Table 4.
Patient cohorts’ follow-up characteristics stratified by tertiles of change in the 6-min walk test distance.
| Variable | Δ 6MWD tertile 1 | Δ 6MWD tertile 2 | Δ 6MWD tertile 3 | p-value |
|---|---|---|---|---|
| (n = 59) | (n = 55) | (n = 56) | ||
| Δ 6MWD, m, border | ≤ − 40 | ≤ + 15 | > + 15 | |
| Time to follow-up, months, median (IQR) | 13 (12–15) | 12 (8–16) | 13 (10–14) | 0.534 |
| 6MWD, m, mean (SD) | 288 (117) | 381 (124) | 424 (134) | <0.001 |
| Δ 6MWD, m, mean (SD) | −101 (61) | −10 (14) | 73 (50) | <0.001 |
| Δ 6MWD absolute threshold, n (%) | 57 (100%) | 2 (3.6%) | 0 (0.0%) | <0.001 |
| Δ 6MWD, %, mean (SD) | −27.8% (16.3%) | −2.5% (4.1%) | 24.7% (20.3%) | <0.001 |
| Δ 6MWD relative threshold, n (%) | 57 (100%) | 17 (30.9%) | 0 (0.0%) | <0.001 |
| Primary endpoint, n (%) | 18 (31.6%) | 16 (29.1%) | 4 (7.1%) | 0.003 |
| Time to primary endpoint, months, median (IQR) | 14.1 (8.9–16.5) | 13.0 (9.7–19.5) | 8.9 (5.5–11.3) | 0.278 |
| NT-proBNP, pg./mL, median (IQR) | 2,593 (1633–5,302) | 2,546 (1661–4,647) | 1,533 (823–2,698) | <0.001 |
| Δ NT-proBNP, pg(mL), median (IQR) | 67 (−648–1,247) | 271 (−250–1,262) | −18 (−1,058–295) | 0.029 |
| TnT, ng/L, median (IQR) | 59.5 (38.0–89.0) | 54.5 (33.5–75.0) | 43.0 (28.0–54.0) | 0.006 |
| Δ TnT, ng/L, median (IQR) | 3.0 (−2.0–22.5) | 1.0 (−3.0–8.0) | −1.0 (−6.0–1.5) | 0.011 |
| eGFR, mL/min/1.73 m2, mean ± SD | 48.1 ± 19.5 | 51.1 ± 18.7 | 59.6 ± 17.7 | 0.002 |
| Δ eGFR, mL/min/1.73 m2, mean ± SD | −4.4 ± 9.8 | −3.9 ± 10.4 | −3.9 ± 12.6 | 0.746 |
| NAC, n (%) | <0.001 | |||
| 1 | 23 (41.1%) | 21 (40.4%) | 38 (67.9%) | |
| 2 | 17 (30.4%) | 20 (38.5%) | 15 (26.8%) | |
| 3 | 16 (28.6%) | 11 (21.2%) | 3 (5.4%) | |
| Tafamidis, n (%) | 57 (100%) | 35 (64.8%) | 50 (89.2%) | <0.001 |
| Started on tafamidis, n (%) | 53 (93.0%) | 35 (64.8%) | 47 (83.9%) | <0.001 |
| Time on tafamidis, months, median (IQR) | 11.4 (6.6–13.1) | 6.6 (6.0–11.6) | 11.3 (6.4–12.9) | 0.034 |
| Loop diuretics, n (%) | 43 (76.8%) | 34 (65.4%) | 31 (56.4%) | 0.074 |
| Loop diuretic dose, mg/kg, median (IQR) | 0.345 (0.000–0.818) | 0.278 (0.000–0.893) | 0.167 (0.000–0.382) | 0.022 |
| Loop diuretic escalation, n (%) | 21 (42.0%) | 17 (36.2%) | 10 (19.2%) | 0.045 |
6MWD indicates 6-min walk test distance; eGFR, estimated glomerular filtration rate; IQR, interquartile range; NAC, United Kingdom National Amyloidosis Centre staging system; NT-proBNP, N-terminal prohormone of B-type natriuretic peptide; SD, standard deviation; TnT, troponin T.
Metric data are given as mean ± standard deviation or median (interquartile range), and categorical data as counts (percentage).
p-values derived from the Kruskal–Wallis test for metric and the chi-squared test for binary/categorical variables. Statistically significant p-values <0.05 marked in bold.