Predictors of arrhythmia during pregnancy in adults with congenital heart disease.

Background: Risk prediction of arrhythmia during pregnancy in adult congenital heart disease (ACHD) patients is currently lacking, and the impact of preconception catheter ablation on future antepartum arrhythmia has not been studied.

Methods: We conducted a single-center, retrospective cohort study of pregnancies in ACHD patients. Clinically significant arrhythmia events during pregnancy were described, predictors of arrhythmia were analyzed, and a risk score devised. The impact of preconception catheter ablation on antepartum arrhythmia was assessed.

Results: The study included 172 pregnancies in 137 patients. Arrhythmia events occurred in 25 (15%) of pregnancies, with 64% of events occurring in the second trimester and sustained supraventricular tachycardia being the most common rhythm. Univariate predictors of arrhythmia were history of tachyarrhythmia (OR 20.33, 95% CI 6.95-59.47, p < 0.001, Fontan circulation (OR 11.90, 95% CI 2.60-53.70, p < 0.001), baseline physiologic class C/D (OR 3.72, 95% CI 1.54-9.01, p = 0.002) and history of multiple valve interventions (OR 3.10, 95% CI 1.20-8.20, p = 0.017). Three risk factors (excluding multiple valve interventions) were used to formulate a risk score, with a cutoff of ≥2 points predicting antepartum arrhythmia with sensitivity and specificity of 84%. While recurrence of the index arrhythmia was not observed following successful catheter ablation, preconception ablation did not impact odds of antepartum arrhythmia.

Conclusions: We provide a novel risk stratification scheme for predicting antepartum arrhythmia in ACHD patients. The role of contemporary preconception catheter ablation in risk reduction needs further refinement with multicenter investigation.