Is all intimal proliferation created equal in cardiac allograft vasculopathy? The quantity-quality paradox.
BACKGROUND
Pre-angiographic detection of intimal proliferation using intravascular ultrasound in heart transplant recipients has focused investigators' attention on the prognostic utility of such early information. Not all heart transplant recipients who exhibit a "prognostically relevant" threshold of severe (>0.5 mm) intimal thickening experience cardiac events. We sought to contrast clinical characteristics of heart transplant recipients who have prognostically relevant, severe intimal proliferation and who experience cardiac events with those who remain event free.


METHODS
We prospectively followed an inception cohort of 54 consecutive heart transplant recipients with severe intimal proliferation (intimal thickness >0.5mm) of the coronary arteries after index intravascular ultrasound examination to assess the development of cardiac events (sudden cardiac death, myocardial infarction) and/or the necessity for coronary revascularization with percutaneous techniques (angioplasty, atherectomy, stent implantation) or surgical bypass.


RESULTS
Based on the occurrence of adverse cardiac events during the subsequent 24 months, we divided the study cohort into 2 groups: Group 1 (no event, n = 33) and Group 2 (cardiac event, n = 21). Both groups demonstrated similar intimal thickness at the index ultrasound (Group 1, 0.89 +/- 0.27 mm, vs Group 2, 0.94 +/- 0.36 mm; p = not significant). Those with cardiac events were more likely than those without events to have hyperlipidemia, to have greater exposure to cumulative and average daily prednisone, and to exhibit greater average biopsy rejection scores at follow-up.


CONCLUSIONS
These observations underscore the importance of the quality and not merely the quantity of intimal proliferation in determining occurrence of morbid cardiac events and further emphasize the interaction of immunologic and non-immunologic factors in determining event vulnerability in cardiac allograft vasculopathy.
Mehra
Mandeep R
MR
Ochsner Cardiomyopathy and Heart Transplantation Center, Ochsner Clinic Foundation, New Orleans, Louisiana, USA. mmehra@ochsner.org
Ventura
Hector O
HO
Uber
Patricia A
PA
Scott
Robert L
RL
Park
Myung H
MH
D016022:Case-Control Studies; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005260:Female; D016027:Heart Transplantation / Q000000981:diagnostic imaging*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012307:Risk Factors; D014184:Transplantation, Homologous; D017539:Tunica Intima / Q000473:pathology*; D018084:Ultrasonography, Interventional
D007166:Immunosuppressive Agents