Standard Treatment Guidelines For Cardiac Disease In Pregnancy

The incidence of heart disease in pregnancy is 1% and it is the third leading cause of death in women of reproductive age group. Risk of maternal mortality ranges from 0 to 50% depending on the cardiac condition.

Ministry of Health and Family Welfare, Government of India has issued the Standard Treatment Guidelines for Cardiac Disease In Pregnancy. Following are its major recommendations :

1. WHEN TO SUSPECT / RECOGNISE?

The physiological adaptations of normal pregnancy can induce symptoms and alter clinical findings that may confound the diagnosis of heart disease.

Heart disease should be suspected or diagnosed at booking for antenatal women. Heart disease may be suspected when a pregnant lady presents with symptoms of progressive dyspnea or orthopnea, nocturnal cough, hemoptysis, syncope or chest pain.

When there are clinical findings like cyanosis, clubbing, distended neck veins, systolic murmur of grade 3/6 or greater, diastolic murmur, cardiomegaly, persistent arrhythmias, persistent split second sound, or pulmonary hypertension.

ii. Case definition:

Rheumatic Heart Disease (RHD) remains an important cause of heart disease especially in developing countries like India. A large number of women undergoing valve replacement surgeries on oral anticoagulants warrant specialized care during pregnancy and childbirth.

With advances in paediatric cardiac surgery more women with congenital heart disease (CHD) are now surviving and reaching child bearing age. Ischemic heart disease is also on the rise as a result of increase prevalence of obesity, hypertension and diabetes in young adults and delayed child bearing.

Maternal mortality is higher in conditions that restrict an increase in pulmonary blood flow especially pulmonary hypertension and mitral stenosis. The situation is at its worst 28 in Eisenmengers syndrome, where there is refractory hypoxaemia when the mortality is 25 to 50 %.

Other cardiac complications associated with pregnancy include infective endocarditis, cardiac arrhythmias, development of cardiomyopathy.

Fetal outcome in pregnancies complicated by maternal RHD is usually good although there is an increased incidence of growth restriction and preterm birth.

The effects of maternal anticoagulant therapy with warfarin could lead to abortions, stillbirths in 7%, warfarin embryopathy in 8%of live born infants. Warfarin exposure in the 2nd and 3rd trimesters could lead to disharmonic growth of organs due to hemorrhage in the fetus and deformation from scarring leading to corpus callosum agenesis, Dandy Walker malformation, cerebellar midline atrophy, optic atrophy and blindness, microphthalmia, mental retardation and developmental delay.

Anticoagulation may be indicated in certain cardiac conditions such as mechanical heart valves, atrial fibrillation and pulmonary hypertension.

Fetal growth restriction and preterm birth are more common in pregnancies complicated by CHD with restricted maternal cardiac output, especially poor in cyanotic varieties when the fetal wastage rates may be as high as 40%. The etiology of CHD is multifactorial and incidence is 0.8 %. Incidence of CHD in the offsprings of parents with CHD ranges from 5 -10%. However, risk may be as high as 50% as in Marfan’s syndrome.

iii. INCIDENCE OF THE CONDITION IN OUR COUNTRY

Nearly 1 % of all pregnant women have cardiac disease

iv. PREVENTION AND COUNSELING

Women may be aware of their cardiac condition before falling pregnant. An assessment of the patient’s clinical status and ventricular function are necessary to best predict the outcome of pregnancy. In more than 50% of women it is first diagnosed during pregnancy.

A Cardiologist should be involved in initial assessment and followup. In some women, life threatening cardiac abnormalities can be reversed by corrective surgery and subsequent pregnancy is less dangerous.

Women with conditions like pulmonary hypertension, severe left sided obstructive lesions, dilated aortopathy(>4cm) and severe systemic ventricular dysfunction should be counseled for early termination of pregnancy to avoid maternal mortality.

Concurrent medical problems like infections, anaemia should be aggressively treated.

