Comparison of baseline characteristics between the low DLco and normal DLco groups
| Low DLco (n=36) | Normal DLco (n=39) | P value | |
| Age, year | 61.1±15.2 | 60.9±12.6 | 0.961* |
| Women | 30 (83.3) | 20 (51.3) | 0.003† |
| Body mass index, kg/m2 | 24.0±5.0 | 22.6±4.4 | 0.192* |
| WHO functional class (I/II/III/IV) | 0/5/29/2 | 0/9/30/0 | 0.186§ |
| Smoking history | 18 (50.0) | 16 (41.0) | 0.435† |
| Median follow-up days, days | 1070 (566–1623) | 833 (472–1581) | 0.371§ |
| Brain natriuretic peptide, pg/mL | 73.4 (18.5–173.2) | 121.0 (57.3–339.9) | 0.075§ |
| Heart rate, bpm | 77±12 | 75±14 | 0.412* |
| Comorbidities¶ | 18 (50.0) | 14 (35.9) | 0.217† |
| Asthma | 6 (16.7) | 2 (5.1) | 0.143‡ |
| Interstitial pneumonia | 1 (2.8) | 0 | 0.480‡ |
| Lung cancer | 0 | 1 (2.6) | >0.999‡ |
| Tuberculosis | 1 (2.8) | 1 (2.6) | >0.999‡ |
| Pneumonitis | 2 (5.6) | 1 (2.6) | 0.605‡ |
| Chronic obstructive pulmonary disease | 0 | 4 (10.3) | 0.116‡ |
| Atypical mycobacteria | 1 (2.8) | 1 (2.6) | >0.999‡ |
| Sleep disordered breathing | 1 (2.8) | 1 (2.6) | >0.999‡ |
| Depression | 3 (8.3) | 3 (7.7) | >0.999‡ |
| Malignancy (except for lung cancer) | 6 (16.7) | 5 (12.8) | 0.751‡ |
| Atrial fibrillation | 1 (2.8) | 0 | 0.480‡ |
| Coagulopathy | 1 (2.8) | 2 (5.1) | >0.999‡ |
| Respiratory function | |||
| FEV1.0%, % | 73.9±9.3 | 74.0±10.9 | 0.996* |
| %VC, % | 88.0±14.8 | 95.9±13.1 | 0.016* |
| %DLco, % | 67.9±8.2 | 94.4±10.7 | <0.001* |
| Medication | |||
| Riociguat administration | 12 (33.3) | 17 (43.6) | 0.362† |
| Diuretics | 15 (41.7) | 12 (30.8) | 0.326† |
| Warfarin | 20 (55.6) | 23 (59.0) | 0.765† |
| Direct anticoagulant drug | 16 (44.4) | 16 (41.0) | 0.765† |
Data are presented as the mean±SD, median (IQR) or n (%). The p value was calculated by the independent t-test (*), χ2 test (†), Fisher’s exact test (‡) or Mann-Whitney U test (§) between the two groups. ¶Some patients had multiple comorbidities.
%DLco, diffusing capacity of the lungs for carbon monoxide as percent of predicted; DLco, diffusing capacity of the lungs for carbon monoxide; FEV1.0%, forced expiratory volume percentage in 1 s; %VC, vital capacity percentage.