Abnormal thallium kinetics in postoperative coarctation of the aorta: evidence for diffuse hypertension-induced vascular pathology

After operative correction of congenital coarctation of the aorta, patients continue to have excess cardiovascular mortality, including manifestations of ischemic heart disease. Previous morphologic studies support the concept of direct hypertensive vascular injury in these patients. To determine whether abnormalities of myocardial perfusion were present in an asymptomatic group of patients with coarctation repair, 18 men and 9 women with a mean age of 26 years (range 19 to 41) were studied between 2 and 25 years after operative correction. Stress electrocardiography and quantitative thallium imaging by a circumferential profile technique were used. These patients were compared with a normal group, statistically defined as having a less than 1 % prevalence of significant obstructive coronary artery disease. The postoperative coarctation group demonstrated a reduction in global thallium redistribution in each view analyzed. As compared with findings in the control subjects, thallium washout in the anterior view (41.9 versus 48.6%, p = 0.02) and left anterior oblique projection (40.5 versus 48.2%, p = 0.007) was significantly diminished. Although the postoperative coarctation group had a lower thallium redistribution rate in the lateral view (41.4 versus 46.3%, p = 0.09) this difference did not reach statistical significance because of the intrinsic variability of this projection. Plots of the median percent thallium washout revealed independence from circumferential profile angle, indicating global abnormalities in perfusion. No correlation between clinical variables and thallium kinetics could be established, suggesting marked individual variability in the development of this vascular lesion. The observation of abnormal thallium kinetics in patients with coarctation repair may have consequences for long-term follow-up and therapy.