Clinical studies have shown that cardiovascular disease has become one of the leading causes of death in pregnancy, and about 0.2-4% of pregnant women can have combined cardiovascular disease; the number of patients with combined heart disease in pregnancy is also on a gradual rise due to increasing childbearing age and successful medical and surgical treatment of precardiac disease. With the adjustment of China’s fertility policy, the management of cardiovascular disease during pregnancy, including pre-birth counseling and answering, has become a task for cardiovascular disease physicians.
Common cardiovascular comorbidities in pregnancy include precardiac disease, aortic disease, valvular disease, coronary artery disease, cardiomyopathy, arrhythmias, blood pressure disorders, and venous embolism. The following describes the management of each cardiovascular complication in the guidelines.
1. Pregnancy combined with precordial disease
The guidelines recommend that patients with preeclampsia should undergo echocardiography and exercise testing prior to pregnancy to analyze the patient’s functional status and risk of pregnancy to determine whether to become pregnant. All patients with preeclampsia should be seen in the first 3 months after pregnancy and have an individualized follow-up plan. Patients with severe pulmonary stenosis should have their stenosis relieved before pregnancy by means of balloon dilatation and angioplasty;
Patients with cyanosis or Ebstein’s disease with heart failure should be treated prior to pregnancy and advised to abstain from pregnancy. Patients with right ventricular dilatation due to pulmonary regurgitation with concomitant symptoms should undergo pulmonary valve replacement prior to pregnancy. Patients with right ventricular dilatation due to pulmonary regurgitation who are not symptomatic should be considered for pulmonary valve replacement prior to pregnancy. Ascending aortography should be performed prior to pregnancy in all patients with a two-lobed aortic valve, and surgical treatment should be considered for aortic diameters >50 mm.
Anticoagulation should be considered in patients with Fontan circulation. patients with PAH, when considered due to or partially due to pulmonary embolism, should be treated with anticoagulation. Patients with PAH should be advised to avoid pregnancy if they have been treated with medication and to avoid pregnancy if their resting oxygen saturation is <85%.
2. Pregnancy combined with aortic lesions
Patients with Marfan syndrome or other aortic disease should be counseled about the risk of aortic coarctation; aortic imaging evaluation (CT/MRI) should be performed prior to pregnancy. Aortic coarctation usually occurs in the last trimester of pregnancy (about 50% of cases) or early postpartum (about 33% of cases). Because aortic coarctation is often missed, the possibility of this diagnosis should be considered in all cases of chest pain during pregnancy. aortic root diameter >45 mm in Marfan syndrome should be treated surgically before pregnancy.
Strict blood pressure control is recommended in cases of aortic dilatation, type B entrapment, and genetic predisposition. Patients with ascending aortic dilatation should undergo ultrasound evaluation every 4-8 weeks. Pregnant women with dilated distal ascending aorta, aortic arch and descending aorta should have MRI to evaluate the condition. Ascending aortography is also recommended in patients with diastolic aortic valves.
3. Heart valve disease in pregnancy
For mitral stenosis with symptoms or pulmonary hypertension, selective β1 receptor blockers should be given; if there are still symptoms of heart failure, diuretics should be given; in patients with severe mitral stenosis, surgical correction should be performed before pregnancy. For atrial fibrillation, left atrial embolism, or previous embolism, anticoagulation should be given; percutaneous mitral valve balloon dilation should be considered in pregnant women who are still symptomatic after drug therapy or have systolic pulmonary artery pressure >50 mmHg.
Patients with aortic stenosis who are symptomatic or have LVEF <50% or symptoms during exercise testing should undergo intervention before pregnancy. Pre-pregnancy intervention should be considered if there is a drop in blood pressure during exercise testing. Severe aortic or tricuspid regurgitation with symptoms and ventricular insufficiency or ventricular dilatation should be treated surgically prior to pregnancy. Symptoms of regurgitation during pregnancy should be treated medically.
For patients with mechanical valves, oral anticoagulants are recommended for 4-9 months of pregnancy; after 9 months, oral anticoagulants should be discontinued and replaced with low-molecular heparin or plain heparin; low-molecular heparin should be replaced with plain heparin 36 hours before delivery, and plain heparin should be discontinued 4-6 hours before delivery and reapplied 4-6 hours after delivery if there are no bleeding complications. Patients with syncope or with embolism should have an immediate sexual cardiac ultrasound.
