Criteria For Pulmonary Embolism Research Articles

Evaluating the use of clinical decision aids in an Australian emergency department: A cross-sectional survey.

To identify healthcare professionals' knowledge, self-reported use, and documentation of clinical decision aids (CDAs) in a large ED in Australia, to identify behavioural determinants influencing the use of CDAs, and healthcare professionals preferences for integrating CDAs into the electronic medical record (EMR) system. Healthcare professionals (doctors, nurses and physiotherapists) working in the ED at the Gold Coast Hospital, Queensland were invited to complete an online survey. Quantitative data were analysed using descriptive statistics, and where appropriate, mapped to the theoretical domains framework to identify potential barriers to the use of CDAs. Qualitative data were analysed using content analysis. Seventy-four healthcare professionals (34 medical officers, 31 nurses and nine physiotherapists) completed the survey. Healthcare professionals' knowledge and self-reported use of 21 validated CDAs was low but differed considerably across CDAs. Only 4 out of 21 CDAs were reported to be used 'sometimes' or 'always' by the majority of respondents (Ottawa Ankle Rule for ankle injury, Wells' criteria for pulmonary embolism, Wells' criteria for deep vein thrombosis and PERC rule for pulmonary embolism). Most respondents wanted to increase their use of valid and reliable CDAs and supported the integration of CDAs into the EMR to facilitate their use and support documentation. Potential barriers impacting the use of CDAs represented three theoretical domains of knowledge, social/professional role and identity, and social influences. CDAs are used variably by healthcare professionals and are inconsistently applied in the clinical encounter. Preferences of healthcare professionals need to be considered to allow the successful integration of CDAs into the EMR.

Incidence of Mortality and Complications in High-Risk Pulmonary Embolism: A Systematic Review and Meta-Analysis

BackgroundThe relationship between the early hemodynamic consequences of acute pulmonary embolism (PE) and short-term morbidity and mortality has long been recognized. The mortality incidence and other complications after high-risk (massive) PE, the most severe category of the disease, are summarized in this meta-analysis.MethodsA systematic review and meta-analysis of studies reporting on patients with massive PE indexed by PubMed and the Cochrane Library over a 10-year period (2010-2020) was conducted. Studies with adequate information to specify a cohort of patients with high-risk PE defined by the American Heart Association and European Society of Cardiology criteria and their clinical outcomes were included. Incidences were calculated as weighted averages with 95% CIs.ResultsA total of 27 publications spanning 1517 patients were identified that met the search criteria for high-risk PE. In-hospital all-cause mortality averaged 28.3% (95% CI, 20.9%-37.0%) in patients at high risk, comparable to the 30-day all-cause mortality of 30.2% (95% CI, 22.3%-39.6%). In-hospital major bleeding was 13.8% (95% CI, 9.3%-20.0%), and intracranial hemorrhage was reported in 3.6% (95% CI, 2.2%-5.9%). The risk of bias in publications was graded as low-to-moderate, with substantial heterogeneity among the studies.ConclusionsThis systematic review and meta-analysis provided low-quality to moderate-quality evidence documenting mortality, major bleeding, and other complications in patients meeting the American Heart Association and European Society of Cardiology criteria for high-risk PE. This information was used to inform the design of the FLowTriever for Acute Massive Pulmonary Embolism (FLAME) study (NCT04795167), a study evaluating an advanced therapy for patients with high-risk PE.

Prognosis assessment of acute pulmonary embolism by multimodality imaging: Is it really necessary?

