{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T04:49:49Z","timestamp":1791521389531,"version":"4.3.4"},"reference-count":20,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T00:00:00Z","timestamp":1790899200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>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\u2013outcome 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\u20132017 as the derivation period and 2018\u20132026 as the validation period. Surgery\u2013mortality associations were compared using fixed baseline and time-dependent exposure definitions. Results: Ninety-two patients (31.4%) died within 180 days, and 122 (41.6%) underwent surgery within 180 days. In the complete-case cohort (n = 278), Model A had an apparent AUC of 0.792 and a bootstrap cross-validated AUC of 0.759. Adding future surgery produced no detectable improvement in apparent discrimination (AUC 0.793 vs. 0.792; \u0394AUC +0.001, 95% CI \u22120.018 to +0.019) or after bootstrap cross-validation (AUC 0.749 vs. 0.759; \u0394AUC \u22120.010, 95% CI \u22120.057 to +0.014). In temporal validation, AUCs were 0.731 for Model A and 0.733 for Model B. Mean predicted 180-day mortality was 27.3% versus an observed Kaplan\u2013Meier risk of 34.7% (95% CI 25.5\u201342.8%); the observed-minus-predicted difference was +7.5 percentage points (bootstrap 95% CI \u22122.4 to +18.8). Fixed baseline coding yielded an adjusted HR of 0.71 (95% CI 0.44\u20131.17) in all 278 complete cases and 0.58 (95% CI 0.34\u20130.99) after excluding five same-day surgery\/death records; in the corresponding 273-patient matched sample, time-dependent coding yielded an HR of 1.44 (95% CI 0.83\u20132.49). Exploratory phase-specific analyses suggested higher mortality during the early postoperative period, but the magnitude was sensitive to same-day event handling. Conclusions: In this cohort, adding a binary indicator of subsequent surgery to the prespecified seven-predictor baseline model produced no detectable improvement in 180-day mortality prediction. In contrast, the estimated surgery\u2013mortality association changed substantially according to temporal exposure coding. Prediction models should respect the intended prediction time, while observational analyses of post-baseline treatments should explicitly account for treatment timing.<\/jats:p>","DOI":"10.3390\/diagnostics16193209","type":"journal-article","created":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T16:50:38Z","timestamp":1790959838000},"page":"3209","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Incremental Predictive Value of Post-Baseline Surgery and the Impact of Temporal Coding on Mortality Associations in Infective Endocarditis: A Temporally Validated Cohort Study"],"prefix":"10.3390","volume":"16","author":[{"given":"Banu","family":"Karaca","sequence":"first","affiliation":[{"name":"Department of Infectious Disease, Ataturk Training and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, Izmir 35360, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7261-8668","authenticated-orcid":false,"given":"Aykan","family":"\u00c7elik","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Ataturk Training and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, Izmir 35360, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mert","family":"\u0130nan","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Ataturk Training and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, Izmir 35360, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Berke","family":"Ege","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Ataturk Training and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, Izmir 35360, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mustafa","family":"Karaca","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Ataturk Training and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, Izmir 35360, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,10,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3948","DOI":"10.1093\/eurheartj\/ehad193","article-title":"2023 ESC Guidelines for the management of endocarditis","volume":"44","author":"Delgado","year":"2023","journal-title":"Eur. 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