Elsevier

Thrombosis Research

Volume 129, Issue 6, June 2012, Pages 710-714
Thrombosis Research

Regular Article
Does the Pulmonary Embolism Severity Index accurately identify low risk patients eligible for outpatient treatment?

https://doi.org/10.1016/j.thromres.2011.08.025Get rights and content

Abstract

Introduction

The pulmonary embolism severity index (PESI) and the recently derived simplified PESI prognostic model have been developed to estimate the risk of 30-day mortality in patients with acute PE. We sought to assess if the PESI and simplified PESI prognostic models can accurately identify adverse events and to determine the rates of events in patients treated as outpatients.

Methods

A retrospective cohort study of patients with acute pulmonary embolism (PE) presenting at the Ottawa Hospital (Canada) was conducted between 1 January 2007 and 31 December 2008.

Results

Two hundred and forty three patients were included. A total of 118 (48.6%) and 81 (33.3%) were classified as low risk patients using the original and simplified PESI prognostic models respectively. None of the low risk patients died within the 3 months of follow-up. One hundred and fifteen (47.3%) patients were safely treated as outpatients with no deaths or bleeding episodes and only 1 recurrent event within the first 14 days or after 30 days of follow-up. Thirty four (29.6%) of these outpatients were classified as high risk patients according to the original PESI and 54 (47.0%) to the simplified PESI prognostic model.

Conclusion

Both PESI strategies accurately identify patients with acute PE who are at low risk and high risk for short-term adverse events. However, 30 to 47% of patients with acute PE and a high risk PESI score were safely managed as outpatients. Future research should be directed at developing tools that predict which patients would benefit from inpatient management.

Introduction

The mortality and morbidity of pulmonary embolism (PE) may vary considerably depending on the severity of the event and co-morbidities. Predicting patient outcomes may enable different management strategies and may inform the clinician which patients can be treated as outpatients [1], [2].

Over the last decade, several studies have suggested that outpatient treatment in a selected group of hemodynamically stable patients with acute PE is safe [3], [4], [5], [6], [7] . Benefits include: 1) cost savings from a decrease in hospitalizations; 2) fewer patients at risk for hospital acquired infections; and 3) an improvement in quality of life, increased physical activity and social functioning [3], [8], [9], [10], [11]. However, physicians are reluctant to treat patients with PE at home due to uncertainty on how to safely identify patients who are at low risk for short-term adverse events [8], irrespective of whether the adverse events could be averted by hospitalization.

Prognostic models that will accurately predict short-term adverse outcomes may help identify patients with acute PE at low-risk of adverse events that can be safely treated as outpatients. Several prognostic models have been developed to assess the risk of death, recurrent venous thromboembolism (VTE) or major bleeding in patients with acute PE [12]. The most extensively validated prognostic models are the Geneva Prognostic Score (GPS) and the Pulmonary Embolism Severity Index (PESI) [12]. The GPS predicts the combined adverse outcomes of death, recurrent VTE and major bleeding episodes during the first three months following the index PE. However, the GPS prognostic model is not frequently used since it requires the use of ultrasound variables and arterial blood gas which decrease feasibility. Moreover, a comparison of GPS low-risk patients with PESI low-risk patients in a cohort of 599 consecutive patients with acute symptomatic PE showed that the PESI low-risk patients had a significantly lower mortality [13].

The PESI prognostic model stratifies patients in five risk classes with increasing risk of all cause short term mortality without any need for ultrasonography or laboratory studies [14]. The use of the PESI prognostic model requires computation of a score based on 11 variables each with a different weight (Table 1). Recently, a PESI-derived simplified model with a less complex scoring system has been proposed and seems to have a similar prognostic accuracy as the original PESI (Table 1) [15].

We sought to evaluate if the original and the simplified PESI prognostic models could identify patients with acute PE at low risk of short term adverse outcome who can be safely managed as outpatients.

Section snippets

Study population

We performed a retrospective cohort study including consecutive patients with high risk and non-high risk acute PE [16], [17] presenting at the Ottawa Hospital between 1 January 2007 and 31 December 2008 [4]. PE was defined as an intraluminal filling defect on CTPA or a high probability V/Q scan. Patients diagnosed with PE during hospitalization, patients with chronic PE and patients in whom anticoagulation was not initiated (e.g. palliative care patients, small clinical non-significant PE)

Results

A total of 243 patients presenting at the Ottawa Hospital with confirmed PE were included in this study. One hundred and fifteen (47.3%) patients were directly discharged from the Emergency Department and were treated out of the hospital, while 128 (52.7%) patients were admitted. According to the original PESI prognostic model, 118 (48.6%; 95% CI, 42.1 – 55.0) patients were classified as low risk (class I and II) and 125 (51.4%; 95% CI, 45.0 – 58.0) were classified as high risk (class III to

Discussion

The results of our study suggest that both PESI prognostic models accurately identify patients with acute PE who are at low risk for short-term adverse events, including death, recurrent venous thromboembolism and major hemorrhage. None of the low risk patients died or had any adverse event within the first 14 days. Both PESI prognostic models also seem to identify patients with acute PE at low risk of adverse outcome who can be safely managed as outpatients.

Our results are consistent with

Statement of conflict of interest

None declared.

References (23)

  • A. Squizzato et al.

    Outpatient treatment and early discharge of symptomatic pulmonary embolism: a systematic review

    Eur Respir J

    (May 2009)
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