Preprocedural CALLY Index as a Novel Predictor of Pacemaker Requirement After Transcatheter Aortic Valve Replacement

Background: Permanent pacemaker implantation (PPI) is a common complication after transcatheter aortic valve replacement (TAVR).While procedural and electro-anatomic factors are well established, patient-related susceptibility markers remain unclear.We aimed to evaluate whether the preprocedural C-reactive protein-albumin-lymphocyte (CALLY) index independently predicts and aids in risk stratification for 30-day PPI after TAVR. Methods:We retrospectively analyzed 812 consecutive TAVR patients with complete baseline labs (2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017)(2018)(2019)(2020)(2021)(2022)(2023)(2024)(2025).The CALLY index was calculated as (albumin lymphocytes CRP) 10, and patients were stratified into quartiles (Q1-Q4).The primary endpoint was new PPI within 30 days.Kaplan-Meier curves and Cox regression assessed the association between CALLY quartiles and PPI risk.Multivariable models adjusted for prespecified clinical, anatomic, and procedural factors.Subgroup analyses evaluated consistency across age, sex, hypertension, and valve type.Results: Median time to PPI was 4 days (IQR 2-9), and 145 patients (17.9%) required implantation.Higher CALLY quartiles were associated with a progressively lower PPI risk compared with Q1: Q2 HR 0.64 (95% CI 0.42-0.99),Q3 HR 0.63 (95% CI 0.41-0.98),and Q4 HR 0.50 (95% CI 0.31-0.79).After multivariable adjustment, Q4 remained independently protective (HR 0.57, 95% CI 0.35-0.94).The protective effect of Q4 was consistent across subgroups, including age 80 years, males, females, hypertensive patients, and recipients of self-expanding valves.No significant effect modification was observed.Conclusions: A higher preprocedural CALLY index was independently linked to a lower 30day pacemaker requirement after TAVR.As a simple, inexpensive marker, CALLY may improve pre-TAVR risk stratification and guide peri-procedural planning.