Acute pulmonary embolism - risk stratification and management

Acute Pulmonary Embolism
Risk stratification & Management
September 2016
Dr Prithvi Puwar
DNB Cardiology
Vijaya Hospital Chennai
September 14, 2016 1

• Risk stratification
• Laboratory tests (D-dimer, Cardiac biomarkers)
• Imaging techniques (CTPA, V/Q scan, Echocardiogram)
• Therapeutic options (thrombolysis, IVC filter,
Thrombectomy)
Todays discussion

Risk stratification
• PERC Rule
• Wells score for PE
• Modified Geneva score for PE
• PESI Index

PERC
Kline JA, Mitchell AM, Kabrhel C, et al. Clinical criteria to prevent unnecessary diagnostic testing in emergency department
patients with suspected pulmonary embolism. J Thromb Haemost 2004;2:1247–55.

Wells score for PE

Geneva score for PE

PESI
to differentiate
Int from Low
Risk

Pulmonary Embolism Severity Index (PESI)

Biomarkers
• Troponin - released from right ventricle Injury
• Cardiac BNP - released from cardiac myocytes in response to elevated pressures 
RVD
*A normal troponin and BNP can safely exclude high risk patients with a negative
predictive value of 97-100%
• H-FABP (heart type fatty acid binding protein) – early marker for injury (good for
prognosis as well)
• NGAL (neutrophil gelatinase associated lipocalin) & Cystatin C – both indicating
kidney injury, also shown to have prognostic value

D-dimer in PE
• D-dimer is a type of
Fibrin degradation
product
• Can be raised due to a
number of reasons
• False positive D-dimer:
infection, pregnancy,
renal failure, post-
operative

– Qualitative
• Bed side RBC agglutination test
• Low Specificity and Sensitivity
– “SimpliRED D-dimer”
– Quantitative
• Enzyme linked immunosorbent assay “Dimertest”
• Positive assay is > 500ng/ml
• VIDAS D-dimer, 2nd
generation ELISA test
• Specificity decreases with age above 80 to 10% so
age-adjusted cut-off points are used for thatSeptember 14, 2016 17

ECG findings in PE

Echocardiogram in PE

Recommendation for echo
• Echocardiographic examination is not recommended as an
element of elective diagnostic strategy in haemodynamically
stable, normotensive patients with suspected PE.

• in a patient with suspected PE who is in a critical condition,
bedside echocardiography is particularly helpful in emergency
management decisions.
• In a patient with shock or hypotension, the absence of
echocardiographic signs of RV overload or dysfunction
practically excludes PE as a cause of haemodynamic
compromise.
• The main role of echocardiography in non-high-risk PE is
further prognostic stratification to the intermediate or low-
risk category.
• In a patient with shock or hypotension, the absence of
echocardiographic signs of RV overload or dysfunction
practically excludes

Ventilation-perfusion scan
Indications:
- Renal failure
- Pregnancy
Procedure:
- Ventilation scan with Xenon inhalation
- Perfusion scan with Tc99m labelled radioactive dye
infusion
- Scan V/Q
- Result: unmatched V/Q

Interpretation:

Recommendation
• A normal perfusion scan is very safe for excluding PE.
• Although less well validated, the combination of a non-diagnostic V/Q scan in
a patient with a low clinical probability of PE is an acceptable criterion for
excluding PE.
• A high-probability V/Q scan establishes the diagnosis of PE with a high degree
of probability
• In all other combinations of V/Q scan result and clinical probability, further
tests should be performed

CTPA
Indications:
- Suspected PE
Contra-indications:
- Renal failure
- Pregnancy
- Allergy to radio-contrast
1.7-5% risk of developing breast cancers (Hurwitz et al. 2007)

Multidetector helical CTPA
• First line modality
• Cover all chest with high spatial resolution in one breath
• Detect peripheral smaller emboli
• Detect other pathologies
• Detect RV strain (straightening or leftward bowing of IV septum)
BUT
• Radiation Exposure
• # in renal failure and contrast allergy

• Anticoagulation:
– IV Heparin, S/C LMWH, Oral Warfarin
• IVC filter: If there is contra-indications for anti-coagulation
• Thrombolysis: tPA eg Alteplase, Tenectaplase
• Surgical procedures: Pulmonary embolectomy
Treatment options

High-Risk (Massive) PE
• Definition: Acute PE with:
– Cardiac arrest / hemodynamic instability
– Sustained hypotension (systolic blood pressure 90 mm Hg for at
least 15 minutes OR requiring inotropic support not due to a
secondary cause (arrhythmia, sepsis)
*Remember: The presence of “lots” of PE isn’t enough to call it
“massive
• High-Risk PE therapy:
– Systemic Anticoagulation ASAP
– Supplemental oxygen for O2 sat <90%
– Admit to the intensive care unit: Significant hypoxemia, Hemodynamic compromise 
thrombolytic therapy
– Mechanical ventilation for respiratory failure
– For Hypotension: IVF, Vasopressor Support

Anticoagulation

Recommendations for Initial Anticoagulation forRecommendations for Initial Anticoagulation for
Acute PEAcute PE (AHA/ASC 2011, ACCP 2012)(AHA/ASC 2011, ACCP 2012)
• Therapeutic anticoagulation with SC LMWH, IV or SC UFH with
monitoring, unmonitored weight-based SC UFH, or SC
fondaparinux + VKA (till INR >2 for 24 hr) should be given to pts with
objectively confirmed PE and no # to anticoagulation (1B)
Preferred than UFH except if # (renal impairment, with thrombolysis or can’t afford)

