The effects of pregnancy in subjects with repaired tetralogy of Fallot.

The effects of pregnancy in subjects with repaired tetralogy of Fallot.

Duarte VE, Yamamura K, Economy KE, Graf JA, Lu M, Assenza GE, Karur GR, Marenco A, Ishikita A, Duncan ME, Geva T, Wald RM, Valente AM. Am Heart J. 2024 Aug;274:95-101. doi: 10.1016/j.ahj.2024.04.015. Epub 2024 Apr 26. PMID: 38677503

Take Home Points:

  • Pregnancy in women with repaired tetralogy of Fallot (rTOF) does not significantly alter right ventricular end-diastolic volume index (RVEDVi) and right ventricular ejection fraction (RVEF), as measured by cardiac magnetic resonance (CMR)
  • A slight increase in right ventricular end-systolic volume index (RVESVi) was observed in women with rTOF who had experienced pregnancy.
  • Long-term follow-up is essential to assess the effects of pregnancy on right ventricular remodeling.

Commentary from Dr. Mathias Possner (Switzerland), section editor of ACHD Journal Watch:

Introduction: 

Published data on right ventricular remodeling during pregnancy in women with rTOF are inconsistent. This study aimed to assess the intermediate effects of pregnancy on ventricular volumes and function in women with rTOF

Study Design: 

This retrospective cohort study was conducted at two high-volume ACHD centers (Boston Adult Congenital Heart Disease Program, Toronto Congenital Cardiac Center for Adults). The study population included 36 women with rTOF who completed pregnancy between 2004 and 2017. The pregnant women were matched 1:2 to nulliparous women with rTOF, using age, RVEDVi, and RVEF as frequency-matching variables. Both groups underwent baseline and follow-up CMR. For the pregnancy group, baseline CMR was performed prior to pregnancy and follow-up CMR was completed after pregnancy. Patients who had undergone pulmonary valve replacement or had more than one pregnancy between baseline and follow-up CMR were excluded.

Key Finding

The time between baseline and follow-up CMR in the pregnancy and control groups was 3.14 ± 1.05 and 2.67 ± 1.26 years (p = 0.056), respectively. CMR variables were comparable between the pregnancy and control groups at baseline. Baseline RVEDVi and pulmonary regurgitation fraction were 132.34 ± 38.69 mL/m2 versus 123.65 ± 29.34 mL/m2 (p=0.240) and 30.67 ± 19.04 % versus 26.40 ± 20.31 % (p=0.296) in the pregnancy and control groups, respectively. No significant changes were found in RVEDVi, RVEF, RV mass, and LV parameters between baseline and follow-up CMR in both groups. A small but statistically significant increase in RVESVi was observed in the pregnancy group. When adjusting for time between baseline and follow-up CMR, no significant difference in the rate of change was found between the pregnancy and control groups.

Strengths

– Study conducted at two high-volume ACHD centers.

–  Use of CMR, the gold standard for evaluating ventricular volumes and function.

–  Core laboratory for CMR data analysis.

Limitations

– Retrospective design with potential selection bias.

– Small sample size

– Short follow-up period between baseline and follow-up CMR

– The study was not powered to perform outcome analyses.

Discussion

This is a well-conducted study using CMR, the gold standard for evaluating volumetric and functional parameters, in patients with rTOF who underwent pregnancy. The study shows that pregnancy in women with rTOF does not significantly worsen RVEDVi or RVEF in the short and intermediate terms. The slight increase in RVESVi warrants further investigation, but overall, pregnancy appears to be well-tolerated. The findings support current clinical practices, though they emphasize the need for longer-term studies to assess future clinical and functional outcomes.

Conclusion

Subjects with rTOF who completed pregnancy did not show significant changes in CMR-derived RVEDVi or ventricular function compared to nulliparous subjects. Over a mean follow-up of 3.14 years, a slight increase in RVESVi was observed in the pregnancy group.