Thrombolysis in Submassive PE

Thrombolysis in Submassive PE

Adam Oster

Grand Rounds

April 4, 2002

Guiding Questions

Should we identify normotensive PE patients with RV dysfunction (submassive PE)?

Should these patients be considered for thrombolytic therapy?

Patient Subgroups

HEMODYNAMICALLY UNSTABLE

HEMODYNAMICALLY STABLE

PULMONARY EMBOLUS

DIAGNOSED OR SUSPECTED

WITH SIGNS OF ORGAN

HYPOPERFUSION (INCL. CARDIAC

ARREST)

EVIDENCE OFRIGHT HEART

STRAIN

NO EVIDENCEOF

RIGHT HEART STRAIN

WITHOUTSIGNS OF HYPOPERFUSION

Outline

• Studies demonstrating the natural history of PE with RV dysfunction

• Trials evaluating thrombolytics in PE with RV dysfunction

• *Special topics– evidence for thrombolytics in PE with shock

and during CPR for PE-related arrest– role of TTE by EPs

History

• Randomised trials comparing thrombolytics to heparin– UPET 1970 -- prospective, Randomised.

– USET

– PIOPED 1990

– Levine et al. 1990

– PAIMS 2. 1992

– Goldhaber et al. 1993

• Non-randomized– Dalla-Volta, 1993

– Konstantanindes, 1997

– Hamel, 2001

Should we attempt to identify normotensive PE patients with right heart strain?

Pathophysiology Review

• Normal RV has a narrow range over which it can compensate for acute increases in afterload. The pericardium has a limited ability to distend.

• Increased RV afterload elevation in RV wall pressures dilation and hypokinesis of the RV wall

shift of intraventricular septum towards left ventricle (tricuspid regurgitation) and decreased LV output.

Grifoni et al. Short-Term Clinical Outcome of Patient With Acute Pulmonary Embolism, Normal Blood Pressure and Echocardiographic Right Ventricular

Dysfunction. Circulation, 101. 2000,

• Prospective clinical outcome study– 209 consecutive patients with documented PE

– all patients had an TTE within 1 hr of admission

– patients stratified into one of four groups

– results only for in-hospital period

Grifoni et al, Circulation, 2000.

• 4 groups– Shock (N=28,13.4%)

• SBP<100 with signs of organ hypoperfusion

– Hypotensive without signs of shock (N=19, 9.1%)

– Normotensive with RV strain (N=65, 31.1%)

– Normotensive without RV strain (N=97, 46.4%)


• Patients with hypotension/shock (22%, N=47)– Mortality 19%

• Normotensive without evidence of RV strain (46.5%, n=97)– 0 PE-related deaths

• Normotensive with RV strain (31.1%, N=65)– 10% (n=6) clinically deteriorated due to PE recurrence

– 5% (n=3) PE-related deaths


• Positive predictive value of echocardiography was low

• NPV was 100%• good tool for screening low risk patients

• The detection of RV dysfunction defines a subset of patients with short-term risk of PE-related mortality.

Ribeiro et al. Echocardiography Doppler in Pulmonary Embolism: Right Ventricular Dysfunction as a Predictor of Mortality Rate. American Heart

Journal, 134. 1997.

• RV dysfunction at diagnosis of PE is a predictor of mortality– 126 ‘consecutive’ PE patients assessed by TTE on day of

diagnosis

– stratified into 2 groups based on severity of RV systolic dysfunction on TTE

– (A) normal to mildly hypokinetic and

– (B) moderate to severely hypokinetic

– Follow-up TTE within 1 year

Ribeiro et al. American Heart Journal, 1997.

• 56 patients in group A and 70 in group B– baseline characteristics similar (except over twice as many with symptoms >14days

(sig.), malignancy and CHF (NS)in B)

• In-hospital PE mortality all in group B (n=9), p=0.002

• 1 year overall mortality rate 15.1% (n=19)– group A, 7.1% (n=4) mortality, all non-PE.

– group B, 27.7 % (n=15) mortality, 9 due to PE (p=0.04)

• Group B– RR for in-hospital death 6.0 (95% CI 1.1 to 111.5)

– RR for death within 1 year 2.4(95% CI 1.2 to 4.5) • *(malignancy RR 3.0).

Ribeiro et al. American Heart Journal, 1997.

• Subgroup analysis of patients without cancer (n=101)– In-hospital mortality

• Group A 0%

• Group B 7.7% (N=4/52)

– 1 year cumulative mortality• Group A 2%, (N=1)

• Group B 9.8%, (N=5)

Should patients with RV dysfunction be considered for thrombolytic therapy?

