Triiodothyronine Supplementation in Infants Undergoing Cardiopulmonary Bypass: A Randomized Controlled Trial

Cardiopulmonary bypass (CPB) profoundly suppresses circulating thyroid hormone levels in infants. We performed a multicenter randomized placebo controlled trial to determine if triiodothyronine (T3) supplementation improves reduces time to extubation (TTE) in infants after CPB. Infants (n = 220) undergoing cardiac surgery with CPB and stratified into 2 age cohorts: ≤30 days and >30 days to <152 days were randomization to receive either intravenous triiodothyronine or placebo bolus followed by study drug infusion until extubated or at 48 hours, whichever preceded. T3 did not significantly alter the primary endpoint, TTE (hazard ratio for chance of extubation (1.08, 95% CI: 0.82-1.43, P = 0.575) in the entire randomized population with censoring at 21 days. T3 showed no significant effect on TTE (HR 0.82, 95% CI:0.55-1.23, P = 0.341) in the younger subgroup or in the older (HR 1.38, 95% CI:0.95-2.2, P = 0.095). T3 also did not significantly impact TTE during the first 48 hours while T3 levels were maintained (HR 1.371, 95% CI:0.942-1.95, P = 0.099) No significant differences occurred for arrhythmias or other sentinel adverse events in the entire cohort or in the subgroups. This trial showed no significant benefit on TTE in the entire cohort. T3 supplementation appears safe as it did not cause an increase in adverse events. The study implementation and analysis were complicated by marked variability in surgical risk, although risk categories were balanced between treatment groups.