Purpose: Although sympathetic reinnervation is accompanied by the improvement of exercise tolerability during several years after heart trans-plantation (HTx), little is known about parasympathetic reinnervation and its clinical impact.

Methods: We enrolled 21 recipients (40 ± 16 years, 71% male) who had received successive cardiopulmonary exercise testing at 6 months, 1, and 2 years after HTx. They also received heart rate (HR) variability analy-ses at post-HTx 6 months, and Minnesota Living with Heart failure (HF) Questionnaire at post-HTx 6 months and 2 years.

Results: Exercise parameters such as peak oxygen consumption or maximum load remained unchanged, whereas recovery parameters including HR recov-ery during 2 minutes and the delay of peak HR, both influened by parasym-pathetic activity, improved significantly during post-HTx 2 years (p<0.05 for both). Among 12 recipients who had also received HR variability analyses at 6 months after HTx, high frequency power, representing parasympathetic activity, was significantly associated with 2 recovery parameters (p<0.05 for all). Recipients with improved recovery parameters enjoyed a better HF-specific quality of life that was demonstrated by improved Minnesota Living with HF Questionnaire at post-HTx 2 years.

Conclusion: Parasympathetic reinnervation emerges along with improved post-exercise recovery of HR and quality of life during post-HTx 2 years.