Racial Discrepancies between Caucasians and African-Americans in Peripartum Cardiomyopathy Requiring Mechanical Circulatory Support

Abstract

Background Peripartum Cardiomyopathy (PPCM) is a rare form of cardiomyopathy diagnosed in the last month of pregnancy or up to five months postpartum in the absence of other underlying etiology. PPCM can result in cardiogenic shock or end-stage heart failure requiring mechanical circulatory support (MCS). It is unclear if there are any racial discrepancies in outcomes of patients requiring MCS. Method We queried the data from the National Inpatient Sample database from 2003-2014 to identify patients with the diagnosis of PPCM using the International Classification of Disease (ICD-9) codes 674.5x. Among the patients with PPCM we then identified those requiring short term mechanical support devices (Intra-aortic balloon pump, Impella, Centrimag, Extracorporeal membrane oxygenation), Ventricular assist devices (VAD) and Orthotopic Heart Transplant (OHT) using the corresponding (ICD-9) codes 33.6, 37.5, 37.51, 37.60 37.61, 37.62 37.65, 37.66, 37.68, 39.65. Using ANOVA and Chi-Square analysis, we compared the differences in outcomes in Caucasian and African American (AA) races with PPCM requiring MCS. Results We identified 16,014 Caucasians and 15,537 AA patients with PPCM. Baseline characteristics including mean age, income quartile was similar except for a difference in average income quartile between Caucasian and AA with PPCM requiring VAD (2.49 vs 1.75, p = 0.02). In Caucasians, 2.03% (325/16,104) required MCS and in AA patients, 1.91% (297/15,537) required MCS, showing no difference between the two races. However, increased in-hospital mortality was noted in AA compared to Caucasians requiring short term MCS (20.9% vs 11.94%, p = 0.02) or requiring OHT (6.95% vs 0% p =0.02). There was a trend towards an increase in mortality in AA requiring VAD (16.51% vs 8.27%, p = 0.066) although it wasn t statistically significant. There was no significant difference in average total charges and average length of stay between Caucasian and AA in all three subgroups. We also noted an uptrend in the use of MCS in PPCM over the years as noted in the graph. Conclusion AA group had higher mortality rates in patients requiring MCS when compared to Caucasians. The reasons for these disparities remain unclear and further investigation is much needed given an uptrend use of MCS in patients with PPCM over the years.