0 points: Low risk (< 1% 30-day mortality), can potentially be treated outpatient
> 1 point: Elevated risk, can be further stratified with full PESI
Points awarded for: Age > 80 years, history of cancer/CHF/COPD, pulse > 110, systolic blood pressure (SBP) < 100, or O₂ saturations < 90%
Massive/submassive: Terminology falling out of favor, not descriptive enough to risk stratify or estimate mortality
Systemic Therapy
Anticoagulation
Options include warfarin (vitamin K antagonist), novel oral anticoagulants (NOACs), such as rivaroxaban, apixaban, dabigatran, or low-molecular-weight heparin
Warfarin therapy most cost effective but requires regular interval monitoring of patient's international normalized ratio (INR)
NOACs do not require therapeutic monitoring but tend to be more expensive
Patient's renal function, comorbidities, and preference should be taken into account when selecting anticoagulation regimen
Systemic thrombolysis
Peripheral administration of tissue plasminogen activator (tPA)
Variable dosing strategies, but 50 mg commonly used
Significantly reduces mortality compared to anticoagulation alone in high-risk PE
Increased risk of major bleeding, including intracranial hemorrhage
May be contraindicated in certain patients
Catheter-Directed Therapies
Generally reserved for patients with intermediate-high or high-risk PE
CDT
Placement of catheters into pulmonary arteries for direct tPA infusion, usually 1 mg of tPA/hour over 24-48 hours
Can be done ± US assistance
No clear consensus of benefit
ULTIMA trial (2014): CDT superior to anticoagulation in improving RV dilation
SEATTLE II study (2015): Decreased RV dilation, PH, and thrombus burden with fewer instances of intracranial hemorrhage
MT
Multiple commercially available devices for direct aspiration &/or mechanical disruption of clot
Do not require use of thrombolytics, and thus have decreased risk of major bleeding
Indigo System (Penumbra Inc)
Aspiration catheter (multiple options up to 12 Fr) with continuous vacuum
Also used for peripheral arterial and venous systems
EXTRACT-PE trial (2021): Significant reduction in RV:LV ratio, low major adverse events
FlowTriever (Inari Medical)
Large-bore aspiration system (16-24 Fr) with negative suction-locking syringe
Optional coaxial component for clot disruption
Wible et al (2019): Significant reduction of mean PA pressure with good safety and survival profile
Buckley et al (2021): Improved mortality and decreased ICU length of stay for those with central PE of elevated risk (PESI 4/5 and ESC intermediate-high/high risk)
Treatment of Low-Risk Pulmonary Embolism
CHEST guidelines: Isolated subsegmental PE may not require treatment in low-risk patients
Low clinical risk patients (sPESI 0) diagnosed in ER may not require hospital admission in order to initiate anticoagulation
PREPROCEDURE
Indications
Contraindications
Preprocedure Imaging
Getting Started
PROCEDURE
Patient Position/Location
Procedure Steps
Findings and Reporting
Alternative Procedures/Therapies
POST PROCEDURE
Things to Do
Things to Avoid
OUTCOMES
Problems
Complications
Expected Outcomes
Selected References
Buckley JR et al: In-hospital mortality and related outcomes for elevated risk acute pulmonary embolism treated with mechanical thrombectomy versus routine care. J Intensive Care Med. 8850666211036446, 2021
Sista AK et al: Indigo aspiration system for treatment of pulmonary embolism: results of the EXTRACT-PE trial. JACC Cardiovasc Interv. 14(3):319-29, 2021
Bryce YC et al: Pathophysiology of right ventricular failure in acute pulmonary embolism and chronic thromboembolic pulmonary hypertension: a pictorial essay for the interventional radiologist. Insights Imaging. 10(1):18, 2019
