Changes in exercise capacity, ventilation, and body weight following heart transplantation.
OBJECTIVE
Peak oxygen uptake adjusted to body weight (peak VO(2)) and ventilatory efficiency (VE/VCO(2)-slope) are important prognostic parameters in chronic heart failure. Our study prospectively examined changes in these parameters over 24 months following heart transplantation (HTx) and evaluated the potentially confounding effects of weight gain.


RESULTS
One hundred patients with chronic heart failure (16 female, mean age at HTx 53.9+/-9.6 years) underwent cardiopulmonary exercise testing before and 3, 6, 12 and/or 24 months after HTx. Twenty-five healthy individuals served as matched normals. VE/VCO(2)-slope during exercise improved significantly at 6 (-23.7%), 12 (-21.3%), and 24 months (-32.3%; all p<0.002 vs. baseline). At 6 months, VE/VCO(2)-slopes were similar to the matched normals (31.8+/-4.3), 46 of 78 patients achieved values within the 95% confidence interval of normal. Peak VO(2) increased significantly after HTx at 6 (+31.8%), 12 (+36.2%), and 24 months (+42.2%; all p<0.005). None of the patients reached values within the 95% CI of normal. Although VE/VCO(2)-slope and peak VO(2) were correlated inversely at every time point (p<0.03), reduction in VE/VCO(2)-slope did not correlate with increase in peak VO(2). Symptoms that limited exercise changed from dyspnoea before HTx to leg fatigue after HTx.


CONCLUSIONS
Following HTX, VE/VCO(2)-slope returns to normal values in the majority of patients; however, despite improvement, peak VO(2) remains abnormal in all patients. Symptoms causing patients to stop exercising change from dyspnoea to leg fatigue.
Habedank
Dirk
D
Division of Applied Cachexia Research, Department of Cardiology, Charité Campus Virchow-Klinikum, Berlin, Germany. dirk.habedank@charite.de <dirk.habedank@charite.de>
Ewert
Ralf
R
Hummel
Manfred
M
Wensel
Roland
R
Hetzer
Roland
R
Anker
Stefan D
SD
D000328:Adult; D000704:Analysis of Variance; D001784:Blood Gas Analysis; D001835:Body Weight / Q000502:physiology*; D016001:Confidence Intervals; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000503:physiopathology* / Q000517:prevention & control; D016027:Heart Transplantation / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D011446:Prospective Studies; D012123:Pulmonary Ventilation / Q000502:physiology*; D013147:Spirometry / Q000379:methods