**1. Introduction**

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[37] Saxena, A, Rauch, U, Berg, K. E, et al. The vascular repair process after injury of the carotid artery is regulated by IL-1RI and MyD88 signalling. Cardiovasc Res (2011). ,

ma formation in culture. Atherosclerosis (2000). , 150, 33-41.

91, 350-7.

160 Artery Bypass

General population suffers at 2-3% by angina. Incidence of angina in men and women aged 55 to 75 is 9% and 5% respectively. [1]

The prevalence of angina is 24,000 people per million. Almost 1 in 1000 undergoes CABG in the USA. This means that half a million people undergo CABG around the world per year and 1.5 million patients undergo Angioplasty/ stenting (1 to 3).

Without revscularization (angioplasty or bypass) four-year survival of patients one, two or three vessels disease is 92%, 84% and 68% respectively. [2] Moreover, in patients with reduced ejection fraction and heart failure (e.g. stroke) the respective survival rates are 67%, 61% and 42%. [3]

Clearly 5-yearsurvival increases with every form of revascularization treatment. Coronary artery bypass grafting (CABG) remains the gold standard revascularisation strategy for complex 3 vessel coronary artery disease and left mainstem disease.

Recent trials such as the SYNTAX have shown that CABG is superior to PCI in most circum‐ stances of coronary artery disease. Although there are certain anatomical lesions such as isolated left main disease treatment options to be elucidated, CABG remains the gold standard treatment for severe coronary artery disease. Data from studies such as SYNTAX and ART confirmed by the National Cardiothoracic Surgery Database have also shown the low mortality risk of CABG.

These recent evidence has prompted a rewrite of the european guidelines with regards to revascularisation. It is now recommended that no ad hoc PCI to be performed and all cases of severe coronary disease should be discussed in a multidisplinary setting involving the "Heart team".

© 2013 Parissis et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Indicatively, with the coronary artery bypass, survival is related to the ejection fraction, according the Cardiothoracic surgeries database of Emory University, where 23960 patients are registered as follows:

Arterial grafts started being systematically used in the 70's. The focus was on the internal

The Impact of Arterial Grafts in Patients Undergoing GABG

http://dx.doi.org/10.5772/54621

163

**1.** Endothelial cells release of nitric oxide (NO), which has vasodilator action and also prevents the accumulation of platelets, the adhesion of neurophils and chemotaxis. NO prevents directly the development of smooth muscle fibers related to the intimal hyper‐

**4.** Maintenance of the inner elastic layer, which prevents the migration of the smooth muscle

**5.** The internal mammary artery has a thin middle layer with a few smooth muscle cells, which seem to reduce infiltration in response to the growth factor produced by platelets.

For all these reasons, the internal mammary artery, contrary to other vascular grafts, is not

IMA's attrition rate compared to the saphenous vein is given in the following table:

mammary artery, which presents great biological properties:

**2.** The protective action of "vasa vasorum"

**3.** Increased prostacyclin production.

affected by intimal hyperplasia.

**Table 3.** IMA and SVG attrition rate over 10 year period

plasia. [8]

cells.


**Table 1.** Mortality as per Ejection Fraction

So, the main benefit from the bypass (CABG) is not only the symptomatic improvement and avoidance of the risk of a stroke, but also the evident prolongation of the patient's survival. On the other hand, it is obvious that even with CABG, long-term survival is decreasing. Even when reviewing the sudden death risk as a result of CABG, there are three (3) stages.


**Table 2.** Risk of death following CABG

There is an early, high-risk period, a period with rapid decrease of the risk and a period after 5 years, with an ascending risk rate. This late phenomenon is related to the atheromatosis of the saphenous vein graft.
