Prognostic value of early post-admission pan-immune-inflammation value in Takotsubo syndrome

BACKGROUND: Inflammation has been associated with adverse outcomes in Takotsubo syndrome (TTS), but the prognostic value of pan-immune-inflammation value (PIV) has not been evaluated in this condition. We assessed whether PIV measured at days 3-5 provides prognostic information beyond clinical characteristics and admission PIV. METHODS: We retrospectively studied 768 patients with TTS from two tertiary centers. PIV was calculated at admission and at days 3-5. A prespecified day-5 landmark analysis evaluated one-year major adverse clinical events (MACE), defined as all-cause death, heart failure events, arrhythmia requiring hospitalization, stroke, or acute myocardial infarction, and the incremental prognostic value of PIV at days 3-5. RESULTS: The landmark cohort included 722 patients with 218 MACE events. In the primary complete-case analysis (n = 692; 206 events), PIV at days 3-5 was independently associated with MACE after adjustment for clinical variables and admission PIV (HR per doubling, 1.28; 95% CI, 1.16-1.42; p < 0.001), whereas admission PIV was not (HR, 0.94; 95% CI, 0.86-1.02; p = 0.142). Adding PIV at days 3-5 to the clinical plus admission-PIV model increased the C-index from 0.659 to 0.682 (ΔC-index, 0.024; 95% CI, 0.005-0.043; bootstrap p = 0.015). The association was approximately linear on the log₂ PIV scale and robust across sensitivity analyses. CONCLUSIONS: PIV measured at days 3-5 was independently associated with one-year MACE and provided incremental prognostic information beyond clinical characteristics and admission PIV. Early post-admission PIV may represent a readily available adjunct to risk assessment, although external validation is required.