Clark
Cardiac disease in pregnancy – some good news SL Clark Baylor College of Medicine/Texas Children’s Hospital, Houston, TX, USA Linked article: This is a mini commentary on CM Lawley et al., pp. 1446–1455 and E Gelson et al., pp. 1552–1559 in this issue. To view these articles visit http://dx.doi.org/10.1111/1471-0528.13491 and http://dx.doi.org/10.1111/14710528.13489. Published Online 29 June 2015. Two articles in this month’s BJOG provide some welcome news for women with some types of cardiac disease during pregnancy. In a meta-analysis including 499 pregnancies, Lawley et al. examined maternal and perinatal outcomes in women with artificial heart valves. Less than 5% of women had the older, ball-and-cage type valves, making their data relevant to current practice. These authors reported a maternal mortality rate of 1.8% for mechanical valves, whereas no deaths were seen in women with bioprosthetic valves. Notably, in contrast to earlier studies no thrombosis-related deaths were identified in the current study. The authors appropriately attribute this improvement to advances in the design of mechanical prostheses and modified anticoagulation regimens and monitoring. Although no deaths from thrombosis were seen, the rate of thromboembolism even with newer mechanical valves was 12.5%; no thromboembolism was seen in women with bioprosthetic valves. Hence, although outcomes have improved, the two fundamental quandaries that have plagued us for decades remain. First, when considering valve replacement in women of childbearing age how does one balance the increased risk of
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mortality and thrombosis during pregnancy in women with mechanical valves against the need for more frequent valve replacement with bioprosthetic devices? Second, how does one balance the lower antithrombotic efficacy of heparin, which does not cross the placenta, with the potential adverse fetal effects of oral anticoagulants? Without the availability of an anticoagulant as effective as Coumadin that does not cross the placenta, this dilemma is likely to persist. In addition, Lawley et al. report a relatively high rate of pregnancy loss and perinatal deaths in women with artificial valves. To what extent these deaths may have been related to anticoagulation, or were a result of unknown factors, is uncertain. Although the value of any specific form of fetal surveillance in these women is unproven, enhanced vigilance – including serial fetal growth assessment and antepartum fetal heart rate testing – seems prudent. In a related article, Gelson et al. compared complications in first and second pregnancies in women with congenital and acquired cardiac disease. The interpretation of pooled data from patients with disparate forms of structural and functional defects must be undertaken with caution, even if these defects involve the same organ. A
report of clinical outcomes in patients with liver disease in pregnancy would have little value if data from patients with both intrahepatic cholestasis of pregnancy and hepatocellular carcinoma were pooled. In addition, one might question the authors’ contention that their data apply to women with both mild to moderate heart disease, since only one woman was NYHA class II – the rest were class I. Because of the limited power of such a study to detect no difference, one should be cautious in using these data to reassure women who have encountered a complication in their first pregnancy that the next pregnancy is not likely to be any worse. However, for women with NHYA class I disease contemplating a first pregnancy who wonder whether the stress of pregnancy might impact their long-term cardiac function and prognosis, the favourable tolerance of a subsequent 40-week ‘stress test’ represented by second pregnancies in this series suggest that the answer to this question is ‘no’. Both studies are good news for pregnant women with cardiac disease.
Disclosure of interest None declared. Completed disclosure of interests form available to view online as supportinginformation &
ª 2015 Royal College of Obstetricians and Gynaecologists
Cardiac disease in pregnancy – some good news SL Clark Baylor College of Medicine/Texas Children’s Hospital, Houston, TX, USA Linked article: This is a mini commentary on CM Lawley et al., pp. 1446–1455 and E Gelson et al., pp. 1552–1559 in this issue. To view these articles visit http://dx.doi.org/10.1111/1471-0528.13491 and http://dx.doi.org/10.1111/14710528.13489. Published Online 29 June 2015. Two articles in this month’s BJOG provide some welcome news for women with some types of cardiac disease during pregnancy. In a meta-analysis including 499 pregnancies, Lawley et al. examined maternal and perinatal outcomes in women with artificial heart valves. Less than 5% of women had the older, ball-and-cage type valves, making their data relevant to current practice. These authors reported a maternal mortality rate of 1.8% for mechanical valves, whereas no deaths were seen in women with bioprosthetic valves. Notably, in contrast to earlier studies no thrombosis-related deaths were identified in the current study. The authors appropriately attribute this improvement to advances in the design of mechanical prostheses and modified anticoagulation regimens and monitoring. Although no deaths from thrombosis were seen, the rate of thromboembolism even with newer mechanical valves was 12.5%; no thromboembolism was seen in women with bioprosthetic valves. Hence, although outcomes have improved, the two fundamental quandaries that have plagued us for decades remain. First, when considering valve replacement in women of childbearing age how does one balance the increased risk of
1456
mortality and thrombosis during pregnancy in women with mechanical valves against the need for more frequent valve replacement with bioprosthetic devices? Second, how does one balance the lower antithrombotic efficacy of heparin, which does not cross the placenta, with the potential adverse fetal effects of oral anticoagulants? Without the availability of an anticoagulant as effective as Coumadin that does not cross the placenta, this dilemma is likely to persist. In addition, Lawley et al. report a relatively high rate of pregnancy loss and perinatal deaths in women with artificial valves. To what extent these deaths may have been related to anticoagulation, or were a result of unknown factors, is uncertain. Although the value of any specific form of fetal surveillance in these women is unproven, enhanced vigilance – including serial fetal growth assessment and antepartum fetal heart rate testing – seems prudent. In a related article, Gelson et al. compared complications in first and second pregnancies in women with congenital and acquired cardiac disease. The interpretation of pooled data from patients with disparate forms of structural and functional defects must be undertaken with caution, even if these defects involve the same organ. A
report of clinical outcomes in patients with liver disease in pregnancy would have little value if data from patients with both intrahepatic cholestasis of pregnancy and hepatocellular carcinoma were pooled. In addition, one might question the authors’ contention that their data apply to women with both mild to moderate heart disease, since only one woman was NYHA class II – the rest were class I. Because of the limited power of such a study to detect no difference, one should be cautious in using these data to reassure women who have encountered a complication in their first pregnancy that the next pregnancy is not likely to be any worse. However, for women with NHYA class I disease contemplating a first pregnancy who wonder whether the stress of pregnancy might impact their long-term cardiac function and prognosis, the favourable tolerance of a subsequent 40-week ‘stress test’ represented by second pregnancies in this series suggest that the answer to this question is ‘no’. Both studies are good news for pregnant women with cardiac disease.
Disclosure of interest None declared. Completed disclosure of interests form available to view online as supportinginformation &
ª 2015 Royal College of Obstetricians and Gynaecologists
