Thrombosis Research 134 (2014) 1358
Contents lists available at ScienceDirect
Thrombosis Research journal homepage: www.elsevier.com/locate/thromres
Letter to the Editors-in-Chief Meta-Analysis to Assess the Quality of International Normalized Ratio Control and Associated Outcomes in Venous Thromboembolism Patients
Dear Editors, Thank you to Mearns and colleagues [1] for their recent publication “Meta-Analysis to Assess the Quality of International Normalized Ratio Control and Associated Outcomes in Venous Thromboembolism Patients”. We note, however, that the adverse clinical outcomes due to poor control of vitamin K antagonist (VKA) anticoagulation in their report were limited to bleeding and thrombosis. We would like to draw attention to an additional important clinical outcome that is related to subtherapeutic VKA anticoagulation, the postthrombotic syndrome (PTS). The finding that subtherapeutic anticoagulation is a risk factor for the development of PTS was shown by van Dongen et al. [2] as well as our group [3]. van Dongen and colleagues studied 244 patients in a prospective study in Padua, Italy. Patients enrolled had a first episode of an objectively confirmed symptomatic proximal deep venous thrombosis (DVT), treated with a VKA for at least 3 months. Multivariate analysis showed that patients who spent more than 50% of their time with an INR of less than 2.0 were at greater risk for PTS (odds ratio (OR) 2.71;95% CI: 1.44–5.10). Our group studied 349 patients with a first unprovoked DVT who were enrolled in a multinational, multicenter study (the REVERSE Study). Patients had received standard anticoagulation with a VKA for 5-7 months. Similarly, we found that in patients who had an INR below 2 for ≥ 20% of the time, the adjusted OR for the development of PTS was 1.88 (95% CI 1.15–3.07). Given that PTS occurs in 25-50% of patients with DVT who are treated with VKAs [4], is the strongest predictor of quality of life at 2 years post DVT [5], markedly increases health care costs [6], and has limited efficacious therapeutic interventions [7], emphasis must be placed on preventative strategies. Hence, alternative interventions such as the newer oral anticoagulants that may improve the time in the therapeutic range may prove to be of value in this regard. The findings in the studies by van Dongen et al and by our group may add weight to the findings and conclusions made by Mearns et al.
http://dx.doi.org/10.1016/j.thromres.2014.08.022 0049-3848/© 2014 Elsevier Ltd. All rights reserved.
References [1] Mearns ES, Kohn CG, Song JS, Hawthorne J, Meng J, White CM, et al. Meta-Analysis to Assess the Quality of International Normalized Ratio Control and Associated Outcomes in Venous Thromboembolism Patients. Thromb Res 2014;134(2):310–9. [2] van Dongen CJ, Prandoni P, Frulla M, Marchiori A, Prins MH, Hutten BA. Relation between quality of anticoagulant treatment and the development of the postthrombotic syndrome. J Thromb Haemost 2005;3:939–42. [3] Chitsike RS, Rodger MA, Kovacs MJ, Betancourt MT, Wells PS, Anderson DR, et al. Risk of post-thrombotic syndrome after subtherapeutic warfarin anticoagulation for a first unprovoked deep vein thrombosis: results from the REVERSE study. J Thromb Haemost 2012;10:2039–44. [4] Ashrani AA, Heit JA. Incidence and cost burden of post-thrombotic syndrome. J Thromb Thrombolysis 2009;28:465–76. [5] Kahn SR, Shbaklo H, Lamping DL, Holcroft CA, Shrier I, Miron MJ, et al. Determinants of health-related quality of life during the 2 years following deep vein thrombosis. J Thromb Haemost 2008;6:1105–12. [6] Guanella R, Ducruet T, Johri M, Miron MJ, Roussin A, Desmarais S, et al. Economic burden and cost determinants of deep vein thrombosis during two years following diagnosis: a prospective evaluation. J Thromb Haemost 2011;9:2397–405. [7] Kahn SR, Shapiro S, Wells PS, Rodger MA, Kovacs MJ, Anderson DR, et al. Compression stockings to prevent post-thrombotic syndrome: a randomised placebo-controlled trial. Lancet Mar 8 2014;383(9920):880–8. http://dx.doi.org/10.1016/S0140-6736 (13)61902-9.
