Grégoire Le Gal1, Michael J Kovacs2, Laurent Bertoletti3, Francis Couturaud4, Carole Dennie5, Andrew M Hirsch6, Menno V Huisman7, Frederikus A Klok7, Noémie Kraaijpoel8, Ranjeeta Mallick9, Amanda Pecarskie10, Elena Pena5, Penny Phillips10, Isabelle Pichon11, Tim Ramsay12, Marc Righini13, Marc A Rodger14, Pierre-Marie Roy15, Olivier Sanchez16, Jeannot Schmidt17, Sam Schulman18, Sudeep Shivakumar19, Albert Trinh-Duc20, Rachel Verdet21, Ulric Vinsonneau22, Philip Wells10, Cynthia Wu23, Erik Yeo24, Marc Carrier10. 1. Centre d'Investigation Clinique, Centre Hospitalier Régional et Universitaire de Brest, Brest, France, and Department of Medicine, University of Ottawa, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (G.L.). 2. Division of Hematology, Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada (M.J.K.). 3. Service de Médecine Vasculaire et Thérapeutique, Hôpital Nord, CHU de St-Etienne, INSERM, SAINBIOSE, U1059, Dysfonction Vasculaire et Hémostase et Université Jean-Monnet, CIC1408, F- 42055 Saint-Etienne, Réseau français F-CRIN INNOVTE, Saint-Etienne, France (L.B.). 4. Centre d'Investigation Clinique, Centre Hospitalier Régional et Universitaire de Brest, and Département de médecine interne, médecine vasculaire et pneumologie, Hôpital de la Cavale Blanche, EA3878-GETBO, Univ Brest, Réseau français F-CRIN INNOVTE, CHRU Brest, Brest, France (F.C.). 5. Department of Radiology, University of Ottawa, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (C.D., E.P.). 6. Department of Medicine, McGill University, Jewish General Hospital, Montreal, Quebec, Canada (A.M.H.). 7. Department of Medicine - Thrombosis and Hemostasis, Leiden University Medical Center, Dutch Thrombosis Network, Leiden, the Netherlands (M.V.H., F.A.K.). 8. Department of Vascular Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (N.K.). 9. Ottawa Methods Center, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (R.M.). 10. Department of Medicine, University of Ottawa, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (A.P., P.P., P.W., M.C.). 11. Service de Recherche Clinique, Hôpital d'Instruction des Armées, Brest, France (I.P.). 12. Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada (T.R.). 13. Division of Angiology and Hemostasis, Geneva University Hospitals and Faculty of Medicine, University of Geneva, Geneva, Switzerland (M.R.). 14. Department of Medicine, McGill University, McGill University Health Center, Montreal, Quebec, Canada (M.A.R.). 15. Univ Angers, MITOVASC, Equipe CarMe, Département de Médecine d'Urgence, Centre Hospitalier Universitaire d'Angers, Réseau français F-CRIN INNOVTE, Angers, France (P.R.). 16. Université de Paris, Service de Pneumologie et Soins Intensifs, Hôpital Européen Georges Pompidou, AP-HP.Centre - Université de Paris, INSERM UMR S 1140 Innovative therapies in hemostasis, Réseau français F-CRIN INNOVTE, Paris, France (O.S.). 17. Département de Médecine d'Urgence, Centre Hospitalier Universitaire Gabriel Montpied, Réseau français F-CRIN INNOVTE, Clermont-Ferrand, France (J.S.). 18. Department of Medicine, Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, Ontario, Canada, and Department of Obstetrics and Gynecology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia (S.S.). 19. Department of Medicine, Dalhousie University, Nova Scotia Health, Halifax, Nova Scotia, Canada (S.S.). 20. Centre Hospitalier d'Agen-Nérac, Agen, France (A.T.). 21. Direction de la Recherche et de l'Innovation, Centre Hospitalier Régional Universitaire de Brest, Brest, France (R.V.). 22. Department of Cardiology, Clermont Tonnerre Hospital of Military Training, Brest, France (U.V.). 23. Department of Medicine, University of Alberta Hospital, Edmonton, Alberta, Canada (C.W.). 24. Department of Medicine, University Health Network, University of Toronto, Toronto, Ontario, Canada (E.Y.).
