Pregnancy in Patients With Structural or Ischaemic Heart Disease
Pregnancy in Patients With Structural or Ischaemic Heart Disease
In this large contemporary international prospective registry of 1321 patients with structural heart disease or IHD, the incidence of cardiac and neonatal complications was, as expected, found to be much higher than in the normal pregnant population and maternal mortality was more than 100 times higher than in the background population. However, clear distinctions could be made between the different types of heart disease and between the outcomes in developed vs. developing countries. The use of caesarean delivery was higher than in the normal population (41 vs. 23%) with a large variation between countries.
This was the largest subgroup in the registry and its outcomes were relatively good compared with other subgroups. Most of these patients were diagnosed and treated long before pregnancy and nowadays have pre-pregnancy counselling; as a consequence, they are better prepared for pregnancy. The high rate of successful prior cardiac corrective surgery, favourable baseline NYHA class, and low use of medication are all factors which are likely to have contributed to the relatively favourable outcomes. However, even in this group with relatively good outcome CS rates were higher and mean birth weight was lower than in the background population. The recent ESC guidelines advocate spontaneous onset of labour with vaginal delivery for most CHD patients. However, this is not based on hard data and clearly needs further investigations. It is possible that doctor's decision was the main reason for the high number of CSs. Premature birth was reported in 13% of our CHD patients, which is slightly lower than the 16% reported in a previous literature review, but higher than the 8% found in the normal population. The prematurity in this group is likely to have been influenced in part by the decision to perform elective CS but nevertheless, prematurity in any context must be taken seriously as it has the potential to influence neonatal outcome adversely.
Patients with VHD were often not known to have heart disease before pregnancy, and many patients were in NYHA classes II and III before pregnancy. As expected, mitral stenosis and/or regurgitation were the most common lesions (63%), while aortic valve disease occurred in 23%. Patients with VHD had a higher maternal mortality rate than patients with CHD. Heart failure was the most frequently observed maternal complication as was also found earlier by Hameed et al. and recorded in 18% of cases. In 38%, hospital admission was necessary and supraventricular arrhythmias were more common than in other patient subgroups. Furthermore, post-partum haemorrhage was encountered more often, probably associated with the use of anticoagulant therapy. The way that this high incidence of complications relates to the diagnosis of VHD, the country of residence, and the time they present for the first time (before or during pregnancy) will be investigated in more depth when more patients have been included in the registry.
In the 88 patients with CMP, the pre-pregnancy NYHA class was even worse than in the patients with VHD. Furthermore, maternal mortality, heart failure, and ventricular arrhythmias occurred more often than in any other group. Currently, the numbers are limited, making it impossible to correct for ejection fraction and type of CMP. As the registry is still ongoing, we expect this analysis will be possible in the future. Until now, no European studies have reported on the prognosis for women with PPCM. In South Africa, case series have demonstrated that mortality rates have slowly improved over time but rates of mortality within 6 months of delivery remain as high as 10%. Our study shows that more attention needs to be paid to this group. A dedicated registry for patients with PPCM will start within the ESC-EURObservational Research Programme.
IHD is seldom encountered during pregnancy, although the incidence is increasing, and it was found to be an important contributor to maternal mortality in the British Enquiry 'Saving Mothers Lives'. In this registry, to date, only 25 patients with IHD have been included. Not surprisingly, this patient group was older at baseline with more risk factors for coronary artery disease. Of the 20 patients who suffered from myocardial infarction prior to pregnancy, only one experienced a new ACS during the current pregnancy. Although these numbers are small, they are encouraging and may positively influence the current practice of cardiologists in counselling these patients. Until now, only case reports on patients becoming pregnant after ACS have been described in the literature. In the five other patients, a 'new' ACS occurred during the current pregnancy; all mothers survived. However, foetal outcome was poor with babies from this group having the greatest proportion of low Apgar scores, preterm deliveries, lowest birth weight, and highest mortality. Whether medication use, smoking, older age, or other factors were the contributors to this unfavourable outcome has to be determined in larger series. Indeed, in some women, the high incidence of preterm deliveries and low birth weight may be the expression of a diffuse vasculopathy causing chronic placental insufficiency.
Cultural and social pressures may have a greater influence on the decision to become pregnant in developing countries, meaning that pregnancies occur in a higher risk population than in developed countries. In this study, we found higher maternal mortality and morbidity in developing countries. This is a very complex issue, but if achievable, pre-conception counselling focusing on the severity of the heart disease with a clear statement of the consequences of pregnancy may save lives.
The pregnancy registry will continue to enrol patients over the next few years. This should allow a very large database to accumulate so that with more detailed analysis in larger disease-specific groups, firmer conclusions can be raised on the available data. These conclusions can then be used as the evidence base for improved management plans. Hopefully, these will make pregnancy safer for both mother and baby in this challenging situation.
