Intravenous Levothyroxine for Unstable Brain-Dead Heart Donors

Area of Science:

• Cardiology
• Transplantation Medicine
• Critical Care Medicine

Background:

• Hemodynamic instability and myocardial dysfunction are critical barriers to heart transplantation from brain-dead donors.
• Observational data suggest hormonal supplementation, including levothyroxine, may improve organ transplant rates.

Purpose of the Study:

• To evaluate the efficacy of intravenous levothyroxine in increasing heart transplant rates from hemodynamically unstable brain-dead donors.

Main Methods:

• A randomized trial was conducted across 15 US organ procurement organizations.
• Hemodynamically unstable brain-dead donors received either levothyroxine (30 μg/hour for ≥12 hours) or saline placebo.
• Primary outcome was heart transplantation; secondary outcomes included graft survival, vasopressor weaning, and ejection fraction.

Main Results:

• No significant difference in heart transplantation rates between levothyroxine (54.9%) and saline (53.2%) groups (aRR, 1.01; 95% CI, 0.97-1.07).
• Graft survival at 30 days was high and similar in both groups (97.4% vs. 95.5%).
• Levothyroxine group experienced more severe hypertension and tachycardia, with no significant differences in vasopressor weaning or ejection fraction.

Conclusions:

• Intravenous levothyroxine infusion did not significantly increase the rate of heart transplantation in hemodynamically unstable brain-dead donors compared to saline.
• The study found no significant benefit of levothyroxine on key secondary outcomes, but noted increased adverse events.
• Current evidence does not support the routine use of levothyroxine for improving heart transplant outcomes in this donor population.