Associations between Self-Reported Physical Function and Exercise Capacity in De Novo Heart Transplant Recipients

Purpose Physical capacity, as assessed by peak oxygen consumption (VO2peak) or self-reported physical function (PF) from Short Form-36 (SF-36), is a strong predictor of long-term survival in heart transplant (HTx) recipients. VO2peak and SF36-PF are highly correlated in maintenance HTx, but their association has previously not been examined in de novo HTx recipients. Methods Seventy-eight patients who completed the HITTS study (High-intensity Interval Training in de novo heart Transplant recipients in Scandinavia) were included in the analyses. Patients were tested at baseline (mean 11 weeks after surgery) and at 12 months follow-up, with self-reported PF (SF-36v2), cardiopulmonary exercise test with measurement of VO2peak, and lower limb isokinetic muscle strength. Pearson´s correlation was used to compare the association between PF and VO2peak (L/min) and PF and muscular strength; early (mean 11 weeks after HTx) and later (1 year after HTx). Results Mean ± SD age was 49 ± 13 years, 73% were men. Both at 11 weeks and after 1 year, there were statistically significant positive correlations indication moderate association between PF and VO2peak (r=0.482 vs. 0.401) (Fig 1), PF and muscular exercise capacity (r= 0.494 vs. 0.388), and PF and maximal muscular strength (r = 0.443 vs. 0.414). Conclusion De novo HTx patients´ self-reported PF is associated with both VO2peak and muscular strength, also found 1 year after HTx. While measuring VO2peak is the preferred method of examining physical capacity and prognosis, self-reported PF is an easy, less resource-demanding assessment that could be considered as a clinical substitute.