Wible BC et al: Safety and efficacy of acute pulmonary embolism treated via large-bore aspiration mechanical thrombectomy using the Inari FlowTriever Device. J Vasc Interv Radiol. 30(9):1370-5, 2019
Behravesh S et al: Pathogenesis of thromboembolism and endovascular management. Thrombosis. 2017:3039713, 2017
Goktay AY et al: Endovascular treatment of thrombosis and embolism. Adv Exp Med Biol. 906:195-213, 2017
Lou BH et al: A meta-analysis of efficacy and safety of catheter-directed interventions in submassive pulmonary embolism. Eur Rev Med Pharmacol Sci. 21(1):184-98, 2017
Teleb M et al: Ultrasound-assisted catheter-directed thrombolysis: a novel and promising endovascular therapeutic modality for intermediate-risk pulmonary embolism. Angiology. 68(6):494-501, 2017
Bajaj NS et al: Catheter-directed treatment for acute pulmonary embolism: systematic review and single-arm meta-analyses. Int J Cardiol. 225:128-39, 2016
Biteker M et al: Thrombolysis in pulmonary embolism: full-dose, low-dose, or catheter-directed thrombolysis? Am J Emerg Med. 34(8):1720-1, 2016
Dilektasli AG et al: Catheter-directed therapy in acute pulmonary embolism with right ventricular dysfunction: a promising modality to provide early hemodynamic recovery. Med Sci Monit. 22:1265-73, 2016
Kaymaz C et al: Ultrasound-assisted catheter-directed thrombolysis in high-risk and intermediate-high-risk pulmonary embolism: results from a single-center cohort. Angiology. 68(5):433-40, 2016
Liang NL et al: Comparative outcomes of ultrasound-assisted thrombolysis and standard catheter-directed thrombolysis in the treatment of acute pulmonary embolism. Vasc Endovascular Surg. 50(6):405-10, 2016
Monteleone PP et al: Multidisciplinary pulmonary embolism response teams and systems. Cardiovasc Diagn Ther. 6(6):662-7, 2016
Sadiq I et al: Risk factors for major bleeding in the SEATTLE II trial. Vasc Med. 1358863X16676355, 2016
Sag S et al: Catheter-directed ultrasound-accelerated thrombolysis may be life-saving in patients with massive pulmonary embolism after failed systemic thrombolysis. J Thromb Thrombolysis. 42(3):322-8, 2016
Sharifi M: Systemic Full dose, half dose, and catheter directed thrombolysis for pulmonary embolism. When to use and how to choose? Curr Treat Options Cardiovasc Med. 18(5):31, 2016
Tafur AJ et al: Catheter-directed treatment of pulmonary embolism: a systematic review and meta-analysis of modern literature. Clin Appl Thromb Hemost. 20(11):1431-40, 2016
Teman NR et al: Massive pulmonary embolism treated with catheter therapy and extracorporeal membrane oxygenation. Heart Surg Forum. 19(6):E303-E305, 2016
Kuo WT et al: Pulmonary embolism response to fragmentation, embolectomy, and catheter thrombolysis (PERFECT): initial results from a prospective multicenter registry. Chest. 148(3):667-73, 2015
Nykamp M et al: Safety and efficacy of ultrasound-accelerated catheter-directed lytic therapy in acute pulmonary embolism with and without hemodynamic instability. J Vasc Surg Venous Lymphat Disord. 3(3):251-7, 2015
Piazza G et al: A prospective, single-arm, multicenter trial of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis for acute massive and submassive pulmonary embolism: the SEATTLE II study. JACC Cardiovasc Interv. 8(10):1382-92, 2015
Kucher N et al: Randomized, controlled trial of ultrasound-assisted catheter-directed thrombolysis for acute intermediate-risk pulmonary embolism. Circulation. 129(4):479-86, 2014
Kuo WT: Endovascular therapy for acute pulmonary embolism. J Vasc Interv Radiol. 23(2):167-79.e4; quiz 179, 2012
Kandarpa K et al. Handbook of Interventional Radiologic Procedures. Lippincott, Williams & Wilkins, 2011
