INTRAVASCULAR ULTRASOUND FINDINGS FOLLOWI NG ORTHOTOPIC HEART-TRANSPLANTATION - COMPARISON TO CLINICAL-PARAMETERS

30 patients (mean age 51.4 +/- 11.6 years; female n = 6) were studied early after orthotopic heart transplantation (11.6 +/- 5.5 weeks). Twe lve recipients had undergone specific treatment for biopsy proven reje ction. Using a mechanical intravascular ultrasound device (3.5-F cathe ter), 153 coronary artery segments (16 left coronary main stem, 122 le ft anterior descending artery, 15 left circumflex artery) were studied . Intimal index and circumferential extension of a three-layer appeara nce of the vessel wall were assessed. In all segments, systolic-diasto lic changes in area (delta A) with respect to vessel area and pressure (delta P) were used to study normalized compliance (normalized compli ance = [delta A/A]/delta P [mm Hg-1 x 10(3)]). Intravascular ultrasoun d findings were correlated to perioperative ischemia time, LDL/HDL-rat io, Lp(a) and donor age. In a subgroup of 13 recipients, intravascular ultrasound investigation was repeated after an interval of 67.4 +/- 1 0.2 weeks. At first investigation, mean intimal index of all coronary segments was 0.07 +/- 0.10. Mean circumferential extension of a three- layer appearance of the vessel wall was 84 +/- 112 degrees. Normalized compliance was 2.43 +/- 1.90 mm Hg-1 in the left main stem 2.45 +/- 1 .47 mm Hg-1 within the left anterior descending artery, and 2.66 +/- 1 .72 mm Hg-1 within the circumflex artery (differences n. s.). No corre lation was found between intimal index and normalized compliance (r = -0.322), nor between circumferential extension of intimal thickening a nd normalized compliance (r = -0.362). Furthermore, there was no corre lation between normalized compliance and donor age. Normalized complia nce was significantly lower in recipients with proven rejection than i n those without (1.76 +/- 0.81 versus 2.95 +/- 1.22 mm Hg-1, p = 0.005 ). Both, intimal index and circumferential extension of intimal thicke ning, were significantly higher in recipients following rejection peri ods (p < 0.05). The extent of coronary vessel wall alterations on ultr asound correlated to donor age but not to perioperative ischemia time, LDL/HDL-ratio and Lp(a). Re-investigation of a subgroup of 13 recipie nts 67.4 +/- 10.2 weeks after the first study showed an insignificant increase of the intimal index (from 0.03 to 0.09) and of the circumfer ential extension of intimal thickening (from 40 to 111 degrees). Norma lized compliance changed from 2.53 +/- 1.48 to 2.87 +/- 1.33 mm Hg-1 ( differences n. s.). Early after orthotopic heart transplantation, a si gnificant correlation between atherosclerotic coronary vessel wall alt erations assessed by intravascular ultrasound and donor age can be con firmed. Heart recipients following rejection periods present with sign ificantly more atherosclerotic vessel wall alterations and a severely reduced compliance of the coronary vessels.