In the first 3 months of pregnancy, warfarin (<5 mg/d) should be given with information and informed consent if anticoagulation is really needed; 6-12 weeks if warfarin dosage is >5 mg/d, consider changing to plain heparin or low molecular heparin; if anti-Xa levels cannot be monitored, avoid low molecular heparin.
Moderate-to-severe mitral stenosis and symptomatic aortic stenosis generally do not tolerate pregnancy and should be treated prior to pregnancy. Percutaneous mitral valve balloon dilatation should be considered if pharmacologic therapy is not effective during pregnancy, with the optimal timing of the procedure in the fourth to seventh trimester. Valvular regurgitation is better tolerated than valvular stenosis in pregnancy but requires close follow-up; when severe regurgitation leads to uncorrectable heart failure or severe ventricular enlargement, surgical treatment is required before pregnancy.
For those with implanted prosthetic valves, oral warfarin is the safest method to prevent valve thrombosis, and guidelines recommend taking it during the fourth to ninth months of pregnancy with INR monitoring (maintenance INR 2-3). In early pregnancy and after the ninth month of pregnancy, it can be replaced by regular heparin or low-molecular heparin.
4.Heart valve disease combined with pregnancy
Acute coronary syndrome during pregnancy is very rare, with an incidence of only 3-6/100,000. PCI is considered to be the best mode of revascularization for ST-segment elevation myocardial infarction, and if there is no residual ischemia, patients with coronary artery disease with LVEF >40% can be pregnant.
For non-ST-segment elevation infarction without significant symptoms, conservative treatment is recommended. In terms of pharmacological treatment, β-blockers and low-dose aspirin are relatively safe, clopidogrel application should be controlled for a minimum period of time, GPIIb/IIIa inhibitors, bivalirudin, prasugrel, and tigretol have unknown effects and are not recommended.
5.Pregnancy combined with arrhythmia
Supraventricular tachycardia is seen in 20-44% of pregnant women. Guidelines suggest that direct electrical cardioversion should be considered for hemodynamically unstable tachycardias; for atrial flutter and atrial fibrillation, electrical cardioversion after anticoagulation is preferred. For PSVT, treatment with adenosine based on vagal stimulation is recommended. for long-term pharmacological control of SVT, digoxin or metoprolol/propranolol is recommended. Atenolol is contraindicated. If indicated, an ICD should be implanted before pregnancy; for long QT syndrome, beta-blockers are recommended.
6. Pregnancy combined with cardiomyopathy
Cardiomyopathy is one of the serious complications of pregnancy. Perinatal cardiomyopathy, dilated cardiomyopathy and hypertrophic cardiomyopathy can all occur during pregnancy. Avoid ACEI, ARB, hydrazine, nitrate; use dobutamine, beta-blockers, digitalis, diuretics, etc. with caution in pregnancy combined with cardiomyopathy. About 50% of patients present with reduced left ventricular systolic function and have a poor prognosis. The guidelines recommend that patients with dilated cardiomyopathy should be informed of the risk of worsening cardiac function during pregnancy and the perinatal period. LVEF <40% is a high-risk predictor; maternal mortality is very high with LVEF <20% and termination of pregnancy should be considered.
7. Combined hypertension in pregnancy
The guidelines emphasize that patients with hypertension and preeclampsia during pregnancy have a significantly increased risk of hypertension and other cardiovascular diseases in the future, despite the normalization of blood pressure after delivery, and that postpartum follow-up and appropriate interventions should be strengthened for such pregnant women. Whether mild to moderate hypertension (<160/110 mmHg) can benefit from antihypertensive therapy has not been confirmed by clinical studies.
SBP 140-150 mmHg and DBP 90-99 mmHg do not require pharmacotherapy; SBP ≥150 mmHg; DBP ≥95 mmHg should be treated pharmacologically; SBP ≥170 mmHg; DBP ≥110 mmHg should be admitted to hospital; severe hypertension in pregnancy requires and can benefit from pharmacotherapy, but ACEI, ARB and renin Inhibitors.
8. Combined venous embolism in pregnancy
All pregnant women or proposed pregnant women should be evaluated for embolism risk; pregnant women should be informed of the symptoms of VTE so that they can contact the physician as soon as possible when suspicious signs occur; all high-risk patients should be treated with LMWH for 6 weeks before and after delivery. Early exercise and avoidance of dehydration are recommended for low-risk patients. High-risk patients are advised to wear compression stockings; follow-up DD and ultrasound are recommended for patients with VTE during pregnancy; UFH is recommended for high-risk patients with VTE during pregnancy and LMWH for low-risk patients; routine screening for embolism is not necessary.