TY - JOUR
T1 - Monitoring of anti-xa in pregnant patients with mechanical prosthetic valves receiving low-molecular-weight heparin
T2 - Peak or trough levels?
AU - Goland, Sorel
AU - Schwartzenberg, Shmuel
AU - Fan, John
AU - Kozak, Natasha
AU - Khatri, Nudrat
AU - Elkayam, Uri
PY - 2014/9
Y1 - 2014/9
N2 - Objectives: We hypothesized that the guideline-recommended peak anti-Xa levels for pregnant women with mechanical prosthetic heart valves (MPHVs) receiving adjusted dose low-molecular-weight heparin (LMWH) are associated with subtherapeutic trough levels and consequently with an inadequate level of anticoagulation. Background: Low-molecular-weight heparin is often used for anticoagulation in pregnant women including those with MPHV. American College of Cardiology/American Heart Association guidelines recommend monitoring of plasma anti-Xa factor peak levels and adjustment of the dose to achieve peak levels of 0.7 to 1.2 U/mL. In spite of these recommendations, cases of valve thrombosis during pregnancy continue to occur. Methods and Results: We studied 30 pregnant patients receiving anticoagulation for various indications with adjusted dose LMWH given subcutaneously twice a day which had both trough and peak anti-Xa levels throughout pregnancy for a total of 187 paired determinations. The recommended peak anti-Xa levels (0.7-1.2 U/mL) were obtained in 123 (66%) of the measurements but in 80% of them, the trough levels were found to be subtherapeutic (<0.6 U/mL). Subtherapeutic trough levels were found in 8 (73%) of the 11 measurements with peak levels of 0.7 to 0.79 U/mL, 17 (74%) of the 23 of 0.8 to 0.89 U/mL, 21 (72%) of the 29 of 0.9 to 0.99 U/ mL, and 28 (44%) of the 63 of 1.0 to 1.2 U/mL. There were 42 measurements with peak anti-Xa levels >1.2 U/mL and even in these cases, 13 (31%) of the trough levels were found to be subtherapeutic. Conclusions: Anticoagulation with adjusted dose LMWH aimed to achieve guideline-recommended peak levels of anti-Xa for patients with MPHVs is commonly associated with subtherapeutic trough levels. Routine measurement of trough anti-Xa levels is therefore advisable in women with MPHV treated with LMWH during pregnancy to assure adequate level of anticoagulation.
AB - Objectives: We hypothesized that the guideline-recommended peak anti-Xa levels for pregnant women with mechanical prosthetic heart valves (MPHVs) receiving adjusted dose low-molecular-weight heparin (LMWH) are associated with subtherapeutic trough levels and consequently with an inadequate level of anticoagulation. Background: Low-molecular-weight heparin is often used for anticoagulation in pregnant women including those with MPHV. American College of Cardiology/American Heart Association guidelines recommend monitoring of plasma anti-Xa factor peak levels and adjustment of the dose to achieve peak levels of 0.7 to 1.2 U/mL. In spite of these recommendations, cases of valve thrombosis during pregnancy continue to occur. Methods and Results: We studied 30 pregnant patients receiving anticoagulation for various indications with adjusted dose LMWH given subcutaneously twice a day which had both trough and peak anti-Xa levels throughout pregnancy for a total of 187 paired determinations. The recommended peak anti-Xa levels (0.7-1.2 U/mL) were obtained in 123 (66%) of the measurements but in 80% of them, the trough levels were found to be subtherapeutic (<0.6 U/mL). Subtherapeutic trough levels were found in 8 (73%) of the 11 measurements with peak levels of 0.7 to 0.79 U/mL, 17 (74%) of the 23 of 0.8 to 0.89 U/mL, 21 (72%) of the 29 of 0.9 to 0.99 U/ mL, and 28 (44%) of the 63 of 1.0 to 1.2 U/mL. There were 42 measurements with peak anti-Xa levels >1.2 U/mL and even in these cases, 13 (31%) of the trough levels were found to be subtherapeutic. Conclusions: Anticoagulation with adjusted dose LMWH aimed to achieve guideline-recommended peak levels of anti-Xa for patients with MPHVs is commonly associated with subtherapeutic trough levels. Routine measurement of trough anti-Xa levels is therefore advisable in women with MPHV treated with LMWH during pregnancy to assure adequate level of anticoagulation.
KW - Anticoagulation
KW - Low-molecular-weight heparin
KW - Mechanical prosthetic heart valves
KW - Pregnancy
UR - http://www.scopus.com/inward/record.url?scp=84913586139&partnerID=8YFLogxK
U2 - 10.1177/1074248414524302
DO - 10.1177/1074248414524302
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
C2 - 24607762
AN - SCOPUS:84913586139
SN - 1074-2484
VL - 19
SP - 451
EP - 456
JO - Journal of Cardiovascular Pharmacology and Therapeutics
JF - Journal of Cardiovascular Pharmacology and Therapeutics
IS - 5
ER -