TAPSE to Diagnose Pulmonary Embolism

Podcast

TAPSE byte


Emergency physician performed tricuspid annular plane systolic excursion in the evaluation of suspected pulmonary embolism

American Journal of Emergency Medicine January 2017 - Pubmed Link


Take Home Points

1. TAPSE may be more sensitive for diagnosis of PE than other signs of right heart strain, but its only 72% sensitive and not very specific (66%).

2. It is feasible to obtain TAPSE with point of care ultrasound.


Background

Right ventricular dysfunction (RVD) occurs in 30-70% of pulmonary embolism (PE). RVD has been associated with increased mortality, longer stays, and pulmonary hypertension. We know that we can detect signs of right heart strain with point of care echo (see post on article for RV Dysfunction in PE but sometimes it can be challenging. TAPSE (tricuspid annular plane systolic excursion) is a measurement of RVD and is know to have prognostic significance in the setting of PE. In one study, the TAPSE was least user dependent measurement of right heart strain. Therefore, these authors thought that maybe the (TAPSE) would be an easier or more feasible method for diagnosing right heart strain and therefore diagnosing pulmonary embolism.


Questions

How accurate is TAPSE at diagnosing PE?

What is the interrater reliability among emergency physicians?

Is a qualitative estimate of TAPSE feasible?

What are the diagnostic characteristics of other measures of right heart strain in PE?


Population

Single urban academic center

ED patients with a suspected PE from 4/2015 to 4/2016


Inclusion

  • ≥ 18 years old

  • undergoing CT angiography to evaluate for possible PE

Exclusion

  • Prisoners

  • Non english speaking

  • Wards of the state


Design

Prospective, observational, convenience sample


Intervention

Patients with suspected PE getting a CT were enrolled

They received a point of care ultrasound performed and interpreted at bedside in the ED, if possible before the CTA (otherwise they were blinded to CTA)

If two investigators present, both would measure TAPSE for interrater reliability

In some patients qualitative estimation of TAPSE (normal or abnormal) was estimated and compared to quantitative

If there were findings of right heart strain, they call their FOCUS study positive for PE. They then compared these results to the CTA results as the standard.


Who did the ultrasounds?

3 US fellowship trained EPs

4 ultrasound fellows

1 resident

1 medical student


Training during residency + significant emergency ultrasound training (except medical student who has no prior POCUS experience)

Medical student underwent 2 week training in POCUS, performed >50 FOCUS exams

Standardized 1 hour didactic training session

At least 20 TAPSE measurements each


The Scan

Phased array probe phased array


TAPSE

Graphic courtesy of the one and only Ben Smith @ultrasoundjelly. Check out more of his stuff at Ultrasound of the Week



“FOCUS” exam - Focused transthoracic cardiac ultrasound.

Evaluating for:

  • TAPSE <1.7 cm

  • RV enlargement

  • Septal flattening

  • TR

  • McConnell's sign


Learn how to ultrasound for Right Heart Strain at 5 minute sono


Results

150 subjects

  • 32 (21.3%) had PE

  • 2 (1.4%) had massive PE

  • looking at other things that could cause right heart strain - there were 7 that were diagnosed with COPD/ILD or pulm htn (4.7%)

3 excluded because could not get echo windows and TAPSE (rough estimate of feasibility - could obtain it in 147/150 = 98%)


Primary Outcome

TAPSE of 1.7 cm was 56% sensitive and 79% specific for PE, +LR 2.6, -LR 0.56

After determination of of optimal cutoff: TAPSE of 2.0 cm was 72% sensitive and 66% specific, +LR 2.1, -LR 0.43

ROC was better for cutoff of 2.0 cm = 0.73


Secondary Outcomes

TAPSE 2.0 was more sensitive than any other measure of RHS

McConnell's was most specific 97%, followed by septal flattening 94%

TAPSE article table


Interrelator reliability on 30 subjects, measured with Intraclass Correlation Coefficient (ICC) = 0.97

Qualitative estimate had kappa of 0.94 (compared to quantitative measurement)


Post-hoc analysis of hypotensive or tachycardic patients (n = 17): sens 94% and FOCUS was 100% sensitive

Medical students correlation with other investigators = 0.97


Limitations

Convenience sample

High overall experience of providers with ultrasound

One fellow had higher false positives than other (but not statistically significant)

The test characteristics of TAPSE in hypotensive/tachycardic patients appear promising, but it was post-hoc and also very small sample (17 patients)


Take Home Points

1. TAPSE may be more sensitive for diagnosis of PE than other signs of right heart strain, but its only 72% sensitive and not very specific (66%).

2. It is feasible to obtain TAPSE with point of care ultrasound.


Our score

3 Probes


Other FOAMed on This Topic

Ultrasound Podcast on TAPSE with James Daley


Published on 08/28/17 02:00 AM
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