Myocardial ischemia in asymptomatic adults with repaired aortic coarctation.

BACKGROUND: Coarctation of the aorta represents a unique mechanism of hypertension with reduced survival even after the anatomic lesion is fixed. Coronary artery disease has been cited as the cause of one-third of deaths in adults with repaired aortic coarctation, yet no prospective studies have identified the substrate for these events. We hypothesized that noninvasive angiography multi-slice computed tomography (CTA) of the coronary arteries and perfusion by cardiac magnetic resonance (CMR) would identify perfusion abnormalities without obstructive coronary disease in vivo in asymptomatic patients with repaired coarctation.
METHODS: Twenty-seven repaired coarctation patients age 27+/-6 years and 10 age and gender-matched controls were prospectively enrolled to undergo clinical assessment, coronary CTA, and CMR. Myocardial perfusion reserve index (MPRI) was quantified using the normalized upslope of myocardial signal enhancement during vasodilator stress versus rest.
RESULTS: No patients had coronary artery atherosclerosis. Quantification of MPRI revealed significant impairment in endocardial to epicardial perfusion reserve ratio in patients versus controls (0.72+/-0.16 versus 0.91+/-0.08, respectively, p<0.0001). This difference remained significant even after excluding four patients with recoarctation (p=0.00013).
CONCLUSION: Adolescent and young adult patients with repaired coarctation of the aorta have abnormal myocardial perfusion reserve in the absence of coronary artery disease. These previously unrecognized findings in vivo may explain late-onset cardiac morbidity in this population.