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Pulmonary embolism in pregnancy
Correspondence
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Bourjeily G, Paidas M, Khalil H, Rosene-Montella K, Rodger M. Pulmonary embolism in pregnancy. Lancet 2010; 375: 500–12. Chabloz P, Reber G, Boehlen F, Holhfeld P. TAFI antigen and D-dimer levels during normal pregnancy and at delivery. Br J Haematol 2001; 115: 150–52. Rosenberg VA, Lockwood CJ. Thromboembolism in pregnancy. Obstet Gynecol Clin N Am 2007; 34: 481–500. Torbicki A, Perrier A, Konstantinides S, et al. Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC). Eur Heart J 2008; 29: 2276–315.
In their Seminar on the diagnosis and management of pulmonary embolism in pregnancy,1 Ghada Bourjeily and colleagues do not mention chest radiography. This investigation should always be the first, to exclude infection or pneumothorax, and to improve the usefulness of scintigraphy. The incidence of non-diagnostic scintigrams is high in non-pregnant patients, mainly due to the presence of non-embolic lung disease such as asthma, obstructive lung disease, and other disorders resulting in an abnormal chest radiograph. Pregnant patients are generally younger and most commonly outpatients, enabling the number of non-diagnostic scans to be reduced by triaging patients with an abnormal chest radiograph and known previous pulmonary disease to computed tomographic pulmonary angiography (CTPA).2 The two studies of lung scintigraphy in pregnant patients quoted by Bourjeily and colleagues did not adopt this method.1,3 When correctly triaged by chest radiography and clinical history for previous pulmonary disease, half-dose perfusion scintigraphy has excellent diagnostic accuracy in pregnant patients, with a low non-diagnostic rate (7%).4 There is also now evidence of a much higher rate of non-diagnostic studies with CTPA (35·7%) compared with lung scintigraphy (4%) in pregnancy.5 Indeed, up to a third of pregnant women risk being exposed to radiation for no measurable benefit if CTPA is used firstline. The available evidence strongly favours perfusion scintigraphy as the 1778
investigation of choice in most pregnant patients with suspected pulmonary embolism. CTPA should be reserved for the small number of pregnant patients with underlying lung disease or a nondiagnostic lung scintigram. We declare that we have no conflicts of interest.
*Chirag Patel, Andrew Scarsbrook, Fergus Gleeson [email protected] Churchill Hospital, Oxford, OX3 7LJ, UK (CP, FG); and St James’s University Hospital, Leeds, UK (AS) 1
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Bourjeily G, Paidas M, Khalil H, Rosene-Montella K, Rodger M. Pulmonary embolism in pregnancy. Lancet 2010; 375: 500–12. Daftary A, Gregory M, Daftary A, Rosene-Montella K, Rodger M. Chest radiograph as a triage tool in the imagingbased diagnosis of pulmonary embolism. Am J Roentgenol 2005; 185: 132–34. Chan WS, Ray JG, Murray S, et al. Suspected pulmonary embolism in pregnancy. Clinical presentation, results of lung scanning, and subsequent maternal and pediatric outcomes. Arch Intern Med 2002; 162: 1170–75. Scarsbrook AF, Bradley KM, Gleeson FV. Perfusion scintigraphy: diagnostic utility in pregnant women with suspected pulmonary embolic disease. Eur Radiol 2007; 17: 2554–60. Ridge CA, McDermott S, Freyne BJ, et al. Pulmonary embolism in pregnancy: comparison of pulmonary CT angiography and lung scintigraphy. AJR Am J Roentgenol 2009; 193: 1223–27.
Ghada Bourjeily and colleagues1 provide a synthesis of current knowledge on pulmonary embolism in pregnancy. We have some concerns about their statement that “pulmonary embolism is the leading cause of maternal mortality in the developed world“, which, in our opinion, does not accord with the epidemiological evidence. The most recent report from the USA2 shows that thrombotic embolism is the third cause of maternal mortality after haemorrhage and hypertensive disorders. It is of major importance to differentiate amniotic fluid embolism from thrombotic embolism—the focus of the paper by Bourjeily and colleagues—since these two disorders have different pathophysiologies and risk factors. Among the few developed countries that conduct confidential enquiries into maternal deaths (recognised as
a unique means of collecting relevant maternal mortality data), the main contributor to maternal mortality is indirect causes in the UK,3 hypertensive disorders in the Netherlands,4 and haemorrhage in France.5 Although thromboembolism constitutes an important issue in pregnancy, it is important to keep in mind the actual pattern of causes of maternal mortality, in order to prioritise prevention strategies. We declare that we have no conflicts of interest.
