Peripartum cardiomyopathy

HEART FAILURE DURING PREGNANCY was recognized as early as 1849, but it was first described as a distinctive form of cardiomyopathy only in the 1930s.1 In 1971, Demakis et al2 described 27 patients who presented during the puerperium with cardiomegaly, abnormal electrocardiographic findings, and congestive heart failure, and named the syndrome peripartum cardiomyopathy. 

The European Society of Cardiology3 recently defined peripartum cardiomyopathy as a form of dilated cardiomyopathy that presents with signs of heart failure in the last month of pregnancy or within 5 months of delivery.

Peripartum cardiomyopathy is defined on the basis of four criteria:

  1-  Development of cardiac failure in the last month of pregnancy or within five months of delivery

  2-  Absence of an identifiable cause for the cardiac failure 

  3-  Absence of recognizable heart disease prior to the last month of pregnancy

 4-  Left ventricular systolic dysfunction demonstrated by classic echocardiographic criteria, such as depressed  shortening fraction or ejection fraction

The true incidence of PPCM is unknown; estimates proposed over the last several decades range from 1 per 1300 to 1 per 15,000 live births.

Unknown etiology

No hormonal disorder has been identified in patients with PPCM, even though estrogen, progesterone, and prolactin have significant effects upon the cardiovascular system

Inflammatory cytokines may play a role in PPCM ( TNF, IL6, Fas receptor, ….)

Myocarditis , evidence by endomyocardial biopsies

A maternal immunologic response to a fetal antigen has been proposed as another potential etiology of PPCM 

Familial or genetic etiology can not be excluded 

Risk Factors

Age greater than 30 years 

Multiparity

Women of African descent 

Pregnancy with multiple fetuses 

A history of preeclampsia, eclampsia, or postpartum hypertension

Association with maternal cocaine abuse or selenium deficiency 

Long term (>4 weeks) oral tocolytic therapy with beta adrenergic agonists such as : Terbutaline.

Diagnosis    

The development of CHF signs and symptoms

EKG: sinus tachy, a-fib, low voltages , prolong PR/QRS, non specific ST-T wave changes

CXR: enlargement of the cardiac silhouette with evidence of pulmonary venous congestion and/or interstitial edema, pleural effusions.

The echocardiogram and Doppler usually reveal left ventricular enlargement with significant global reduction in overall performance without LVH  

The role of endomyocardial biopsy remains unclear. 

Viral and bacterial cultures, as well as selected viral titers (eg, Coxsackie B) should also be considered.

Management

Heart failure treatment during pregnancy

When considering tests or treatments in pregnancy, the welfare of the fetus is always considered along with that of the mother. Coordinated management with specialists (an obstetrician and maternal-fetal medicine team) is essential, with fetal heart monitoring.

• Angiotensin-converting enzyme (ACE) inhibitors and ARBs are contraindicated in pregnancy because they can cause birth defects, although they are the main treatments for postpartum women with heart failure. The teratogenic effects occur particularly in the second and third trimester, with fetopathy characterized by fetal hypotension, oligohydramnios-anuria, and renal tubular dysplasia. However, a recent study suggested a risk of malformations even after first trimester exposure to ACE inhibitors.
• Digoxin, beta-blockers, loop diuretics, and drugs that reduce afterload such as hydralazine and nitrates have been proven to be safe and are the mainstays of medical therapy of heart failure during pregnancy.Beta-blockers have strong evidence of efficacy in patients with heart failure, but they have not been tested in peripartum cardiomyopathy. Nevertheless, beta-blockers have long been used in pregnant women with hypertension without any known adverse effects on the fetus, and patients taking these agents prior to diagnosis can continue to use them safely.
• Heart failure treatment postpartum
• After delivery, the treatment is identical to that for nonpregnant women with dilated cardiomyopathy. ACE inhibitors and ARBs. The target dose is one-half the maximum antihypertensive dose.

Diuretics are given for symptom relief

Spironolactone or digoxin is used in patients who have New York Heart Association class III or IV symptoms. The goal with spironolactone is 25 mg/day after dosing of other drugs is maximized. The goal with digoxin is the lowest daily dose to obtain a detectable serum digoxin level, which should be kept at less than 1.0 ng/mL. In the Digitalis Investigation Group trial,55 serum digoxin levels of 0.5 to 0.8 ng/mL (0.6–1.0 nmol/L) were most beneficial, and levels of 1.1 to 1.5 ng/mL (1.4–1.9 nmol/L) were associated with an increase in deaths related to heart failure.

Beta-blockers are recommended for peripartum cardiomyopathy,44 as they improve symptoms, ejection fraction, and survival. Nonselective beta-blockers such as carvedilol (Coreg) and selective ones such as metoprolol succinate (Toprol XL) have shown benefit. The goal dosage is carvedilol 25 mg twice a day (50 mg twice a day for larger patients) or metoprolol succinate 100 mg once a day.

Anticoagulation treatment

During pregnancy, the risk of thromboembolic complications increases due to higher concentrations of coagulation factors II, VII, VIII, and X, and of plasma fibrinogen. The risk may persist up to 6 weeks postpartum.1 Cases of arterial, venous, and cardiac thrombosis have been reported in women with peripartum cardiomyopathy, and the risk may be related to the degree of chamber enlargement and systolic dysfunction and the presence of atrial fibrillation.

Patients with evidence of systemic embolism, with severe left ventricular dysfunction or documented cardiac thrombosis, should receive anticoagulation. Anticoagulation should be continued until a return of normal left ventricular function is documented.

We await the results of the Warfarin Versus Aspirin in Reduced Cardiac Ejection Fraction trial, which should determine which drug will best prevent death or stroke in patients with ejection fractions of less than 35%.

Warfarin can cause spontaneous fetal cerebral hemorrhage in the second and third trimesters and therefore is generally contraindicated during pregnancy. However, guidelines from the American College of Cardiology and the American Heart Association on the management of patients with heart valve disease say that “warfarin is probably safe during the first 6 weeks of gestation, but there is a risk of embryopathy if the warfarin is taken between 6 and 12 weeks of gestation.” The guidelines also say warfarin is “relatively safe” during the second and third trimesters but must be stopped and switched to a heparin several weeks before delivery. Unfractionated heparin or low-molecular-weight heparin can be used during pregnancy. However, should warfarin be needed for any reason, we believe a cesarian section should be performed to reduce the risk to the infant.

by

Akshaya Srikanth, Dr. Archana

Pharm.D Intern, Asst.Prof. of Obs & Gyn

RIMS Medical College, Kadapa

India