Agnelli G et al: Acute pulmonary embolism. N Engl J Med. 363(3):266-74, 2010
Kuo WT et al: Catheter-directed therapy for the treatment of massive pulmonary embolism: systematic review and meta-analysis of modern techniques. J Vasc Interv Radiol. 20(11):1431-40, 2009
Weiss CR et al: CT pulmonary angiography is the first-line imaging test for acute pulmonary embolism: a survey of US clinicians. Acad Radiol. 13(4):434-46, 2006
Sacks D et al: Society of Interventional Radiology clinical practice guidelines. J Vasc Interv Radiol. 14(9 Pt 2):S199-202, 2003
Related Anatomy
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Related Differential Diagnoses
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References
Tables
Tables
KEY FACTS
Terminology
Preprocedure
Procedure
Outcomes
TERMINOLOGY
Definitions
Pulmonary embolism (PE): Embolized blood clot within pulmonary artery (PA) causing obstruction and altered lung perfusion
Estimated annual incidence: 1/1,000
3rd most common cause of cardiovascular death in USA per year
Deep vein thrombosis (DVT) is most common cause
Variable symptoms
Asymptomatic
Chest pain, dyspnea, cough, palpitations
Hypotension, syncope, cardiogenic shock, death
Right ventricular (RV) dysfunction: Dilation, impaired function and ischemia that occurs in setting of acute PE as result of increased afterload
Present in 45% of patients with PE
Associated with increased mortality (25% if normotensive, up to 65% if hypotensive)
If untreated, ultimately progresses to cause decreased left ventricular (LV) output, cardiogenic shock, and death
Imaging
CTA: Increased RV:LV ratio (> 0.9), reflux of contrast into hepatic veins
Echo: RV dilatation, impaired contractility
Laboratory: Evidence of myocardial necrosis [elevated troponin or brain natriuretic peptide (BNP)]
Chronic thromboembolic pulmonary hypertension (CTEPH): Subtype of pulmonary hypertension (PH) that develops from nonresolution of PE
Develops in ~ 4% of patients with PE
Presence of obstructive fibrotic thromboembolic material in major pulmonary vessels
Causes progressive, severe right heart failure
Catheter-directed thrombolysis (CDT): Infusion of thrombolytics through catheter positioned directly in PA
Mechanical thrombectomy (MT): Mechanical disruption and removal of thrombus via suction without thrombolytics
Risk Stratification
European Society of Cardiology (ESC) risk stratification (2019)
Low risk: No shock, signs of RV dysfunction, or elevated cardiac biomarkers (troponin/BNP)
Intermediate risk: RV dysfunction, no shock or hypotension
Intermediate-low risk: Without elevated cardiac biomarkers (troponin/BNP)
Intermediate-high risk: With elevated cardiac biomarkers (troponin/BNP)
High risk: RV dysfunction with shock or hypotension
PE Severity Index (PESI) Score
Escalating levels of severity (class I to class V), corresponding to escalating 30-day mortality risk (1-25%)
Calculated with demographic and clinical information rather than imaging/labs
0 points: Low risk (< 1% 30-day mortality), can potentially be treated outpatient
> 1 point: Elevated risk, can be further stratified with full PESI
Points awarded for: Age > 80 years, history of cancer/CHF/COPD, pulse > 110, systolic blood pressure (SBP) < 100, or O₂ saturations < 90%
Massive/submassive: Terminology falling out of favor, not descriptive enough to risk stratify or estimate mortality
Systemic Therapy
Anticoagulation
Options include warfarin (vitamin K antagonist), novel oral anticoagulants (NOACs), such as rivaroxaban, apixaban, dabigatran, or low-molecular-weight heparin
Warfarin therapy most cost effective but requires regular interval monitoring of patient's international normalized ratio (INR)