Prognostic assessment of pulmonary embolism (PE) by transthoracic echocardiography (TTE) and CT-scan has been proposed in patients with intermediate risk according to the ESC guidelines. The aim of this study is to assess the accuracy of this multimodality imaging strategy in routine practice. We reviewed from our database all consecutive patients hospitalized for acute PE between July 2011 and June 2019. Right ventricular (RV) size/dysfunction was systematically assessed by TTE and CT-scan in patients classified as intermediate risk (defined as a sPESI score ≥ 1) and was defined as RV/LV ratio ≥ 1. In-hospital outcome was systematically assessed and was compared according to the classification of PE severity and the combined use of TTE and CT-scan and the separated use of these 2 imaging modalities. We studied 708 patients (49.5% female, median age 68 years) presenting with acute PE. Fifty patients (7%) had shock or hypotension on arrival, meeting the criteria for high-risk PE with an in-hospital mortality of 38%. Among the 658 patients without high-risk PE, 336 patients had a sPESI score ≥ 1 and were considered as intermediate risk PE. TTE classified 124 patients as intermediate–high-risk PE versus 132 patients by CT-scan, 165 patients by TTE or CT-scan and 91 patients by both TTE and CT-scan. In intermediate–high-risk PE (RV dysfunction), in-hospital mortality was 11.3% using TTE alone, 9.8% using CT-scan alone, 9.1% with positive TTE or CT-scan and 13.2% using TTE and CT-scan ( P = 0.75). In-hospital mortality was 5.6% in intermediate-low risk PE and 0.6% in low risk PE (sPESI = 0). In intermediate–high-risk PE, the accuracy of combined TTE and CT-scan or TTE or CT-scan used alone is similar for the assessment of PE prognosis.

Prognostic Performance of Hestia Criteria in Acute Pulmonary Embolism: A Systematic Review and Meta-Analysis.

Previous studies have suggested that Hestia criteria could effectively identifying patients with acute pulmonary embolism (PE) who were at low risk of mortality for outpatient treatment or early discharge. But the performance of Hestia criteria in stratifying patients at different risk class is still unknown. We sought to comprehensively evaluate the prognostic impact of Hestia criteria for PE. The literatures search was conducted in PubMed, Web of Science and EMBASE from 1 August 2011 to 31 October 2021. Finally, Eight studies with 4110 patients were included in our meta-analysis. Overall, the pool percentage of patients classified as low-risk group and high-risk group were 41.4%% and 58.6% respectively, and the all-course mortality rates of each group were 2.3% and 10.6%, respectively. The pooled rate of PE-related composite adverse outcomes in high-risk group was increasingly higher than in low-risk group (15.7% vs 4.4%). High risk group was also markedly associated with overall mortality (OR: 7.21, 95%CI: 4.96-10.46, p < 0.00001), and PE-related adverse outcomes (OR:5.38, 95% CI:3.95-7.32, p < 0.00001). The pooled sensitivity, specificity, PLR, NLR of Hestia criteria for overall mortality were 0.90 (95% CI:0.83-0.94), 0.43 (95% CI:0.31-0.55), 1.6 (95% CI:1.3-1.9), 0.23 (95% CI: 0.15-0.35), respectively. The area under SROC curve (AUC) was 0.81 (95% CI: 0.77-0.84). The result of our meta-analysis indicate that Hestia criteria can effectively identify PE patients at low risk of poor prognosis with high sensitivity and NPV, but its prognostic role in patients with higher risk class still need to be verified.

Genetic testing for thrombophilia in case of unprovoked episode of pulmonary embolism

Venous thromboembolism (pulmonary embolism (PE) and deep vein thrombosis (DVT)) is the third among all cardiovascular syndromes in the world, second only to heart attack and stroke. Estimation of clinical probability of this condition takes into account many factors, including age. But in case of PE probability in young patient data of scales such as Geneva Score (Revised), Wells' criteria for pulmonary embolism, the PERC rule may be misleading. For this group a new influential factor emerges – thrombophilia. The aim of our work was to demonstrate the approach to identifying whom and when to test for genetic predisposition for thrombosis, based on a clinical case of young male with unprovoked episode of PE. Testing patients for thrombophilia is a good way to develop a personalised approach in case of prescribing long-term anticoagulant treatment. Moreover, patient’s awareness about congenital condition helps to increase complience which is crucial, due to the fact that in case of unprovoked pulmonary embolism another episode can occur in up to 50 % of cases during the next 5 years. In addition, further accumulation and analysis of data on the amount of genetic risk factors for thrombosis will expand our understanding of this issue and in the future will allow us to better diagnose and treat this condition.