Pneumococcal and influenza vaccines are recommended to avoid respiratory infections precipitating cardiac failure. Cigarette smoking and illicit drug abuses are prohibited to prevent cardiorespiratory side effects and infective endocarditis.

Women with cardiac disease should be counseled regarding the risk of maternal death, possible reduction in maternal life expectancy, fetal issues, need for timely switch over of anticoagulant therapy, need for frequent hospital attendance and possible admission, intense feto-maternal monitoring during labour.

v. DIFFERENTIAL DIAGNOSIS

a) Normal physiological changes of pregnancy

b) Anaemia

vi. OPTIMAL DIAGNOSTIC CRITERIA, INVESTIGATIONS, TREATMENT & REFERRAL CRITERIA .

Situation 1: At Secondary Hospital/Non-Metro situation: Optimal Standards of treatment in situations where technology and resources are limited

a. Clinical Diagnosis:

A clinical suspicion or recognition of cardiac disease based on history, clinical symptoms and signs as explained above is made

b. Investigations:

Basic work up like complete blood counts, urine routine, blood grouping Rh typing, serology,VDRL, APTT, PT INR, scans for dating, aneuploidy screening qnd foetal anomalies.

Nonivasive studies like electrocardiography, echocardiography and chest radiography with abdominal shielding can be conducted during pregnancy to support the diagnosis.

c. Treatment:

Clinical Classification Schemes commonly used are that of NYHA and ACOG These classification systems are useful to clinicians to evaluate the functional capacity and to aid in counseling the woman regarding advisability of conception or continuation of pregnancy.

New York Heart Association (NYHA) Classification Scheme:

 Class 1 Uncompromised. No limitation of physical activity.

 Class II Slightly compromised. Slight limitation of physical activity.

 Class III Markedly compromised. Marked limitation of physical activity.

 ClassIV Severely compromised. Inability to perform any physical activity without discomfort

Risk of Maternal mortality Caused by Various Types of Heart Disease (ACOG1992a):

Cardiac disorder

Group 1 - Minimal Risk 0-1% Mortality

 Atrial septal defect

 Ventricular septal defect

 Patent ductus arteriosus

 Pulmonic or tricuspid disease

 Corrected Tetrology of Fallot

 Bioprosthetic Valve

 Mitral stenosis (NYHA Classes 1 and II)

Group 2- Moderate Risk -5-15% mortality

2A:

 Mitral stenosis (NYHA Classes III and IV)

 Aortic stenosis

 Aortic coarctation without valvar involvement

 Uncorrected Fallot tetrology

 Previous myocardial infarction

 Marfans syndrome, normal aorta

2B:

 Mitral stenosis with atrial fibrillation

 Artificial valve

Group 3- Major risk - 25-50% Mortality

 Pulmonary hypertension

 Aortic coarctation with valvar involvement

 Marfan syndrome with aortic involvement The management in most instances is by a multidisciplinary team involving:

 Obstetrician

 Physician /Cardiologist

 Anaesthetist

 Paediatrician

Most women with functional Class 1 and 2 go through pregnancy without morbidity. However, special attention should be directed toward both prevention and early recognition of heart failure. Indicators being cough, progressive edema, tachycardia, haemoptysis and basal rales. Empirical therapy with diuretics and beta-blockers could be hazardous, so opinion of cardiologist /physician should be taken.

Labour and Delivery:

Vaginal delivery is recommended unless there is an obstetric indication for caesarean section.

Await spontaneous onset of labour. Avoid induction of labour to minimize risk of intervention thereby haemorrhage and infections. However, despite the increased risks of hemorrhage, infection and large fluid shifts, there are a few conditions in which labor is ill-advised and cesarean delivery is recommended:

 Dilated aortic root ( >4cm) or aortic aneurysm

 Acute severe congestive heart failure

 A history of recent myocardial infarction

 Severe symptomatic aortic stenosis

 Warfarin administration within 2 weeks of delivery

 Need for emergency valve replacement immediately after delivery Careful fluid balance should be monitored. Avoid supine position. A semi recumbent position with lateral tilt preferred.

