Peripartum cardiomyopathy, a form of heart failure that develops late in pregnancy or shortly after delivery, results in a frightening turn of events that can leave new mothers suffering from a lifelong chronic heart condition that is often fatal.
Now, investigators at Beth Israel Deaconess Medical Center have discovered clues behind this dangerous condition, providing the first clear evidence that peripartum cardiomyopathy is a vascular disease, brought about by an imbalance of angiogenic proteins in the heart during the peripartum period.
Reporting in the May 17 issue of Nature, a team of researchers led by Zoltan Arany ’98, an HMS assistant professor of medicine and an investigator in Beth Israel’s CardioVascular Institute, details the underlying mechanisms for the condition and identifies preeclampsia and multiple gestations as risk factors. In addition, the investigators point out the beneficial effects that proangiogenic therapies could have for women with this vascular disease.
Peripartum cardiomyopathy affects approximately one in 1,000 women with no known history of heart disease. Symptoms can be mild to severe, and include shortness of breath caused by the heart’s diminished pumping ability. About one-half of women who develop the condition will spontaneously recover, but others will grow worse, even to the point of requiring a heart transplant.
“It’s been a real mystery,” says Arany. “The majority of women who develop this condition are otherwise healthy, even active. We know that the real stressors of pregnancy occur in the first trimester. Why then, are these mothers-to-be developing such serious problems at the end of pregnancy?”
Through a series of studies in both animal models and humans, the researchers determined that peripartum cardiomyopathy is a two-hit disease that begins with elevated late-pregnancy signals to prevent angiogenesis, or normal blood vessel growth, and continues when something as yet undiscovered leaves women susceptible to cardiac damage—possibly an infection or genetic predisposition.
“This is really a whole new way to think about peripartum cardiomyopathy,” says Arany.