Prognosis assessment of acute pulmonary embolism by multimodality imaging: Is it really necessary?

Prognostic assessment of pulmonary embolism (PE) by transthoracic echocardiography (TTE) and CT-scan has been proposed in patients with intermediate risk according to the ESC guidelines. The aim of this study is to assess the accuracy of this multimodality imaging strategy in routine practice. We reviewed from our database all consecutive patients hospitalized for acute PE between July 2011 and June 2019. Right ventricular (RV) size/dysfunction was systematically assessed by TTE and CT-scan in patients classified as intermediate risk (defined as a sPESI score ≥ 1) and was defined as RV/LV ratio ≥ 1. In-hospital outcome was systematically assessed and was compared according to the classification of PE severity and the combined use of TTE and CT-scan and the separated use of these 2 imaging modalities. We studied 708 patients (49.5% female, median age 68 years) presenting with acute PE. 50 patients (7%) had shock or hypotension on arrival, meeting the criteria for high-risk PE with an in-hospital mortality of 38%. Among the 658 patients without high-risk PE, 336 patients had a sPESI score ≥ 1 and were considered as intermediate risk PE. TTE classified 124 patients as intermediate–high risk PE versus 132 patients by CT-scan, 165 patients by TTE or CT-scan and 91 patients by both TTE and CT-scan. In intermediate-high risk PE (RV dysfunction), in-hospital mortality was 11.3% using TTE alone, 9.8% using CT-scan alone, 9.1% with positive TTE or CT-scan and 13.2% using TTE and CT-scan ( P = 0.75). In-hospital mortality was 5.6% in intermediate-low risk PE and 0.6% in low risk PE (sPESI = 0). In intermediate-high risk PE, the accuracy of combined TTE and CT-scan or TTE or CT-scan used alone is similar for the assessment of PE prognosis.

Saddle pulmonary embolism on non-contrast CT

Background: A saddle pulmonary embolism (PE) is a large embolism that straddles the bifurcation of the pulmonary trunk. This PE extends into the right and left pulmonary arteries. There is a greater incidence in males. Common features of a PE include dyspnea, tachypnea, cough, hemoptysis, pleuritic chest pain, tachycardia, hypotension, jugular venous distension, and severe cases Kussmaul sign. The Wells criteria for PE is used as the pretest probability. Diagnostics include D-dimer levels, CT pulmonary angiography (CTPA), ventilation/perfusion scintigraphy (V/Q scan), echocardiography, lower extremity venous ultrasound, chest x-ray, pulmonary angiography, and electrocardiography (ECG). Case description: We present a 65-year-old male that presented with a two-week history of dyspnea with non-radiating intermittent chest pressure. Initial V/Q scan showed a low probability for PE, but a subsequent non-contrast CT revealed that he indeed had a saddle PE.

Diagnosing Dyspneic Older Adult Emergency Department Patients: A Pilot Study.

Dyspnea is the second leading cause of US emergency department (ED) visits and an independent predictor of morbidity and mortality1 in older adult patients aged ≥65 years. Unfortunately, the diagnosis of the cause of dyspnea presents diagnostic challenges to emergency physicians2-4 that disproportionately affects older adults.5 One in 5 dyspneic older adults experience missed diagnosis in the ED2 and 21% are treated for ≥1 pneumonia, acute exacerbation of chronic obstructive pulmonary disease [COPD], and acute exacerbation of heart failure [HF].5 Importantly, some may have multiple causes of their dyspnea but accurate diagnosis remains critical.

Higher Imaging Yield When Clinical Decision Support Is Used.

