Levothyroxine falls short of increasing heart transplant rates in brain-dead donors

In haemodynamically unstable brain-dead potential heart donors, the use of levothyroxine infusion appears to be only as good as saline infusion in terms of the rate of hearts being transplanted, according to a study.

The study included 852 haemodynamically unstable potential heart donors from 15 organ-procurement organizations in the US. These donors were randomly assigned to receive open-label infusion of intravenous levothyroxine (30 μg per hour for a minimum of 12 hours; n=419) or saline placebo (n=419) within 24 hours after declaration of death according to neurologic criteria.

Efficacy was assessed in terms of transplantation of the donor heart (primary outcome), while recipient safety was assessed in terms of graft survival at 30 days after transplantation. Vasopressor therapy, donor ejection fraction, and number of organs transplanted per donor were evaluated as secondary endpoints.

The number of hearts that were transplanted from donors did not significantly differ between the levothyroxine and saline groups (54.9 percent vs 53.2 percent; adjusted risk ratio, 1.01, 95 percent confidence interval [CI], 0.97–1.07; p=0.57).

Likewise, the rate of graft survival at 30 days was similar between the two groups (97.4 percent vs 95.5 percent; difference, 1.9 percentage points, 95 percent CI, −2.3 to 6.0; p<0.001 for noninferiority at a margin of 6 percentage points).

No significant between-group differences were seen in weaning from vasopressor therapy, ejection fraction on echocardiography, or organs transplanted per donor. However, levothyroxine treatment led to higher cases of severe hypertension and tachycardia than in the saline group.