Abstract
BACKGROUND: The incidence of pulmonary embolism has been increasing, but its case-fatality rate is decreasing, suggesting a lesser severity of illness. The clinical importance of patients with pulmonary embolism isolated to the subsegmental vessels is unknown. OBJECTIVE: To determine the rate of recurrent venous thromboembolism in patients with subsegmental pulmonary embolism managed without anticoagulation. DESIGN: Multicenter prospective cohort study. (ClinicalTrials.gov: NCT01455818). SETTING: Eighteen sites between February 2011 and February 2021. PATIENTS: Patients with isolated subsegmental pulmonary embolism. INTERVENTION: At diagnosis, patients underwent bilateral lower-extremity venous ultrasonography, which was repeated 1 week later if results were negative. Patients without deep venous thrombosis did not receive anticoagulant therapy. MEASUREMENTS: The primary outcome was recurrent venous thromboembolism during the 90-day follow-up period. RESULTS: Recruitment was stopped prematurely because the predefined stopping rule was met after 292 of a projected 300 patients were enrolled. Of the 266 patients included in the primary analysis, the primary outcome occurred in 8 patients, for a cumulative incidence of 3.1% (95% CI, 1.6% to 6.1%) over the 90-day follow-up. The incidence of recurrent venous thromboembolism was 2.1% (CI, 0.8% to 5.5%) and 5.7% (CI, 2.2% to 14.4%) over the 90-day follow-up in patients with single and multiple isolated subsegmental pulmonary embolism, respectively. No patients had a fatal recurrent pulmonary embolism. LIMITATION: The study was restricted to patients with low-risk subsegmental pulmonary embolism. CONCLUSION: Overall, patients with subsegmental pulmonary embolism who did not have proximal deep venous thrombosis had a higher-than-expected rate of recurrent venous thromboembolism. PRIMARY FUNDING SOURCE: Heart and Stroke Foundation of Canada and French Ministry of Health Programme Hospitalier de Recherche Clinique.
BACKGROUND: The incidence of pulmonary embolism has been increasing, but its case-fatality rate is decreasing, suggesting a lesser severity of illness. The clinical importance of patients with pulmonary embolism isolated to the subsegmental vessels is unknown. OBJECTIVE: To determine the rate of recurrent venous thromboembolism in patients with subsegmental pulmonary embolism managed without anticoagulation. DESIGN: Multicenter prospective cohort study. (ClinicalTrials.gov: NCT01455818). SETTING: Eighteen sites between February 2011 and February 2021. PATIENTS: Patients with isolated subsegmental pulmonary embolism. INTERVENTION: At diagnosis, patients underwent bilateral lower-extremity venous ultrasonography, which was repeated 1 week later if results were negative. Patients without deep venous thrombosis did not receive anticoagulant therapy. MEASUREMENTS: The primary outcome was recurrent venous thromboembolism during the 90-day follow-up period. RESULTS: Recruitment was stopped prematurely because the predefined stopping rule was met after 292 of a projected 300 patients were enrolled. Of the 266 patients included in the primary analysis, the primary outcome occurred in 8 patients, for a cumulative incidence of 3.1% (95% CI, 1.6% to 6.1%) over the 90-day follow-up. The incidence of recurrent venous thromboembolism was 2.1% (CI, 0.8% to 5.5%) and 5.7% (CI, 2.2% to 14.4%) over the 90-day follow-up in patients with single and multiple isolated subsegmental pulmonary embolism, respectively. No patients had a fatal recurrent pulmonary embolism. LIMITATION: The study was restricted to patients with low-risk subsegmental pulmonary embolism. CONCLUSION: Overall, patients with subsegmental pulmonary embolism who did not have proximal deep venous thrombosis had a higher-than-expected rate of recurrent venous thromboembolism. PRIMARY FUNDING SOURCE: Heart and Stroke Foundation of Canada and French Ministry of Health Programme Hospitalier de Recherche Clinique.