African Americans Have Highest Risk of Peripartum Cardiomyopathy

February 09, 2010

February 9, 2010 (Augusta, Georgia) — A new case-control study shows that African American women have significantly higher odds of developing peripartum cardiomyopathy (PPCM)--heart failure around the time of pregnancy--than do non–African Americans [1]. "This is really the first study to show this," lead author Dr Mindy B Gentry (Medical College of Georgia, Augusta) told heartwire .

Gentry and colleagues found that "race was by far the largest risk factor for development of PPCM," she said. One of the problems in identifying this "relatively uncommon" disease, says Gentry, is that the symptoms of PPCM--such as fatigue and shortness of breath--are "difficult to separate from the symptoms of late-stage pregnancy or the postpartum period. The new research might help OB/GYNs and family practitioners keep PPCM in the back of their minds if they have African American patients, in particular, who have symptoms that might be consistent with this condition," she noted.

This is important, she says, because women with PPCM have a grim prognosis--they have a significant risk of thromboembolism, atrial fibrillation, persistent cardiomyopathy, and severe or fatal recurrence with subsequent pregnancies. "You are talking about new, young mothers here, and only about 50% of those affected will fully recover normal cardiac function, and about 20% will require a heart transplant or die," she explains. She and her colleagues report their findings in the February 16, 2010 issue of the Journal of American College of Cardiology.

Unique Study in a Heterogeneous Population

Previous studies have shown that the frequency of PPCM is much higher in countries where the women are predominantly of African descent, such as South Africa, parts of western Africa, and Haiti, Gentry explained. But because these tend to be homogeneous populations, "it's difficult to assess the effect of race if all of your patients are of the same race," she notes. So the current study is "unique," she says; it was conducted in the US, in a racially heterogeneous population, at her institution.

You are talking about new, young mothers here, and only about 50% of those affected will fully recover normal cardiac function.

Medical records were screened for a five-year period between July 2003 and July 2008, and 28 cases of PPCM were included, with three healthy controls for each case randomly selected from women who had delivered babies at the Medical College of Georgia within the same month as the cases.

African American women had an almost 16-fold higher relative risk of PPCM than non–African Americans (odds ratio 15.7; CI 3.5–70.6). Other significant risk factors were hypertension (OR 10.8), being unmarried (OR 4.2), and having had two or more previous pregnancies (OR 2.9). And black ethnicity remained a significant risk factor for PPCM when other risk factors were considered in multivariable (OR 31.5) and stratified (OR 12.9) analyses.

"The OR of the African American ethnicity was similar when stratified across all risk factors, as indicated by homogeneity tests. Thus, none of the other risk factors explained the strong risk of African American descent for the development of PPCM," say the authors.

The frequency of PPCM at this center (185 of 100 000 deliveries) was higher than in previous US reports but was comparable to the frequencies found in countries with more women of African descent (100 to 980 of 100 000), say Gentry et al.

"Hopefully, this will help us to focus in on being able to find out what causes PPCM, so we can identify higher-risk patients upfront," Gentry said. A number of potential causes of PPCM are being investigated, including genetic, nutritional, and infectious, she noted.

This work was supported in part by a grant from the National Institutes of Health.