Monitor vitals pulse, respiration, BP, Oxygen saturation and intake output.

Epidural analgesia by a skilled senior anaesthetist considering its hypotensive effect.

Cut short 2nd stage of labour with outlet forceps or vacuum extractor to reduce maternal effort.

Infective endocarditis prophylaxis is recommended preferably 30-60 minutes before the procedure. Either Ampicillin 2g or Ceftriaxone 1g is given iv ( ±1g vancomycin if Enterococcus infection is a concern) 600mg Clindamycin iv is recommended in cases of Penicillin allergy.

Avoid methyl ergometrine which causes intense vasoconstriction, hypertension and heart failure. Instead use syntocinon for delivery of placenta.

Close monitoring of cardiac patient should continue after delivery because early postpartum period is often a time of acute de-compensation.

d. Referral Criteria:

All patients with moderate and major risk of maternal mortality should be referred to a higher centre for following facilities:-

a) Super specialists in cardiology and anesthesia with in-depth understanding of each cardiac condition are available.

b) facilities should be available for obstetric care with intensive monitoring of mother and fetus under the supervision of a high risk pregnancy specialist(Obstetrician)

c) Neonatologist with a well equipped NICU is available.

d) Referral may be necessary for fetal echocardiography to plan neonatal care in advance.

Situation 2: At superspeciality Facility in Metro location where higher –end technology is available

a. Clinical diagnosis

A clinical suspicion or recognition of cardiac disease based on history, clinical symptoms and signs as explained above is made.

b.Investigations

Basic work up as in any pregnancy like complete blood counts, urine routine, blood grouping Rhtyping, VDRL, serology, APTT, PT, INR, ultrasound for dating, aneuploidy screening, anomaly scan. Fetal echocardiography when indicated depending upon the risk of transmission.

Nonivasive studies like electrocardiography, echocardiography and chest radiography with abdominal shielding can be conducted during pregnancy to support the diagnosis.

If indicated, cardiac catheterization can be performed with limited x-ray fluoroscopy by an interventional cardiologist.

c. Treatment

Clinical Classification Schemes commonly used are that of NYHA and ACOG. These classification systems are useful to clinicians to evaluate the functional capacity and to aid in counseling the woman regarding advisability of conception or continuation of pregnancy.

The management in most instances is by a multidisciplinary team involving:

 Obstetrician

 Cardiologist

 Cardiac Anaesthetist

 Neonatologist

 Intensivists

Antenatal period

Severe mitral stenosis is associated with a higher risk of pulmonary edema. Both beta blockers and balloon mitral valvotomy are safe in pregnancy. Pulmonary edema should be treated in the usual way with oxygen and diuretics.

Women with prosthetic heart valves on oral anticoagulants will need replacement with heparin in early pregnancy between 6 to 12 weeks, to prevent embryopathy. Again warfarin should be discontinued and replaced with heparin at 35-36 weeks to allow clearance of warfarin from the circulation. Heparin is discontinued 4-6hrs before delivery and regional anesthesia to minimize risks of obstetric hemorrhage and spinal hematoma. Intravenous heparin is restarted 6 hrs after vaginal delivery and 24 hours after a caesarean section. Warfarin is usually started the night after delivery provided there are no bleeding complications and heparin is continued until an INR of 2 or more is achieved. In an emergency situation VitK or fresh frozen plasma can be used to reverse warfarin anticoagulation and protamine sulfate for heparin anticoagulation.

Labor and Delivery

Vaginal delivery is recommended unless there is an obstetric indication for cesarean section.

1. Await spontaneous onset of labor and induction of labor should be very judiciously attempted to minimize risk of intervention thereby hemorrhage and infections.

2. Careful fluid balance with central venous pressure monitoring may be necessary to manage conditions like mitral stenosis and aortic stenosis optimally. Such monitoring is rarely indicated in women who have remained in functional class 1& 2

3. Avoid supine position. A semi recumbent position with lateral tilt is preferred.

4. Monitor vitals - pulse, respiration, BP, Oxygen saturation and intake output.

5. Epidural analgesia is administered by cardiac anaesthetist judiciously based on the cardiac hemodynamics, as it causes hypotension.