*C Deneux-Tharaux, M Saucedo, M H Bouvier-Colle [email protected] French National Confidential Enquiry into Maternal Deaths (ENCMM), INSERM U 953 Epidemiological Research Unit on Perinatal Health and Women’s and Children’s Health, UPMC Paris 6, Paris, France 1
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3
4
5
Bourjeily G, Paidas M, Khalil H, Rosene-Montella K, Rodger M. Pulmonary embolism in pregnancy. Lancet 2010; 375: 500–12. Berg CJ, Chang J, Callaghan WM, Whitehead SJ. Pregnancy-related mortality in the United States, 1991-1997. Obstet Gynecol 2003; 101: 289–96. Lewis G. Saving mothers’ lives: reviewing maternal deaths to make motherhood safer: 2003–2005. The seventh report of the Confidential Enquiries into maternal deaths in the United Kingdom. London: CEMACH, 2007. Schutte JM, Steegers EA, Schuitemaker NW, et al. Rise in maternal mortality in the Netherlands. BJOG 2010; 117: 399–406. Institut du Vielle Sanitaire. Rapport du Comité National d’Experts sur la Mortalité Maternelle (CNEMM). http://www.invs.sante.fr/ publications/2006/mortalite_maternelle/ index.html (accessed April 28, 2010).
Authors’ reply We disagree with Jaime García de Tena and colleagues that primary evidence supports the use of D-dimer concentrations for suspected pulmonary embolism in pregnancy. The narrative review and guideline they cite do not provide primary evidence (ie, diagnostic cohort studies in pregnancy) that shows the safety or clinical use of D-dimer concentrations in the diagnostic approach for suspected pulmonary embolism in pregnancy. No primary diagnostic cohort studies validate a diagnostic approach for suspected pulmonary embolism that incorporates D-dimer in pregnancy. Tests of D-dimer concentrations are likely to perform www.thelancet.com May 22, 2010
1
2
3
4
Bourjeily G, Paidas M, Khalil H, Rosene-Montella K, Rodger M. Pulmonary embolism in pregnancy. Lancet 2010; 375: 500–12. Chabloz P, Reber G, Boehlen F, Holhfeld P. TAFI antigen and D-dimer levels during normal pregnancy and at delivery. Br J Haematol 2001; 115: 150–52. Rosenberg VA, Lockwood CJ. Thromboembolism in pregnancy. Obstet Gynecol Clin N Am 2007; 34: 481–500. Torbicki A, Perrier A, Konstantinides S, et al. Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC). Eur Heart J 2008; 29: 2276–315.
In their Seminar on the diagnosis and management of pulmonary embolism in pregnancy,1 Ghada Bourjeily and colleagues do not mention chest radiography. This investigation should always be the first, to exclude infection or pneumothorax, and to improve the usefulness of scintigraphy. The incidence of non-diagnostic scintigrams is high in non-pregnant patients, mainly due to the presence of non-embolic lung disease such as asthma, obstructive lung disease, and other disorders resulting in an abnormal chest radiograph. Pregnant patients are generally younger and most commonly outpatients, enabling the number of non-diagnostic scans to be reduced by triaging patients with an abnormal chest radiograph and known previous pulmonary disease to computed tomographic pulmonary angiography (CTPA).2 The two studies of lung scintigraphy in pregnant patients quoted by Bourjeily and colleagues did not adopt this method.1,3 When correctly triaged by chest radiography and clinical history for previous pulmonary disease, half-dose perfusion scintigraphy has excellent diagnostic accuracy in pregnant patients, with a low non-diagnostic rate (7%).4 There is also now evidence of a much higher rate of non-diagnostic studies with CTPA (35·7%) compared with lung scintigraphy (4%) in pregnancy.5 Indeed, up to a third of pregnant women risk being exposed to radiation for no measurable benefit if CTPA is used firstline. The available evidence strongly favours perfusion scintigraphy as the 1778
investigation of choice in most pregnant patients with suspected pulmonary embolism. CTPA should be reserved for the small number of pregnant patients with underlying lung disease or a nondiagnostic lung scintigram. We declare that we have no conflicts of interest.
