Cardiomyopathy and Other Myocardial Disorders Among Hospitalizations for Pregnancy in the United States

Abstract

OBJECTIVES: To estimate the rate of pregnancy hospitalizations for women with two groups of myocardial disorders, cardiomyopathy and other myocardial disorders, and report the rate of severe obstetric complications among these hospitalizations in delivery and postpartum periods. METHODS: We performed a cross-sectional study using 14,323,731 hospitalizations for pregnancy identified from the 2004–2006 Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project. We reported rates of pregnancy hospitalizations with cardiomyopathy and other myocardial disorders per 1,000 deliveries and rates of severe complications per 1,000 hospitalizations during delivery and postpartum periods by myocardial disease status. We compared these rates by using χ² tests with adjustment of P values for multiple comparisons using the Bonferroni method. RESULTS: Among all pregnancy hospitalizations, the overall prevalence of hospitalizations with myocardial disorders was 1.33 per 1,000 deliveries. The rate of pregnancy hospitalizations with cardiomyopathy was 0.46 per 1,000 deliveries (0.18 for apparent peripartum cardiomyopathy and 0.28 for other cardiomyopathies). The rate of pregnancy hospitalizations with other myocardial disorders was 0.87 per 1,000 deliveries. Myocardial disorders were rare during delivery hospitalizations (0.01%) but not uncommon among postpartum hospitalizations (4.2%). Among hospitalizations with myocardial disorders, the rate of severe complications ranged from 13.2 for acute myocardial infarction to 128.6 for adult respiratory distress syndrome and from 10.7 for pulmonary edema to 193.0 for fluid and electrolyte disorders per 1,000 delivery and postpartum hospitalizations, respectively. Among hospitalizations without myocardial disorders, the rate of severe complications ranged from 0.07 to 1.9 and from 0.4 to 65.5 for cardiac arrest and for fluid and electrolyte disorders per 1,000 hospitalizations, in delivery and postpartum periods, respectively. CONCLUSION: Although only a minority of hospitalizations for cardiomyopathy are consistent with peripartum cardiomyopathy, cardiomyopathy and other myocardial disorders are important contributors to severe obstetric complications. LEVEL OF EVIDENCE: III