Racial and Ethnic Disparities in the Trends and Outcomes of Cardiogenic Shock Complicating Peripartum Cardiomyopathy

Abstract

Cardiogenic shock (CS) is a recognized complication of peripartum cardiomyopathy (PPCM) associated with poor prognosis. Although racial and ethnic disparities have been described in the occurrence and outcomes of PPCM, it is unclear if these disparities persist among patients with PPCM and CS. To evaluate the temporal trends in CS incidence among hospitalized patients with PPCM stratified by race and ethnicity and to investigate the racial and ethnic differences in hospital mortality, mechanical circulatory support (MCS) use, and heart transplantation (HT). This multicenter retrospective cohort study included hospitalized patients with PPCM complicated by CS in the US from 2005 to 2019 identified from the National Inpatient Sample (NIS). Data analysis was conducted in November 2021. PPCM complicated by CS. The main outcome was incidence of CS in PPCM stratified by race and ethnicity. The secondary outcome was racial and ethnic differences in hospital mortality, MCS use, and HT. Of 55 804 hospitalized patients with PPCM, 1945 patients had CS, including 947 Black patients, 236 Hispanic patients, and 702 White patients, translating to an incidence rate of 35 CS events per 1000 patients with PPCM. The mean (SD) age was 31 (9) years. Black and Hispanic patients had higher CS incidence rates (39 events per 1000 patients with PPCM) compared with White patients (33 events per 1000 patients with PPCM). CS incidence rates significantly increased across all races and ethnicities over the study period. Overall, the odds of developing CS were higher in Black patients (aOR, 1.17 [95% CI, 1.15-1.57]; P < .001) and Hispanic patients (aOR, 1.37 [95% CI, 1.17-1.59]; P < 001) compared with White patients during the study period. Compared with White patients, the odds of in-hospital mortality were higher in Black (adjusted odds ratio [aOR], 1.67 [95% CI, 1.21-2.32]; P = .002) and Hispanic (aOR, 2.20 [95% CI, 1.45-3.33]; P < .001) patients. Hispanic patients were more likely to receive any type of MCS device (aOR, 2.23 [95% CI, 1.60-3.09]; P < .001), intraaortic balloon pump (aOR, 1.65 [95% CI, 1.11-2.44]; P < .001), and ventricular assisted device (aOR, 4.45 [95% CI, 2.45-8.08]; P < .001), compared with White patients. Black patients were more likely to receive VAD (aOR, 2.69 [95% CI, 1.63-4.42]; P < .001) compared with White patients. Black and Hispanic patients were significantly less likely to receive HT compared with White patients (Black patients: aOR, 0.51 [95% CI, 0.33-0.78]; P = .02; Hispanic patients: aOR, 0.15 [95% CI, 0.06-0.42]; P < .001). These findings highlight significant racial disparities in mortality and HT among hospitalized patients with PPCM complicated by CS in the US. More research to identify factors of racial and ethnic disparities is needed to guide interventions to improve outcomes of patients with PPCM.