© 2007 European Society of Cardiology
Changes in exercise capacity, ventilation, and body weight following heart transplantation
a Division of Applied Cachexia Research, Department of Cardiology, Charité Campus Virchow-Klinikum Augustenburger Platz 1, D-13353, Berlin, Germany
b Department of Cardiothoracic and Vascular Surgery Deutsches Herzzentrum Berlin, Germany
c Department of Internal Medicine II University of Regensburg, Germany
d Clinical Cardiology, National Heart and Lung Institute Imperial College, London, UK
* Corresponding author. Tel.: +49 30 450 553625; fax: +49 30 450 553963. E-mail address: dirk.habedank{at}charite.de
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Abstract |
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Aims: Peak oxygen uptake adjusted to body weight (peak VO2) and ventilatory efficiency (VE/VCO2-slope) are important prognostic parameters in chronic heart failure. Our study prospectively examined changes in these parameters over 24months following heart transplantation (HTx) and evaluated the potentially confounding effects of weight gain.
Methods and results: One hundred patients with chronic heart failure (16 female, mean age at HTx 53.9±9.6years) underwent cardiopulmonary exercise testing before and 3, 6, 12 and/or 24months after HTx. Twenty-five healthy individuals served as matched normals. VE/VCO2-slope during exercise improved significantly at 6 (–23.7%), 12 (–21.3%), and 24months (–32.3%; all p<0.002 vs. baseline). At 6months, VE/VCO2-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 VO2 increased significantly after HTx at 6 (+31.8%), 12 (+36.2%), and 24months (+42.2%; all p<0.005). None of the patients reached values within the 95% CI of normal. Although VE/VCO2-slope and peak VO2 were correlated inversely at every time point (p<0.03), reduction in VE/VCO2-slope did not correlate with increase in peak VO2. Symptoms that limited exercise changed from dyspnoea before HTx to leg fatigue after HTx.
Conclusion: Following HTX, VE/VCO2-slope returns to normal values in the majority of patients; however, despite improvement, peak VO2 remains abnormal in all patients. Symptoms causing patients to stop exercising change from dyspnoea to leg fatigue.
Key Words: Heart transplantation • Peak VO2 • Ventilatory efficiency • VE/VCO2-slope • Body weight
Received November 10, 2005; Revised May 23, 2006; Accepted July 7, 2006