ENHANCED HEPATIC-UPTAKE OF TL-201 IN PATIENTS WITH SEVERE NARROWING OF THE RIGHT CORONARY-ARTERY

To assess the hepatic uptake of thallium-201 after exercise treadmill testing and to investigate whether hepatic uptake of thallium-201 may be a useful marker of right coronary artery (RCA) disease, 43 patients were studied: 17 with RCA disease (9 with 1-vessel disease, 8 with mu ltivessel disease including tile RCA), 8 with left coronary system dis ease alone, and 18 with a low probability (<5%) of coronary disease. A ll subjects were studied with symptom-limited exercise and redistribut ion thallium-201 single-photon emission computed tomographic(SPECT) sc intigraphy. Two indexes of hepatic uptake were derived: a liver-to-hea rt ratio after stress, and a stress-to-rest hepatic ratio. The low-pro bability group had a liver/heart ratio of 0.48 +/- 0.02. In the group with RCA disease alone, liver/heart ratio was 1.29 +/- 0.20 (p < 0.005 vs low-probability group). Patients with multivessel coronary artery disease involving the RCA had a ratio of 1.19 +/- 0.16 (p < 0.005 vs l ow-probability group), and patients with only left coronary system dis ease had a liver/heart ratio of 0.87 +/- 0.15 (p < 0.05 vs low-probabi lity group). The stress/rest ratio of the low-probability group was 0. 83 +/- 0.04.