Abstract 4368766: Timing of Onset of Peripartum Cardiomyopathy: Risk Factors and Clinical Outcomes

Background: Peripartum cardiomyopathy (PPCM) is a rare but serious form of heart failure in young women, defined by new-onset LVEF <45% near the end of pregnancy or postpartum. Risk factors include advanced maternal age, African American race, hypertensive disorders, cesarean delivery, and multiple gestation. Although PPCM typically presents postpartum, a subset develops acute heart failure during the index hospitalization for delivery. A case presented at AHA 2024 described a young woman who developed acute pulmonary edema and severe left ventricular dysfunction during cesarean section, with rapid LVEF recovery—suggestive of Takotsubo cardiomyopathy rather than classic PPCM. Hypothesis: Patients with peripartum heart failure diagnosed during delivery hospitalization (Group 1) would have lower odds of heart-failure readmission compared to those diagnosed 7–42 days postpartum (Group 2). Methods: Using the 2022 National Readmissions Database, women aged 18–40 hospitalized for delivery with acute systolic heart failure (ICD-10: I5021, I5041, O903) either during delivery or within 7–42 days postpartum were identified. Those with prior heart failure were excluded. Delivery factors and outcomes were compared. Multivariable logistic regression assessed readmission risk (excluding the defining readmission in Group 2), adjusting for age, obesity, hypertension, CKD, CAD, atrial fibrillation/flutter, type 2 diabetes, anemia, depression, stroke/TIA, substance use, and thyroid disease. Results: Among 938 patients (Group 1: n=492; Group 2: n=446), cesarean delivery occurred in 55.7% of Group 1. Preeclampsia rates were similar (30.7% vs. 29.4%). Group 1 had higher readmission rates (19.7% vs. 11.0%) and greater in-hospital mortality (2.2% vs. 0.67%). In adjusted models, Group 2 had 56% lower odds of readmission (OR 0.44; 95% CI 0.21–0.90; p=0.025). Discussion: Patients diagnosed with heart failure during delivery hospitalization had worse outcomes, including higher readmission and mortality. Group 1 may represent a more acutely decompensated cohort influenced by operative stress, fluid shifts, and comorbidity burden. National data also suggest pregnancy-associated stress cardiomyopathy may be linked to higher in-hospital mortality and prolonged stay. Conclusion: Our study identified a subset of patients with early-onset cardiomyopathy and worse prognosis, highlighting the need for further research to identify specific risk factors and intervene to improve outcomes.