Atrial Fib Can Raise Risk in Pregnant Women With Structural Heart Disease: Cohort Study

Marlene Busko

August 26, 2015

WASHINGTON, DC — Atrial fibrillation (AF) and atrial flutter (AFL) are rare in pregnant women with structural heart disease—occurring in 1.3% of such women—but these arrhythmias are associated with an increased risk of maternal death and low fetal birth weight[1]. These findings, by Dr Amar M Salam (Hamad Medical Corp, Doha, Qatar) and colleagues, from an analysis of data from more than 1000 women who were part of the international Registry on Pregnancy and Cardiac Disease (ROPAC), were reported in the August 2015 issue of JACC: Clinical Electrophysiology.

Thus, pregnant women with structural heart disease—including those with a history of AF/AFL or beta-blocker use or who have left-sided disease such as aortic-valve disease, mitral-valve disease, or cardiomyopathies—should be closely followed throughout pregnancy and delivery, senior author Dr Jolien W Roos-Hesselink and coauthor Dr Iris M van Hagen (Erasmus Medical Center, Rotterdam, the Netherlands) told heartwire from Medscape in an email. The study also suggests that these women should be routinely screened for AF/AFL during the second trimester, since the incidence of AF/AFL peaked at 23 to 26 weeks of gestation, they note.

Two of the 17 pregnant women with heart disease who developed AF/AFL (12%) died, which "underscores the need for appropriate preconception counseling, prepregnancy interventions when appropriate, frequent surveillance during pregnancy, and the need for pregnancy care by a multidisciplinary team with expertise in pregnancy and heart disease," Drs Candice K Silversides and Danna A Spears (University of Toronto, ON) note in an accompanying editorial[2].

The study also confirmed the existence of disparities between the developed and developing world. The women who died were from developing countries, where women "suffer significantly more frequently from adverse outcomes of pregnancy (maternal mortality, heart failure, and fetal demise)," Roos-Hesselink and van Hagen added.

Incidence, Risk Factors, and Outcomes of AF in Pregnancy

Arrhythmia is a recognized complication in pregnant women with heart disease, but little is known about the incidence, timing, and consequences of the development of AF/AFL in such women.

Between 2008 and 2011, ROPAC enrolled 1321 pregnant women with structural heart disease—congenital heart disease (872), valvular heart disease (334), cardiomyopathy (88), and ischemic heart disease (25)—from 60 hospitals in 28 countries around the world. About half of the women already had a child, and most women knew they had cardiac disease, Roos-Hesselink and van Hagen said.

Seventeen patients developed AF/AFL during pregnancy, including patients with valvular heart disease (3%), cardiomyopathy (1%), and congenital heart disease (0.7%), but not ischemic heart disease.

"It was not surprising that AF before pregnancy was an independent predictor of AF/AFL during pregnancy," the researchers write. Mitral-valve disease and left-sided lesions may increase the risk of developing AF/AFL because they may amplify wall stress, and previous use of beta-blockers may indicate that these patients had more severe heart disease, they suggest.

Predictors of Atrial Fibrillation/Atrial Flutter in Pregnancy

Factor OR (95% CI) P
Mitral-valve disease 6.9 (2.6–18.3) <0.001
Left-sided lesion 2.9 (1.0–8.3) 0.046
AF before pregnancy 7.1 (1.5–32.8) 0.01
Beta-blocker before pregnancy 3.3 (1.2–9.0) 0.02

Compared with the other women with heart disease, those who developed AF/AFL during pregnancy were more likely to have a child with a low (<2500 g) birth weight (35% vs 14%, P=0.02).

These preliminary findings need confirmation in larger populations, Roos-Hesselink and colleagues caution. "Further studies are warranted to examine the incidence and effects of asymptomatic AF/AFL occurring during pregnancy in patients with structural heart disease (using 24-hour Holter or transtelephonic monitoring), particularly in the second trimester," they conclude.

"Multicenter collaborative studies, such as the ROPAC, continue to help improve our understanding of pregnancy risk in women with rare conditions and rare complications," Silversides and Spears note.


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