Increased utilization of CT pulmonary angiography (CTPA) for the evaluation of pulmonary embolism has been associated with decreasing diagnostic yields and rising concerns about the harms of unnecessary testing. The objective of this study was to determine whether clinical decision support (CDS) use would be associated with increased imaging yields after controlling for selection bias. We performed a retrospective cohort study in the emergency departments of two tertiary care hospitals of all CTPAs performed between August 2015 and September 2018. Providers ordering a CTPA are routed to an optional CDS tool, which allows them to use Wells' Criteria for pulmonary embolism. After propensity score matching, CTPA yield was calculated for the CDS-use and CDS-dismissal groups and stratified by provider type. A total of 7,367 CTPAs were ordered during the study period. Of those, providers used the CDS tool in 2,568 (35%) cases and did not use the tool in 4,799 (65%) of cases. After propensity score matching, CTPA yield was 11.99% in the CDS-use group and 8.70% in the CDS-dismissal group (P < .001). Attending physicians, residents, and physician assistant CDS users demonstrated a 56.5% (P= .006), 38.7% (P= .01), and 16.7% (P= .03) increased yield compared with those who dismissed the tool, respectively. Diagnostic yield was 38% higher for CTPAs when the provider used the CDS tool, after controlling for selection bias. Yields were higher for every provider type. Further research is needed to discover successful strategies to increase provider use of these important tools.

Right ventricular strain in patients with pulmonary embolism and syncope.

Patients with acute pulmonary embolism (PE) can present with various clinical manifestations including syncope. The mechanism of syncope in PE is not fully elucidated and data of right ventricular (RV) function in patients has been limited. We retrospectively identified 477 consecutive patients hospitalized with acute PE diagnosed with a computed tomogram (CT) who also had a transthoracic echocardiogram (TTE) 24h prior to or 48h after diagnosis. Parameters of RV strain on CT, TTE, electrocardiogram (ECG), and clinical characteristics and adverse outcomes were collected. Patients with all three studies available for assessment were included (n = 369) and those with syncope (n = 34) were compared to patients without syncope (n = 335). Patients with syncope were more likely to demonstrate RV strain on all three modes of assessment compared to those without syncope [17 (50%) vs. 67 (20%); p = 0.001], and those patients were more likely to receive advanced therapies [9 (53%) vs. 15 (22%); p = 0.02]. PE-related mortality was highest among those presenting with high-risk PE and syncope (36%, OR 20.1, 95% CI 5.3-81.1; p < 0.001) and was low in patients with syncope without criteria for high-risk PE (3%, OR 1.2, 95% CI 0.2-10.0; p < 0.001). In conclusion, acute PE patients with syncope are more likely to demonstrate multimodality evidence of RV strain and to receive advanced therapies. Syncope was only associated with increased PE-related mortality in patients presenting with a high-risk PE. Syncope alone without evidence of RV strain is associated with low short-term adverse events and is similar to those without syncope.

P5591Efficacy and safety of lower dose slow infusion of t-PA for intermediate-risk pulmonary embolism patients with risk for bleeding

