Diagnosis and management of pulmonary thromboembolism DR.VIVEKANANTHAN D.A.,FRCA.,EDIC.,FFICM.,
Jan 19, 2016
Diagnosis and management of pulmonary thromboembolismDR.VIVEKANANTHAN D.A.,FRCA.,EDIC.,FFICM.,
OVERVIEW
Diagnosis – tests available and diagnostic strategies used
Prognostic assessment
Management- therapeutic strategies and methods available
Special circumstances
Pulmonary thromboembolism
Venous Thromboembolism (VTE) spectrum- DVT & PE
Major morbidity and mortality
Not uncommon
Diagnosis could be Elusive
Risk factors
pathophysiology
Diagnosis- Symptoms galore!
Pollack et.al 2011
pitfall amongst symptoms and signs
30% patients with Confirmed PE do not have predisposing factors
40% patients with confirmed PE do not have hypoxaemia
20% patients with confirmed PE have normal alveolar arterial oxygen gradient
40% patients with confirmed PE have sinus tachycardia on ECG rather than classical ECG changes
59% of fatal PE were undiagnosed during life time
Acute PE- Initial diagnostic strategy
With shock and without shock-
High risk PE
Moderate and low risk PE
Diagnosis -Assessing clinical probability
Wells rule
Geneva rule
Three group category -Low, intermediate, high risk grouping
Two group category- PE likely, PE unlikely grouping
WELLS RULE
GENEVA RULE
Diagnosis- D-dimer
Positive predictive value is low
Negative predictive value is high
ELISA derived assay Vs latex derived assay reliability
Usefulness- can exclude PE in up to 30% of patients suspected with low or intermediate risk PE- (class I recommendation)
Age adjusted D-dimer cut off value improved specificity by 10%, if not specificity decreases with age
Diagnosis- CT pulmonary angiogram
83% sensitivity and 96% specificity –PIOPED II trial
Negative predictive value for CTPA is >89-96% in intermediate and low risk group
Segmental clot presence confirms PE -(class I recommendation)
CT venography combined with CTPA increases sensitivity from 83 to 90%, however specificity remains the same
Incidental CT diagnosis of PE is 1%
Sub segmental PE incidence is 4.5% with lower clinical significance
Diagnosis- ventilation perfusion scintigraphy
V/Q scan- technicium99
Well validated test
Safe, less allergic, <50% radiation exposure
Special groups of patients will benefit from it
Results are grouped into three- normal, high probability and non diagnostic scan
Diagnosis- other imaging techniques
SPECT imaging-
Pulmonary angiogram-
DSA-
MRI-
Diagnosis- Echocardiography
RV free wall contractility depressed as against the apex- “Mc Connell sign”
Disturbed RV ejection fraction- “60-60 sign”
RV dilatation – found in 25% of all cases of PE
Negative predictive value is only 40-50% due to other confounders
Not an investigation for low risk, non shocked patients
Diagnosis- compression venous ultrasonography
90% sensitivity and 95% specificity for symptomatic DVT
>70 % of PE patients have DVT
Proximal DVT in PE suspected patients is good enough to start anticoagulation- (class I recommendation)
Incomplete compressibility is a validated criterion for DVT diagnosis
Flow measurements are unreliable
Diagnostic strategy
Patients suspected to have PE, presenting
With shock
Without shock
Suspected PE with shock
Suspected PE without shock
PE exclusion -validated parameters
Treatment of PE- Overview
Haemodynamic, ventilatory support
Anti coagulation
Thrombolysis
Surgical embolectomy, percutaneous techniques, use of IVC filter
Treatment- resuscitation and supportive care
RV failure- main cause for mortality
adrenaline helps in RV failure
Modest fluid challenge helps improve cardiac index- caution needed
Effects of PEEP during ventilation needs careful titration
Levosimendan and nitric oxide might be useful
Treatment- anticoagulation
To prevent early death and recurrent VTE
Initial parenteral anticoagulation for 7-10 days necessary- heparin, LMWH, fondaparinux
vit.K antagonist after the initial phase for up to 3 months duration is essential
Duration of anticoagulation- unprovoked PE ( 3 months) unprovoked relapse of PE ( indefinite)- (class I recommendation)
Newer anticoagulants can be started earlier- rivaroxaban, apixaban
Treatment- choice of anticoagulant
UFH- shorter duration of action, suitable for pt. with renal impairment, obesity, APPT monitoring needed
LMWH- twice daily or single dose administration, caution with renal impairment, HIT possibility, anti Xa level monitoring possible
