Background Cardiovascular complications of pregnancy present an opportunity to assess risk for subsequent cardiovascular disease. We sought to determine whether peripartum cardiomyopathy and hypertensive disorder of pregnancy subtypes predict future myocardial infarction, heart failure or stroke independent of one another and of other risks such as gestational diabetes, preterm birth and intrauterine growth restriction.
Methods and results The California Healthcare Cost and Utilization Project database was used to identify all hospitalised pregnancies from 2005 to 2009, with follow-up through 2011, for a retrospective cohort study. Pregnancies, exposures, covariates and outcomes were defined by International Classification of Diseases, Ninth Revision codes. Among 1.6 million pregnancies (mean age 28 years; median follow-up time to event excluding censoring 2.7 years), 558 cases of peripartum cardiomyopathy, 123 603 hypertensive disorders of pregnancy, 107 636 cases of gestational diabetes, 116 768 preterm births and 23 504 cases of intrauterine growth restriction were observed. Using multivariable Cox proportional hazards models, peripartum cardiomyopathy was independently associated with a 39.2-fold increase in heart failure (95% CI 30.0 to 51.9), resulting in ~1 additional hospitalisation per 1000 person-years. There was a 13.0-fold increase in myocardial infarction (95% CI 4.1 to 40.9) and a 7.7-fold increase in stroke (95% CI 2.4 to 24.0). Hypertensive disorders of pregnancy were associated with 1.4-fold (95% CI 1.0 to 2.0) to 7.6-fold (95% CI 5.4 to 10.7) higher risk of myocardial infarction, heart failure and stroke, resulting in a maximum of ~1 additional event per 1000 person-years. Gestational diabetes, preterm birth and intrauterine growth restriction had more modest associations.
Conclusion These findings support close monitoring of women with cardiovascular pregnancy complications for prevention of early cardiovascular events and study of mechanisms underlying their development.
- peripartum cardiomyopathy
- hypertensive disorders of pregnancy
- cardiovascular disease
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Contributors NP and RA conceived of the research questions and analysis with input from all authors. GN performed the analyses, with guidance and help from NP and RA. RA and NP wrote the manuscript with input from all authors.
Funding RA was supported by NIH (K08HL125945) and the American Heart Association (15GPSPG238300004). ZT was supported by NIH (R01 Hl102090), NIH (R01 HL126555), CDC (DP14-1403) and NIH (R24 A1067039). NP was supported by NIH (R21 7R21HL115398).
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval Analyses were performed in accordance with the HCUP Data Use Agreement and are considered exempt research per UCSF CHR. To preserve patient anonymity, any groups in which there were fewer than 10 patients are listed in the tables as <10. Certification to use de-identified HCUP data was obtained from the University of California San Francisco Committee on Human Research.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement No additional data are available.
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