Discussion
In this large contemporary international prospective registry of 1321 patients with structural heart disease or IHD, the incidence of cardiac and neonatal complications was, as expected, found to be much higher than in the normal pregnant population and maternal mortality was more than 100 times higher than in the background population. However, clear distinctions could be made between the different types of heart disease and between the outcomes in developed vs. developing countries. The use of caesarean delivery was higher than in the normal population (41 vs. 23%) with a large variation between countries.
Congenital Heart Disease
This was the largest subgroup in the registry and its outcomes were relatively good compared with other subgroups. Most of these patients were diagnosed and treated long before pregnancy and nowadays have pre-pregnancy counselling; as a consequence, they are better prepared for pregnancy. The high rate of successful prior cardiac corrective surgery, favourable baseline NYHA class, and low use of medication are all factors which are likely to have contributed to the relatively favourable outcomes. However, even in this group with relatively good outcome CS rates were higher and mean birth weight was lower than in the background population. The recent ESC guidelines advocate spontaneous onset of labour with vaginal delivery for most CHD patients. However, this is not based on hard data and clearly needs further investigations. It is possible that doctor's decision was the main reason for the high number of CSs. Premature birth was reported in 13% of our CHD patients, which is slightly lower than the 16% reported in a previous literature review, but higher than the 8% found in the normal population. The prematurity in this group is likely to have been influenced in part by the decision to perform elective CS but nevertheless, prematurity in any context must be taken seriously as it has the potential to influence neonatal outcome adversely.
Valvular Heart Disease
Patients with VHD were often not known to have heart disease before pregnancy, and many patients were in NYHA classes II and III before pregnancy. As expected, mitral stenosis and/or regurgitation were the most common lesions (63%), while aortic valve disease occurred in 23%. Patients with VHD had a higher maternal mortality rate than patients with CHD. Heart failure was the most frequently observed maternal complication as was also found earlier by Hameed et al. and recorded in 18% of cases. In 38%, hospital admission was necessary and supraventricular arrhythmias were more common than in other patient subgroups. Furthermore, post-partum haemorrhage was encountered more often, probably associated with the use of anticoagulant therapy. The way that this high incidence of complications relates to the diagnosis of VHD, the country of residence, and the time they present for the first time (before or during pregnancy) will be investigated in more depth when more patients have been included in the registry.
Cardiomyopathy
In the 88 patients with CMP, the pre-pregnancy NYHA class was even worse than in the patients with VHD. Furthermore, maternal mortality, heart failure, and ventricular arrhythmias occurred more often than in any other group. Currently, the numbers are limited, making it impossible to correct for ejection fraction and type of CMP. As the registry is still ongoing, we expect this analysis will be possible in the future. Until now, no European studies have reported on the prognosis for women with PPCM. In South Africa, case series have demonstrated that mortality rates have slowly improved over time but rates of mortality within 6 months of delivery remain as high as 10%. Our study shows that more attention needs to be paid to this group. A dedicated registry for patients with PPCM will start within the ESC-EURObservational Research Programme.
Ischaemic Heart Disease
IHD is seldom encountered during pregnancy, although the incidence is increasing, and it was found to be an important contributor to maternal mortality in the British Enquiry 'Saving Mothers Lives'. In this registry, to date, only 25 patients with IHD have been included. Not surprisingly, this patient group was older at baseline with more risk factors for coronary artery disease. Of the 20 patients who suffered from myocardial infarction prior to pregnancy, only one experienced a new ACS during the current pregnancy. Although these numbers are small, they are encouraging and may positively influence the current practice of cardiologists in counselling these patients. Until now, only case reports on patients becoming pregnant after ACS have been described in the literature. In the five other patients, a 'new' ACS occurred during the current pregnancy; all mothers survived. However, foetal outcome was poor with babies from this group having the greatest proportion of low Apgar scores, preterm deliveries, lowest birth weight, and highest mortality. Whether medication use, smoking, older age, or other factors were the contributors to this unfavourable outcome has to be determined in larger series. Indeed, in some women, the high incidence of preterm deliveries and low birth weight may be the expression of a diffuse vasculopathy causing chronic placental insufficiency.
Developed vs. Developing Countries
Cultural and social pressures may have a greater influence on the decision to become pregnant in developing countries, meaning that pregnancies occur in a higher risk population than in developed countries. In this study, we found higher maternal mortality and morbidity in developing countries. This is a very complex issue, but if achievable, pre-conception counselling focusing on the severity of the heart disease with a clear statement of the consequences of pregnancy may save lives.
Future Directions
The pregnancy registry will continue to enrol patients over the next few years. This should allow a very large database to accumulate so that with more detailed analysis in larger disease-specific groups, firmer conclusions can be raised on the available data. These conclusions can then be used as the evidence base for improved management plans. Hopefully, these will make pregnancy safer for both mother and baby in this challenging situation.
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