Clinical Pearls & Morning Reports
Published January 10, 2024
Peripartum cardiomyopathy is now a leading cause of death in pregnant persons in many parts of the United States and around the world. Read the NEJM Review Article here.
Q: How is peripartum cardiomyopathy defined?
A: The disorder is generally defined as maternal heart failure with systolic dysfunction (left ventricular ejection fraction, <45%) that develops in the last month of pregnancy or in the first 5 months after delivery, in the absence of known preexisting cardiac dysfunction. In some cases, however, the disease occurs earlier in pregnancy or more than 5 months after delivery. Although cardiac function typically recovers in more than 50% of affected patients, morbidity and mortality are nevertheless high, with some patients requiring a left ventricular assist device or cardiac transplantation.
Q: What are some of the risk factors for peripartum cardiomyopathy?
A: Peripartum cardiomyopathy complicates approximately 1 in 2000 births worldwide, with substantial variation among regions, including rates as high as 1 in 300 births in Haiti and 1 in 100 in parts of Nigeria. In the United States, the disease is four times as likely to develop in Black women as it is in White women. One third to one half of cases occur in women with hypertensive diseases of pregnancy, including preeclampsia. Other strong risk factors for peripartum cardiomyopathy include multiple gestations, advanced maternal age, and anemia.
A: The causes of peripartum cardiomyopathy remain poorly understood. Studies have suggested that the disorder is triggered by hormones that emanate from the pituitary and placenta during the peripartum period, synergizing, in ways still poorly understood, with intrinsic cardiac factors that render some women susceptible to these hormonal imbalances. Together, these studies of pregnancy hormones have suggested a vasculohormonal model of the pathogenesis of peripartum cardiomyopathy, whereby imbalances in peripartum hormones cause cardiovascular dysfunction and consequent heart failure in susceptible women. What intrinsic cardiac factors render some women but not others susceptible to these hormonal imbalances? This question remains largely unanswered, but recent studies have revealed a strong genetic predisposition to peripartum cardiomyopathy in some cases.
A: Patients with peripartum cardiomyopathy typically present with symptoms and signs of heart failure, including dyspnea, orthopnea, elevated jugular venous pressure, pulmonary rales, and edema. The diagnosis requires a high index of suspicion and is often delayed because symptoms mirror those of pregnancy itself. Peripartum cardiomyopathy is a diagnosis of exclusion. The differential diagnosis includes preexisting structural heart disease, preeclampsia-induced pulmonary edema in the absence of systolic dysfunction, pulmonary embolism, spontaneous coronary artery dissection, and exposure to toxins, including alcohol and chemotherapeutic agents. Currently, there is no biomarker that is diagnostic for peripartum cardiomyopathy. Genetic testing is increasingly offered to patients with peripartum cardiomyopathy, and it should be considered in most cases. Few randomized trials have evaluated therapies for peripartum cardiomyopathy, and none of these studies have had conclusive results. Current management is thus largely extrapolated from guideline-directed medical treatment for nonischemic dilated cardiomyopathy and other forms of heart failure with a reduced ejection fraction.