Goldhaber, S. et al. Alteplase versus Heparin in Acute Pulmonary Embolism: Randomised Trial Assessing Right-Ventricular Function and Pulmonary

Perfusion. The Lancet. 1993, no 8844. vol 341.

• Thrombolysis plus heparin is better than heparin alone in reversing echo evidence of RV dysfunction– Prospective and randomized, non-consecutive.

– 99 hemodynamically stable PE patients

– PE confirmed by high probability V/Q and/or pulmonary angiogram

– excluded if at high risk of adverse hemorrhage.

– all had TTE assessments of right ventricular wall motion at baseline, then repeated at 3 and 24 hours.

– Angiograms were obtained at baseline and at 24h

Goldhaber et al. The Lancet. 1993.

• 46 patients randomized to rt-PA followed by heparin and 55 to heparin alone

• Endpoints; mortality, recurrent PE and major bleeding (72h)

• Followed for 14 days for adverse outcomes (PE recurrence or death), or longer if in hospital. 72 hrs for bleeding.


• Results– follow-up echo (89 patients)

• rtPA group vs heparin– 3 hrs -- greater improvement in RV wall motion (p=0.01)

– 24 hrs -- 39% improved, 2% worse vs 17% improved and 17% worse vs 17% improvement and 17% worse in heparin group (p=0.005)

– follow-up angiogram at 24hrs (95 patients)• rtPA vs heparin -- mean absolute improvement in pulmonary

perfusion of 14.6% vs 1.5% in heparin (p<0.0001).

Goldhaber et al. The Lancet. 1993

• Subgroup analysis – patients with right ventricular hypokinesis on echo (N=36)

• rtPA -- 89% improvement, 6% worsened• heparin -- 44% improvement, 28% worsened (p=0.03)

• Deaths– 2 in heparin group (1 refractory CA and 1 with CI to tPA)

• Recurrent PEs– rtPA -- none– heparin -- 5 (2 fatal)

• Significant hemorrhage– heparin -- 1– rtPA -- 3


• Conclusions– rtPA group

• improved right heart function at 24 hours• improvement in pulmonary perfusion• decrease in recurrent PEs• lower rate of death

• Strong points• randomization and similarities between groups• echo and angiogram readers blinded to treatment and timing in relation to

therapy

• Limitations• non-blinded to clinicians and open-labeled• no long -term morbidity or mortality data

Konstantinides, et al. Association Between Thrombolytic Treatment and the prognosis of hemodynamically Stable Patients with Major Pulmonary Embolism: Results of a Multicenter Registry. Circulation, 96. 1997

• Early thrombolysis favorably affects in-hospital clinical outcome.– Multicentred, registry study

– 719 consecutive patients analyzed; 73% PE confirmed by one or more imaging study

– evidence of either increased right ventricular afterload or pulmonary hypertension based on TTE or cath.

– all patients “hemodynamically stable”• also included patients who were hypotensive (SBP<90) without signs

of shock and those on low dose (<5mcg/kg/min) dopamine.

Konstantinides, et al. Circulation. 1997

• primary end-point -- overall 30-day mortality

• secondary endpoints -- PE recurrence, major bleeding


• Treatment decisions made at discretion of physician

• 23.5% (n=169) received thrombolytic therapy within 24h of diagnosis followed by heparin

• remaining patients treated with heparin alone– unless the physician thought that they required thrombolytics after

the first 24h of heparin.


Findings

• overall 30d mortality higher in heparin group 11.1% vs 4.7% (p=0.016).

• thrombolytic treatment was found by multivariate analysis to be the only independent predictor of survival (OR 0.46 for in-hospital death)

• 95% CI 0.21 to 1.00

• thrombolytic group;– lower rates of recurrent PE (7.7 vs. 18.7, p=0.001)– higher rates of major bleeding events (21.9 vs 7.8, p=0.001)

• ICH and deaths due to bleeding were the same in the two groups


• Subgroup analysis– patients with a dilated right ventricle on echo

• 30 day mortality in (N=380) 10% compared with 4.1% in those without (p=0.018), a 58% reduction in mortality.

• 58% reduction in mortality in patients treated with thrombolytics (4.7% vs 11.1% heparin, p=0.16)


• Limitations– study design;

• non-randomised, heterogeneous thrombolytic regimens• many patients had clinical signs of disease severity • more with chronic lung disease in UF heparin group• choice of treatment was at the discretion of the physician

– selection bias is likely

• distribution of many clinical variables were statistically different between the two groups (esp. age, pre-existing CHF, higher in heparin)

• major end point analyses required multivariate regression model to account for the unequal distribution of clinical variables


• 40% of patients thrombolysed had contraindications to lytics

• 25% in the heparin group ‘crossed over’ and received thrombolytics. This data was not reported.

