Peripartum Cardiomyopathy and Social Vulnerability: An Epidemiological Analysis of Mortality Outcomes.

Background: Peripartum cardiomyopathy (PPCM) outcomes have been previously linked to demographic and social factors. The social vulnerability index (SVI) is a measure of social vulnerability in the United States. We explored PPCM disparities and the impact of SVI on PPCM mortality.

Methods and results: Mortality from 1999 to 2020, SVI, and demographic data were obtained from CDC databases. County-specific SVI rankings were linked to PPCM age-adjusted mortality rates (AAMRs), allowing for a comparative analysis of AAMRs across both cumulative populations and subpopulations to identify disparities. All US counties were then stratified into low- and high-SVI groups, facilitating comparison of SVI rankings by estimation of excess-deaths per 1 000 000 person-years attributable to greater social vulnerability and rate ratios (RR) through univariable Poisson regression. We identified a total of 1026 deaths related to PPCM between 1999 and 2020. Overall AAMR increased from 0.180 in 1999 to 0.326 in 2020. Black populations (AAMR: 1.081) and Southern US counties (AAMR: 0.444) had the highest AAMRs compared with other racial and US census groups, respectively. Higher SVI accounted for 0.172 excess deaths per 1 000 000 person-years (RR=1.800). Among Black and White populations, higher SVI also accounted for 0.248 and 0.071 excess deaths per 1 000 000 person-years, respectively. Similar impacts of greater social vulnerability were observed when comparing the US census regions (Northeast RR=1.609, Midwest RR=1.819, South RR=1.934, West RR=1.776).

Conclusions: PPCM mortality disparities exist across racial and geographic populations in the United States. A greater burden of social vulnerability is associated with higher PPCM mortality on a national level.