abstracts, we reviewed 49 full text manuscripts, including 13 studies for analysis. Risk of bias was low across all domains for only 5/13 studies. Figures 1 shows the Forest plots grouped by sensitivity and specificity for PE and DVT. The pooled estimates for D-dimer in the diagnosis of VTE in cancer patients (regardless of clinical probability) were 96.4% (95% confidence interval (CI) 94.8 to 97.5%) sensitivity and 26.4% (95% CI 18.1 to 37.0%) specificity. For PE, D-dimer was 96.9% (96.1 to 97.5%) sensitive (I 2 0%, N=2,299) and 14.0% (12.1 to 16.0%) specific, (I 2 69%, N=11,455). For DVT, D-dimer was 94.3% (89.8 to 97.6%) sensitive, (I 2 61%, N=546) and 46.4% (39.8 to 53.3%) specific, (I 2 59%, N=724). The efficiency of combining a low D-dimer (using the manufacturer recommended cutoff) and low clinical probability to exclude DVT or PE was 9.3%, (95% CI 6.9 to 11.9%), N=1,347. There were only 122 patients in the false negative rate analysis of whom 1 patient was diagnosed with VTE in follow up. A pooled analysis was not performed for the false negative rate. Conclusions D-dimer is a sensitive test for both PE and lower limb DVT in people who have cancer. Approximately 10% of patients with cancer and suspected VTE can have VTE excluded with D-dimer and clinical probability prior to ordering diagnostic imaging. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Pragmatic Evaluation of an Algorithm Using D-Dimer Adjusted to Clinical Probability in the Diagnosis of Pulmonary Embolism

BACKGROUND: Diagnosis of pulmonary embolism (PE) using clinical decision rules in combination with D-dimer (DD) values is a standard practice. The Wells score is the most commonly used rule, either in its original (3-category) or modified (2-category) versions, and in conjunction with a (DD) &lt;500 ng/mL allows to exclude a PE in approximately 30% of patients. The recent PEGeD study (Kearon et al. 2019) concluded that a PE can be safely excluded by using a DD threshold adjusted to the clinical pre-test probability (C-PTP). In that study PE was excluded in patients with low C-PTP and a DD &lt;1000 ng/mL or a moderate C-PTP and a DD &lt;500 ng/mL In the present study we aimed to evaluate the performance of the PEGeD algorithm in daily practice. METHODS: We conducted a retrospective cohort study involving all adult patients who presented at London Health Sciences Centre or St. Joseph's Health Care Emergency Departments in London, Ontario, Canada between November 1, 2018 and December 31, 2020 with signs or symptoms suggestive of a pulmonary embolism and for whom a DD was ordered electronically. They were excluded if they did not have complete follow-up information for at least 90 days from the initial visit, they were pregnant, they were on long term anticoagulation for other indications, or had chest imaging prior to DD order. Using the electronic hospital chart, we extracted demographics, imaging results, and the Wells score with all its individual components. In our center, information about the Wells score and its components is routinely and prospectively collected when ordering DD. Since the PEGeD algorithm is not routinely used in our hospital, data of the C-PTP was utilized to determine which DD cut-off should be applied to the patient. Decision to perform imaging studies was taken by the ED physician at the time of assessment. The outcome of interest was the proportion of a PE or DVT at 90 days after the visit to the ED in patients with a low or intermediate C-PTP and who did not receive an initial diagnosis of PE and 99% confidence intervals (CI) were estimated using the Wilson's score method. RESULTS: A total of 2769 patient charts were reviewed and 1070 were included (Table 1, Figure 1). Of the 1070 patients, 71 (7%) of patients had a pulmonary embolism on initial presentation to the emergency department. At 90 days of follow up none (99% CI 0, 0.84) of the 787 patients who had a low C-PTP or a moderate C-PTP score and a DD &lt;1000 ng/mL or &lt;500 ng/mL, respectively, were positive for a PE . This included 194 patients who had a low C-PTP and a DD level of 500-999 ng/mL and 26 patients who had an intermediate C-PTP and a DD level of &lt;500 ng/mL. Notably, 8 (1.02%, 99% CI 0.42-2.43) PEs would have been missed using the PEGeD protocol when using DD cut-off levels of &lt;1000 ng/mL in the low C-PTP group, or &lt;500 ng/mL in the intermediate C-PTP. CONCLUSIONS: In this cohort we found that if the PEGeD algorithm had been used, it would have resulted in a low risk of VTE during follow up in patients without an initial diagnosis of PE and who had either a low C-PTP and a DD &lt;1000 ng/mL or a moderate C-PTP and a DD &lt;500 ng/mL. We also found it would have been associated with 194 (48%) less diagnostic imaging studies in the low C-PTP range and 2 (6%) less studies in the intermediate C-PTP range. Despite this, 1% of patients with PE (99% upper confidence limit 2.43%) would have been missed. This study is limited by its retrospective nature with an inherent risk of misclassification. Further studies are needed before recommending the use of this algorithm in clinical practice. Work Cited Kearon, C., de Wit, K., Parpia, S., Schulman, S., Afilalo, M., Hirsch, A., Spencer, F. A., Sharma, S., D'Aragon, F., Deshaies, J.-F., Le Gal, G., Lazo-Langner, A., Wu, C., Rudd-Scott, L., Bates, S. M., & Julian, J. A. (2019). Diagnosis of Pulmonary Embolism with d -Dimer Adjusted to Clinical Probability. New England Journal of Medicine, 381(22), 2125-2134. https://doi.org/10.1056/NEJMoa1909159 Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

THE RELIABILITY OF CLINICAL PROBABILITY SCORE IN (WELLS SCORE) THE DIAGNOSIS OF PULMONARY EMBOLISM (PE) IN COVID-19 PATIENTS

Background: The risk of developing pulmonary embolism (PE) is high in patients infected with COVID-19, and its diagnosis is a severe challenge for healthcare professionals duringthe COVID-19 pandemic. Physicians are frequently usingcomputed tomography pulmonary angiography(CTPA), d-dimer, and well score for the diagnosis of PE. Methods: A retrospective study was used in which we investigated the reliability of clinical well scores by collecting data, such as medical records in registered form (serum D-dimer level and Wells scores) of every patient for whom physicians have requested whose CTPA with suspicion of PE at King Faisal Medical Center (KFMC) from the period from 1st of April to the 1st of October. Results: The study results showed significantly higher values of d-dimer in patients with positive PEcompared to those with negative values. In addition wells score is not a reliable preclinical score in diagnosis PE in COVID 19 patient. Conclusions: As per the results of the well score, there is no significant difference between vulnerable people with PE +ve and -ve.