Table 2. Cardiopulmonary Exercise Testing (CPET) Parameters by Treatment Assignment.
| CPET variable | Aficamten, mean (SD) (n = 133) | Placebo, mean (SD) (n = 130) | Adjusted difference (95% CI)b | P value | ||||
|---|---|---|---|---|---|---|---|---|
| Baseline | Week 24 | Absolute difference (SD)a | Baseline | Week 24 | Absolute difference (SD)a | |||
| Integrated 2-component z score metricc | −0.01 (0.82) | 0.16 (0.76) | 0.17 (0.51) | 0.02 (0.75) | −0.17 (0.74) | −0.19 (0.45) | 0.35 (0.25 to 0.46) | <.001 |
| pVO2, mL/kg/min | 18.4 (4.5) | 20.2 (5.2) | 1.8 (3.1) | 18.6 (4.6) | 18.6 (4.7) | 0 (2.7) | 1.7 (1.0 to 2.4) | <.001 |
| Peak workload, W | 120 (40) | 134 (50) | 14 (27) | 126 (43) | 127 (44) | 1 (21) | 12 (6 to 18) | <.001 |
| Peak METS, metabolic equivalents | 5.3 (1.3) | 5.8 (1.5) | 0.51 (0.89) | 5.3 (1.3) | 5.3 (1.3) | 0 (0.78) | 0.49 (0.29 to 0.69) | <.001 |
| Peak circulatory power, mm Hg × mL/kg/min | 3013 (924) | 3550 (1140) | 537 (995) | 3160 (1136) | 3074 (1152) | −86 (731) | 586 (379 to 793) | <.001 |
| Exercise duration, min | 11.2 (3.0) | 12.4 (3.9) | 1.2 (2.1) | 11.5 (3.0) | 11.7 (3.2) | 0.1 (1.5) | 1.0 (0.5 to 1.4) | <.001 |
| Peak RER | 1.19 (0.10) | 1.20 (0.11) | 0.01 (0.10) | 1.18 (0.09) | 1.19 (0.10) | 0.01 (0.10) | 0.00 (−0.02 to 0.02) | .84 |
| Heart rate reserve, beats/min | 59 (18) | 66 (22) | 7 (15) | 57 (19) | 59 (20) | 1 (10) | 6 (3 to 9) | <.001 |
| Peak heart rate, beats/min | 128 (20) | 135 (23) | 8 (14) | 128 (23) | 127 (23) | −1 (12) | 9 (6 to 12) | <.001 |
| Oxygen pulse at peak exercise, mL/beat | 0.14 (0.03) | 0.15 (0.03) | 0 (0.02) | 0.15 (0.03) | 0.15 (0.03) | 0 (0.02) | 0.003 (−0.002 to 0.008) | .21 |
| Proportionate pulse pressure, peak exercise | 0.49 (0.11) | 0.51 (0.12) | 0.02 (0.14) | 0.50 (0.10) | 0.50 (0.11) | 0 (0.10) | 0.01 (−0.01 to 0.04) | .29 |
| Proportionate pulse pressure, rest | 0.39 (0.10) | 0.37 (0.09) | −0.02 (0.10) | 0.39 (0.10) | 0.38 (0.10) | −0.01 (0.11) | −0.01 (−0.03 to 0.01) | .33 |
| Ventilatory efficiency pre-VAT, VE/VCO2 slope | 29.2 (5.4) | 27.4 (4.4) | −1.9 (4.7) | 29.1 (4.7) | 28.8 (5.6) | −0.3 (4.2) | −1.5 (−2.5 to −0.6) | .002 |
| Ventilatory efficiency throughout exercise, VE/VCO2 slope | 33.2 (6.4) | 30.9 (5.7) | −2.2 (4.0) | 32.9 (6.0) | 32.9 (6.4) | 0.1 (3.7) | −2.3 (−3.2 to −1.4) | <.001 |
| Ventilatory power, mm Hg | 5.1 (1.5) | 5.9 (1.6) | 0.8 (1.3) | 5.2 (1.6) | 5.1 (1.5) | −0.1 (1.0) | 0.9 (0.6 to 1.1) | <.001 |
| Ventilatory anaerobic threshold, mL/min | 898 (266) | 958 (276) | 60 (107) | 931 (261) | 927 (257) | −3 (108) | 59 (33 to 85) | <.001 |
| Aerobic efficiency, mL/min/W | 8.3 (2.5) | 8.6 (2.5) | 0.3 (1.8) | 8.2 (2.3) | 8.2 (2.4) | 0.1 (1.7) | 0.2 (−0.2 to 0.6) | .22 |
Abbreviations: LSM, least squares mean; METS, metabolic equivalents; pVO2, peak oxygen uptake; RER, respiratory exchange ratio; VAT, ventilatory anaerobic threshold; VCO2, carbon dioxide output; VE, minute ventilation.
a
The absolute difference corresponds to the change from baseline to week 24.
b
The adjusted difference corresponds to the LSM treatment difference.
c
Integrated exercise performance was defined as the 2-component z score of pVO2 and ventilatory efficiency throughout exercise (VE/VCO2 slope). The z score was derived by reversing the directionality of VE/VCO2 slope values such that increases in both z score components indicate benefit; equal weights were used for each component.