Fondaparinux- once daily s/c inj. , results comparable to that of UFH, no reported HIT like effects, accumulates in renal failure
Treatment- oral anticoagulants
Warfarin –Vit K Antagonist(VKA) started as soon as possible, INR target of 2.0-3.0 is aimed
Pharmacogenetics' guided therapy is not found to be superior
Newer oral anticoagulants (NOAC)- dabigatran, rivaroxaban.,
NOAC- not inferior to UFH/ VKA regimen, possibly the bleeding risk is lesser –(class I recommendations for rivaroxaban apixaban and edoxaban)
Treatment- thrombolytic therapy
Restores pulmonary perfusion earlier than anticoagulation therapy
Two hours’ accelerated therapy preferred over 12-24 hour prolonged infusion therapy
>90% patients have clinical recovery within 36 hours of therapy, greatest benefit seen if therapy initiated within 48 hours of onset of symptoms
Normotensive patients with raised biochemical parameters and echocardiographic features of RV dysfunction, if thrombolysed, 7 day mortality and further complications were prevented (PEITHO trial)
Major bleeding risk- intra cranial and non intracranial bleeds- 2%
Treatment- surgical embolectomy
Surgical technique used since 1924
Indicated for failed thrombolytic therapy or where it is contraindicated amongst intermediate or high risk patients
Treatment- percutaneous catheter directed treatment
Thrombus fragmentation, rotational thrombectomy, suction thrombectomy, rheolytic thrombectomy techniques are available
Systemic Thrombolysis contraindicated patients are suitable for these techniques
RCT: Catheter directed clot thrombolysis technique has been found superior in reversing RV function within 48 hours as compared to systemic thrombolysis WITHOUT bleeding complications in intermediate risk group of patients
Treatment – IVC filter
Infra renal placement is usually done
IVC filters should be considered in patients with acute PE with absolute contraindications to anticoagulation. ( class II a recommendation)
IVC filters should be considered in case of recurrence of PE, despite therapeutic levels of anticoagulation. ( class II a recommendation)
Routine use of IVC filters in patients with PE is not recommended ( class I recommendation)
Special circumstances- pregnancy
D-Dimer is useful to avoid unnecessary irradiation
Venous compression ultrasonography is considered to avoid irradiation risk
Perfusion scintigraphy may be considered to rule out suspected PE when the chest x ray is normal
CT angiography considered only when chest x ray is abnormal
LMWH adjusted to weight is treatment of choice in pts without shock
Special circumstances- cancer and PE
Incidental PE on cancer screening is treated along the same guidelines for non cancer patients suspected to have PE
Negative D-dimer has similar negative diagnostic value
LMWH adjusted to body weight is used for 3-6 months
Extended anticoagulation with LMWH is considered until cancer is cured- (class II a recommendation)
Chronic thromboembolic pulmonary hypertension
Incidence of 1.5 % in patients diagnosed with earlier PE
Diagnostic criteria: findings after 3 months of effective anticoagulation:
1. mean pulmonary arterial pressure ≥25 mm Hg, with pulmonary arterial wedge pressure≤15 mm Hg
2. at least one (segmental) perfusion defect detected by perfusion lung scan or pulmonary artery obstruction seen by MDCT angiography or conventional pulmonary cine angiography
V/Q scan is investigation of choice
Pulmonary endarterectomy offered if operable, if not extended anticoagulation advised - (Class I recommendation)
Prognosis in PE
Simplified predicted severity in PE (sPSE score)- validated clinical score
Age >80, Cancer
Chronic cardiac, pulmonary disease
Heart rate >110, blood pressure <100, saturation <90%
0 points =1% mortality, >1 point= 10% risk of 30 day mortality- used for low and intermediate severity- ( class II a recommendation)
Patients to be assessed for presence of shock- carries higher mortality – (class I recommendation)
Lab tests and biomarkers- BNP, Pro BNP, troponin T, I ( class II a)
acknowledgment
http://www.escardio.org/guidelinessurveys/esc-guidelines/about/Pages/rules-writing.aspx
European society of cardiology guideline 2014
European heart Journal August 2014
Summary- Diagnosis and treatment of PE
Strong clinical suspicion is necessary to investigate and use the diagnostic strategies
Judicious use of investigations will avoid unnecessary burden in patient care delivery
Choice of therapy is vital in dictating better patient outcome
Thank you