Post-operative obesity and cachexia after heart transplantation

LETTERS TO THE EDITOR POST-OPERATIVE OBESITY AND CACHEXIA AFTER HEART TRANSPLANTATION To the Editor: With interest we read the article by Grady et al,1 and their findings of increased mortality in both cachexia and obesity after heart transplantation are of great value in clinical practice. However, the huge statistical sample of 3,540 patients should have been used to answer some more questions, even if data were taken retrospectively. As the authors mentioned themselves, the changed cut-off point for body mass index (BMI) prevents a direct comparison with former studies of the Cardiac Transplant Database Group. This might be of lesser importance as far as obesity is concerned, but the very low cut-off at 18.5 kg/m2 for cardiac cachexia might lead to some incorrect conclusions: the proportion of cachectic patients at time of transplantation is now 3%, compared with 11% in the former report of Grady et al2 with a cut-off at 20.7 kg/m2, or 12% of cachectic patients in the SOLVD trial.3 The application of the formerly and generally accepted cut-off would allow further investigations, for instance, of whether the prevalence of cardiac cachexia is constant over years and in this way opposite to an increasing BMI in the entire population. Table 2 of Grady et al shows that the proportion of cachectic patients is declining from heart transplantation to 3 years after transplantation; but regrettably, the authors do not mention this finding. The lower cut-off for cachexia might have contributed to the underestimation of this fact. According to our own findings in a prospective study,4 cardiac cachexia as a mortalityincreasing illness is reversible after heart transplantation, thus not indicating simple weight gain but curing of the initial disease. It would be interesting to calculate with the vast sample size mentioned above why 1% of patients remain cachectic even at 3 years after heart transplantation. Moreover, Grady et al wrote that BMI before and BMI after heart transplantation is very strongly correlated (p ⬍ 0.0001). We consider that this calculation is too simple: it would require extensive changes of BMI in both directions to fail significance. Instead of that, we suggest a correlation of BMI before heart transplantation with weight changes after heart transplantation (in kg or in percentage of previous weight). It might also be a weakness of retrospective analyses that the effect of concomitant diseases can not be calculated. Especially the influence of renal failure on BMI and mortality (cf. the “reverse epidemiology” in dialysis)5 and the effect of cytomegalovirus infection would provide further valuable information. Thus, 368

many questions concerning cachexia and obesity after heart transplantation still remain open. Dirk Habedank Division of Applied Cachexia Research Department of Cardiology Charité Campus Virchow-Klinikum Berlin, Germany Stefan D. Anker Clinical Cardiology National Heart and Lung Institute Imperial College London, United Kingdom REFERENCES 1. Grady KL, Naftel D, Pamboukian SV, et al and the Cardiac Transplant Research Database Group. Post-operative obesity and cachexia are risk factors for morbidity and mortality after heart transplant: multi-institutional study of postoperative weight change. J Heart Lung Transplant 2005; 24:1424 –30. 2. Grady KL, White-Williams C, Naftel D, et al. Are preoperative obesity and cachexia risk factors for post heart transplant morbidity and mortality: a multi-institutional study of preoperative weight-height indices. Cardiac Transplant Research Database (CTRD) Group. J Heart Lung Transplant 1999;18:750 – 63. 3. Anker SD, Negassa A, Coats AJS, et al. Prognostic importance of weight loss in chronic heart and the effect of treatment with angiotensin-converting-enzyme inhibitors: an observational study. Lancet 2003;361:1077– 83. 4. Habedank D, Hummel M, Hetzer R, Anker SD. Reversibility of cardiac cachexia after heart transplantation. J Heart Lung Transplant 2005;24:1757– 62. 5. Kalantar-Zadeh K, Kopple JD, Kilpatrick RD, et al. Association of morbid obesity and weight change over time with cardiovascular survival in hemodialysis population. Am J Kidney Dis 2005;46:489 –500.

A CALL TO DISARM: IS MALIGNANCY HIGHER IN POST-TRANSPLANT PATIENTS? To the Editor: In the August issue of the Journal of Heart and Lung Transplantation, Hauptmann and Mehra1 wrote an interesting article with a provocative title “It is time to stop ignoring malignancy in heart transplant patients: a call to arms.” In this eloquent manuscript the authors “call to arms” the scientists in the transplantation community to “shift our attention to the abrogation of cancer risk.” While this effort is important in all patients, the real question is if cancer develops at a higher rate in the transplant recipient than in the general population, or is this observation due to competing risks. Cancer is the leading cause of death in the demographic groups that