Successful thrombolytic therapy using ultraslow low-dose infusion during pregnancy for mitral mechanical valve thrombosis: a case series and review of the literature

According to the modified World Health Organization (WHO) classification, pregnant women with mechanical valves face a very high risk of complications (Risk Category III). Mechanical valve thrombosis is a serious complication that significantly increases during pregnancy due to multiple mechanisms. Thrombolytic therapy has recently been used as a first-line treatment for mechanical valve thrombosis during pregnancy. However, the consensus regarding the optimal treatment strategy, type, dose and route of administration was unclear. We present three cases of mechanical mitral valve thrombosis during pregnancy treated successfully with repeated doses of ultraslow infusion of low-dose tissue-type plasminogen activator (t-PA) alteplase. We also present a review of the literature on this subject. LEARNING POINTS: Pregnancy in women with mechanical heart valves significantly increases the risk of maternal mortality or severe morbidity.Non-compliance with anticoagulant therapy and/or less frequent monitoring of therapeutic levels during pregnancy can result in serious complications such as valve thrombosis and thromboembolism.Thrombolytic therapy with low-dose tissue-type plasminogen activator can be an attractive alternative to surgical valve replacement and medical treatment in appropriately selected pregnant women with thrombosis of a mechanical valve.