2026-09-18T23:45:17Z rgu-repository.worktribe.com

oai:rgu-repository.worktribe.com:3463773 2026-08-24T11:59:00Z 084104101115105115 openaccess

Thesis Can CIED-derived physical activity provide as a biomarker to predict all-cause-mortality? Validation of previous predictive modelling approaches. Physical activity (PA) is a well-established determinant of health outcomes yet monitoring deterioration of patients' health using cardiac implantable electronic device (CIED)-derived PA levels lacks external validation when predicting mortality. The primary aim was to investigate the relationship between CIED-derived PA and all-cause mortality. The secondary aim was to replicate and externally validate predictive models incorporating PA to evaluate their performance in predicting mortality. Methods: A retrospective longitudinal analysis was conducting using CIED-derived PA data in 513 cardiac patients to measure the prediction of all-cause-mortality. External validation was conducted by replicating eight previous predictive modelling approaches and measured discrimination and calibration scores across each model. PA was an independent predictor of all-cause mortality with low PA having higher risk of survival probability in univariate and multivariate analysis (p<0.001) when stratified by baseline PA levels. Predictive modelling approaches scored modest discrimination in univariate analysis (C-index = 0.65), good to excellent in multivariate cox regressions (C-index = 0.71 to 0.84) and perfect calibrations scores across all models (calibration slope = 1.00). Overall, baseline CIED-derived PA, stratified at baseline successfully predicts risk of mortality. Additionally, replication and external validation of predictive models incorporating PA demonstrated modest to excellent discrimination. Cowie, Greig 2026-02-28 A. Hall and P. Swinton oai:rgu-repository.worktribe.com:3463773 https://rgu-repository.worktribe.com/3463773/1/COWIE%202026%20Can%20CIED-derived%20physical%20activity https://doi.org/10.48526/rgu-wt-3463773 No Funder Acknowledged (Outputs) Physical activity (PA) Cardiac implantable electronic devices (CIEDs) All-cause mortality Predictive modelling External validation Cardiovascular disease https://rgu-repository.worktribe.com/output/3463773 2026 en openAccess https://creativecommons.org/licenses/by-nc/4.0/ Public