Diagnostics
Incremental Predictive Value of Post-Baseline Surgery and the Impact of Temporal Coding on Mortality Associations in Infective Endocarditis: A Temporally Validated Cohort Study
By Banu Karaca, Aykan Çelik, Mert İnan and 2 others.
Abstract
Background
Risk prediction in infective endocarditis (IE) may be compromised when treatments occurring after the initial evaluation are incorporated as though they were baseline predictors. Surgical treatment is inherently time-dependent, yet subsequent surgery has been incorporated as a static predictor in contemporary prognostic models, potentially affecting both predictive performance and treatment–outcome associations. We evaluated whether adding subsequent surgery improves mortality prediction beyond information obtained during the initial index-episode evaluation and examined how temporal representation of surgery influences its association with mortality.
Methods
We retrospectively studied 293 consecutive patients with IE. The primary outcome was 180-day all-cause mortality. Model A incorporated seven prespecified predictors obtained during the initial index-episode evaluation: age, NYHA functional class, hemoglobin, blood urea nitrogen, left ventricular ejection fraction, severe regurgitation, and C-reactive protein. Model B additionally incorporated a binary indicator of surgery within 180 days. Predictive performance was assessed using time-dependent AUC, Brier score, 1000-replicate bootstrap cross-validation, and temporal validation using 2008–2017 as the derivation period and 2018–2026 as the validation period. Surgery–mortality associations were compared using fixed baseline and time-dependent exposure definitions.