Effective October 1, 2011, code 414.4, Coronary atherosclerosis due to calcified coronary lesion, has been created to distinguish calcified coronary lesions from other ischemic coronary lesions. The deposits of calcium in these lesions present a rigid obstacle that puts patients at increased risk for complications such as inadequate stent expansion, acute stent thrombosis and restenosis when treated by stent and angioplasty. Research has also shown that an increased amount of calcium deposits leads to a higher incidence of major adverse events, in particular the rate of non-Q wave myocardial infarction, when compared to non-calcified lesions.
Calcific deposits are found more frequently,and in greater amounts, in the elderly and in more advancedlesions. There is speculation that the process of formation of coronary artery calcification is the body's attempt to stabilize itself to protect the threatened myocardium by strengtheningweakened atherosclerotic plaque that is prone to rupture. When heavily calcified, the artery is about fivetimes stiffer than a cellular lesion or normal vessel wall andvery resistant to rupture. Treatment consists of medical management or more invasive cardiac procedures when severely calcified coronary lesions cannot be crossed during angioplasty.