Impact of pregnancy and risk factors for ventricular arrhythmias in women operated for tetralogy of Fallot

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): South-Eastern Norway Regional Health Authority Background Patients with tetralogy of Fallot (TOF) have a high survival rate 30 years after surgical repair, and generally enjoy a satisfactory quality of life. Many female patients experience pregnancy during adulthood, however the effects of pregnancy on the long-term cardiovascular outcome in this group of patients are not well known. Purpose We aimed to investigate the association of pregnancy and cardiac function with occurrence of ventricular arrhythmia (VA) in women operated for TOF. Methods We included 80 patients recruited from the national database for patients diagnosed for TOF. All were examined with echocardiography, including strain echocardiography. We assessed mechanical dispersion of right ventricle (RV) as measure of heterogeneous contraction. Holter monitoring or implanted devices detected ventricular arrhythmias (VA), defined as non-sustained or sustained ventricular tachycardia or aborted cardiac arrest. Blood tests included N-terminal pro-brain natriuretic peptide (NT-proBNP). Results In all, 55 (69%) women had experienced pregnancy (age 40 ± 9 years, parity median 1, range 1-4), while 25 (31%) women were nulliparous. The mean age was lower in nulliparous compared to those with children (30 ± 9 vs 40 ± 9, p < 0.01). VA was more prevalent in women who had experienced pregnancy (n = 16, 94%) compared to nulliparous (n = 1, 6%) (p = 0.02), and importantly also when adjusted for age [adjusted OR 9.8 (95% CI 1.2-79.1), p = 0.02]. RV mechanical dispersion was more pronounced in patients with VA [39.2 ± 14 ms vs. 49.6 ± 8 ms, p = 0.009, adjusted OR 2.1 (95% CI 1.3 - 7.5), p = 0.01 adjusted for age]. Higher NT-proBNP was also a marker of VA [211 ng/L (127-836) vs. 139 ng/L (30-465), p = 0.007, adjusted OR 1.4 (95% CI 1.1 - 1.8) p = 0.017 adjusted for age]. NT-proBNP >182 ng/L (normal values < 170 ng/L) optimally detected women with VA (p = 0.019), also independent of age [OR 7.2 (95% CI 1.7-30.1), p = 0.007]. Conclusion History of pregnancy was associated with higher prevalence of VA among women with surgically corrected TOF. Right ventricular mechanical dispersion and NT-proBNP were age independent markers of VA. These findings may have importance for risk stratification and preconception counselling of these patients.