Background
Methods
Study design and patients
Six-minute walking test
Phase synchronization analysis
Instrumentation
Signal processing and Synchrogram index
Statistical analysis
Results
Demographic characteristics of patient
Total (n = 55) | Synchronized (n = 43) | Desynchronized (n = 12) | p-value | |
---|---|---|---|---|
Age, years | 69 (51–84) | 69 (51–84) | 77 (52–84) | 0.02 |
Male, n (%) | 54 (98.2) | 42 (97.7) | 12 (100) | 1 |
Smoker, n (%) | 49 (89.1) | 38 (88.4) | 11 (91.7) | 1 |
Current, n (%) | 27 (49.1) | 20 (46.5) | 7 (58.3) | 1 |
Ex-smoker, n (%) | 22 (40) | 17 (39.5) | 5 (41.7) | 1 |
BMI, kg/m2 | 24.7 (16.7–32.1) | 24.2 (16.7–32.0) | 26.2 (20.3–30.8) | 0.03 |
Eosinophil Count, number/l | 129 (0–615.6) | 134.5 (0–615.6) | 115.0 (0–329.8) | 0.74 |
Allergic status, n (%) | 36 (65.5) | 28 (65.1) | 8 (66.7) | 1 |
a-IgE, pg/ml | 59.7 (2–1652) | 65.2 (3.59–1652) | 47.0 (2–691) | 0.59 |
HS-CRP, mg/dl | 1.7 (0.2–189.7) | 1.64 (0.2–37.9) | 1.75 (0.2–189.7) | 0.65 |
CAT | 10 (2–29) | 10 (2–29) | 6 (3–29) | 0.99 |
mMRC | 1 (0–4) | 1 (0–3) | 1 (0–4) | 0.73 |
Presence of emphysema, n (%) | 33 (60) | 27 (62.7) | 6 (50) | 1 |
AE history, n (%) | 19 (34.5) | 16 (37.2) | 3 (25) | 0.49 |
Underlying disease | ||||
ACO, n (%) | 1 (1.8) | 0 (0) | 1 (8.3) | 0.21 |
Hypertension, n (%) | 17 (30.9) | 11 (25.6) | 6 (46.2) | 0.16 |
DM, n (%) | 8 (14.5) | 5 (11.6) | 3 (23.1) | 0.35 |
CAD, n (%) | 3 (5.5) | 3 (7.0) | 0 (0) | 1 |
Liver Disease, n (%) | 6 (10.9) | 6 (14.0) | 0 (0) | 0.32 |
Kidney Disease, n (%) | 1 (1.8) | 0 (0) | 1 (7.7) | 0.21 |
Cardiac echo | ||||
Diastolic dysfunction, n (%) | 24 (43.6) | 20 (46.5) | 4 (33.3) | 0.51 |
E/e' ratio | 8.9 (4.5–20.0) | 8.8 (4.5–13.0) | 11.4 (5.2–20.0) | 0.06 |
EF, % | 65.5 (52–90) | 66.5 (52–90) | 64.5 (52–78) | 0.33 |
LA, mm | 34 (23–46) | 34 (23–46) | 33.5 (28–41) | 0.99 |
Drugs | ||||
LABA alone, n (%) | 4 (7.3) | 3 (7.0) | 1 (8.3) | 1 |
LAMA alone, n (%) | 1 (1.8) | 1 (2.3) | 0 (0) | 1 |
LABA + LAMA, n (%) | 20 (36.4) | 15 (34.9) | 5 (41.7) | 0.74 |
LABA + ICS, n (%) | 3 (5.5) | 2 (4.7) | 1 (8.3) | 0.54 |
Triple, n (%) | 26 (47.3) | 22 (51.2) | 4 (33.3) | 0.35 |
OCS, n (%) | 5 (9.1) | 4 (9.3) | 1 (8.3) | 1 |
Anti-psychotic agents, n (%) | 2 (3.6) | 0 (0) | 2 (4.8) | 1 |
ECG, flow signal, CRC data, and synchrogram index
Comparing coupling tests with six-minute walking test
Pre- and post-exercise (6MWT) | COPD (n = 55) | Synchronized (n = 43) | Desynchronized (n = 12) | p-value |
---|---|---|---|---|
Pre-FVC, L | 2.6 (1.2–4.4) | 2.7 (1.2–4.4) | 2.45 (1.3–3.3) | 0.28 |
Pre-FVC, % | 78.7 (38–129) | 82.5 (39–129) | 77 (38–96) | 0.89 |
Pre-FEV1, L | 1.5 (0.5–2.7) | 1.39 (0.6–2.7) | 1.43 (0.5–2.0) | 0.49 |
