Assessment of improvements in exercise tolerance following pulmonary valve replacement using physical accelerometry

Pulmonary valve replacement may be required for patients with pulmonary valve disease. Exertional symptoms related to cardiovascular disease are an indication for pulmonary valve replacement; however, quantification of symptom improvement postoperatively is challenging, and previous studies have yielded mixed data. Accelerometry has the potential to remotely monitor changes in exercise tolerance following pulmonary valve replacement.

Individuals (n = 18) age >13 years scheduled for catheter-based or surgical pulmonary valve replacement were prospectively enrolled. Participants were instructed to wear two Link GT9X accelerometers, placed on dominant wrist and one ankle, for seven days and nights before pulmonary valve replacement and again 3-6 months after the procedure.

The cohort's median age was 26.5 [16.0, 35.0] years old. Compliance of both wrist and ankle accelerometers had a median of 96% or greater at both timepoints suggesting adequate participation. Accelerometry showed stability between participants. Quantitative analysis using pre-and post-pulmonary valve replacement accelerometer-derived measures yielded no significant differences. There was a significant decrease in the average score for items "Shortness of Breath with Strenuous Activity," "Extent Symptoms Impact Daily Activities," and "Challenges with Activities of Daily Living." Furthermore, all 9 individuals with baseline exertional intolerance had resolution of symptom in postoperative assessment.

Reliability of accelerometer-derived activity measurements supports usage of physical accelerometry as a remote outcome measure to reduce patient burden for onsite assessment. Mixed qualitative versus quantitative improvement in physical activity tolerance observed in this study aligns with previous studies on variable improvement in exercise tolerance following pulmonary valve replacement. This discrepancy suggests the need for a different quantitative mechanism to measure benefit.