Influence of pregnancy on long-term durability of allografts in right ventricular outflow tract

Background: There is very limited published evidence about the influence of pregnancy on allograft durability in right ventricular outflow tract position. We present the first study using mixed and joint modeling.

Methods: This retrospective study compared clinical and valve related outcomes of all consecutive female hospital survivors in their fertile life phase (18-50 years) based on pregnancy. Serial echocardiographic measurements of pulmonary gradient and regurgitation were analyzed for their association with valve replacement using joint models for longitudinal and time-to-event data. Occurrence of first pregnancy was included as a time-dependent intermediate event in both the longitudinal and survival analyses of the joint model to assess its impact on the hemodynamic and clinical outcome.

Results: In total, 196 consecutive women in their fertile life-phase with an allograft were included. Complete information of 176 (90%) allografts in 165 women was available, including 1395 echocardiograms. Of these women, 51 (30.9%) women had 84 completed pregnancies at an average age of 29.1 ± 3.9 (SD) years; 8.1 ± 6.1 years since allograft implantation. Tetralogy of Fallot was the most common diagnosis in both groups. After a mean follow-up of 15.2 years (range 0.1-30), 7 (13.7%) parous women underwent valve replacement versus 20 (17.5%) nulliparous women. During this follow-up, the mean allograft gradient in parous (24.2 mm Hg) and nulliparous (21.0 mm Hg) women was comparable (P = .225). A 1-mm Hg increase in pulmonary gradient increased the instantaneous risk of pulmonary valve replacement (PVR) by a ratio of 1.051 (P < .001), regardless of pregnancy. Similarly, development of moderate or severe regurgitation increased the risk of PVR (P = .038), regardless of pregnancy. Pregnancy was not associated with a change in the allograft gradient (P = .258), regurgitation grade (P = .774), or hazard of PVR (P = .796) during follow-up.

Conclusions: Pregnancy is not associated with impaired allograft durability in women with good cardiac health.