cular ▁layer ▁of ▁the ▁blood ▁vessels ▁appear ▁to ▁play ▁a ▁significant ▁role ▁in ▁st iff ening ▁the ▁ar ter ies ▁and ▁indu cing ▁the ▁early ▁phase ▁of ▁coron ary ▁ar ter ios cl eros is . ▁This ▁can ▁be ▁seen ▁in ▁a ▁so - called ▁met ast atic ▁mechanism ▁of ▁calci phy la xis ▁as ▁it ▁occurs ▁in ▁chron ic ▁kid ney ▁disease ▁and ▁hem od ial ysis ▁( R ainer ▁Lied t ke ▁ 2 0 0 8 ). ▁Although ▁these ▁people ▁suffer ▁from ▁a ▁kid ney ▁d ys function , ▁almost ▁fifty ▁percent ▁of ▁them ▁die ▁due ▁to ▁coron ary ▁ar tery ▁disease . ▁Pla ques ▁can ▁be ▁thought ▁of ▁as ▁large ▁" p im ples " ▁that ▁pro tr ude ▁into ▁the ▁channel ▁of ▁an ▁ar tery , ▁causing ▁a ▁partial ▁obst ruction ▁to ▁blood ▁flow . ▁People ▁with ▁coron ary ▁ar tery ▁disease ▁might ▁have ▁just ▁one ▁or ▁two ▁pla ques , ▁or ▁might ▁have ▁do z ens ▁distributed ▁throughout ▁their ▁coron ary ▁ar ter ies . ▁A ▁more ▁severe ▁form ▁is ▁chron ic ▁total ▁occ l usion ▁( CT O ) ▁when ▁a ▁coron ary ▁ar tery ▁is ▁completely ▁ob struct ed ▁for ▁more ▁than ▁ 3 ▁months . ▁ ▁Card iac ▁synd rome ▁X ▁is ▁ch est ▁pain ▁( ang ina ▁p ector is ) ▁and ▁ch est ▁dis com fort ▁in ▁people ▁who ▁do ▁not ▁show ▁signs ▁of ▁block ages ▁in ▁the ▁larger ▁coron ary ▁ar ter ies ▁of ▁their ▁hearts ▁when ▁an ▁ang i ogram