Abstract Background Current guidelines do not recommend thrombolytic therapy for the treatment of intermediate-risk pulmonary embolism (PE) because of the tight balance between the benefit and safety with classic protocols. Aim The aim of this study was to compare the new thrombolytic protocol with lower-dose slow-infusion (LDSI) of tissue plasminogen activator (tPA) to classic 2-hours tPA infusion protocol or no-reperfusion in patients with intermediate-high risk PE with higher bleeding risk regarding 30-day efficacy and safety. Methods Among 849 patients with PE from the Serbian multicenter registry, 469 patients who fulfilled criteria for intermediate-risk PE were involved in the study. After propensity score matching 425 patients [263 (61.9%), 99 (23.3%) and 63 (14.8%) were treated with no-reperfusion, classic tPA protocol (100 mg for 2 hours) and LDSI of tPA (2–5 mg/hour either vie local catheter or systemic venous infusion with dose range of 25–50 mg)]. The basic characteristics of patients were well balanced between groups except that patients treated with LDSI of tPA had significantly higher usage of drugs which can be associated to bleeding and more previous bleeding events. Thirty day all-cause and PE-caused mortality and 7-day major bleeding were the main efficacy and safety end-points, respectively. Results All-cause and PE-cause 30-day mortality were 8.7% vs 16.2% vs 1.6% (Log rank p=0.007) and 4.5% vs 11.0% vs 0.0% (Log rank p=0.008) in patients with no-reperfusion, classic tPA protocol and LDSI of tPA protocol, respectively. Major bleeding at 7 days were 2.7% vs 8.1% vs 14.3% (Log rank p=0.001) in patients with no-reperfusion, classic tPA protocol and LDSI of tPA protocol, respectively. There was one fatal intracranial bleeding during catheter infusion of tPA. Conclusion Lower-dose slow-infusion of tPA protocol decreased significantly all-cause and PE-cause mortality at 30-day at the cost of excess of non-fatal major bleeding at 7-day in patients with intermediate-risk PE and higher risk for bleeding. Acknowledgement/Funding None

Improving Provider Adoption With Adaptive Clinical Decision Support Surveillance: An Observational Study.

BackgroundSuccessful clinical decision support (CDS) tools can help use evidence-based medicine to effectively improve patient outcomes. However, the impact of these tools has been limited by low provider adoption due to overtriggering, leading to alert fatigue. We developed a tracking mechanism for monitoring trigger (percent of total visits for which the tool triggers) and adoption (percent of completed tools) rates of a complex CDS tool based on the Wells criteria for pulmonary embolism (PE).ObjectiveWe aimed to monitor and evaluate the adoption and trigger rates of the tool and assess whether ongoing tool modifications would improve adoption rates.MethodsAs part of a larger clinical trial, a CDS tool was developed using the Wells criteria to calculate pretest probability for PE at 2 tertiary centers’ emergency departments (EDs). The tool had multiple triggers: any order for D-dimer, computed tomography (CT) of the chest with intravenous contrast, CT pulmonary angiography (CTPA), ventilation-perfusion scan, or lower extremity Doppler ultrasound. A tracking dashboard was developed using Tableau to monitor real-time trigger and adoption rates. Based on initial low provider adoption rates of the tool, we conducted small focus groups with key ED providers to elicit barriers to tool use. We identified overtriggering of the tool for non-PE-related evaluations and inability to order CT testing for intermediate-risk patients. Thus, the tool was modified to allow CT testing for the intermediate-risk group and not to trigger for CT chest with intravenous contrast orders. A dialogue box, “Are you considering PE for this patient?” was added before the tool triggered to account for CTPAs ordered for aortic dissection evaluation.ResultsIn the ED of tertiary center 1, 95,295 patients visited during the academic year. The tool triggered for an average of 509 patients per month (average trigger rate 2036/30,234, 6.73%) before the modifications, reducing to 423 patients per month (average trigger rate 1629/31,361, 5.22%). In the ED of tertiary center 2, 88,956 patients visited during the academic year, with the tool triggering for about 473 patients per month (average trigger rate 1892/29,706, 6.37%) before the modifications and for about 400 per month (average trigger rate 1534/30,006, 5.12%) afterward. The modifications resulted in a significant 4.5- and 3-fold increase in provider adoption rates in tertiary centers 1 and 2, respectively. The modifications increased the average monthly adoption rate from 23.20/360 (6.5%) tools to 81.60/280.20 (29.3%) tools and 46.60/318.80 (14.7%) tools to 111.20/263.40 (42.6%) tools in centers 1 and 2, respectively.ConclusionsClose postimplementation monitoring of CDS tools may help improve provider adoption. Adaptive modifications based on user feedback may increase targeted CDS with lower trigger rates, reducing alert fatigue and increasing provider adoption. Iterative improvements and a postimplementation monitoring dashboard can significantly improve adoption rates.

