Effect of receiving a heart transplant: analysis of a national cohort entered on to a waiting list, stratified by heart failure severityCommentary: Time for a controlled trial?

Dear Editor,

We read with interest the article by Deng et al (1) regarding mortality
benefit from heart transplant. We entirely agree with the overall
conclusions of the paper, that only patients with a predicted high
mortality should be listed for transplantation.

However, we feel it is important to look closely at the patient
characteristics, particular with regards to the peak exercise oxygen
consumption data. Peak exercise oxygen consumption is recognized as an
important predictor of outcome in heart failure patients (2) and has stood
the test of time (3). Indeed, it is an important factor in the HFSS
statistical model (4) as used in the present paper (1). Mancini et al (2)
have shown that in patients with a peak exercise oxygen consumption less
than 14 ml/kg/min that there was a significantly higher mortality compared
to patients with a peak exercise oxygen consumption greater than 14
ml/kg/min. However, in the present study (1), in the COCPIT cohort mean
peak exercise oxygen consumption is significantly higher than the Mancini
criteria at 15.8 ml/kg/min. In addition this data was available in only
139 of the 889 patients. This leads to several questions.

Firstly, it
appears that this group of patients is relatively ‘well’ and so would not
be predicted to have a high mortality, and therefore perhaps many of these
patients should not have been listed for transplant.

Secondly it must be
questioned as to why this important predictor of outcome is only presented
for 16% of the patients?

The accurate assessment of patients for heart transplant is a critical
issue to derive mortality benefit from this procedure. Failure to use
accepted and meaningful tests such as peak exercise oxygen consumption may
result in inappropriate listing of heart failure patients for
transplantation.

Yours sincerely,

Guy A. MacGowan, MD FACC,

Assistant Professor of Medicine,

Section of Heart Failure and Transplantation Cardiology,
Cardiovascular Institute of the University of Pittsburgh Medical Center.

Srinivas Murali, MD FACC,

Associate Professor of Medicine,

Director of Transplantation Cardiology,

Section of Heart Failure and Transplantation Cardiology,
Cardiovascular Institute of the University of Pittsburgh Medical Center.

No competing interests.

References:

1. Deng MC, De Meester JMJ, Smits JMA, Heinecke J, Scheld HH. Effect of
receiving a heart transplant: analysis of a national cohort entered on to
a waiting list, stratified by heart failure severity. BMJ 2000;321:540-545

2. Mancini DM, Eisen H, Kussmaul W, Mull R, Edmunds LH, Wilson JR. Value
of peak exercise oxygen consumption for optimal timing of cardiac
transplantation in ambulatory patients with heart failure. Circulation
1991;83:778-786

3. Mancini D, LeJemtel T, Aaronson K. Peak VO2. A simple yet enduring
standard. Circulation 2000;101:1080-1082

4. Aaronson K, Schwartz JS, Chen T, Mancini D. Development and prospective
validation of a clinical index to predict survival in ambulatory patients
referred for cardiac transplant evaluation. Circulation. 1997;95:2660-2667