RESUMO
BACKGROUND: Many patients with the antiphospholipid antibody syndrome and recurrent thrombosis receive doses of warfarin adjusted to achieve an international normalized ratio (INR) of more than 3.0. However, there are no prospective data to support this approach to thromboprophylaxis. METHODS: We performed a randomized, double-blind trial in which patients with antiphospholipid antibodies and previous thrombosis were assigned to receive enough warfarin to achieve an INR of 2.0 to 3.0 (moderate intensity) or 3.1 to 4.0 (high intensity). Our objective was to show that high-intensity warfarin was more effective in preventing thrombosis than moderate-intensity warfarin. RESULTS: A total of 114 patients were enrolled in the study and followed for a mean of 2.7 years. Recurrent thrombosis occurred in 6 of 56 patients (10.7 percent) assigned to receive high-intensity warfarin and in 2 of 58 patients (3.4 percent) assigned to receive moderate-intensity warfarin (hazard ratio for the high-intensity group, 3.1; 95 percent confidence interval, 0.6 to 15.0). Major bleeding occurred in three patients assigned to receive high-intensity warfarin and four patients assigned to receive moderate-intensity warfarin (hazard ratio, 1.0; 95 percent confidence interval, 0.2 to 4.8). CONCLUSIONS: High-intensity warfarin was not superior to moderate-intensity warfarin for thromboprophylaxis in patients with antiphospholipid antibodies and previous thrombosis. The low rate of recurrent thrombosis among patients in whom the target INR was 2.0 to 3.0 suggests that moderate-intensity warfarin is appropriate for patients with the antiphospholipid antibody syndrome.
Assuntos
Anticoagulantes/administração & dosagem , Síndrome Antifosfolipídica/tratamento farmacológico , Trombose Venosa/prevenção & controle , Varfarina/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antifosfolipídeos/sangue , Anticoagulantes/efeitos adversos , Síndrome Antifosfolipídica/sangue , Síndrome Antifosfolipídica/complicações , Método Duplo-Cego , Feminino , Seguimentos , Hemorragia/induzido quimicamente , Humanos , Coeficiente Internacional Normatizado , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/prevenção & controle , Embolia Pulmonar/prevenção & controle , Prevenção Secundária , Acidente Vascular Cerebral , Varfarina/efeitos adversosRESUMO
OBJECTIVE: To compare live birth rates in women with recurrent pregnancy loss (RPL) and either autoantibodies or a coagulation abnormality, treated with low molecular weight heparin plus aspirin (LMWH/ASA) or ASA alone, and to place our results in context with other randomized clinical trials (RCT) with similar cohorts. METHODS: The HepASA Trial was an RCT including patients with a history of RPL and at least 1 of the following: antiphospholipid antibody (aPL), an inherited thrombophilia, or antinuclear antibody. Treatment groups were stratified by aPL status and history of early versus late pregnancy losses. Patients received either LMWH/ASA or ASA alone. The primary outcome was live birth; secondary outcomes included adverse events and bone loss at the spine and femoral neck. Literature over the past 20 years was reviewed to identify comparable RCT. RESULTS: Over 4 years, 859 women with RPL were screened: 88 (10.2%) fulfilled inclusion criteria, became pregnant and were randomized to receive either LMWH/ASA or ASA alone. aPL were present in 42 (47.7%) patients in each group. The trial was stopped after 4 years when an interim analysis showed no difference in live birth rates in the 2 groups, and a lower rate of pregnancy loss in the ASA only group than expected. In the LMWH/ASA group, 35/45 (77.8%) had a live birth versus 34/43 (79.1%) in the ASA only group (p = 0.71). Neither number of prior losses nor aPL status was correlated with pregnancy outcome. There were no cases of pregnancy related thrombosis in either group. Mean change in BMD did not differ by treatment group at either the lumbar spine (p = 0.57) or femoral neck (p = 0.15). RCT since 2000 for aPL positive women with RPL and similar inclusion criteria report a mean live birth rate of 75% with either LMWH or ASA. CONCLUSION: LMWH/ASA did not confer incremental benefit compared to ASA alone for this population. Regardless of treatment regimen, number of prior losses, or aPL positivity, almost 80% of women in our RPL cohort had a successful pregnancy outcome. These findings contribute to a growing body of literature that contests the emerging standard of care comprising LMWH/ASA for this population.