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 (CHD) 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. “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, which produced an independent threefold increased risk.
▸ Left heart obstruction, which linked with a 2.5-fold increased 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 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, which ranged in time from 1995 to 2007, was a shunt lesion, in 87 women, followed by tetralogy of Fallot in 70, aortic coarctation in 52, and congenital aortic stenosis in 45 patients.
These findings have increasing relevance to U.S. practice because the number of American women with CHD who became pregnant steadily rose in 1998-2006, according to a study 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 CHD rose steadily by an overall 26%, reaching roughly 3,500 deliveries in both 2005 and 2006, compared with an 11% rise in U.S. adults with CHD during the same period.
Pregnant U.S. women with CHD during the study period matched their pregnant counterparts without congenital disease by their average age, 27, but their risk for peripartum complications or death was far higher, said Dr. Siddiqi, a physician at the University of Pennsylvania in Philadelphia, and his associates. Risks increased in pregnant women with CHD 22-fold for heart failure, 11-fold for arrhythmia, 31-fold for stroke, and 12-fold for death, compared with pregnant women without CHD.
Vitals
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.