Table 1.
Characteristics of the Donors at Baseline.*
| Characteristic | Levothyroxine Group (N = 419) | Saline Group (N = 419) |
|---|---|---|
| Age — yr | 36±11 | 36±10 |
| Female sex — no./total no. (%)† | 127/403 (32) | 153/400 (38) |
| Race or ethnic group — no./total no. (%)† | ||
| White, non-Hispanic | 252/403 (63) | 278/397(70) |
| Black | 75/403 (19) | 49/397 (12) |
| Hispanic or Latino | 60/403 (15) | 63/397 (16) |
| Asian, Pacific Islander, or other | 16/403 (4) | 7/397 (2) |
| Blood group — no. (%) | ||
| O | 224 (53) | 214 (51) |
| A | 134 (32) | 148 (35) |
| B | 50 (12) | 49 (12) |
| AB | 11 (3) | 8 (2) |
| Coexisting conditions — no./total no. (%) | ||
| Hypertension | 98/403 (24) | 104/397 (26) |
| Diabetes | 38/403 (9) | 31/397 (8) |
| Cigarette use | 58/403 (14) | 76/397 (19) |
| Cocaine use | 92/403 (23) | 105/397 (26) |
| Cause of death — no./total no. (%) | ||
| Anoxia | 162/403 (40) | 195/397 (49) |
| Stroke | 87/403 (22) | 79/397 (20) |
| Trauma | 143/403 (35) | 117/397 (29) |
| Other | 11/403 (3) | 6/397 (2) |
| Weight — kg | 86±24 | 85±23 |
| Median creatinine level (IQR) — mg/dl | 1.2 (0.9–1.9) | 1.2 (0.8–2.0) |
| Median troponin I level (IQR) — ng/ml‡ | 0.7 (0.07–10.2) | 0.7 (0.08–7.3) |
| Positivity for hepatitis C virus — no./total no. (%) | 27/403 (7) | 25/397 (6) |
| Median vasopressor–inotrope score (IQR)§ | 10.2 (5–24) | 10.5 (5–22) |
| Median time from declaration of brain death to start of infusion (IQR) — hr | 8.6 (6.3–11.7) | 7.5 (4.9–11.1) |
| Free T4 levels¶ | ||
| Median (IQR) — ng/dl | 1.00 (0.77–1.30) | 1.00 (0.77–1.30) |
| Level below 0.9 ng/dl — no./total no. (%) | 141/370 (38) | 128/346 (37) |
| Median expected heart yield (IQR)‖ | 0.63 (0.15–0.86) | 0.59 (0.15–0.82) |
Plus–minus values are means ±SD. Unless otherwise indicated, the numbers of donors with missing data were as follows: for weight, 38 in the levothyroxine group and 44 in the saline group; for creatinine level, 2 and 10; for troponin level, 65 and 91; for vasopressor–inotrope score, 14 and 32; for time from declaration of brain death to start of infusion, 8 and 35; and for expected heart yield, 16 and 22. Percentages may not total 100 because of rounding. To convert the values for creatinine to micromoles per liter, multiple by 88.4. IQR denotes interquartile range.
Data on sex, race, and ethnic group were obtained from the Scientific Registry of Transplant Recipients (SRTR) donor database, as reported by the patient’s legal representative or extracted from the medical records (more details in Table S4).
The normal range for troponin levels is 0 to 0.04 ng per milliliter.
The vasopressor–inotrope score is calculated as the weighted sum of all vasopressor and inotropic medications: dopamine dose (in micrograms per kilogram of body weight per minute) + dobutamine dose (in micrograms per kilogram per minute) + (100 × epinephrine dose [in micrograms per kilogram per minute]) + (100 × norepinephrine dose [in micrograms per kilogram per minute]) + (10 × milrinone dose [in micrograms per kilogram per minute]) + (10 × phenylephrine dose [in micrograms per kilogram per minute]) + (10,000 × vasopressin dose [in units per kilogram per minute]). We excluded vasopressin from this calculation if infused at less than 1 unit per hour because this dose was used primarily for control of diabetes insipidus and not as a vasopressor.
The normal range for free T4 (levothyroxine) levels is 0.9 to 2.3 ng per deciliter.
Expected heart yield is derived from the SRTR calculator with the use of donor characteristics.