Native coronary artery patency after coronary artery bypass surgery

Thursday, September 4, 2014

Submitted by

Joel Dunning

Source

Source Name: JACC Cardiovascular Interventions

Source URL: http://www.ncbi.nlm.nih.gov/pubmed/25060019

Author(s)

Pereg D, Fefer P, Samuel M, Wolff R, Czarnecki A, Deb S, Sparkes JD, Fremes SE, Strauss BH

. – In contrast to the large body of information regarding graft patency, data regarding atherosclerosis progression and vessel patency in surgically bypassed native coronary arteries are less clear. The aim of this study was to determine native coronary artery patency 1 year after coronary artery bypass grafting, and to identify clinical and angiographic predictors for the development of a chronic total occlusion (CTO). Researchers found that CTO of surgically bypassed coronary arteries 1 year after coronary artery bypass grafting is extremely common.

Methods

Of the 440 patients who underwent 1–year follow–up angiography as part of the multicenter RAPS (Radial Artery Patency Study), this study included 388 patients (88%) for whom angiograms were available for review.
Angiograms were reviewed for native coronary artery patency in an independent blinded manner.

Results

On the pre–operative angiogram, CTO of at least 1 native coronary vessel was demonstrated in 240 patients (61.9%) having 305 occluded vessels.
At 1 year after coronary artery bypass grafting, at least 1 new native coronary artery CTO occurred in 169 patients (43.6%).
In 7.5% of patients, the native artery and the graft supplying that territory were both occluded.
A new CTO was almost 5 times more likely to occur in coronary vessels with a pre–operative proximal stenosis >90% compared with vessels with proximal stenosis <90% (45.5% vs. 9.5%, respectively, p<0.001).
Patients with a new CTO had significantly more baseline Canadian Cardiovascular Society class 4 angina compared with patients without a new CTO.
A new CTO was less likely to occur in the left anterior descending artery (18.4%), supplied by the left internal thoracic artery.
When comparing radial artery and saphenous vein grafts, neither the type of graft nor graft patency had any association with native coronary artery occlusion.

Comments

Submitted by Ferenc Tarr on Sat, 2014-10-04 01:56

Congratulations for the study. However, one is inclined to make a few notes regarding certain point of the conclusions. As a surgeon I would have been interested more in the following MORPHOLOGICAL characteristics of the graft recipient vessels: 1. diameter 2. Run off caliber. Functional points: 1. collateral circulation 2.Wall motion alteration in the region of the graft recipient vessel. CASS status of the new CTO pts surely reflects to advanced atherosclerosis. Finally, IMA supplied recipient arteries (LAD predominantly) per se will develop singular character compared to any other coronaries and other bypass grafts (radial,, saphenous vein) owing to the special biochemical milieu provided by the IMA (due to enhanced production of nitric oxide, resulting in constant vasodilatation, reduced thrombocytes aggregation and adhesion in the recipient coronary vessel.)

Submitted by David Mull on Sun, 2014-10-12 12:14

Postoperative avoidance of CTO might, in part. also be attributed to diastolic flow of pedicled IMA grafts. Analysis of postoperative CTO in other left coronary distribution vessels receiving pedicled arterial grafts may also diminish sequalae of coronary atherosclerosis. Augmented diastolic coronary flow in and of itself, may be a seperate predictor of avoiding CTO, regardless of conduit choice. ,