Hamel et al. Thrombolysis or Heparin Therapy in Massive Pulmonary Embolism With Right Ventricular Dilation. Chest, 2001. Vol. 120:1.

• There is a benefit to thrombolysis over heparin in stable PE patients with RVD– Retrospective, cohort study of 153 consecutive patients

– PE confirmed by, V/Q or angiography

– RV function evaluated by TT E on admission

– 64 patients in each treatment group were matched on the basis of RV/LV diameter ratio

– perfusion scans repeated on day 7 to 10 or earlier if recurrent PE suspected

Hamel et al. Chest, 2001.

• Inclusion criteria – included PIOPED criteria for high prob. V/Q

– Pulmonary vascular obstruction >40% on V/Q or Miller index of 20/34

– RV to LV ratio of >0.6* in absence of LV or Mv disease

• Exclusion criteria– SBP <90

– contraindications to thrombolysis

– inotropes

– syncope prior to presentation


• thrombolysis versus heparin– higher mean relative improvement in lung scan at 7-10 days (54%

vs 42%, p=0.01)

– >50% relative improvement in lung scan perfusion defect seen in 57% (vs 37%)

– at day 7-10 follow-up scan, average defect equal between two groups


• PE recurrence – rates were the same in both groups, 4.7% (N=3).

• Mortality– 4 (6.3%) in thrombolytic and 0 in heparin (NS)

• Bleeding events – 6 severe, 3 intracranial; significantly higher in thrombolytic group.

4 died as a result. (15.6%, N=10 vs 0, p=0.001)


• Retrospective, case-controlled, consecutive patients

• small numbers

• Two groups comparable at baseline for historic factors, RV dysfunction, LS defect and all free of signs of PE severity – LS defect, RV/LV ratio and higher PAP higher in thrombolysis

group (not significant)

• heterogeneous treatment regimen in thrombolytic group

Levine et al. A Randomised Trial of a Single Bolus Dosage Regimen of Recombinant Tissue Plasminogen Activator in Patients with Acute Pulmonary

Embolism. Chest. 1990. 98:1473.

• rt-PA will benefit pulmonary perfusion in patients with PE and demonstrated perfusion deficits– Inclusion -- ‘symptomatic’ patients with either high probability

V/Q or angiographically proven PE and no contraindications to thrombolytics.

– Excluded if hypotensive or hemodynamically unstable

– All patients received heparin bolus. Then randomized to either rt-PA (0.6mg/kg, given as a bolus over 2min) or placebo.

– 10 day study period

Levine et al. Chest. 1990

• End-points were >50% improvement in perfusion defect over baseline and major bleeding events;– intracranial, retroperitoneal, requires transfusion >2U or fall in

Hgb >20g/L


• 58 patients randomized (33 to rt-PA) and groups were comparable for baseline characteristics.

• Comparison lung scans (at 24h and 7days) available for 57– At 24 hours

• rt-PA group -- 34.4% demonstrated a greater than 50% improvement in perfusion scan (12% improved >50% in the placebo group (p=0.017).

• Mean absolute improvement of 9.7% in rt-PA (5.2% in placebo, p=0.07)


• At 7 days– no statistically significant difference in lung scan resolution

• No recurrent PEs in either group

• No major bleeding episodes

Dalla-Volta, S. et al. : Alteplase Combined With Heparin Versus Heparin in the Treatment of Acute Pulmonary Embolism. Plasminogen Activator Italian

Multicentre Study 2 (PAIMS 2). Journal of the American College or Cardiology 1992. 20; 520.

• tPA will result in more rapid improvement in angiographic and hemodynamic variables.– Open, parallel, multicenter, randomized trial, N=36.

– PE confirmed by angiogram with PA pressures recorded.

– all patients hemodynamically stable

– excluded if contraindications to thrombolytics

– all patients received bolus UF heparin then Randomised to rt-PA or heparin

– follow-up angiogram at end of randomized treatment (2hrs), subset had lung scans at 7 and 30d.

Dalla-Volta, S. et al. JACC. 1993

• Interim data analyzed for first 32 patients randomized• study terminated due to >3 SD (p<0.01) in the difference

between the angiographic index of the two groups• patients treated with rt-PA

– decrease in Miller Score (mean 28.3 to 24.8) at 2 hours– decrease in mean PA pressure (mean of 30.2mmHg to 21.4mmHg,

p<0.01).– CI increased from 2.1 to 2.4 L/min/m2, p<0.01

• patients treated with heparin– no change in Miller Score or CI– increase in PA pressure, p<0.001.

