Abstract Background COPD is the fourth leading cause of death worldwide, yet the only approved surrogate endpoints for disease progression are FEV₁ decline and exacerbation rates. SPIROMICS, a multicenter longitudinal study of COPD cases and smoking and non-smoking controls, was designed to identify additional surrogate endpoints of disease progression. Given the high short-term (6-week) reproducibility of quantitative computed tomography (CT) measures, we tested if their 1-year progression predicted subsequent 5-year decline in the FEV₁. Methods SPIROMICS comprised four annual visits and a fifth visit 5-7 years after initial enrollment, all with post-bronchodilator spirometry. At Visits 1 and 2, post-bronchodilator CT scans were acquired at full inspiration and expiration and QC’d following the SPIROMICS CT protocol. Quantitative CT parameters were selected for short-term reproducibility, including novel CT emphysema subtypes (combined bronchitic-apical emphysema CBaE and diffuse emphysema), density-based measures (percent emphysema-950HU, volume-adjusted lung density VALD), AMFM-derived texture, disease probability measures, pulmonary vascular volume, and segmental airway measures (wall area percent WA%). Among participants with acceptable inspiratory scans and 3-4 subsequent valid spirometry tests, we tested associations between progression of CT parameters from Visits 1-2 and subsequent FEV₁ decline in Visits 2-5 using linear mixed-effects models with random intercepts adjusting for demographics, enrollment strata, site, baseline CT measure and time-varying height, weight, smoking status, and pack-years. Results Among 880 participants (43% mild/moderate COPD, 17% severe COPD, 29% smoking control, 11% non-smoking control), one-year increases in CBaE and diffuse emphysema were associated with subsequent accelerated FEV₁ decline over a mean of 4.7 years follow up (SD 0.6) in both unadjusted and adjusted analyses (adjusted: CBaE, −4.7 mL/year/one-year increase SD unit; 95% CI: −8.98, −0.36; diffuse, −5.5 mL/year/one-year increase SD unit; 95% CI: −9.86, −1.19). Percent emphysema-950, VALD, and %WA also predicted FEV₁ decline (all P 0.05). Comparison of these five parameters demonstrated that only CBaE and diffuse emphysema were independently predictive of FEV₁ decline. Other quantitative CT measures showed limited or no associations. The figure shows one-year change in CBaE, diffuse emphysema and percent emphysema-950 (top vs bottom quartile) and subsequent FEV1 decline in among 375 participants with complete data. Conclusions One-year progression of several quantitative CT parameters, particularly the novel, machine-learned CT emphysema subtypes of CBaE and diffuse emphysema, predict long-term FEV1 decline in COPD. These findings support the potential of quantitative CT parameters to serve as intermediate endpoints in COPD clinical trials. This abstract is funded by: SPIROMICS was supported by contracts from the NIH/NHLBI (HHSN268200900013C, HHSN268200900014C, HHSN268200900015C, HHSN268200900016C, HHSN268200900017C, HHSN268200900018C, HHSN268200900019C, HHSN268200900020C, 75N92024D00012), grants from the NIH/NHLBI (U01HL137880, U24HL141762, R01HL182622, R01HL144718, and R01HL093081), and supplemented by contributions made through the Foundation for the NIH and the COPD Foundation from Amgen; AstraZeneca/MedImmune; Bayer; Bellerophon Therapeutics; Boehringer-Ingelheim Pharmaceuticals, Inc.; Bristol Myers Squibb; Chiesi Farmaceutici S.p.A.; Forest Research Institute, Inc.; Genentech; GlaxoSmithKline; Grifols Therapeutics, Inc.; Ikaria, Inc.; MGC Diagnostics; Novartis Pharmaceuticals Corporation; Nycomed GmbH; Polarean; ProterixBio; Regeneron Pharmaceuticals, Inc.; Sanofi; Sunovion; Takeda Pharmaceutical Company; Theravance Biopharma; Verona; and Mylan/Viatris
Hermann et al. (Fri,) studied this question.