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Mechanical heart valves increased risk for thrombotic events among pregnant women
The risk for experiencing a thrombotic event is higher among pregnant women with a mechanical heart valve compared with a tissue heart valve or no prosthetic valve, according to research published in Circulation.
Using data from the EURObservational Research Programme of the European Society of Cardiology, researchers compared data collected from 212 patients with a mechanical heart valve with 134 patients with a tissue heart valve and 2,620 without a prosthetic heart valve. Evaluated factors included pregnancy outcomes, as well as incidence of thrombotic events, major bleeding and other serious adverse events. Anticoagulant use was also assessed for each patient during the first trimester (up to 14 weeks), 14-26 weeks and from 36 weeks to delivery.
Maternal mortality occurred in 1.4% of patients with mechanical heart valves, compared with 1.5% of patients with tissue heart valves (P = 1) and 0.2% of patients without a prosthetic heart valve (P = .025). Incidence of miscarriage before 24 weeks and fetal death after 24 weeks were both significantly higher in the mechanical valve group. Pregnancies survived by both mother and child were less common in this group (81.6% of patients) compared with those with no prosthetic valve (97.7%; P < .001). Significantly more patients with tissue heart valves (79%) or without prosthetic valves (78%) had pregnancies free of serious adverse events compared with patients with mechanical heart valves (58%) (P < .001 for both comparisons).
Among those with a mechanical heart valve, 4.7% experienced mechanical valve thrombosis. Hemorrhagic events occurred in 23.1% of patients in the mechanical valve group, compared with 5.1% of those with a tissue heart valve and 4.9% of patients without a prosthetic valve (P < .001 for both).
Use of a vitamin K antagonist in the first trimester rather than heparin was associated with higher rates of miscarriage (28.6% vs. 9.2%; P < .001) and late fetal death (7.1% vs. 0.7%; P = .016), the researchers wrote.
“Patients with a mechanical heart valve are at increased risk of maternal and fetal mortality and morbidity, particularly thrombotic and hemorrhagic complications during pregnancy,” the researchers concluded. “Women with a mechanical heart valve should be counseled about the potential consequences of pregnancy and receive extensive guidance and care throughout pregnancy, delivery and the postpartum period from a specialized multidisciplinary team.” – by Trish Shea, MA
Disclosure: van Hagen reports no relevant financial disclosures.