Background: Acute cardiac allograft rejection is associated with early dias
tolic dysfunction. The development of chronic rejection is dependent on the
frequency and severity of acute rejection episodes. Therefore, early diagn
osis and therapy influence long-term survival significantly. For the first
time, acoustic quantification, a new echocardiographic technology for on-li
ne measurement of cardiac volumes and their changes, facilitates quantitati
ve assessment of systolic and diastolic function noninvasively.
Methods: Since May 1996, all consecutive patients after cardiac transplanta
tion (n = 94) underwent 475 endomyocardial biopsies and the same number of
echocardiographic studies within 6 hours after biopsy before the histologic
al results were available.
Results: Nineteen patients showed 23 episodes of acute rejection (ISHLT gre
ater than or equal to 2). There was a significant decrease in left ventricu
lar peak filling rate (PFR: end-diastolic volume (EDV)/second) as a paramet
er of diastolic function during rejection (2.9 +/- 0.4, n 23) as compared t
o PFR measured under nonrejection status (4.5 +/- 0.8; n = 452; p < 0.0001)
. Most importantly we found that in these 19 patients showing rejection, th
e PFR was normal in the last examination before rejection, but was signific
antly reduced during rejection (2.9 +/- 0.4 vs 4.5 +/- 0.7 n = 23, p < 0.00
01). After successful rejection therapy, PFR again normalized in all patien
ts, with the exception of 1 patient with steroid-refractory humoral rejecti
on. We calculated sensitivity and specificity for several cutpoints for the
event "first rejection" in 15 patients and plotted them in a receiver oper
ating characteristic curve, showing that a PFR greater than or equal to 4.0
EDV/second is never associated with treatable rejection. A decrease of PFR
of more than 18% from its prevalue of the last biopsy with no rejection in
creases the accuracy for the diagnosis of rejection significantly.
Conclusions: We conclude that diastolic dysfunction during acute cardiac al
lograft rejection can be accurately detected by noninvasive measurement of
peak filling rate with acoustic quantification echocardiography. Monitoring
of this parameter provides reliable discrimination between treatable and n
ontreatable rejection.