Cardiac Function in 10-year-old Twins Following Different Fetal Therapies for Twin-twin Transfusion Syndrome

Objectives: To compare cardiac function at 10 years of age in four groups of monochorionic diamniotic (MCDA) twin pairs: uncomplicated MCDA twins (n = 6) (Group 1); twins that had had twin-twin transfusion syndrome (TTTS) managed by amnioreduction (TTTS-amnio, n = 9) (Group 2) or laser photocoagulation (TTTS-laser, n = 10) (Group 3); and dichorionic diamniotic controls (DCDA, n = 6) (Group 4).

Methods: Echocardiograms optimizing apical four-chamber and short-axis left ventricular views were stored for offline speckle-tracking analysis, blinded to twin type. Myocardial long-axis shortening and lengthening velocities were measured using pulsed Doppler ultrasound at the cardiac base. M-mode measurements of fractional shortening (short axis) and maximal excursion of the atrioventricular annulus (four-chamber) were recorded. Syngo Vector Velocity Imaging software tracked left ventricular myocardial motion offline to produce free wall strain, strain rate and rotation. Intertwin pair and group differences were investigated using ANOVA.

Results: Cardiac measurements were within the normal ranges for 10-year-olds. No significant within-twin-pair and intergroup differences were found in current size, heart rates, strain or strain rate. Compared to DCDA controls, TTTS twins showed less cardiac rotation (TTTS-laser, P < 0.001 and TTTS-amnio, P = 0.054) with significant intertwin reduction in the ex-recipient (TTTS-amnio, P = 0.006) and larger MCDA twins (P = 0.027) compared with their cotwins. A similar pattern was seen in left ventricular early diastolic mitral valve tissue velocity (MVE') in all monochorionic groups, but only achieving significance in TTTS-amnio twins (P = 0.037). Intrapair differences in rotation and MVE' were significantly different following treatment at Quintero stages III or IV.

Conclusions: Within-twin-pair patterns of left ventricular rotation and diastolic function differ at 10 years of age in ex-recipients of TTTS twins treated with amnioreduction compared with those treated by laser photocoagulation and controls. .