NOACs do not require therapeutic monitoring but tend to be more expensive
Patient's renal function, comorbidities, and preference should be taken into account when selecting anticoagulation regimen
Systemic thrombolysis
Peripheral administration of tissue plasminogen activator (tPA)
Variable dosing strategies, but 50 mg commonly used
Significantly reduces mortality compared to anticoagulation alone in high-risk PE
Increased risk of major bleeding, including intracranial hemorrhage
May be contraindicated in certain patients
Catheter-Directed Therapies
Generally reserved for patients with intermediate-high or high-risk PE
CDT
Placement of catheters into pulmonary arteries for direct tPA infusion, usually 1 mg of tPA/hour over 24-48 hours
Can be done ± US assistance
No clear consensus of benefit
ULTIMA trial (2014): CDT superior to anticoagulation in improving RV dilation
SEATTLE II study (2015): Decreased RV dilation, PH, and thrombus burden with fewer instances of intracranial hemorrhage
MT
Multiple commercially available devices for direct aspiration &/or mechanical disruption of clot
Do not require use of thrombolytics, and thus have decreased risk of major bleeding
Indigo System (Penumbra Inc)
Aspiration catheter (multiple options up to 12 Fr) with continuous vacuum
Also used for peripheral arterial and venous systems
EXTRACT-PE trial (2021): Significant reduction in RV:LV ratio, low major adverse events
FlowTriever (Inari Medical)
Large-bore aspiration system (16-24 Fr) with negative suction-locking syringe
Optional coaxial component for clot disruption
Wible et al (2019): Significant reduction of mean PA pressure with good safety and survival profile
Buckley et al (2021): Improved mortality and decreased ICU length of stay for those with central PE of elevated risk (PESI 4/5 and ESC intermediate-high/high risk)
Treatment of Low-Risk Pulmonary Embolism
CHEST guidelines: Isolated subsegmental PE may not require treatment in low-risk patients
Low clinical risk patients (sPESI 0) diagnosed in ER may not require hospital admission in order to initiate anticoagulation
PREPROCEDURE
Indications
Contraindications
Preprocedure Imaging
Getting Started
PROCEDURE
Patient Position/Location
Procedure Steps
Findings and Reporting
Alternative Procedures/Therapies
POST PROCEDURE
Things to Do
Things to Avoid
OUTCOMES
Problems
Complications
Expected Outcomes
Selected References
Buckley JR et al: In-hospital mortality and related outcomes for elevated risk acute pulmonary embolism treated with mechanical thrombectomy versus routine care. J Intensive Care Med. 8850666211036446, 2021
Sista AK et al: Indigo aspiration system for treatment of pulmonary embolism: results of the EXTRACT-PE trial. JACC Cardiovasc Interv. 14(3):319-29, 2021
Bryce YC et al: Pathophysiology of right ventricular failure in acute pulmonary embolism and chronic thromboembolic pulmonary hypertension: a pictorial essay for the interventional radiologist. Insights Imaging. 10(1):18, 2019
Wible BC et al: Safety and efficacy of acute pulmonary embolism treated via large-bore aspiration mechanical thrombectomy using the Inari FlowTriever Device. J Vasc Interv Radiol. 30(9):1370-5, 2019
Behravesh S et al: Pathogenesis of thromboembolism and endovascular management. Thrombosis. 2017:3039713, 2017
Goktay AY et al: Endovascular treatment of thrombosis and embolism. Adv Exp Med Biol. 906:195-213, 2017
Lou BH et al: A meta-analysis of efficacy and safety of catheter-directed interventions in submassive pulmonary embolism. Eur Rev Med Pharmacol Sci. 21(1):184-98, 2017
