Major Findings: Women with congenital heart disease had a 12% rate of late cardiac events after pregnancy. The strongest independent risk factor for such an event was a cardiac event before or during pregnancy.
Source of Data: Analysis of 318 women, with a total of 405 deliveries, at one center in Toronto.
Disclosures: Dr. Balint and her associates had no financial disclosures to report.
ORLANDO — During long-term follow-up after pregnancy, women with congenital heart disease had a 12% rate of late cardiac events in a series of 318 patients followed at one center for a median of 2.6 years.
The analysis also identified four clinical factors that flagged women with congenital heart disease who faced the highest risk for a late event (starting more than 6 months after delivery). Women with one of these risk factors had a 27% rate of long-term cardiac events, women with more than one had a 47% rate, whereas women with none of them had an 8% rate, Dr. Olga H. Balint said at the annual scientific sessions of the American Heart Association.
“We can use this data to discuss with patients” the risk they face from pregnancy, said Dr. Balint, a physician in the pregnancy and heart disease research program at the University of Toronto. The findings highlight the significance of cardiac events that occur before or during pregnancy, a factor that raised the risk for a late event by 2.5-fold independent of any other risk. “It's important to take into account a pregnancy event. These patients are most likely to need intervention after pregnancy.”
The other three significant independent risk factors for late cardiac events were as follows:
▸ Subpulmonary ventricular dysfunction, pulmonary regurgitation, or both, which conferred a 3.4-fold independent increased risk for a late event.
▸ Subaortic ventricular dysfunction (a left ventricular ejection fraction of less than 40%), which produced an independent threefold increased risk.
▸ Left heart obstruction, which linked with a 2.5-fold–higher risk.
The late events, which occurred following 50 of the total 405 deliveries, were most frequently arrhythmia, with pulmonary edema as the next most common event. Three late events were cardiac arrest or death, and one was a stroke. This 12% rate of late cardiac events matched the 12% rate of cardiac events that preceded pregnancy and the 11% rate during pregnancy.
The analysis did not address how the late event rate in these women following pregnancy compared with the event rate that similar women with congenital heart disease would have had if they did not become pregnant, Dr. Balint noted. The women in the Toronto series had an average age of 28, and 66% were nulliparous prior to the index pregnancy. Dr. Balint stressed that parity was not a significant univariate risk factor for late cardiac events nor was it a significant risk factor in the multivariate analysis.
The most common congenital disease in the series was a shunt lesion, in 87 women, followed by tetralogy of Fallot in 70, aortic coarctation in 52, and congenital aortic stenosis in 45. The pregnancies in the series occurred during 1995–2007.
These findings have increasing relevance to U.S. practice because the number of American women with congenital heart disease who became pregnant steadily rose during 1998–2006, according to data reported in a poster at the meeting.
Using data from nearly 38 million pregnant U.S. women hospitalized during that period and collected by the Nationwide Inpatient Sample, Dr. Omar K. Siddiqi and his associates found that during those 9 years the number of deliveries from women with congenital heart disease rose steadily by an overall 26%, reaching roughly 3,500 deliveries in both 2005 and 2006. The rate of increase was disproportionate to the rise in number of U.S. adults with congenital heart disease, which increased by about 11% during the same period.
During the 9 years studied, pregnant women with congenital heart disease had a 22-fold increased risk for heart failure, an 11-fold increased risk for arrhythmia, a 31-fold increased risk for stroke, and a 12-fold increased risk for death, compared with pregnant women without congenital heart disease, said Dr. Siddiqi, a physician at the University of Pennsylvania in Philadelphia, and his associates.