In women with long QT syndrome, pregnancy reduced the risk of cardiac events (HR 0.28; P=0.01), whereas the 9-month postpartum period significantly increased the risk (HR 2.7; P<0.001).
Cohort (n=391)
Does the peripartum period alter the risk of adverse cardiac events in women with long QT syndrome?
Women with long QT syndrome face a significantly increased risk of adverse cardiac events during the 9-month postpartum period, particularly those with the LQT2 genotype, and this risk is reduced by beta-blocker therapy.
Hazard Ratio: 0.28 (95% CI 0.1–0.76)
p-value: p=0.01
OBJECTIVES: This study was designed to investigate the clinical course of women with long QT syndrome (LQTS) throughout their potential childbearing years. BACKGROUND: Only limited data exist regarding the risks associated with pregnancy in women with LQTS. METHODS: The risk of experiencing an adverse cardiac event, including syncope, aborted cardiac arrest, and sudden death, during and after pregnancy was analyzed for women who had their first birth from 1980 to 2003 (n = 391). Time-dependent Kaplan-Meier and Cox proportional hazard methods were used to evaluate the risk of cardiac events during different peripartum periods. RESULTS: Compared with a time period before a woman's first conception, the pregnancy time was associated with a reduced risk of cardiac events (hazard ratio HR 0.28, 95% confidence interval CI 0.10 to 0.76, p = 0.01), whereas the 9-month postpartum time had an increased risk (HR 2.7, 95% CI 1.8 to 4.3, p < 0.001). After the 9-month postpartum period, the risk was similar to the period before the first conception (HR 0.91, 95% CI 0.55 to 1.5, p = 0.70). Genotype analysis (n = 153) showed that women with the LQT2 genotype were more likely to experience a cardiac event than women with the LQT1 or LQT3 genotype. The cardiac event risk during the high-risk postpartum period was reduced among women using beta-blocker therapy (HR 0.34, 95% CI 0.14 to 0.84, p = 0.02). CONCLUSIONS: Women with LQTS have a reduced risk for cardiac events during pregnancy, but an increased risk during the 9-month postpartum period, especially among women with the LQT2 genotype. Beta-blockers were associated with a reduction in cardiac events during the high-risk postpartum time period.
“Pregnancy and postpartum are not especially high-risk periods for cardiac events in women with long QT syndrome”
Seth et al. (2007) conducted a cohort in Long QT syndrome (n=391). Pregnancy vs. Time period before first conception was evaluated on Adverse cardiac event (syncope, aborted cardiac arrest, and sudden death) (HR 0.28, 95% CI 0.10 to 0.76, p=0.01). In women with long QT syndrome, pregnancy reduced the risk of cardiac events (HR 0.28; P=0.01), whereas the 9-month postpartum period significantly increased the risk (HR 2.7; P<0.001).