Heart rate: Activity mismatch as a prognostic marker of survival in metastatic non-small cell lung cancer (NSCLC).

Background: Performance status (PS) is the foundation for clinical trial eligibility criteria and the basis for treatment decisions in the treatment of NSCLC, but it is limited by subjectivity and potential miscommunication between patient, physician, and family. Activity trackers use is widespread and offers the potential to collect a broad range of patient generated data (steps, activity, heart rate, calories, sleep, etc.) to supplement the assessment of PS while minimizing subjectivity. Here we evaluated a clinical observation that elevated heart rate at rest is prognostic of survival. Methods: Patients with metastatic NSCLC were asked to participate in a prospective, observational study of potential prognostic survival factors that included wearing a FitBit tracker with a goal to measure HR-Activity mismatch measured by 2 parameters: 1) Heart Rate-Activity Mismatch (HAM) by percent of time when HR is high and activity is moderate or low over a day;2) inappropriate HR (iHR) is the ratio of time with elevated HR/sedentary minutes average over a week. Correlation and regression analyses were performed for the initial 55 patients enrolled prior to COVID restrictions using data limited to the average of 7 days with wear > 500 minutes closest to date of consent. Results: We enrolled 55 patients with metastatic NSCLC. There were 35 females and 20 males with a median age of 67 years. A majority of patients were never (38%, n = 21) or former smokers (40%, n = 22);adenocarcinoma (83%, n = 83%) was the most common histology. 30% (n = 17) patients were on 2 or greater line of therapy. 52 were included for survival analysis and 21 expired with median survival 226 days (149, NA). As average daily steps increased by 1000, the hazard of death decreased by a factor of 0.65 (95% CI: 0.45, 0.93, p = 0.018). As daily average distance increased by 1 mile, the hazard of death decreased by 0.55 (95% CI: 0.33, 0.91, p = 0.019). For HAM, the risk of death increased by 1.14 (95% CI: 1, 1.13, p = 0.046) for every 10% increase in HAM. For iHR 1. Steps, Distance, HAM and iHR were not statistically different by gender. Conclusions: Tracker-based measures of steps/distance and HR-Activity are prognostic of survival in NSCLC and may be useful to supplement evaluation of PS in clinical trials and practice.