Dalla-Volta, S. et al. JACC. 1993

• Patient Subset with 7 and 30day follow-up perfusion scans– No difference in Miller Scores (p<0.05)

• Bleeding complications – 14/20 in tPA had, 3 were severe (Hb decreased by >50g/L)

– 6/16 and 2 severe in heparin group (NS)

• Deaths – 2 in tPA group (ICH, tamponade).

Summary of Studies To-Date

• Grifoni -- RVD confers increased risk of death and PE recurrence.

• Ribeiro -- extent of RVD correlates with early and late death

• Levine -- early improvement in scan but no benefit at 7 days

• Goldhaber -- improved short-term hemodynamics and lower rate of short-term rec. PE and death. Randomised, non-blinded.

• Konstantinides -- lower rate of mortality in subgroup of pts with RVD and thrombolysis. *Non-randomized, groups sig. different at baseline.

• Dalla-Volta negative for mortality

• Hammel no better survival (mortality higher in thrombolysis group) and higher rate of serious bleeding.

Take Home

• RV dysfunction proportionately increases the risk of death in PE (8% to 14%)

• Severity of RV dysfunction correlates with worse prognosis• TTE can identify low-risk population• Thrombolytic therapy results in prompt (approx 24h)

improvement in RV function, PA pressures and lung scan deficit

• Any benefit to thrombolysis does not appear to be present after ?24hrs.

• Likely does not decrease risk of recurrent PEs

Thrombolytics in Severe Shock or During CPR in Fulminant Pulmonary Embolism?

• Fulminant PE can produce CA in approx. 40% of cases

• Mortality ranges from 65% to 95%

• Multiple purported mechanisms– RV strain, AMI, arrhythmia.

– PEA or asystole

Patient Subgroups

HEMODYNAMICALLY UNSTABLE

HEMODYNAMICALLY STABLE

PULMONARY EMBOLUS

DIAGNOSED OR SUSPECTED

WITH SIGNS OF ORGAN

HYPOPERFUSION (INCL. CARDIAC

ARREST)

EVIDENCE OFRIGHT HEART

STRAIN

NO EVIDENCEOF

RIGHT HEART STRAIN

WITHOUTSIGNS OF HYPOPERFUSION

Jerjes-Sanchez C. et al. Streptokinase and Heparin versus Heparin Alone in Massive Pulmonary Embolism: A Randomised Controlled Trial. Journal of

Thrombosis and Thrombolysis. 1995.

• Prospective and Randomised trial, N=8– all had “massive” PE and in cardiogenic shock

• high prob. V/Q, with abnormal RH echo or

• >9 obstructed segments on V/Q

• autopsy in 3

– no significant baseline differences between the two groups, except time elapsed from onset of symptoms to randomization (2.5 vs 34.75hrs)

– 100% survival in streptokinase plus heparin group

– 100% mortality in heparin group

– no bleeding complications

Thrombolytics in Severe Shock or During CPR in Fulminant Pulmonary Embolism?

Ruiz Bailen M. et al., Thrombolysis During Cardiopulmonary Resuscitation in Fulminant Pulmonary Embolism: A Review. Critical Care Medicine. 2001.

Vol 29, No. 11.

– single cases and small series demonstrate promising outcomes when PE suspected clinically.

• Kurkciyan et al. 2000 – retrospective, N=42 (thrombolysis 21, 21 no treatment)

» 9.5% survival in thrombolysis vs 4.5% in no treatment

» ROSC in 81% vs 33.3%

• Survival from 9.5% to 100% (Sienblenlist, 1990; Sigmund, 1991; Hopf, 1991; Bittiger, 1991; Scheeren, 1994)

Moore, et al. Determination of Left Ventricular Function by Emergency Physician Echocardiography of Hypotensive Patients. Academic Emergency

Medicine, vol. 9, no. 3, 2002.

• Prospective, observational study, convenience sample of 51.• EPs with prior US training underwent focused echo training• inclusion: symptomatic hypotension• exclusion: trauma, CPR, ECG of AMI• EPs estimation of EF

– compared with cardiologist; correlation coefficient of 0.86

– between cardiologists 0.84

• EP categorization of EF, – agreement 84% (kappa 0.61)

Relationship between degree of RV dysfunction and degree of perfusion scan deficits

• Wolfe, 1994. N=90– degree of perfusion deficit greater in patients with RVD (54% vs

30%, p<0.001)• all patients with recurrent PE in group with initial RVD, p<0.01

• Ribiero, 1998– correlation between RVD and perfusion scan deficit but wide CI.

• Miller, 1998. N=64– failed to demonstrate a correlation between RVD and perfusion

deficit

Thrombolysis in Submassive PE

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