CORONARY-ARTERY INTIMAL THICKENING IN THE TRANSPLANTED HEART - AN IN-VIVO INTRACORONARY ULTRASOUND STUDY OF IMMUNOLOGICAL AND METABOLIC RISK-FACTORS

This study examined the hypothesis that immunologic factors are the ma jor correlates of coronary artery intimal thickening and luminal steno sis. The study population included 116 adult heart transplant recipien ts with a mean age of 44.7 +/- 12.0 years (89 men and 27 women) underg oing annual coronary angiography and intracoronary ultrasound 3.4 +/- 2.7 (range, 1.0-14.6) years after transplantation. Mean intimal thickn ess was obtained from several distinct sites along the left anterior d escending and/or left circumflex coronary artery by intracoronary ultr asound. Coronary artery stenosis defined by angiography was classified as mild (< 30% luminal stenosis), moderate (greater than or equal to 30-70% luminal stenosis), or severe (> 70% luminal stenosis or diffuse pruning of distal vessels). Prevalence of any transplant coronary art ery disease (TxCAD) was 85% by intracoronary ultrasound and 15% by ang iography. By multiple regression analysis, only average fasting plasma triglyceride level (P < 0.006) and average weight (P < 0.007) were si gnificantly correlated with severity of intimal thickening (R = 0.54, P < 0.0001). Donor age (P < 0.006) and average fasting plasma triglyce ride level (P < 0.009) were significantly correlated with stenosis by angiography. Correlation of multiple immunologic and metabolic factors with intimal thickness by univariate analysis suggests a multifactori al etiology for TxCAD. Among the multiple univariate correlates of TxC AD, higher fasting plasma triglyceride levels and body weight are the only independent correlates of TxCAD. The absence of acute rejection a s an independent predictor of intimal thickening suggests that mechani sms beyond those mediating typical cellular rejection should be target ed for advancing our understanding of TxCAD.