Therapeutic parenteral anticoagulation during the
diagnostic workup should be given to pts with intermediate (if
diag. delay >4hrs) or high clinical probability of PE & no # to
anticoagulation (2C)
Therapeutic parenteral anticoagulation during the
diagnostic workup is not given in low probability (if diag. not
delayed than 24 hrs) (2C)

The results of the trials (RE-COVER, RECORD-3, EINSTEIN-PE, AMPLIFY, Hokusai-
VTE) using NOACs in the treatment of VTE indicate:
These agents are non-inferior (in terms of efficacy) and possibly safer
(particularly in terms of major bleeding) than the standard heparin/VKA
regimen.

Optimal Duration of AnticoagulationOptimal Duration of Anticoagulation
ACCP 2012

Thrombolysis
• Indications:
– Massive PE
– Sub-massive PE where risk of bleeding low (in RVD?!)

•Drugs:
(Most rapid)

Fibrinolysis in PE: Evidence

No survival benefit
No increase in ROSC
Increased risk of ICH among survived

ACC/AHA & ACCP RecommendationsACC/AHA & ACCP Recommendations

IVC filter
• Indications:
- DVT with massive pulmonary embolus
- Recurrent PE not treatable with anticoagulation
- Absolute contra-indications for anti-coagulation
- Trauma patients
• Not used in:
- DVT in distal vessels / nonmassive DVT, DVT not involving
proximal vessels.
- Patients scheduled for systemic thrombolysis, surgical
embolectomy, or pulmonary thrombendarterectomy.

• Complications associated with IVC filterComplications associated with IVC filter
Early complications
• Device malposition (1.3%)
• Hematoma (0.6%)
• Air embolism (0.2%)
• Inadvertent carotid artery
puncture (0.04%)
• Arteriovenous fistula
(0.02%)
Late complications
• Recurrent DVT (21%)
• IVC thrombosis (2% to
10%),
• IVC penetration (0.3%)
• Filter migration (0.3%)
• Recurrent PE (2-5%)
• Fatal PE (0.7%)

• Various inferior vena caval filters:Various inferior vena caval filters:
A Greenfield filterA Greenfield filter
B Titanium Greenfield filterB Titanium Greenfield filter
C Simon-Nitinol filterC Simon-Nitinol filter
D LGM or Vena Tech filterD LGM or Vena Tech filter
E Amplatz filterE Amplatz filter
F Bird’s Nest filterF Bird’s Nest filter
GG Günther Tulip filter (2000)Günther Tulip filter (2000)
**Located below renal veinsLocated below renal veins
(Adapted from Becker et al.)
Retrievable IVC filters: Günther Tulip filter, Celect filter,
OptEase filter, Bard G2 filter, Crux filter, and ALN filter.

Recommendations on IVC Filters in theRecommendations on IVC Filters in the
Setting of Acute PESetting of Acute PE

Catheter-Based InterventionsCatheter-Based Interventions
• Performed as an alternative to thrombolysis
 When there are contraindications
 When emergency surgical thrombectomy is unavailable or
contraindicated
 Hybrid therapy that includes both catheter-based clot
fragmentation and local thrombolysis is an emerging strategy

• Categories of percutaneous intervention
 Suction thrombectomy with aspiration catheters
 Thrombus fragmentation with pigtail or balloon catheters
 Rheolytic thrombectomy with hydrodynamic catheters (saline jet or
drug)
 Rotational thrombectomy
 Conventional catheter directed thrombolysis (drugs)
 U/S accelerated thrombolysis
 Pharmaco-mechanical thrombolysis (combined technique)

Catheter-directed therapy: OptionsCatheter-directed therapy: Options
Local delivery of streptokinase
-- Extensive lysis (by perfusion scan and pulmonary arteriography at 12 to 24
hour follow-up)
Intrapulmonary versus peripheral route
-- no advantage over the intravenous route
Direct delivery into clot
--Enhanced thrombolysis, relatively low doses (in an animal model of PE)
-- Could prove advantageous over the intravenous route

Angiojet
Rheolytic

• Side Effects (2%)
 Death from worsening RV failure,
 Distal embolization,
 Pulmonary artery perforation with lung hemorrhage,
 Systemic bleeding complications,
 Pericardial tamponade,
 Heart block or bradycardia,
 Haemolysis,
 Contrast-induced nephropathy, and
 Puncture-related complications

Surgical EmbolectomySurgical Embolectomy
• When contraindications preclude thrombolysis
• Surgical excision of a right atrial thrombus
• Rescue patients whose condition is refractory to thrombolysis
• Older case series suggest a mortality rate between 20% and 30%
• In more recent studies, patients underwent surgical embolectomy in a 4-
year period, with a 96% survival rate
Am Heart J 2011;134:479-87September 14, 2016 77

Recommendations (AHA – ACCP)Recommendations (AHA – ACCP)

PE in Pregnancy
• D-dimer has high negative predictive value. False positive result is
common
• V/Q scan is preferred technique
• CTPA can be done if V/Q is inconclusive
• Preferred treatment option: LMWH
• Warfarin is contraindicated

PE in Cancer

Acute pulmonary embolism - risk stratification and management

In this document