Physician failure to stratify patients hospitalized with acute pulmonary embolism

ABSTRACTObjectives: In 2011, the AHA recommended risk stratification of patients with acute pulmonary embolism (PE). Failure to risk stratify may cause under recognition of intermediate-risk PE and its attendant short- and long-term consequences. We sought to determine if patients hospitalized with acute PE were appropriately risk stratified according to the 2011 AHA Scientific Statement within our hospital system and whether differences exist in adherence to risk stratification by hospital or treating hospital service. We also wished to know the frequency of in-hospital consultations for acute PE which might assist in the risk stratification process.Methods: This is a retrospective chart audit of all patients hospitalized with a diagnosis of acute PE between January 2011 and December 2013 at our 937-bed metropolitan, three hospital system comprised of academic University, neuroscience Specialty, and teaching Community hospitals. We evaluated the presence of imaging, laboratory tests, and specialty consultation within 72 h of PE diagnosis by hospital.Results: 701 patients with acute PE were admitted to our hospital system during the study period. 308 patients (43.9%) met criteria for intermediate-risk PE. 347 patients (49.5%) were considered ‘Low-Risk – At Risk’, patients defined in a low-risk category not having undergone all recommended risk stratification testing and so truly may have been in a higher risk category. No specialty consultations were utilized for 265 patients (37.8%).Conclusions: Our large metropolitan hospital system inadequately risk stratifies hospitalized patients with acute PE. Because nearly one-half of patients with acute PE did not have all recommended testing, clinicians may be under recognizing patients with intermediate-risk PE and their risk for long-term morbidity. Specialty consultations were underutilized and may help guide medical decision-making.

Getting to Choosing Wisely: The Value of a PE Clinical Decision Tool to Enhance Appropriateness of Care

Pulmonary embolism (PE) is the third most common cause of cardiovascular death, affecting between 300,000 and 600,000 patients annually. Presentation is nonspecific, resulting in the reflexive decision to evaluate with computed tomography (CT) pulmonary angiography, which has a low diagnostic yield (10%-20%). However, clinical tools such as the Wells’ Criteria for Pulmonary Embolism and D-dimer levels are validated nonradiographic methods to rule out PE and effectively reduce diagnostic time, cost, and potential complications. The aim of this study was to determine diagnostic yield and implement a clinical decision-making tool to reduce overutilization. A retrospective record review of all patients (n = 699) who underwent CT pulmonary angiography from January to June 2016 was completed. An electronic medical document using the Wells’ Criteria was then created with embedded order links for D-dimer and CT pulmonary angiography based on score. Physician education and introduction of the document was focused on the internal medicine services. Postintervention data were then collected from November to January 2016, with a total of 458 CT scans completed. Of the 699 preintervention studies reviewed, a positive CT PE result was present in 7.3% (51 patients), 91.5% (639 patients) were negative, and 1.3% (9 patients) were ruled nondiagnostic due to contrast timing or motion artifact. Of the 35.8% (250 patients) who were assigned a low modified Wells’ score (≤4), only 2% (5 patients) had a positive CT PE vs 96.8% (242 patients) with a negative result. For patients with a high modified Wells’ score, 10.2% (46 patients) had a positive CT PE vs 88.4% (397 patients) with a negative result. Of the 458 postintervention studies reviewed, a positive CT PE result was present in 7.4% (34 patients). However, the diagnostic yield for the interval medicine service was 10.9% vs 3.5% (preintervention). Overuse of CT pulmonary angiography is a pervasive problem with national diagnostic rates of only 10% to 20%. Our results demonstrate a diagnostic rate below the national average but confirm the well-established validity of Wells’ Criteria as a clinical decision-making tool. Furthermore, as evidenced by the improved diagnostic rate of the internal medicine service (Fig 1), education and systematic tools (Fig 2) can effectively aid physician decision making.Fig 2Process intervention for diagnosing pulmonary embolism.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Analysis of National Trends in Admissions for Pulmonary Embolism

