ABC | Volume 114, Nº5, May 2020

Statement Brazilian Cardiology Society Statement for Management of Pregnancy and Family Planning in Women with Heart Disease – 2020 Arq Bras Cardiol. 2020; 114(5):849-942 Table 33 – Risk of venous thromboembolism associated with different thrombophilias Factor Prevalence in the general population (%) Risk during pregnancy (%) (with no prior history) Risk during pregnancy (%) (with prior history) Percentage of all thromboembolisms Factor V Leiden heterozygote 1 to 15 0.5 to 3.1 10 40 Factor V Leiden homozygote < 1 2.2 to 14 17 2 G20210A heterozygote 2 to 5 0.4 to 2.6 > 10 17 G20210A homozygote < 1 2.0 to 4.0 > 17 0.5 Factor V Leiden/G20210A heterozygote 0.01 4.0 to 8.2 > 20 1 to 3 Antithrombin deficiency 0.02 0.2 to 11.6 40 1 Protein C deficiency 0.2 to 0.4 0.1 to 1.7 4 to 17 14 Protein S deficiency 0.03 to 0.13 0.3 to 6.6 0 to 22 3 G20210A: mutation of the prothrombin gene. are present, the negative predictive value appears to be 100% but this method still needs to be validated by larger prospective studies. 340,341 • The variables considered by risk scores for DVT are the following: • Presentation of thrombosis in the left leg; • Difference of ≥ 2 cm in calf circumference (edema); • Presentation during the first trimester of pregnancy. Table 34 lists the complementary examinations used for diagnosing DVT, their sensitivity, specificity, advantages, and disadvantages. 5.2.4.2. D-dimer D-dimer dosage is present in the classical algorithm for diagnosing thromboembolism; during pregnancy, however, this marker loses its accuracy for diagnosing PTE, given that it undergoes an increase of approximately 40%during all trimesters, the postpartum period, and complications such as preeclampsia and placenta abruption. 342 These uncertainties influence the disagreement regarding use of D-dimer in the algorithm for diagnosing thromboembolism during gestation. 336,340,343 5.2.4.3. Venous Ultrasound A practical approach to suspected DVT begins with the use of compression ultrasound in the affected limb. Analysis of vein compressibility on this examination presents a sensitivity of 96% and a specificity of 98% for diagnosis of DVT above the knee; this is slightly lower for those beneath the knee, although there is a substantial chance of diagnosis in these as well. Knowledge of the fact that DVT frequently presents in proximal veins, but that it may be isolated in iliac veins may limit the ability to exclude DVT with compression ultrasound alone in symptomatic pregnant women. Given that compression maneuvers may not be performed in iliac veins, iliac vein thrombi are diagnosed by direct visualization of intraluminal echogenic mass or absence of spontaneous venous flow on Doppler. If ultrasound is positive, diagnosis is confirmed, and treatment is initiated immediately. In the event that it is negative and the patient continues to present symptoms, the examination should be repeated every 3 to 7 days, and treatment should be initiated if diagnosis is confirmed. Figure 9 shows 2 flowcharts for diagnosis of DVT during gestation: a venous compression ultrasound starting with the femoral veins and the use of D-dimer to evaluate the need for investigation of the iliac region; and complete venous ultrasound in the leg, including evaluation of the iliac vein. 5.2.4.4. Iliac Vein Magnetic Resonance When the clinical picture of isolated iliac thrombosis arises (whole limb edema, with or without pain in the flanks, buttocks, or lumbar regions), ultrasound does not resolve the situation well, and magnetic resonance should be used. Magnetic resonance may be used to diagnose DVT involving iliac veins during pregnancy, but it depends on the examiner’s expertise. 336,340,341 5.2.4.5. Pulmonary Thromboembolism Currently, approach to diagnosis of PTE during gestation is uncertain, and further studies are required. Approximately seven guidelines consider diagnosis of PTE during gestation, and the orientations regarding the use of rules for predicting risk, using D-dimer dosage, and choosing imaging methods diverge. Most of the guidelines do not include D-dimer dosage in the diagnostic algorithm for PTE. In relation to ultrasound, some guidelines initially use investigation for diagnosis of DVT; its positivity, however, is only 20% to 40% for PTE, and, if it is negative, diagnosis has to be confirmed by other imaging methods. Examinations of choice for diagnosing PTE are pulmonary V/Q scintigraphy or CTPA; both tests, however, carry the risk of maternal and fetal exposure to radiation. Pulmonary V/Q scintigraphy exposes the fetus to a greater radiation dose than CTPA; thus, if chest X-ray is normal, only perfusion scintigraphy is considered, therefore reducing the radiation dose. V/Q scintigraphy also exposes the child to a greater risk of neoplasm, and CTPA exposes the mother to a higher radiation dose, leading to a small, yet significant increase in the risk of breast cancer (1 case in 280,000 versus less than 1 case in 1,000,000). 907