Factors Associated With the Change in Prevalence of Cardiomyopathy at Delivery in the Period 2000 to 2009

Abstract

P regnancy-associated cardiomyopathy (CM) is uncommon, but is potentially life threatening. It now accounts for an increasing proportion of maternal deaths even as other etiologies such as hemorrhage and hypertensive disorders are decreasing. CM-related deaths during pregnancy increased from 11.5% of maternal mortality in 1998 to 2005 to nearly 13% in 2005 to 2006. CM can also contribute to other severe medical complications in pregnancy, including acute myocardial infarction, pulmonary edema, and acute respiratory distress syndrome. Women with underlying heart disease and baseline cardiac dysfunction may not be able to tolerate the strain associated with the cardiovascular changes of pregnancy. This population-based prevalence study was undertaken to identify preexisting medical conditions and medical and obstetric complications that might explain the increasing prevalence of CM in parturients.The Nationwide Inpatient Sample (NIS) was used to identify cases containing a pregnancy-related discharge for delivery from 2000 through 2009, and ICD-9-CM codes were used to find those delivery admissions that involved CM. The number of deaths occurring during the delivery admissions was determined for each study year. Only peripartum CMs and primary CMs that were diagnosed during the delivery hospitalization were included. Logistic regression was used to compute odds ratios and 95% confidence intervals (CI)s for age, race, preexisting medical conditions, and medical and obstetric complications in women with CM at delivery compared with women without CM. Rates of preexisting medical conditions and medical and obstetric complications among pregnant women with CM at delivery were calculated for each of the 10 years of the study.The prevalence of CM at delivery admission increased from 0.25/1000 deliveries in 2000 to 0.43/1000 deliveries in 2009 (P < 0.001). During the 10-year period, significant linear increases (P < 0.01) were noted in the prevalence of congenital heart disease, cardiac conduction disorders, history of ischemic heart disease, chronic hypertension, gestational diabetes, preeclampsia, and fetal growth restriction along with increases in other noncardiac conditions and diseases. Significant linear decreases (P < 0.01) were seen in the prevalence of valvular heart disease and fetal death during delivery admissions during the 10-year period. Significant linear increases (P < 0.01) Epidemiologic Reports, Surveys