Translational Methods for Wearable Heart Rate Variability Monitoring in Older Adults: Preoperative Risk Stratification and Postoperative Monitoring.

Low preoperative heart rate variability (HRV) is associated with adverse cardiovascular outcomes and delirium after geriatric surgery, but in-person testing is burdensome and impractical. To evaluate wrist-based wearables for remotely capturing preoperative outpatient and postoperative inpatient data for HRV analysis. RR-intervals were extracted, and data missingness was assessed for systematic differences. Delirium incidence was evaluated. Preoperatively, 76.9% of participants provided high-quality outpatient data, with no systematic demographic or clinical differences. Postoperatively, 80.2% had high-quality inpatient data; however, missing data were associated with older age, lower BMI, ICU admission, and longer surgeries and hospitalizations. Postoperative HRV did not significantly differ between participants with and without delirium. Outpatient HRV capture via wrist-based wearables is broadly feasible in older surgical patients, while postoperative inpatient data are disproportionately missing in higher-risk patients. These differences highlight both the translational potential and limitations of wearable HRV measurements for perioperative outcome prediction.