Session Information
Session Type: ACR Poster Session A
Session Time: 9:00AM-11:00AM
Background/Purpose: Systemic sclerosis (SSc) carries high risk for progressive interstitial lung disease (ILD), but there are no valid methods for early detection of SSc-ILD or algorithms for ILD progression available. The aim of this study was to assess the impact of baseline FVC on lung fibrosis, fibrosis progression and mortality.
Methods: Paired pulmonary function tests (PFT) and high resolution computed tomography (HRCT) images were obtained at baseline and follow-up in consecutive SSc patients (n=305) from the prospective Oslo University Hospital (OUH) cohort. All patients met the 2013 ACR/EULAR classification criteria. Extent of fibrosis was scored on 10 sections from every HRCT and expressed as percentage of total lung volumes. The annual fibrosis progression was defined as the difference in extent of fibrosis between the baseline and follow-up HRCT divided by the actual follow-up period in years.
Results: At baseline, 186/305 patients (61%) had a baseline FVC <100% (Table 1). Lower baseline FVC (<90, 80 and 70%) was associated with male gender and higher extent of fibrosis at baseline and follow up (Table 1). In multivariate cox regression analyses, all baseline FVC thresholds (<100, 90, 80 and 70%) were significantly associated with mortality (Table 2). Other parameters significantly associated with mortality were age at onset (HR 1.1, 95% CI 1.1-1.2, p-value<0.001) and diffuse cutaneous SSc (HR 2.2, 95% CI 1.2-3.6, p-value 0.002). All baseline FVC thresholds were also associated with annual fibrosis progression in univariate cox regression analyses (Table 2). In multivariate analyses, only baseline FVC <80% was associated with annual fibrosis progression (HR 1.8, 95% CI 1.0-3.0, p-value 0.042), as well as male gender (HR 1.9, 95% CI 1.1-3.4, p-value 0.023) and anti-Topoisomerase I (HR 2.2, 95% CI 1.3-3.9, p-value 0.006). Of the 119 patients with baseline FVC>100%, 56 had no lung fibrosis. These 56 patients were predominantly female (90.4%); most of them had limited cutaneous SSc (91%) and anti-centromere antibodies (76%) and 18% died during the observation period.
Conclusion: These prospective cohort data suggest that baseline FVC%, including normal range values, predict mortality and fibrosis progression in SSc. Based on these data, we suggest that all SSc patients should be assessed with PFT and HRCT at baseline, and followed with PFTs on a regular basis. Table 1: Demographics, extent of fibrosis at baseline and follow-up, annual fibrosis progression and pulmonary function segregated by baseline FVC% in 305 SSc patients
|
Baseline FVC |
|
|||||
|
>100% 119 (39) |
90-100% 60 (20) |
80-90% 48 (16) |
70-80% 32 (11) |
<70% 46 (15) |
p-value¹ |
|
| Age at onset, yrs |
51 (12.9) |
46¹(16.3) |
49(16.5) |
47(17.9) |
45¹ (14) |
n.s. |
| Gender, no (%) |
15 (13) |
11 (18) |
9 (19) |
8 (25) |
20 (44) |
<0.001 |
| Follow-up duration, yr |
3.9 (2.8) |
4.1 (3.6) |
3.4 (2.3) |
3.8 (2.7) |
3.9 (3.2) |
n.s. |
| Disease duration, yr |
10.2 (6.6) |
11.9(9.1) |
10.6(6.7) |
10.3(9.1) |
11.8 (8.6) |
n.s. |
| Deceased, no (%) |
19 (16) |
14 (23) |
16 (33) |
10 (31) |
22 (48) |
<0.001 |
| lcSSc, no (%) |
102 (86) |
40 (68) |
30 (64) |
21 (68) |
21 (47) |
<0.001 |
| ACA, no (%) |
82 (69) |
22 (37) |
17 (35) |
12 (37) |
6 (13) |
<0.001 |
| Any fibrosis, n (%) |
63 (53) |
36 (60) |
31 (65) |
22 (69) |
45 (98) |
<0.001 |
| Baseline fibrosis % |
1.6 (3.8) |
4.7 (9.3) |
5.3 (7.8) |
5.3(10.9) |
25.7(14.9) |
<0.05 |
| Follow up fibrosis % |
2.1 (4.9) |
6.5(11.7) |
6.7 (9.2) |
8.3(15.4) |
28.8(20.9) |
<0.05 |
| Annual fibrosis progression% |
0.1 (1.1) |
0.7 (2.5) |
0.6 (1.8) |
1.0 (3.1) |
1.0 (3.5) |
n.s. |
| Annual FVC decline |
1.8 (5.7) |
1.9 (6.1) |
2.2 (7.8) |
2.8 (9.5) |
2.6 (5.4) |
n.s. |
| Baseline DLCO % |
77.2(20.1) |
65.8(15.9) |
65.5(15.7) |
62 (14.9) |
43.6(14.9) |
<0.05 |
| Annual DLCO decline |
2.9 (4.3) |
0.7¹(15.5) |
1.8 (6.4) |
4.7 (9.1) |
2.5 (6.8) |
n.s. |
¹:p-value < 0,05 compared to baseline FVC>100%, n.s. not significant except for values marked: x¹ (p-value<0.05), (SD) if not stated differently Table 2: Univariate cox regression analyses with mortality and annual fibrosis progression as outcome measures
|
N (%) |
Mortality HR (95% CI) |
p-value |
Annual fibrosis progression HR (95% CI) |
p-value |
|
| Baseline FVC<100% |
186 (61) |
2.1 (1.3-3.6) |
0.005 |
1.8 (1.0-3.2) |
0.045 |
| Baseline FVC <90% |
126 (41) |
2.0 (1.2-3.2) |
0.004 |
2.2 (1.3-3.7) |
0.003 |
| Baseline FVC <80 |
98 (32) |
2.0 (1.2-3.2) |
0.006 |
2.3 (1.4-3.9) |
0.001 |
| Baseline FVC <70% |
46 (15) |
2.5 (1.4-4.5) |
0.003 |
2.1 (1.2-3.6) |
0.012 |
To cite this abstract in AMA style:
Hoffmann-Vold A, Volkmann ER, Midtvedt O, Garen T, Heiervang Tennøe A, Aalokken TM, Lund MB, Molberg Ø. Forced Vital Capacity Predicts Lung Fibrosis Progression and Mortality in Systemic Sclerosis [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/forced-vital-capacity-predicts-lung-fibrosis-progression-and-mortality-in-systemic-sclerosis/. Accessed .« Back to 2016 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/forced-vital-capacity-predicts-lung-fibrosis-progression-and-mortality-in-systemic-sclerosis/