Author + information
- Gregg M. Lanier, MD∗ ()
- ↵∗Reprint requests and correspondence:
Dr. Gregg M. Lanier, Division of Cardiology, New York Medical College/Westchester Medical Center, 100 Woods Road, Macy Pavilion, Valhalla, New York 10595.
Few diseases are as dramatic as peripartum cardiomyopathy (PPCM). This rare illness has been described in cultures across the world, is little understood, and afflicts a woman right at the moment she brings forth life. Several mechanisms of disease have been proposed, including myocarditis, inflammation and oxidative stress, the interplay of prolactin, autoimmune processes, fetal chimerism, and genetics (1). The current incidence varies depending on the population studied, from 1 in 1,000 live births in South Africa to 1 per 2,289 to 4,000 in the United States. In the current literature, some possible risk factors have emerged: African-American race (2), pre-eclampsia, gestational hypertension, advanced maternal age, and multiparity (3). The majority of women affected have recovery of left ventricular (LV) function, but a 6% to 10% mortality remains a real and serious consequence of PPCM (4). Identifying those at highest risk of morbidity and mortality remains a challenge. In 1 study, a dilated LV end-diastolic diameter (LVEDD) >6 cm on the echocardiogram at the time of diagnosis portended a lower chance of recovery (5). Other emerging markers of prognosis may include biomarkers, delayed enhancement on cardiac magnetic resonance imaging, and right ventricular dysfunction (6).
Understanding the natural history of PPCM in the current era of neurohormonal therapy is crucial in determining the frequency of clinical monitoring and the use of implantable cardioverter-defibrillators, LV assist devices, and orthotopic heart transplantation. In this issue of the Journal, McNamara et al. (7) and the 30 North American centers of the Peripartum Cardiomyopathy Network, funded by the National Heart, Lung, and Blood Institute, report the largest prospective study to date of PPCM. In this study, 100 women with PPCM were followed for 1 year post-partum with echocardiography and clinical follow-up. Mean age was 30 ± 6 years, 30% were black, and mean LV ejection fraction (EF) was 35 ± 0.10%. Eight patients were lost to follow-up. At 1 year after diagnosis, the mean LVEF improved from 35 ± 0.10% to 53 ± 1%, which is consistent with our current understanding of PPCM. The patients were well-managed medically, with beta-blocker and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use about 80%. Only 1 patient was treated with bromocriptine. What is interesting is not that the majority of patients had an improvement in EF, but rather the characteristics of those patients who did not. At 1 year, 13% experienced either a persistent cardiomyopathy with an LVEF <35% or had a major clinical event such as death, need for LV assist device support, or orthotopic heart transplantation. A very well-executed analysis of the trial data identified that self-identified black race, LVEDD >6 cm, and an initial EF <30% predicted a lower chance of improvement on follow-up. In fact, none of the patients with an LVEDD >6 cm and EF <30% had recovery of their LV function. It is also important to point out that the current trial showed no interaction on recovery by previously reported risk factors, such as multiparity, maternal age, blood pressure, and New York Heart Association class at presentation. Additionally, breast feeding was not found to have an effect on EF improvement.
Some limitations of this trial deserve mention, such as a higher rate of hypertension and a later time of diagnosis of PPCM in black subjects. This could be interpreted as a significant flaw in the analysis of race and outcomes, or potentially underline hypothesis-generating racial differences in the pathophysiology of the condition.
Beyond routine medical therapy for heart failure, current therapies that have shown promise in the treatment of PPCM include bromocriptine (8), pentoxifylline (9), and intravenous immunoglobulin (10). None of these studies were definitive, likely because in the majority of patients, EF normalizes regardless of intervention. This prospective cohort is a landmark trial in PPCM because it may pave the way for future treatment studies. Perhaps by enrolling only patients with an LVEDD >6 cm and/or an EF <30% at diagnosis will allow for more robust trial results. Hopefully, the 1-year results of the Peripartum Cardiomyopathy Network cohort will be only the first of several analyses to come. Many questions still need to be addressed, such as the risk of recurrent heart failure after additional pregnancies in patients with PPCM. The multicenter framework of this large cohort will likely continue to add new insights into this rare and potentially devastating cardiomyopathy.
↵∗ Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology.
Dr. Lanier has reported that he has no relationships relevant to the contents of this paper to disclose.
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