PURLS / PEER REVIEWED

A Better Approach to the Diagnosis of PE

Clinician Reviews. 2019 October;29(10):4e-5e

References

1. van der Hulle T, Cheung WY, Kooij S, et al; YEARS study group. Simplified diagnostic management of suspected pulmonary embolism (the YEARS study): a prospective, multicentre, cohort study. Lancet. 2017;390:289-297.
2. Beckman MG, Hooper WC, Critchley SE, et al. Venous thromboembolism: a public health concern. Am J Prev Med. 2010;38(suppl 4):S495-S501.
3. Douma RA, Mos ICM, Erkens PMG, et al; Prometheus Study Group. Performance of 4 clinical decision rules in the diagnostic management of acute pulmonary embolism. Ann Intern Med. 2011;154:709-718.
4. van Es N, van der Hulle T, van Es J, et al. Wells Rule and d -dimer testing to rule out pulmonary embolism: a systematic review and individual-patient data meta-analysis. Ann Intern Med. 2016;165:253-261.
5. Roy P-M, Meyer G, Vielle B, et al; EMDEPU Study Group. Appropriateness of diagnostic management and outcomes of suspected pulmonary embolism. Ann Intern Med. 2006;144:157-164.
6. Newnham M, Stone H, Summerfield R, et al. Performance of algorithms and pre-test probability scores is often overlooked in the diagnosis of pulmonary embolism. BMJ. 2013;346:f1557.
7. Righini M, Van Es J, Den Exter PL, et al. Age-adjusted d -dimer cutoff levels to rule out pulmonary embolism. JAMA. 2014;311:1117-1124.
8. van Es J, Beenen LFM, Douma RA, et al. A simple decision rule including d -dimer to reduce the need for computed tomography scanning in patients with suspected pulmonary embolism. J Thromb Haemost. 2015;13:1428-1435.
9. Kooiman J, Klok FA, Mos ICM, et al. Incidence and predictors of contrast-induced nephropathy following CT-angiography for clinically suspected acute pulmonary embolism. J Thromb Haemost. 2010;8:409-411.
10. Sarma A, Heilbrun ME, Conner KE, et al. Radiation and chest CT scan examinations: what do we know? Chest. 2012;142:750-760.
11. Berrington de González A, Mahesh M, Kim KP, et al. Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med. 2009;169:2071-2077.
12. Verma K, Legnani C, Palareti G. Cost-minimization analysis of venous thromboembolism diagnosis: comparison of standalone imaging with a strategy incorporating d -dimer for exclusion of venous thromboembolism. Res Pract Thromb Haemost. 2017;1:57-61.
13. Pasha SM, Klok FA, Snoep JD, et al. Safety of excluding acute pulmonary embolism based on an unlikely clinical probability by the Wells rule and normal d -dimer concentration: a meta-analysis. Thromb Res. 2010;125:e123-e127.
14. Mos ICM, Klok FA, Kroft LJM, et al. Safety of ruling out acute pulmonary embolism by normal computed tomography pulmonary angiography in patients with an indication for computed tomography: systematic review and meta-analysis. J Thromb Haemost. 2009;7:1491-1498.

Of the 1743 patients who had none of the 3 YEARS items, 1320 had a D-dimer concentration below the 1000-ng/mL threshold. Of the 423 who had a D-dimer ≥ 1000 ng/mL, 55 had PE confirmed by CTPA. In the 1722 patients who had at least 1 YEARS item, 1391 had a D-dimer concentration ≥ 500 ng/mL threshold; 401 of them had PE confirmed by CTPA.

Eighteen of the 2964 patients who had PE ruled out by the YEARS algorithm at baseline were found to have symptomatic VTE during the follow-up period (0.61%), with 6 patients (0.20%) sustaining a fatal PE. The 3-month incidence of VTE in patients who did not have CTPA was 0.43%, which is similar to the 0.34% reported in a previous meta-analysis of the Wells rule algorithm.¹³ Overall, fatal PE occurred in 0.3% of patients in the YEARS cohort vs 0.6% in a meta-analysis of studies using standard algorithms.¹⁴

Using an intention-to-diagnose analysis, 1611 (46%) patients did not have a CTPA indicated by the YEARS algorithm compared with 1174 (34%) using the Wells algorithm, for an absolute difference of 13% and estimated cost savings of $283,176 in this sample. The per-protocol analysis also had a decrease of CTPA examinations in favor of the YEARS algorithm, ruling out 1651 (48%) patients—a decrease of 14% and an estimated savings of $309,096.

WHAT’S NEW

High-level evidence says 14% fewer CTPAs

The YEARS study provides a high level of evidence that a new, simple diagnostic algorithm can reliably and efficiently exclude PE and decrease the need for CTPA by 14% (absolute difference) when compared with using the Wells rule and fixed D-dimer threshold of < 500 ng/mL.

CAVEATS

No adjusting D-dimer for age

The YEARS criteria do not consider an age-adjusted D-dimer threshold, which has been shown to further decrease CTPA use.⁶ This does not preclude the use of the YEARS criteria; applying age-adjusted D-dimer thresholds would have led to an absolute reduction of 8.7% in CTPA.⁷

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