Pulmonary embolism (PE) remains a significant cause of hospital admission and health-care costs. Estimates of PE incidence came from the 1990s, and data are limited to describe trends in hospital admissions for PE over the past decade. We analyzed Nationwide Inpatient Sample data from 1993 to 2012 to identify patients admitted with PE. We included admissions with International Classification of Diseases, 9th revision, codes listing PE as the principal diagnosis as well as admissions with PE listed secondary to principal diagnoses of respiratory failure or DVT. Massive PE was defined by mechanical ventilation, vasopressors, or nonseptic shock. Outcomes included hospital lengths of stay, adjusted charges, and all-cause hospital mortality. Linear regression was used to analyze changes over time. Admissions for PE increased from 23 per 100,000 in 1993 to 65 per 100,000 in 2012 (P< .001). The percent of admissions meeting criteria for massive PE decreased (5.3%to 4.4%, P= .002), but the absolute number of admissions for massive PE increased (from 1.5 to 2.8 per 100,000, P< .001). Median length of stay decreased from 8 (interquartile range [IQR], 6-11) to 4 (IQR, 3-6) days (P< .001). Adjusted hospital charges increased from $16,475 (IQR, $10,748-$26,211) in 1993 to $25,728 (IQR, $15,505-$44,493) in 2012 (P< .001). All-cause hospital mortality decreased from 7.1%to 3.2%(P< .001), but population-adjusted deaths during admission for PE increased from 1.6 to 2.1 per 100,000 (P< .001). Total admissions and hospital charges for PE have increased over the past two decades. However, the population-adjusted admission rate has increased disproportionately to the incidence of patients with severe PE. We hypothesize that these findings reflect a concerning national movement toward more admissions of less severe PE.

Predicting the Outcomes of Rhabdomyolysis

Predicting the Outcomes of Rhabdomyolysis

CT pulmonary angiography for pulmonary embolism: role beyond diagnosis?

CT pulmonary angiography for pulmonary embolism: role beyond diagnosis?

Prediction of pulmonary embolism outcome and severity by computed tomography

Pulmonary embolism (PE) is the third most common cause of cardiovascular death. When PE is fatal, right ventricular failure usually occurs within the first few hours, so right ventricular dysfunction (RVD) should be diagnosed rapidly to identify patients who could benefit from fibrinolytic therapy. To determine whether quantification of PE with computed tomography (CT) pulmonary angiography and ventricular measurements is of value in the diagnosis of PE severity and prediction of patient outcome. Multidetector-row CT studies of 48 hospitalized patients with proven pulmonary embolism were reviewed. Pulmonary artery (PA) obstructive index was derived for each patient on the basis of location and degree of obstruction. Ventricular measurements, including right ventricular (RV) short axis, left ventricular (LV) short axis, and RV/LV ratio, were evaluated and compared among survivors and nonsurvivors. Also, the ventricular measurements were correlated with the PA obstructive index. RV/LV ratio and related PA obstructive index were correlated to the patient outcome and hospital stay. Comparison of the PA obstructive index and ventricular measurements between survivors and nonsurvivors showed significant difference in PA obstructive index (P<0.001), RV short axis (P<0.001), and RV/LV ratio (P=0.03), and no significant difference was noted in LV short axis (P=0.95). Good correlation was found between PA obstructive index and LV short axis (-0.326), RV short axis (0.539), and RV/LV ratio (0.696). A significant difference was found between the PA obstructive indexes of the different categories of RV/LV ratio (P<0.001). PA obstructive index of more than 50% and RV/LV ratio >1.5 are useful diagnostic criteria for severe PE and poor patient outcome.

