Skin Thickness Over Cardiac Implantable Electronic Devices: Prognostic Impact and Longitudinal Changes

BACKGROUND: Skin thinning over cardiac implantable electronic devices (CIEDs) is frequently observed; however, its clinical implications and temporal progression remain unclear. This study aimed to investigate the clinical significance of skin thickness over CIEDs by examining its association with adverse outcomes, including all-cause mortality and device-related infections, and evaluating its temporal changes and associated clinical factors. METHODS: This study included 96 patients who underwent ultrasonographic measurement of skin thickness over CIEDs between June 2020 and June 2021. Adverse outcomes were monitored through August 2023. Of those, 34 patients had follow-up ultrasonography to assess temporal changes in skin thickness. RESULTS: Among 34 patients with repeated measurements, skin thickness significantly declined over a median of 42 (IQR: 41-44) months (p = 0.001), and thinning was correlated with changes in hemoglobin levels (r = 0.392, p = 0.024). During a median follow-up of 32 (IQR: 11-34) months, patients with skin thickness ≤ 3.3 mm (thin group) had significantly higher all-cause mortality than those with a thickness > 3.3 mm (normal group) (log-rank p < 0.001). In multivariable Cox regression analysis, skin thickness ≤ 3.3 mm remained an independent predictor of mortality (HR 2.42; 95% CI, 1.01-5.80; p = 0.046). Device-related infections were more frequent in the thin group (8%) than in the normal group (2%), but the difference was not statistically significant. CONCLUSIONS: Skin thickness over CIEDs progressively declined over time and was significantly correlated with hemoglobin levels. In addition, skin thickness ≤ 3.3 mm was independently associated with increased all-cause mortality.