Long-term Morphofunctional Remodeling of Internal Thoracic Artery Grafts: A Frequency-Domain Optical Coherence Tomography Study

I. Porto, M. Gaudino, G. L. De Maria, L. Di Vito, R. Vergallo, P. Bruno, G. Bonalumi, F. Prati, L. Bolognese, F. Crea, M. Massetti
2013 Circulation. Cardiovascular Interventions  
Elective patients with positive stress test or recurring effort angina or previous (>10 years) LITA grafting to the left anterior descending artery were screened before angiography. Patients with acute coronary syndrome were not included. Patients with previous angiographic documentation of LITA occlusion were excluded. Other exclusion criteria were severe Background-Internal thoracic arteries (ITAs) are frequently anastomosed to the coronary circulation for bypass grafting. The purpose of this
more » ... research was to investigate in vivo the long-term morphofunctional changes of ITAs after their use as coronary artery bypass conduits, by comparing the morphological features and vasoreactivity of the grafted left ITA (LITA) with the native, nonharvested right ITA (RITA) in the same patient. Methods and Results-At least 10 years after surgery, in 10 patients, LITA graft and nonharvested RITA were assessed by quantitative angiography and frequency-domain optical tomography. Endothelium-dependent and independent vasodilation was tested by selective infusion of acetylcholine and isosorbide dinitrate. Quantitative angiography showed that baseline mean diameter of LITA graft was significantly smaller than that of RITA ( 2.59 mm [2.29-3.04] versus 3.05 mm [2.75-3.32]; P=0.01). LITA showed a significant intimal thickening (P=0.05) and a nonsignificant medial thinning (P=0.22) compared with RITA, leading to an increased intima-media ratio (intima-media ratio, 0.72 [0.53-0.91] versus 0.23 [0.12-0.38]; P=0.02). The intima-media ratio correlated inversely with the vasodilatatory response in RITA (r=−0.68, P=0.03 for acetylcholine and r=−0.62, P=0.05 for isosorbide dinitrate) but not in LITA (r=−0.18, P=0.63 for acetylcholine and r=−0.11, P=0.75 for isosorbide dinitrate). Conclusions-Ten years after implantation to the coronary circulation, LITA grafts show intimal thickening, increased intima/media ratio, and maintained endothelium-derived vasodilation. These changes are likely to be an adaptive answer to the different flow dynamics typical of coronary circulation. (Circ Cardiovasc Interv. 2013;6:269-276.) Key Words: endothelium-dependent vasodilation ◼ frequency-domain-optical coherence tomography ◼ left internal thoracic artery ◼ right internal thoracic artery
doi:10.1161/circinterventions.113.000200 pmid:23716001 fatcat:suw7w3ljafccbbcbauome7xpru