Obstetric complications and comorbidities associated with peripartum cardiomyopathy vary by race and time to presentation

Background Peripartum cardiomyopathy (PPCM) remains a leading cause of maternal mortality globally, with a higher morbidity and mortality in black populations, and a worse prognosis associated with delayed presentation. Previous studies have suggested differences between white and black mothers presenting antepartum vs. postpartum. However, the infrequency of PPCM has limited study of race differences beyond white and black mothers, particularly with respect to timing of disease onset. Purpose Use large, real-world data to characterize the differences between timing of PPCM onset with respect to race. Methods U.S. hospital discharge data were obtained for the states of Arizona, Colorado, Florida, Louisiana, Arkansas, Maryland, North Carolina, New York, South Dakota, Washington, and Wisconsin at varying intervals between (2003-2019). Delivering mothers, comorbid conditions and procedures were identified using ICD-9 and -10 codes. Analysis was limited to delivering mothers with unique patient identifiers enabling tracking of hospital readmissions. PPCM was defined as PPCM coded at any time from 1 month antepartum to 150 days postpartum. Antepartum was defined as PPCM reported during a distinct hospitalization before delivery, peripartum as being first reported at the same hospitalization as delivery, and postpartum as readmission for PPCM after a delivery hospitalization without mention of PPCM. Mothers were stratified by white, black, Hispanic, asian and native american (NA). Associations were determined using multivariable logistic regression. Results In total, 5,834,387 delivering mothers were identified of whom 5,048 were diagnosed with PPCM. 92 (1.8%) mothers presented antepartum, 1,487 (29.4%) presented peripartum, and 3,469 (68.7%) presented postpartum. Black mothers had the highest rate of postpartum presentation (73.3%) compared to other races. Timing of PPCM presentation relative to delivery varied between races with 85% of cases presenting within 16 days post-delivery for white mothers, 14 days for Hispanic mothers, 14 days for Asian mothers, 10 days for NA mothers, and 37 days for Black mothers. Multivariable analysis found caesarean section (OR 3.69) and RBC transfusion (OR: 5.86) were associated with peripartum presentation only in Asian mothers (p<0.001 for both). For NA mothers, diabetes mellitus was more prevalent than other races and associated with postpartum presentation (OR: 3.47 p=0.004). For black patients, premature labor was associated with peripartum presentation (OR:1.71), while C-section (OR: 1.33) and red blood cell transfusion (OR:1.7) were associated with an increased risk for postpartum PPCM (p<0.001 for all). Conclusion Comorbidities and delivery complications associated with PPCM development vary by time to presentation and race. Clear differences exist between antepartum, peripartum, and postpartum presenting patients, which may reflect underlying differences in pathophysiology.