Pregnancies in women after peri-partum cardiomyopathy: the global European Society of Cardiology EuroObservational Research Programme Peri-Partum Cardiomyopathy Registry.

Background and aims: The risk of heart failure progression or mortality in patients with peri-partum cardiomyopathy (PPCM) during subsequent pregnancies (SSPs) is a significant concern for patients, their families, and healthcare providers. However, there is limited contemporary, prospective data on SSP outcomes in PPCM patients from diverse ethnic and sociodemographic groups. This study aimed to assess maternal and neonatal outcomes in PPCM patients undergoing SSPs.

Methods: This is a sub-study on PPCM and SSPs of the global European Society of Cardiology PPCM Registry that recruited patients from 2012 to 2023. Maternal and neonatal outcomes were reported.

Results: From 332 patients with PPCM, there were 98 SSPs among 73 women. Of these, 25 (26%) SSPs ended prematurely due to therapeutic termination (20/25), miscarriage (4/25), and stillbirth (1/25). The median follow-up from the end of the SSP was 198 days (inter-quartile range 160-240). Left ventricular ejection fraction (LVEF) was persistently reduced to <50% prior to the SSP in 26% of patients, with only 6% having an LVEF <40%. Patient characteristics were similar, irrespective of SSP baseline LVEF. Clinical worsening [composite of all-cause death, cardiovascular rehospitalization, or decline in LVEF ≥10% (percentage points) and to <50%] occurred in 20% SSPs, with 2% all-cause maternal mortality. Signs/symptoms of heart failure and worsening of New York Heart Association class occurred in 26% and 22% of SSPs, respectively. At follow-up, the mean LVEF was 50% (±12%), and in 69% of SSPs, the LVEF was ≥50%. African women had similar outcome as the other ethnic groups. Pre-term delivery occurred in 24% of SSPs, 20% of babies were of low birth weight, and there was 3% all-cause neonatal mortality. Compared with women with SSP baseline LVEF <50%, fewer women with LVEF ≥50% were on heart failure pharmacotherapies prior to the SSP, and in this group of women, there was a significant decline in LVEF.

Conclusions: Maternal morbidity and mortality rates were lower than anticipated. Baseline LVEF <50% was not associated with an increased frequency of adverse maternal outcomes, and no further decline in LVEF was observed in this group. In contrast, women with SSPs and a baseline LVEF ≥50% experienced a decline in LVEF, potentially attributable to reduced use of heart failure pharmacotherapy during pregnancy and the post-partum period. Therapeutic termination was performed in approximately a fifth of cases. The findings suggest that reclassification of a SSP with persisting mild left ventricular impairment from modified World Health Organization (mWHO) Class IV (contraindicated) to mWHO III may be considered, while remaining under the care of an experienced medical team and with appropriate pharmacological management.