*Chirag Patel, Andrew Scarsbrook, Fergus Gleeson [email protected] Churchill Hospital, Oxford, OX3 7LJ, UK (CP, FG); and St James’s University Hospital, Leeds, UK (AS) 1
2
3
4
5
Bourjeily G, Paidas M, Khalil H, Rosene-Montella K, Rodger M. Pulmonary embolism in pregnancy. Lancet 2010; 375: 500–12. Daftary A, Gregory M, Daftary A, Rosene-Montella K, Rodger M. Chest radiograph as a triage tool in the imagingbased diagnosis of pulmonary embolism. Am J Roentgenol 2005; 185: 132–34. Chan WS, Ray JG, Murray S, et al. Suspected pulmonary embolism in pregnancy. Clinical presentation, results of lung scanning, and subsequent maternal and pediatric outcomes. Arch Intern Med 2002; 162: 1170–75. Scarsbrook AF, Bradley KM, Gleeson FV. Perfusion scintigraphy: diagnostic utility in pregnant women with suspected pulmonary embolic disease. Eur Radiol 2007; 17: 2554–60. Ridge CA, McDermott S, Freyne BJ, et al. Pulmonary embolism in pregnancy: comparison of pulmonary CT angiography and lung scintigraphy. AJR Am J Roentgenol 2009; 193: 1223–27.
Ghada Bourjeily and colleagues1 provide a synthesis of current knowledge on pulmonary embolism in pregnancy. We have some concerns about their statement that “pulmonary embolism is the leading cause of maternal mortality in the developed world“, which, in our opinion, does not accord with the epidemiological evidence. The most recent report from the USA2 shows that thrombotic embolism is the third cause of maternal mortality after haemorrhage and hypertensive disorders. It is of major importance to differentiate amniotic fluid embolism from thrombotic embolism—the focus of the paper by Bourjeily and colleagues—since these two disorders have different pathophysiologies and risk factors. Among the few developed countries that conduct confidential enquiries into maternal deaths (recognised as
a unique means of collecting relevant maternal mortality data), the main contributor to maternal mortality is indirect causes in the UK,3 hypertensive disorders in the Netherlands,4 and haemorrhage in France.5 Although thromboembolism constitutes an important issue in pregnancy, it is important to keep in mind the actual pattern of causes of maternal mortality, in order to prioritise prevention strategies. We declare that we have no conflicts of interest.
*C Deneux-Tharaux, M Saucedo, M H Bouvier-Colle [email protected] French National Confidential Enquiry into Maternal Deaths (ENCMM), INSERM U 953 Epidemiological Research Unit on Perinatal Health and Women’s and Children’s Health, UPMC Paris 6, Paris, France 1
2
3
4
5
Bourjeily G, Paidas M, Khalil H, Rosene-Montella K, Rodger M. Pulmonary embolism in pregnancy. Lancet 2010; 375: 500–12. Berg CJ, Chang J, Callaghan WM, Whitehead SJ. Pregnancy-related mortality in the United States, 1991-1997. Obstet Gynecol 2003; 101: 289–96. Lewis G. Saving mothers’ lives: reviewing maternal deaths to make motherhood safer: 2003–2005. The seventh report of the Confidential Enquiries into maternal deaths in the United Kingdom. London: CEMACH, 2007. Schutte JM, Steegers EA, Schuitemaker NW, et al. Rise in maternal mortality in the Netherlands. BJOG 2010; 117: 399–406. Institut du Vielle Sanitaire. Rapport du Comité National d’Experts sur la Mortalité Maternelle (CNEMM). http://www.invs.sante.fr/ publications/2006/mortalite_maternelle/ index.html (accessed April 28, 2010).
Authors’ reply We disagree with Jaime García de Tena and colleagues that primary evidence supports the use of D-dimer concentrations for suspected pulmonary embolism in pregnancy. The narrative review and guideline they cite do not provide primary evidence (ie, diagnostic cohort studies in pregnancy) that shows the safety or clinical use of D-dimer concentrations in the diagnostic approach for suspected pulmonary embolism in pregnancy. No primary diagnostic cohort studies validate a diagnostic approach for suspected pulmonary embolism that incorporates D-dimer in pregnancy. Tests of D-dimer concentrations are likely to perform www.thelancet.com May 22, 2010