Since 1981, 77 of 116 patients undergoing heart transplantation (HTx) have survived from 6 months to 8 years. Graft control involved a total of 871 endomyocardial biopsies (EMB) and 141 angiographies. Sixteen patients developed coronary artery disease (CAD) manifesting itself 7-60 months after HTx (20.7%). These patients (15 male, 1 female) experienced multiple rejection episodes (RE) and more than half suffered from hypercholesterolaemia and hypertension (n = 10). A mean rejection score (Billingham grading) of greater than 1 (mean = 1.6 +/- 1.1) was calculated in all patients with CAD at the time of angiography or autopsy. By contrast, the mean rejection score ranked less than 1 in patients with undetectable or resolved CAD (means = 0.4 +/- 0.38). This rate is not remarkably different from the rejection score in patients (n = 61) without CAD (mean = 0.2 +/- 0.4). The 8 patients alive (56 +/- 18 months) showed a low number of RE/year (mean = 1.1 +/- 0.4) compared with means = 1 +/- 0.9 in patients without CAD. Eight patients expired within a short period (mean = 31 +/- 26.9) and had a significantly higher number of RE/year (mean = 4.3 +/- 2.9; P less than 0.01 vs. no CAD, CAD alive). Autopsy (n = 6) and angiographic studies (n = 46) demonstrated diffuse, concentric, obliterative arterial disease in all vessels (type A) in 6 patients (RE/yr: mean = +/- 5.5 +/- 2.3), single stenoses in major coronary vessels (type B) in 7 patients and ordinary atherosclerosis (3-vessel disease) comparable to ischaemic heart disease (type C) in 3 patients.(ABSTRACT TRUNCATED AT 250 WORDS)