Chest
Volume 137, Issue 6, June 2010, Pages 1382-1390
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ORIGINAL RESEARCH
ANTITHROMBOTIC THERAPY
Early Anticoagulation Is Associated With Reduced Mortality for Acute Pulmonary Embolism

https://doi.org/10.1378/chest.09-0959Get rights and content

Background

Acute pulmonary embolism (PE) may be rapidly fatal if not diagnosed and treated. IV heparin reduces mortality and recurrence of PE, but the relationship between survival and timing of anticoagulation has not been extensively studied.

Methods

We studied 400 consecutive patients in the ED diagnosed with acute PE by CT scan angiography and treated in the hospital with IV unfractionated heparin from 2002 to 2005. Patients received heparin either in the ED or after admission. Time from ED arrival to therapeutic activated partial thromboplastin time (aPTT) was calculated. Outcomes included in-hospital and 30-day mortality, hospital and ICU lengths of stay, hemorrhagic events on heparin, and recurrent venous thromboembolism within 90 days.

Results

In-hospital and 30-day mortality rates were 3.0% and 7.7%, respectively. Patients who received heparin in the ED had lower in-hospital (1.4% vs 6.7%; P = .009) and 30-day (4.4% vs 15.3%; P < .001) mortality rates as compared with patients given heparin after admission. Patients who achieved a therapeutic aPTT within 24 h had lower in-hospital (1.5% vs 5.6%; P = .093) and 30-day (5.6% vs 14.8%; P = .037) mortality rates as compared with patients who achieved a therapeutic aPTT after 24 h. In multiple logistic regression models, receiving heparin in the ED remained predictive of reduced mortality, and ICU admission remained predictive of increased mortality.

Conclusions

We report an association between early anticoagulation and reduced mortality for patients with acute PE. We advocate further study with regard to comorbidities to assess the usefulness of modifications to hospital protocols.

Section snippets

Patient Selection and Characterization

We conducted a retrospective review of a cohort of adult patients who presented to a single tertiary care ED with acute PE between June 17, 2002, and September 6, 2005. All PE diagnoses were confirmed by CT scan angiography. Patients were excluded if diagnosis was prior to arrival or if anticoagulation was contraindicated. All patients were initially treated with an IV weight-based heparin nomogram similar to the one described by Raschke et al14 as per our institutional practice. This study was

Results

Search of the Mayo Clinic electronic medical record yielded 400 patients seen in the ED between 2002 and 2005 who met the aforementioned criteria for acute PE (Tables 1, 2). Median age was 68.0 years (IQR, 54.0–76.0), with 48.8% men. Patients were hospitalized for a median 4.6 days (IQR, 2.1–6.9). Seventy-seven patients (19.3%) required ICU admission, and the median ICU length-of-stay was 2.0 days (IQR, 1.0–3.0). The median follow-up time was 1,411.9 days (IQR 294.9–1,777.8), and 392 patients

Discussion

Guidelines recommend early anticoagulation for patients with acute PE.3, 17 These guidelines come from data showing that anticoagulation reduces overall mortality and VTE recurrence.6, 9, 11, 12, 13, 21, 22, 23, 24, 25, 26, 27 However, prior studies have not evaluated how the timing of anticoagulation relates to mortality. This study is the first to consider how the timing of anticoagulation is associated with mortality for acute PE. Our data demonstrate reduced in-hospital and 30-day mortality

Conclusions

We provide novel data regarding how the timing of anticoagulation relates to mortality for patients with acute PE. Delayed anticoagulation in our cohort was a risk factor associated with increased mortality. Further investigations are warranted to elucidate the influence of certain demographics and comorbidities, but we nevertheless advocate that quality improvement measures be considered to expedite management of acute PE.

Acknowledgments

Author Contributions: Dr Smith: contributed to collecting and analyzing the data.

Dr Geske: contributed to collecting and analyzing the data.

Dr Maguire: contributed to collecting and analyzing the data.

Mr Zane: contributed to collecting and analyzing the data.

Dr Carter: contributed to providing statistical support.

Dr Morgenthaler: contributed to providing review, guidance, and manuscript preparation.

Financial/nonfinancial disclosures: The authors have reported to CHEST that no potential

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    Funding/Support: This study was supported by the National Center for Research Resources, a component of the National Institutes of Health (NIH) [Grant 1 UL1 RR024150-01] and the NIH Roadmap for Medical Research. The Center for Translation Science Activities at Mayo Clinic has NIH funding.

    Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestpubs.org/site/misc/reprints.xhtml).

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