6. Cut short 2nd stage of labor with outlet forceps or vacuum extractor to reduce maternal effort.

7. Infective endocarditis prophylaxis to be given with broad spectrum antibiotics.

8. Avoid methyl ergometrine which causes intense vasoconstriction, hypertension and heart failure. Instead use syntocinon for delivery of placenta.

Epidural anesthesia is preferred by most clinicians. Hypotension can be very hazardous with pulmonary hypertension or aortic stenosis , when narcotic conduction analgesia or general anesthesia may be preferable.

Peripartum Cardiomyopathy

Risk factors include multiparity, multiple pregnancy, hypertension, increased age.

Diagnostic criteria

a) Development of cardiac failure in the last month of pregnancy or within 5 months after delivery.

b) Absence of an identifiable cause for the cardiac failure.

c) Absence of recognizable heart disease prior to the last month of pregnancy

d) LV systolic dysfunction shown on echo as ejection fraction <45%, and LV end – diastolic dimension >2.7cm/sqm

Recommended treatment

a) Fluid and salt restriction, treatment of hypertension, routine exercise postpartum if stable.

b) Drugs like digoxin, beta blockers, diuretics, vasodilators may be used.

c) In selected patients’ aldosterone antagonists, inotropes, anticoagulation, implantable defibrillators, biventricular pacing, cardiac transplantation may be the last resort.

Prognosis and recurrence depends on the normalization of left ventricular size within 6 months of delivery.

d.Referral Criteria

Even in a metro situation a multidisciplinary specialist team with skill and facilities may not always be available under one roof. In such instances referral may be required to an optimal setup under one roof for best feto-maternal outcome.

FURTHER READING / REFERENCES

 Williams Obstetrics 23nd edition 2008

 Obstetrics and gynaecology Clinics Update on Medical disorders in Pregnancy, volume 37, No 2, June 2010

 American College of Obstetricians and Gynaecologists -Cardiac disease in pregnancy. Technical Bulletin No 168, June 1992a

RESOURCES REQUIRED FOR ONE PATIENT / PROCEDURE (PATIENT WEIGHT 60 KGS)

(Units to be specified for human resources, investigations, drugs, and consumables and equipment. Quantity to also be specified)

Situation	Human resources	Investigations	Drugs and consumables	Equipment
1.	Obstetrician Physician Anesthetist Pediatrician Nurses x 2 Ot technician Lab technician House keeping	CBC RBS Urine r/e, c/s Blood Group Rh typing TSH Serology VDRL APTT,PT,INR USG ECHO ECG X Ray	Gloves x 10 pairs Drapes for delivery/Caesarean Suture materials Foleys catheter Urobag CVP line Arterial line Venflons Drip sets IV Fluids TED Stockings	Stethoscope BP appar Pulse oximeter USG machine ECG monitors X ray Lab equipment Labour room Labour couch Delivery/Cesarean tray Vacuum apparatus Boyles apparatus OT table Light source Oxygen Suction Baby warmer
2.	Obstetrician Interventional - Cardiologist Pediatric - Cardiologist Cardiac - Anaesthetist Neonatologist Intensivist Nurses x 5 Ot technician Lab technician Porters House keeping	CBC RBS Urine r/e, c/s Blood Gp Rh TSH Serology VDRL APTT,PT,INR USG ECHO ECG X Ray Cardiac catheterization ABG studies	Gloves x 15 pairs Drapes for delivery/Caesarean Suture materials Foleys catheter Urobag CVP line Arterial line Venflons Drip sets IVFluids Epidural anaesthesia kit General anaesthesia kit	Stethoscope BP appar Pulse oximeter USG machine ECG, Xray Lab equipment Cath lab Labour room Labour couch Delivery tray Caesarean tray Vacuum appar Boyles appar OT table Light source Oxygen Suction ICU bed Syringe pumps Baby warmer