Nadia Caron1, Georges-Étienne Rivard2, Nicole Michon3, Francine Morin3, Danielle Pilon1, Jean-Marie Moutquin4, Évelyne Rey3. 1. Department of Medicine, CHU Sherbrooke, Université de Sherbrooke, Sherbrooke QC. 2. Department of Pediatrics, CHU Sainte-Justine, Université de Montréal, Montreal QC. 3. Department of Obstetrics and Gynecology, CHU Sainte-Justine, Université de Montréal, Montreal QC. 4. Department of Obstetrics and Gynecology, CHU Sherbrooke, Université de Sherbrooke, Sherbrooke QC.
Abstract
OBJECTIVES: To study the platelet function response to low-dose ASA with the Platelet Function Analyzer (PFA-100) in pregnant women and to identify maternal characteristics associated with non-responsiveness. METHODS: We conducted a prospective cohort study involving 87 pregnant women on ASA. The platelet function response to ASA was measured as the closure time obtained with epinephrine cartridges (CT-EPI) by the PFA-100. Non-response to ASA was defined as a CT-EPI < or =150 seconds after four weeks of therapy. Non-responders were given an escalating dose of ASA and their CT-EPI was tested again. RESULTS: After four weeks of enteric-coated ASA 81 mg daily, 25/87 women (28.7%) were non-responders (95% CI 16.1 to 41.4). Among these women, a CT-EPI < or =150 seconds was found in 8/24 women (33.3%) after another four weeks of alternating ASA 81 mg and 162 mg daily. After a further four-week course of ASA 162 mg daily, a CT-EPI < or =150 seconds was found in 3/6 women (50.0%). Among the women who initially responded and who were reassessed at 24-32 weeks of pregnancy, the CT-EPI was < or =150 seconds in 9/36 (25.0%). There was no statistical difference in maternal characteristics between ASA responders and non-responders. CONCLUSION: A significant number of pregnant women showed a lack of platelet function response to ASA 81 mg that was in most cases overcome with higher dosing. Furthermore, the prevalence of non-responsiveness increased with advancing pregnancy.
OBJECTIVES: To study the platelet function response to low-dose ASA with the Platelet Function Analyzer (PFA-100) in pregnant women and to identify maternal characteristics associated with non-responsiveness. METHODS: We conducted a prospective cohort study involving 87 pregnant women on ASA. The platelet function response to ASA was measured as the closure time obtained with epinephrine cartridges (CT-EPI) by the PFA-100. Non-response to ASA was defined as a CT-EPI < or =150 seconds after four weeks of therapy. Non-responders were given an escalating dose of ASA and their CT-EPI was tested again. RESULTS: After four weeks of enteric-coated ASA 81 mg daily, 25/87 women (28.7%) were non-responders (95% CI 16.1 to 41.4). Among these women, a CT-EPI < or =150 seconds was found in 8/24 women (33.3%) after another four weeks of alternating ASA 81 mg and 162 mg daily. After a further four-week course of ASA 162 mg daily, a CT-EPI < or =150 seconds was found in 3/6 women (50.0%). Among the women who initially responded and who were reassessed at 24-32 weeks of pregnancy, the CT-EPI was < or =150 seconds in 9/36 (25.0%). There was no statistical difference in maternal characteristics between ASA responders and non-responders. CONCLUSION: A significant number of pregnant women showed a lack of platelet function response to ASA 81 mg that was in most cases overcome with higher dosing. Furthermore, the prevalence of non-responsiveness increased with advancing pregnancy.
Authors: Fionnuala Mone; Cecilia Mulcahy; Peter McParland; Fionnuala Breathnach; Paul Downey; Dorothy McCormack; Marie Culliton; Alice Stanton; Fiona Cody; John J Morrison; Sean Daly; John Higgins; Amanda Cotter; Alyson Hunter; Elizabeth C Tully; Patrick Dicker; Zarko Alfirevic; Fergal D Malone; Fionnuala M McAuliffe Journal: BMJ Open Date: 2018-07-28 Impact factor: 2.692