Maternal Obesity and Risk of Hospital Readmission in Peripartum Cardiomyopathy: A Retrospective Cohort Study

Peripartum cardiomyopathy (PPCM) is a major cause of maternal heart failure. Hospital readmission remains a common and serious complication. Maternal obesity is increasingly prevalent, but its association with readmission in PPCM has not been well defined.

We performed a retrospective multicenter cohort study using the TriNetX research network. Women with a first diagnosis of PPCM were identified using standard diagnostic codes, yielding 1,323 patients. "Maternal obesity" was defined as a body mass index >30 kg/m². The primary outcome was all-cause hospital readmission within 30 days. We built a propensity score-matched cohort using 1:1 nearest neighbor matching with a caliper of 0.05, adjusting for demographics, comorbidities, and markers of disease severity. Conditional logistic regression was used to calculate odds ratios (ORs) with corresponding Wald χ² statistics.

Overall, 247 patients (18.7%) experienced 30-day readmission. After matching (459 pairs, total 918 patients), obesity was associated with significantly higher readmission odds (OR 1.52, 95% confidence interval (CI) 1.18-1.96, Wald χ² = 7.56, p = 0.006). Absolute readmission rates were 22.7% in obese women versus 16.6% in non-obese women (absolute difference 6.1%). At 90 days, rates were 52.2% versus 24.4% (OR 1.47, 95% CI 1.16-1.87, Wald χ² = 6.63, p = 0.01). In multivariable analysis, obesity remained an independent predictor (aOR, 1.49; 95% CI, 1.17-1.90; Wald χ² = 8.31; p = 0.004). The association was stronger in Black women (OR 1.68, 95% CI 1.22-2.31, Wald χ² = 6.63, p = 0.01) than in non-Black women (OR 1.29, 95% CI 0.94-1.78, Wald χ² = 2.88, p = 0.09). An exploratory analysis combining Hispanic, Asian, and other races showed an attenuated, non‑significant association (OR 1.18, 95% CI 0.82-1.70, Wald χ² = 1.16, p = 0.28). The interaction between obesity and Black race was significant (Wald χ² = 4.20, p = 0.04).

Maternal obesity independently predicts a higher risk of hospital readmission in PPCM after accounting for disease severity and comorbidities. These findings support targeted risk assessment and more intensive post‑discharge follow‑up for this high‑risk group, especially among Black women.