Correspondence
Correction
Thinking Outside the Box
N Engl J Med 2006; 355:851-852August 24, 2006
- Article
To the Editor:
Farzaneh-Far et al. (June 1 issue)1 describe a case of massive pulmonary embolism, stating that in more than 80 percent of patients with acute pulmonary embolism, echocardiography reveals abnormalities. However, others report that most patients with pulmonary embolism have normal echocardiographic results.2 For that reason, echocardiography has not been recommended as a routine imaging test for the diagnosis of suspected pulmonary embolism.3
3 ReferencesAriel Jaitovich, M.D.
Northwestern University, Chicago, IL 60611
a-jaitovich@northwestern.edu 1
Farzaneh-Far R ,Schwarzberg T ,Mushlin SB . Thinking outside the box. N Engl J Med 2006;354:2376-2381
Full Text | Web of Science | Medline2
Goldhaber SZ . Pulmonary embolism. N Engl J Med 1998;339:93-104
Full Text | Web of Science | Medline3
Goldhaber SZ . Echocardiography in the management of pulmonary embolism. Ann Intern Med 2002;136:691-700
Web of Science | Medline
To the Editor:
Farzaneh-Far et al. state that “although this is the patient's first thromboembolic event, testing him for a hypercoagulable state would be reasonable.” This statement requires clarification.
There is currently no consensus regarding whom to test for the inherited thrombophilias. Each year, approximately 250,000 patients receive a diagnosis of acute venous thromboembolism. It has been argued that testing of all patients with an initial episode of venous thromboembolism is not cost-effective.1 For patients with an initial episode of idiopathic venous thromboembolism, routine testing for an inherited thrombophilic defect would only be warranted if the results changed the treatment approach. However, Farzaneh-Far et al. later state that they “favor providing long-term anticoagulation with warfarin.” If the decision has already been made to provide long-term anticoagulation, then the clinical utility of testing for a hypercoagulable state is limited.
1 ReferencesMarc Itskowitz, M.D.
Allegheny General Hospital, Pittsburgh, PA 15212
mitskowi@wpahs.org 1
Murin S ,Marelich GP ,Arroliga AC ,Matthay RA . Hereditary thrombophilia and venous thromboembolism. Am J Respir Crit Care Med 1998;158:1369-1373
Web of Science | Medline
Author/Editor Response
Dr. Jaitovich correctly points out that many patients with pulmonary embolism do not have echocardiographic abnormalities; we wish to clarify that the high rate of echocardiographic abnormalities we noted would apply to patients with massive pulmonary embolism. Nevertheless, echocardiographic evidence of right ventricular dysfunction in patients with unexplained hemodynamic instability can suggest the diagnosis of pulmonary embolism and may warrant further diagnostic testing by spiral computed tomography of the chest with intravenous contrast.1 The primary role of echocardiography in acute pulmonary embolism is risk stratification. As we noted in our commentary, right ventricular hypokinesis is a powerful independent predictor of 90-day mortality in patients with submassive pulmonary embolism (defined as a systolic arterial pressure greater than 90 mm Hg).2
Dr. Itskowitz makes an important point regarding the lack of consensus about indications for testing for inherited thrombophilias. We agree that routine testing of all patients with idiopathic venous thromboembolism is not cost-effective. However, one could argue that a patient who has an idiopathic venous thromboembolism before 50 years of age has thrombophilia, and therefore, laboratory investigation is warranted.3 Given that abnormalities predisposing patients to venous thromboembolism, including protein S deficiency, are more common in patients with HIV infection, testing a 35-year-old man with HIV is not unreasonable, albeit costly. Although long-term anticoagulation was favored in this patient regardless of the test results, because of the life-threatening nature of his pulmonary embolism, such results could influence the intensity of anticoagulation. If the patient were found to have clinically significant titers of antiphospholipid antibodies, for example, his target international normalized ratio might be higher than that of a patient without this finding.
3 ReferencesRamin Farzaneh-Far, M.D.
University of California, San Francisco, San Francisco, CA 94117Talya Schwarzberg, M.D.
Beth Israel Deaconess Medical Center, Boston, MA 02215
tschwar1@bidmc.harvard. edu 1
Goldhaber SZ . Echocardiography in the management of pulmonary embolism. Ann Intern Med 2002;136:691-700
Web of Science | Medline2
Kucher N ,Rossi E ,De Rosa M ,Goldhaber SZ . Prognostic role of echocardiography among patients with acute pulmonary embolism and a systolic arterial pressure of 90 mm Hg or higher. Arch Intern Med 2005;165:1777-1781
CrossRef | Web of Science | Medline3
Kitchens CS, Alving BM, Kessler CM, eds. Consultative hemostasis and thrombosis. Philadelphia: W.B. Saunders, 2002.
