Early alterations of myocardial blood flow reserve in heart transplant recipients with angiographically normal coronary arteries.
BACKGROUND
The evaluation of the coronary reserve provides valuable information on the status of coronary vessels. Therefore, we studied with positron emission tomography (PET) and 13N-ammonia the myocardial blood flow (MBF) reserve in heart transplant recipients free of allograft rejection and with angiographically normal coronary arteries early after heart transplantation (HTx). The MBF reserve was calculated as the ratio between MBF after dipyridamole injection and basal MBF normalized for the rate-pressure product.


METHODS
Patients were studied within 3 months (group A, n = 12) or more than 9 months (group B, n = 12) after HTx. Five patients have been studied both during the early and late period after HTx. Results were compared to those obtained in 7 normal volunteers (NL).


RESULTS
Group A recipients had a significantly lower dipyridamole MBF (in ml/min/100 gr of tissue) than that of group B recipients (142+/-34 vs 195+/-59, p<0.05). This resulted in a significant decrease in MBF reserve early after HTx (group A: 1.82+/- 0.33) and a restoration to normal values thereafter (group B: 2.52+/- 0.53 vs NL: 2.62+/-0.51, p = ns). Separate analysis of 5 patients studied twice is consistent with these results.


CONCLUSIONS
This study shows that in heart transplant recipients free of allograft rejection and with normal coronary angiography, MBF reserve is impaired early after HTx. Restoration within one year suggests that this abnormality does not represent an early stage of cardiac allograft vasculopathy.
Preumont
N
N
Department of Cardiology, Erasme Hospital, Free University of Brussels, Brussels, Belgium.
Berkenboom
G
G
Vachiery
J
J
Jansens
J
J
Antoine
M
M
Wikler
D
D
Damhaut
P
P
Degré
S
S
Lenaers
A
A
Goldman
S
S
D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000187:drug effects / Q000502:physiology*; D003331:Coronary Vessels / Q000187:drug effects / Q000502:physiology*; D004176:Dipyridamole / Q000008:administration & dosage; D005260:Female; D016027:Heart Transplantation / Q000000981:diagnostic imaging / Q000502:physiology*; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011379:Prognosis; D012146:Rest / Q000502:physiology; D014019:Tissue Donors; D014055:Tomography, Emission-Computed; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000008:administration & dosage
D014665:Vasodilator Agents; D004176:Dipyridamole