PPG Heart Age via ECG-Guided Cross-Modal Pretraining (arXiv:2608.01620)

Donglin Xie, Xueying Gui, Yutian Zhu, Feng Xu, Guangkun Nie, Chenyang Xu, Jun Li, Shuailong Tang

Summary

Very fresh preprint (Aug 5, 2026). Uses consumer smartwatch PPG to estimate "heart age" — a digital biomarker of vascular aging — by leveraging ECG-guided cross-modal pretraining. ECG provides richer cardiac information than PPG; the pretraining transfers this knowledge to a PPG-only model that runs on smartwatches at inference time.