Pre-FEV1, % | 56.7 (18–102) | 55.5 (18–102) | 62.5 (18–76) | 0.79 |
Pre-FEV1/FVC | 0.56 (0.31–0.72) | 0.57 (0.31–0.72) | 0.56 (0.35–0.7) | 0.64 |
Post-FVC, L | 2.7 (1.1–4.4) | 2.7 (1.1–4.4) | 2.7 (1.4–3.3) | 0.29 |
Post-FVC, % | 81 (42–130) | 81.5 (42–130) | 87 (43–96) | 0.78 |
Post-FEV1, L | 1.47 (0.53–2.82) | 1.44 (0.67–2.82) | 1.49 (0.53–2.09) | 0.53 |
Post-FEV1, % | 60 (21–105) | 57 (22–105) | 60 (21–79) | 0.60 |
Post-FEV1/FVC | 0.59 (0.35–0.73) | 0.59 (0.35–0.73) | 0.56 (0.37–0.70) | 0.62 |
Pre-HR, beats/min | 83 (57–109) | 83.5 (57–109) | 80.5 (60–98) | 0.66 |
Post-HR, beats/min | 107 (69–149) | 108 (69–149) | 105 (70–122) | 0.48 |
Pre-Borg | 0 (0–3) | 0 (0–3) | 1 (0–3) | 0.06 |
Post-Borg | 4 (1–7) | 4 (2–7) | 4 (1–7) | 0.77 |
pre-spO2, % | 95 (88–99) | 95.5 (88–99) | 95 (90–98) | 0.31 |
post-spO2, % | 90.5 (75–96) | 90.5 (75–96) | 90 (80–95) | 0.61 |
pre-IC, ml | 1.78 (0.92–2.77) | 1.78 (1.07–2.77) | 1.73 (0.92–2.04) | 0.20 |
post-IC, ml | 1.73 (0.94–2.83) | 1.73 (0.97–2.83) | 1.7 (0.94–2.43) | 0.45 |
∆IC, ml | 0 (− 1.1–0.55) | − 0.02 (− 0.49—0.55) | 0.11(− 1.1–0.28) | 0.37 |
∆spO2, % | − 4.5 (− 22 ~ 0) | − 4.5 (− 22 ~ 0) | − 4.0 (− 18 ~ 0) | 0.97 |
Distance, m | 456 (182–624) | 468 (328–624) | 408 (182–517) | 0.03 |
DSP, m% | 411.1 (149.2–536.6) | 421.2 (255.6–536.6) | 373.2 (149.2–464.6) | 0.04 |
Variable | Distance | DSP | ||
---|---|---|---|---|
r value | p value | r value | P value | |
Age, years | − 0.53 | < 0.001 | − 0.53 | < 0.001 |
Synchrogram Index | 0.42 | 0.001 | 0.41 | 0.001 |
BMI, kg/m2 | − 0.07 | 0.62 | − 0.05 | 0.69 |
Male, n (%) | 0.13 | 0.34 | 0.17 | 0.21 |
CAT | − 0.44 | < 0.001 | − 0.44 | < 0.001 |
mMRC | − 0.53 | < 0.001 | − 0.61 | < 0.001 |
Smoking, n (%) | 0.02 | 0.86 | 0.03 | 0.83 |
Presence of emphysema, n (%) | − 0.42 | 0.002 | − 0.45 | 0.001 |
EF, % | − 0.12 | 0.39 | − 0.13 | 0.35 |
E/e' ratio | − 0.34 | 0.06 | − 0.35 | 0.06 |
Left atrial, mm | 0.04 | 0.78 | 0.09 | 0.50 |
Presence of diastolic dysfunction | 0.07 | 0.59 | 0.05 | 0.72 |
EOS count, number/l | 0.08 | 0.59 | 0.10 | 0.45 |
IgE, pg/ml | − 0.13 | 0.37 | − 0.11 | 0.43 |
variable | Beta | SE | t value | p-value |
---|---|---|---|---|
Age, year | − 3.1 | 1.2 | − 2.6 | 0.01 |
Synchrogram Index | 93.3 | 42.2 | 2.2 | 0.03 |
CAT score | − 1.4 | 1.7 | − 0.8 | 0.41 |
mMRC | − 37.9 | 12.9 | − 2.9 | 0.005 |
Presence of emphysema | − 38.6 | 21.2 | − 1.8 | 0.08 |
variable | Beta | SE | t value | p-value |
---|---|---|---|---|
Age, year | − 2.8 | 1.1 | − 2.4 | 0.02 |
Synchrogram Index | 89.1 | 39.0 | 2.3 | 0.03 |
CAT score | − 0.9 | 1.6 | − 0.6 | 0.57 |
mMRC | − 40.7 | 14.3 | − 2.8 | 0.007 |
Presence of emphysema | − 41.1 | 19.6 | − 2.1 | 0.04 |