EANM guidelines for ventilation/perfusion scintigraphy

Pulmonary embolism (PE) can only be diagnosed with imaging techniques, which in practice is performed using ventilation/perfusion scintigraphy (V/P(SCAN)) or multidetector computed tomography of the pulmonary arteries (MDCT). The epidemiology, natural history, pathophysiology and clinical presentation of PE are briefly reviewed. The primary objective of Part 1 of the Task Group's report was to develop a methodological approach to and interpretation criteria for PE. The basic principle for the diagnosis of PE based upon V/P(SCAN) is to recognize lung segments or subsegments without perfusion but preserved ventilation, i.e. mismatch. Ventilation studies are in general performed after inhalation of Krypton or technetium-labelled aerosol of diethylene triamine pentaacetic acid (DTPA) or Technegas. Perfusion studies are performed after intravenous injection of macroaggregated human albumin. Radiation exposure using documented isotope doses is 1.2-2 mSv. Planar and tomographic techniques (V/P(PLANAR) and V/P(SPECT)) are analysed. V/P(SPECT) has higher sensitivity and specificity than V/P(PLANAR). The interpretation of either V/P(PLANAR) or V/P(SPECT) should follow holistic principles rather than obsolete probabilistic rules. PE should be reported when mismatch of more than one subsegment is found. For the diagnosis of chronic PE, V/P(SCAN) is of value. The additional diagnostic yield from V/P(SCAN) includes chronic obstructive lung disease (COPD), heart failure and pneumonia. Pitfalls in V/P(SCAN) interpretation are considered. V/P(SPECT) is strongly preferred to V/P(PLANAR) as the former permits the accurate diagnosis of PE even in the presence of comorbid diseases such as COPD and pneumonia. Technegas is preferred to DTPA in patients with COPD.

Combined Clot Fragmentation and Aspiration in Patients With Acute Pulmonary Embolism*

Massive angiographic pulmonary embolism (PE) with right ventricular dysfunction (RVD) is associated with a high early mortality rate. The therapeutic alternatives for this condition include thrombolysis, surgical embolectomy, or percutaneous mechanical thrombectomy (PMT). We describe our experience using PMT in patients with massive PE and RVD with unsuccessful thrombolysis, increased bleeding risk, or major contraindications for thrombolytic therapy. Clinical, hemodynamic, and angiographic parameters prior to and following PMT were evaluated. Our primary objective was to describe the incidence of in-hospital cardiovascular death, and of major and minor complications. Mid-term outcomes included analysis of occurrence of cardiovascular death, recurrent pulmonary embolism, change of New York Heart Association functional class, and hospital readmission. From July 2004 to May 2007, 69 patients were referred to the cardiac catheterization laboratory with a diagnosis of acute PE, 18 of whom met the criteria for massive PE and are the subject of this study. All patients underwent thrombus fragmentation using a pigtail catheter that was complemented in 13 patients with thrombus aspiration. A percutaneous thrombectomy device (Aspirex; Straub Medical; Wangs, Switzerland) was used in 11 patients. Hemodynamic, angiographic, and blood oxygenation parameters improved after the procedure. A significant increase was observed for systolic systemic BP (74.3+/-7.5 mm Hg vs 89.4+/-11.3 mm Hg, p=0.001) [mean+/-SD], as was a decrease in mean pulmonary artery pressure (37.1+/-8.5 mm Hg vs 32.3+/-10.5 mm Hg , p=0.0001). The in-hospital major complications rate was 11.1%; one patient died from refractory shock, and one patient had intracerebral hemorrhage with minor neurologic sequelae. No cardiovascular deaths or recurrent pulmonary thromboembolism were documented during clinical follow-up (12.3+/-9.4 months). In patients with massive PE, RVD and major contraindications to thrombolytic therapy, increased bleeding risk, failed thrombolysis, or unavailable surgical thrombectomy, PMT appears to be a useful therapeutic alternative.