Teleb M et al: Ultrasound-assisted catheter-directed thrombolysis: a novel and promising endovascular therapeutic modality for intermediate-risk pulmonary embolism. Angiology. 68(6):494-501, 2017
Bajaj NS et al: Catheter-directed treatment for acute pulmonary embolism: systematic review and single-arm meta-analyses. Int J Cardiol. 225:128-39, 2016
Biteker M et al: Thrombolysis in pulmonary embolism: full-dose, low-dose, or catheter-directed thrombolysis? Am J Emerg Med. 34(8):1720-1, 2016
Dilektasli AG et al: Catheter-directed therapy in acute pulmonary embolism with right ventricular dysfunction: a promising modality to provide early hemodynamic recovery. Med Sci Monit. 22:1265-73, 2016
Kaymaz C et al: Ultrasound-assisted catheter-directed thrombolysis in high-risk and intermediate-high-risk pulmonary embolism: results from a single-center cohort. Angiology. 68(5):433-40, 2016
Liang NL et al: Comparative outcomes of ultrasound-assisted thrombolysis and standard catheter-directed thrombolysis in the treatment of acute pulmonary embolism. Vasc Endovascular Surg. 50(6):405-10, 2016
Monteleone PP et al: Multidisciplinary pulmonary embolism response teams and systems. Cardiovasc Diagn Ther. 6(6):662-7, 2016
Sadiq I et al: Risk factors for major bleeding in the SEATTLE II trial. Vasc Med. 1358863X16676355, 2016
Sag S et al: Catheter-directed ultrasound-accelerated thrombolysis may be life-saving in patients with massive pulmonary embolism after failed systemic thrombolysis. J Thromb Thrombolysis. 42(3):322-8, 2016
Sharifi M: Systemic Full dose, half dose, and catheter directed thrombolysis for pulmonary embolism. When to use and how to choose? Curr Treat Options Cardiovasc Med. 18(5):31, 2016
Tafur AJ et al: Catheter-directed treatment of pulmonary embolism: a systematic review and meta-analysis of modern literature. Clin Appl Thromb Hemost. 20(11):1431-40, 2016
Teman NR et al: Massive pulmonary embolism treated with catheter therapy and extracorporeal membrane oxygenation. Heart Surg Forum. 19(6):E303-E305, 2016
Kuo WT et al: Pulmonary embolism response to fragmentation, embolectomy, and catheter thrombolysis (PERFECT): initial results from a prospective multicenter registry. Chest. 148(3):667-73, 2015
Nykamp M et al: Safety and efficacy of ultrasound-accelerated catheter-directed lytic therapy in acute pulmonary embolism with and without hemodynamic instability. J Vasc Surg Venous Lymphat Disord. 3(3):251-7, 2015
Piazza G et al: A prospective, single-arm, multicenter trial of ultrasound-facilitated, catheter-directed, low-dose fibrinolysis for acute massive and submassive pulmonary embolism: the SEATTLE II study. JACC Cardiovasc Interv. 8(10):1382-92, 2015
Kucher N et al: Randomized, controlled trial of ultrasound-assisted catheter-directed thrombolysis for acute intermediate-risk pulmonary embolism. Circulation. 129(4):479-86, 2014
Kuo WT: Endovascular therapy for acute pulmonary embolism. J Vasc Interv Radiol. 23(2):167-79.e4; quiz 179, 2012
Kandarpa K et al. Handbook of Interventional Radiologic Procedures. Lippincott, Williams & Wilkins, 2011
Agnelli G et al: Acute pulmonary embolism. N Engl J Med. 363(3):266-74, 2010
Kuo WT et al: Catheter-directed therapy for the treatment of massive pulmonary embolism: systematic review and meta-analysis of modern techniques. J Vasc Interv Radiol. 20(11):1431-40, 2009
Weiss CR et al: CT pulmonary angiography is the first-line imaging test for acute pulmonary embolism: a survey of US clinicians. Acad Radiol. 13(4):434-46, 2006
Sacks D et al: Society of Interventional Radiology clinical practice guidelines. J Vasc Interv Radiol. 14(9 Pt 2):S199-202, 2003
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