Risks of repeat pregnancy after peripartum cardiomyopathy: Double jeopardy

Peripartum cardiomyopathy is a relatively infrequent disorder (1 to 1,800 to 1 to 4,000 deliveries in the United States) that results in severe systolic dysfunction in the hearts of previously healthy women in and around the time of pregnancy (1). The cause of the condition is unknown, and inflammatory, autoimmune, and environmental causes have been considered. Patients submitted to endomyocardial biopsy early after their diagnosis often display myocarditis (2). The natural history of this disorder is not well understood. From the early observations of Demakis and Rahimtoola, it was evident that some patients have a dramatic recovery of heart function, whereas others develop a dilated cardiomyopathy (3). More recent data imply that the prognosis may be better for patients with this condition than previously considered (2,4). The investigation of peripartum cardiomyopathy is limited by the infrequency of its occurrence and the inability of a single center or investigator to gather sufficient experience to judge its natural history and cause. There is even less information available concerning patients who have had peripartum cardiomyopathy who undertake an additional pregnancy. Demakis and Rahimtoola (2) found that in the 50% of women who failed to improve their ventricular function, attempts at repeat pregnancy were complicated by maternal and fetal morbidity and mortality. A limited number of case reports have emerged since that time, most of which speak to the “safety” of repeat pregnancy. Martin St John Sutton followed 4 patients with a prior diagnosis of peripartum cardiomyopathy through an additional pregnancy (5). All of his patients’ heart function had returned to normal before initiating the second pregnancy. These patients experienced no significant alterations in ventricular function as assessed by echocardiograms performed prospectively during the repeat pregnancy. Filho (6) reported on the course of 12 patients with probable peripartum cardiomyopathy who undertook an additional pregnancy. In this study, even patients who had failed to return heart functions to normal were able to tolerate pregnancy; although several who had persistent myocardial dysfunction experienced cardiovascular symptoms of heart failure during their ordeal. De Souza in this issue of Journal of Cardiac Failure (7) similarly reports that in 9 patients with peripartum cardiomyopathy who undertook a repeat pregnancy, the pregnancy was relatively well tolerated and the ventricular function unchanged. Unfortunately, the current article adds little to our knowledge of this condition. The echocardiographic data were obtained randomly. Only 2 patients (number 4 and 7) had echocardiograms performed in follow-up after the initial episode of peripartum cardiomyopathy, when resolution of echocardiographic changes might be expected. The use of “baseline” echocardiograms obtained in the throws of peripartum cardiomyopathy or with a new pregnancy cannot be considered valid baseline data. Therefore, the degree of ventricular functional improvement after the initial episode of peripartum cardiomyopathy is not adequately evaluated, and follow-up studies were not obtained in a fashion that allows any definitive observations of the change in function to be made. Echocardiographic data reported would be enhanced by using a standard protocol for chamber measurement and wall stress. Wall stress data are particularly important in patients experiencing the hemodynamic changes of pregnancy or the effects of afterload reduction therapy. It is exceedingly important that a standard definition for peripartum cardiomyopathy be accepted. Only by the inclusion of patients in the last month of pregnancy or From the Division of Cardiology, Department of Medicine, The Johns Hopkins Hospital, Baltimore, Maryland. Reprint requests: Kenneth L. Baughman, MD, Dept. of Medicine, 600 North Wolfe Street/Blalock 536, Baltimore, MD. Copyright © 2001 by Churchill Livingstonet 1071-9164/01/0701-0006$35.00/0 doi:10.1054/jcaf.2001.23106 Journal of Cardiac Failure Vol. 7 No. 1 2001