TY - JOUR
T1 - Association Between Hypertensive Disorders of Pregnancy and Later Risk of Cardiomyopathy
AU - Behrens, Ida
AU - Basit, Saima
AU - Lykke, Jacob Alexander
AU - Ranthe, Mattis Flyvholm
AU - Wohlfahrt, Jan
AU - Bundgaard, Henning
AU - Melbye, Mads
AU - Boyd, Heather A
PY - 2016/3/8
Y1 - 2016/3/8
N2 - IMPORTANCE: Women with hypertensive disorders of pregnancy, preeclampsia in particular, have an increased risk of cardiomyopathy during the peripartum period. Whether hypertensive disorders of pregnancy are also associated with cardiomyopathy later in life is unknown.OBJECTIVE: To determine whether hypertensive disorders of pregnancy are associated with cardiomyopathy beyond the peripartum period.DESIGN, SETTING, AND PARTICIPANTS: Nationwide register-based cohort study using Cox regression to compare rates of cardiomyopathy in women with and without a history of hypertensive disorders of pregnancy in a cohort of 1,075,763 women with at least 1 pregnancy ending in live birth or stillbirth in Denmark, 1978-2012, with follow-up through December 31, 2012.EXPOSURES: A hypertensive disorder of pregnancy (severe or moderate preeclampsia or gestational hypertension) registered in the National Patient Register.MAIN OUTCOMES AND MEASURES: Cardiomyopathy more than 5 months after delivery (outside the peripartum period) up to 34 years 7 months.RESULT: The women in the primary cohort had 2,067,633 eligible pregnancies during the study period, 76,108 of which were complicated by a hypertensive disorder of pregnancy. During follow-up, 1577 women (mean age, 48.5 years at cardiomyopathy diagnosis; 2.6% with multiple pregnancies) developed cardiomyopathy. Compared with women with normotensive pregnancies (18,211,603 person-years of follow-up; n = 1408 cardiomyopathy events, 7.7/100,000 person-years [95% CI, 7.3-8.2]), women with a history of hypertensive disorders of pregnancy had significantly increased rates of cardiomyopathy (in 173,062 person-years of follow-up among women with severe preeclampsia, n = 27 cardiomyopathy events; 15.6/100,000 person-years [95% CI, 10.7-22.7]; adjusted hazard ratio [HR], 2.20 [95% CI, 1.50-3.23]; in 697,447 person-years of follow-up among women with moderate preeclampsia, n = 102 cardiomyopathy events; 14.6/100,000 person-years [95% CI, 12.0-17.8]; adjusted HR, 1.89 [95% CI, 1.55-2.23]; in 213,197 person-years of follow-up among women with gestational hypertension, n = 40 cardiomyopathy events; 17.3/100,000 person-years [95% CI, 12.7-23.6]; adjusted HR, 2.06 [95% CI, 1.50-2.82]). These increases persisted more than 5 years after the latest pregnancy. Mediation analyses suggested that only about 50% of the association was an indirect association through postpregnancy chronic hypertension. In this cohort, 11% of all cardiomyopathy events occurred in women with a history of hypertensive disorders of pregnancy.CONCLUSIONS AND RELEVANCE: Women with a history of hypertensive disorders of pregnancy, compared with women without such a history, had a small but statistically significant increased risk of cardiomyopathy more than 5 months after delivery. Further research is necessary to understand whether there is a causal mechanism behind this association.
AB - IMPORTANCE: Women with hypertensive disorders of pregnancy, preeclampsia in particular, have an increased risk of cardiomyopathy during the peripartum period. Whether hypertensive disorders of pregnancy are also associated with cardiomyopathy later in life is unknown.OBJECTIVE: To determine whether hypertensive disorders of pregnancy are associated with cardiomyopathy beyond the peripartum period.DESIGN, SETTING, AND PARTICIPANTS: Nationwide register-based cohort study using Cox regression to compare rates of cardiomyopathy in women with and without a history of hypertensive disorders of pregnancy in a cohort of 1,075,763 women with at least 1 pregnancy ending in live birth or stillbirth in Denmark, 1978-2012, with follow-up through December 31, 2012.EXPOSURES: A hypertensive disorder of pregnancy (severe or moderate preeclampsia or gestational hypertension) registered in the National Patient Register.MAIN OUTCOMES AND MEASURES: Cardiomyopathy more than 5 months after delivery (outside the peripartum period) up to 34 years 7 months.RESULT: The women in the primary cohort had 2,067,633 eligible pregnancies during the study period, 76,108 of which were complicated by a hypertensive disorder of pregnancy. During follow-up, 1577 women (mean age, 48.5 years at cardiomyopathy diagnosis; 2.6% with multiple pregnancies) developed cardiomyopathy. Compared with women with normotensive pregnancies (18,211,603 person-years of follow-up; n = 1408 cardiomyopathy events, 7.7/100,000 person-years [95% CI, 7.3-8.2]), women with a history of hypertensive disorders of pregnancy had significantly increased rates of cardiomyopathy (in 173,062 person-years of follow-up among women with severe preeclampsia, n = 27 cardiomyopathy events; 15.6/100,000 person-years [95% CI, 10.7-22.7]; adjusted hazard ratio [HR], 2.20 [95% CI, 1.50-3.23]; in 697,447 person-years of follow-up among women with moderate preeclampsia, n = 102 cardiomyopathy events; 14.6/100,000 person-years [95% CI, 12.0-17.8]; adjusted HR, 1.89 [95% CI, 1.55-2.23]; in 213,197 person-years of follow-up among women with gestational hypertension, n = 40 cardiomyopathy events; 17.3/100,000 person-years [95% CI, 12.7-23.6]; adjusted HR, 2.06 [95% CI, 1.50-2.82]). These increases persisted more than 5 years after the latest pregnancy. Mediation analyses suggested that only about 50% of the association was an indirect association through postpregnancy chronic hypertension. In this cohort, 11% of all cardiomyopathy events occurred in women with a history of hypertensive disorders of pregnancy.CONCLUSIONS AND RELEVANCE: Women with a history of hypertensive disorders of pregnancy, compared with women without such a history, had a small but statistically significant increased risk of cardiomyopathy more than 5 months after delivery. Further research is necessary to understand whether there is a causal mechanism behind this association.
KW - Adult
KW - Cardiomyopathies
KW - Cohort Studies
KW - Confounding Factors (Epidemiology)
KW - Female
KW - Follow-Up Studies
KW - Humans
KW - Hypertension, Pregnancy-Induced
KW - Middle Aged
KW - Postpartum Period
KW - Pre-Eclampsia
KW - Pregnancy
KW - Proportional Hazards Models
KW - Registries
KW - Risk
KW - Time Factors
KW - Young Adult
KW - Journal Article
KW - Research Support, Non-U.S. Gov't
U2 - 10.1001/jama.2016.1869
DO - 10.1001/jama.2016.1869
M3 - Journal article
C2 - 26954411
SN - 0098-7484
VL - 315
SP - 1026
EP - 1033
JO - J A M A: The Journal of the American Medical Association
JF - J A M A: The Journal of the American Medical Association
IS - 10
ER -