R.S. Chitsike Division of Hematology, Department of Medicine, Memorial University of Newfoundland, Eastern Health, St John's S.R. Kahn Centre for Clinical Epidemiology and Community Studies, Jewish General Hospital, Montreal Department of Medicine, McGill University, Montreal M.A. Rodger Thrombosis Program, Division of Hematology, Department of Medicine, University of Ottawa Clinical Epidemiology Unit, Ottawa Health Research Institute, The Ottawa Hospital, Ottawa for the REVERSE investigators 22 July 2014
Contents lists available at ScienceDirect
Thrombosis Research journal homepage: www.elsevier.com/locate/thromres
Letter to the Editors-in-Chief Meta-Analysis to Assess the Quality of International Normalized Ratio Control and Associated Outcomes in Venous Thromboembolism Patients
Dear Editors, Thank you to Mearns and colleagues [1] for their recent publication “Meta-Analysis to Assess the Quality of International Normalized Ratio Control and Associated Outcomes in Venous Thromboembolism Patients”. We note, however, that the adverse clinical outcomes due to poor control of vitamin K antagonist (VKA) anticoagulation in their report were limited to bleeding and thrombosis. We would like to draw attention to an additional important clinical outcome that is related to subtherapeutic VKA anticoagulation, the postthrombotic syndrome (PTS). The finding that subtherapeutic anticoagulation is a risk factor for the development of PTS was shown by van Dongen et al. [2] as well as our group [3]. van Dongen and colleagues studied 244 patients in a prospective study in Padua, Italy. Patients enrolled had a first episode of an objectively confirmed symptomatic proximal deep venous thrombosis (DVT), treated with a VKA for at least 3 months. Multivariate analysis showed that patients who spent more than 50% of their time with an INR of less than 2.0 were at greater risk for PTS (odds ratio (OR) 2.71;95% CI: 1.44–5.10). Our group studied 349 patients with a first unprovoked DVT who were enrolled in a multinational, multicenter study (the REVERSE Study). Patients had received standard anticoagulation with a VKA for 5-7 months. Similarly, we found that in patients who had an INR below 2 for ≥ 20% of the time, the adjusted OR for the development of PTS was 1.88 (95% CI 1.15–3.07). Given that PTS occurs in 25-50% of patients with DVT who are treated with VKAs [4], is the strongest predictor of quality of life at 2 years post DVT [5], markedly increases health care costs [6], and has limited efficacious therapeutic interventions [7], emphasis must be placed on preventative strategies. Hence, alternative interventions such as the newer oral anticoagulants that may improve the time in the therapeutic range may prove to be of value in this regard. The findings in the studies by van Dongen et al and by our group may add weight to the findings and conclusions made by Mearns et al.
http://dx.doi.org/10.1016/j.thromres.2014.08.022 0049-3848/© 2014 Elsevier Ltd. All rights reserved.
References [1] Mearns ES, Kohn CG, Song JS, Hawthorne J, Meng J, White CM, et al. Meta-Analysis to Assess the Quality of International Normalized Ratio Control and Associated Outcomes in Venous Thromboembolism Patients. Thromb Res 2014;134(2):310–9. [2] van Dongen CJ, Prandoni P, Frulla M, Marchiori A, Prins MH, Hutten BA. Relation between quality of anticoagulant treatment and the development of the postthrombotic syndrome. J Thromb Haemost 2005;3:939–42. [3] Chitsike RS, Rodger MA, Kovacs MJ, Betancourt MT, Wells PS, Anderson DR, et al. Risk of post-thrombotic syndrome after subtherapeutic warfarin anticoagulation for a first unprovoked deep vein thrombosis: results from the REVERSE study. J Thromb Haemost 2012;10:2039–44. [4] Ashrani AA, Heit JA. Incidence and cost burden of post-thrombotic syndrome. J Thromb Thrombolysis 2009;28:465–76. [5] Kahn SR, Shbaklo H, Lamping DL, Holcroft CA, Shrier I, Miron MJ, et al. Determinants of health-related quality of life during the 2 years following deep vein thrombosis. J Thromb Haemost 2008;6:1105–12. [6] Guanella R, Ducruet T, Johri M, Miron MJ, Roussin A, Desmarais S, et al. Economic burden and cost determinants of deep vein thrombosis during two years following diagnosis: a prospective evaluation. J Thromb Haemost 2011;9:2397–405. [7] Kahn SR, Shapiro S, Wells PS, Rodger MA, Kovacs MJ, Anderson DR, et al. Compression stockings to prevent post-thrombotic syndrome: a randomised placebo-controlled trial. Lancet Mar 8 2014;383(9920):880–8. http://dx.doi.org/10.1016/S0140-6736 (13)61902-9.
R.S. Chitsike Division of Hematology, Department of Medicine, Memorial University of Newfoundland, Eastern Health, St John's S.R. Kahn Centre for Clinical Epidemiology and Community Studies, Jewish General Hospital, Montreal Department of Medicine, McGill University, Montreal M.A. Rodger Thrombosis Program, Division of Hematology, Department of Medicine, University of Ottawa Clinical Epidemiology Unit, Ottawa Health Research Institute, The Ottawa Hospital, Ottawa for the REVERSE investigators 22 July 2014
