Session Information
Session Title: Systemic Sclerosis, Fibrosing Syndromes, and Raynaud’s - Clinical Aspects and Therapeutics I
Session Type: Abstract Submissions (ACR)
Background/Purpose: The purpose of this study was to asses sequential pulmonary function measurements (forced vital capacity [FVC] % predicted) in a large systemic sclerosis (SSc) cohort over a mean observation period of 5.2 (+/- 2.8) years.
Methods: The study cohort included all the 304 SSc patients with sequential pulmonary measurements enrolled in the Norwegian systemic connective tissue disease and vasculitis registry (NOSVAR) at the Department of Rheumatology, Oslo University Hospital (OUH). Lung function measurements were registered at baseline and then prospectively at annual follow-up visits. Altogether, 1125 lung function tests were analysed. Patients were segregated according to their baseline unadjusted FVC % predicted (<70% and >70%). Descriptive statistics were applied to obtain baseline characteristics and the FVC% decline over the observation period. Vital status at 1 January 2013 was provided for all participants by the national population register. Kaplan-Meyer and Cox proportional hazard models were used to analyse survival.
Results: In total, 52 patients (17%) had a baseline FVC <70% (Table 1). Patients with a baseline FVC <70% were more often anti-topoisomerase antibody (ATA) positive than patients with baseline FVC >70% (p-value <0.05). They were also more frequently classified as diffuse cutaneous (dc) SSc (p-value <0.001) and with male gender (p-value <0.001). There were 52 deaths during the observation period and the death rate (22/52, 41%) in patients with a baseline FVC < 70% was significantly higher than in patients with baseline FVC >70% (47/205, 19%). The 10-year survival rate was estimated to 69% and 84% for FVC<70% and FVC>70%, respectively (p-value 0.006, data not shown).
The longitudinal analyses showed that 114/304 patients (38%) had declining FVC values over the study period. The mean +/- SD decline in the FVC was -2.2 +/- 9% per year. No significant predictors were detected for progressive lung disease, but the 10-year survival rate was lower in patients with declining FVC compared to patients who did not display significant decline from their baseline FVC value, 74% versus 93% (p-value 0.03, data not shown).
Conclusion: The data from our large SSc cohort suggest that male gender, ATA and dcSSc are associated with early development of restrictive pulmonary disease, as evaluated by the baseline FVC. Moreover, survival is decreased for SSc patients with baseline FVC <70%. Interestingly, survival was also decreased in patients with progressive fall in FVC and this association was independent of the patients’ baseline FVC value.
Table 1: Clinical characteristics of 304 SSc patients stratified by baseline FVC%
|
|
Baseline FVC |
p-value |
|
|
|
<70% |
>70% |
|
|
Number of patients (%) |
52 (17) |
254 (83) |
|
|
Age, years (SD) |
52.4 (12.9) |
54.3 (14.2) |
|
|
Disease duration (SD) |
7.0 (7.7) |
5.6 (7.0) |
|
|
Male sex, no (%) |
23 (44) |
43 (17) |
0.000 |
|
Ever smoker, no (%) |
15 (29) |
67 (27) |
0.318 |
|
Deceased, no (%) |
22 (42) |
47 (19) |
0.000 |
|
SSc type |
|
|
0.000 |
|
Diffuse cutaneous SSc, no (%) |
26 (50) |
51 (20) |
|
|
Limited cutaneous SSc, no (%) |
26 (50) |
201 (80) |
|
|
ATA positive |
15 (29) |
29 (12) |
0.000 |
|
ACA positive |
9 (17) |
115 (46) |
0.000 |
|
Declining FVC, no (%) |
15 (29) |
99 (39) |
0.264 |
SSc: systemic sclerosis; ATA: anti-topoisomerase antibody, ACA: ant-centromere antibody
Disclosure:
A. M. Hoffmann-Vold,
None;
T. Garen,
None;
O. Midtvedt,
None;
M. B. Lund,
None;
J. T. Gran,
None;
Molberg,
None.
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