Troponin

Troponin-Based Risk Stratification of Patients With Acute Nonmassive Pulmonary Embolism
Systematic Review and Metaanalysis
David Jiménez, MD,
Fernando Uresandi, MD,
Remedios Otero, MD,
José Luis Lobo, MD,
Manuel Monreal, MD,
David Martí, MD,
Javier Zamora, MD,
Alfonso Muriel, MD,
Drahomir Aujesky, MD and
Roger D. Yusen, MD, FCCP
+ Author Affiliations

From the Respiratory Department (Dr. Jiménez), the Cardiology Department (Dr. Martí), and the Biostatistics Unit (Drs. Zamora and Muriel), Ramón y Cajal Hospital, Madrid, Spain; the Respiratory Department (Dr. Uresandi), Cruces Hospital, Bilbao, Spain; the Respiratory Department (Dr. Otero), Virgen del Rocío Hospital, Sevilla, Spain; the Respiratory Department (Dr. Lobo), Txagorritxu Hospital, Vitoria, Spain; the Medicine Department (Dr. Monreal), Germans Trias i Pujol Hospital, Barcelona, Spain; the Division of General Internal Medicine (Dr. Aujesky), University of Lausanne, Lausanne, Switzerland; and the Divisions of Pulmonary and Critical Care Medicine and General Medical Sciences (Dr. Yusen), Washington University School of Medicine, St. Louis, MO.
David Jiménez, MD, Respiratory Department, Ramón y Cajal Hospital, Colmenar Rd, Kilometer 9.100, 28034 Madrid, Spain; e-mail: djc_69_98@yahoo.com
Abstract
Background: Controversy exists regarding the usefulness of troponin testing for the risk stratification of patients with acute pulmonary embolism (PE). We conducted an updated systematic review and a metaanalysis of troponin-based risk stratification of normotensive patients with acute symptomatic PE. The sources of our data were publications listed in Medline and Embase from 1980 through April 2008 and a review of cited references in those publications.
Methods: We included all studies that estimated the relation between troponin levels and the incidence of all-cause mortality in normotensive patients with acute symptomatic PE. Two reviewers independently abstracted data and assessed study quality. From the literature search, 596 publications were screened. Nine studies that consisted of 1,366 normotensive patients with acute symptomatic PE were deemed eligible. Pooled results showed that elevated troponin levels were associated with a 4.26-fold increased odds of overall mortality (95% CI, 2.13 to 8.50; heterogeneity χ2 = 12.64; degrees of freedom = 8; p = 0.125). Summary receiver operating characteristic curve analysis showed a relationship between the sensitivity and specificity of troponin levels to predict overall mortality (Spearman rank correlation coefficient = 0.68; p = 0.046). Pooled likelihood ratios (LRs) were not extreme (negative LR, 0.59 [95% CI, 0.39 to 0.88]; positive LR, 2.26 [95% CI, 1.66 to 3.07]). The Begg rank correlation method did not detect evidence of publication bias.
Conclusions: The results of this metaanalysis indicate that elevated troponin levels do not adequately discern normotensive patients with acute symptomatic PE who are at high risk for death from those who are at low risk for death.
Footnotes
Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal.org/site/misc/reprints.xhtml).

New Heparin Reference Standard

Heparin: Change in Reference Standard
Audience: Pharmacists, physicians, hospital risk managers and consumers
[Posted - 10/01/2009] FDA notified healthcare professionals and patients of a change to heparin, effective October 1, 2009, which will include a new reference standard and test method used to determine the potency of the drug and able to detect impurities that may be present in heparin. The change, which will also harmonize the USP unit dose with the WHO International Standard unit dose, will result in approximately a 10% reduction in the potency of the heparin marketed in the United States.
This may have clinical significance in some situations, such as when heparin is administered as a bolus intravenous dose and an immediate anticoagulant effect is clinically important. Healthcare providers should be aware of the decrease in heparin potency as they monitor the anticoagulant effect of the drug; more heparin may be required to achieve and maintain the desired level of anticoagulation in some patients.
There will be simultaneous availability of heparin manufactured to meet the “old” and “new” USP monograph, with potential differences in potency. Products using the new “USP unit” potency definition are anticipated to be available on or after October 8. FDA is working with the manufacturers of heparin to ensure that an appropriate identifier is placed on heparin made under the new USP monograph. Most manufacturers will place an “N” next to the lot number. FDA is also working with the heparin manufacturers to study the impact of this variation in potency and will make the results available when the studies have concluded.
[10/01/2009 - Public Health Alert - FDA]
[10/01/2009 - Information for Consumers - FDA]

Chest Tubes