Table 4.
Cardiopulmonary exercise testing results by NT-proBNP quartiles
| Quartile 1 (n = 174) | Quartile 2 (n = 171) | Quartile 3 (n = 172) | Quartile 4 (n = 168) | p-value | |
|---|---|---|---|---|---|
| NT-proBNP range, ng/L | 5–35 | 36–71 | 72–135 | 136–4284 | |
| Duration of CPET test, min, mean ± SD | 10.55 (2.31) | 9.92 (2.41) | 9.70 (2.31) | 8.80 (2.25) | < 0.001 |
| Peak VO2, mL/Kg/min, mean ± SD | 17.18 (3.81) | 15.79 (3.63) | 15.34 (3.93) | 14.55 (3.34) | < 0.001 |
| VE/VCO2 slope, mean ± SD | 30.58 (4.70) | 30.70 (5.13) | 31.53 (5.55) | 32.08 (6.05) | 0.031 |
| Peak respiratory exchange rate, mean ± SD | 1.17 (0.09) | 1.18 (0.11) | 1.18 (0.09) | 1.18 (0.09) | 0.81 |
| Predicted % peak VO2, mean (SD) | 54.87 (10.57) | 53.74 (11.20) | 52.72 (12.25) | 50.74 (10.68) | 0.006 |
| Peak heart rate, beats per min, mean (SD) | 138.49 (17.24) | 131.63 (19.36) | 128.03 (18.74) | 124.83 (18.74) | < 0.001 |
| Peak systolic blood pressure, mmHg, mean (SD) | 186.57 (26.45) | 181.16 (28.73) | 175.94 (23.27) | 171.61 (25.98) | < 0.001 |
| Peak diastolic blood pressure, mmHg, mean (SD) | 87.43 (15.37) | 85.11 (16.87) | 85.05 (14.83) | 83.87 (12.48) | 0.18 |
| Oxygen pulse (VO2/heart rate), ml/beat, mean (SD) | 0.12 (0.03) | 0.12 (0.03) | 0.12 (0.03) | 0.12 (0.03) | 0.12 |
NT-proBNP, N-terminal pro-B-type natriuretic peptide; CPET, cardiopulmonary exercise testing; VO2, maximal oxygen consumption; VE/VCO2, ventilatory efficiency; SD, standard deviation.