Abstract 3301: Left Main Calcification By Computed Tomography Angiography (cta) Signifies Poor Prognosis
Introduction It has been shown with invasive coronary angiography that stenosis of one vessel is associated with better survival than two vessel disease, three vessel disease, or left main (LM) disease, in that order. In patients with single vessel disease, LM disease followed by left anterior descending artery (LAD) disease carries the worst prognosis. Whether coronary artery calcium (CAC) scans demonstrate similar per-vessel prediction has not been shown.
Hypothesis We hypothesize that coronary artery calcification (CAC) of the LM will be associated with a poorer prognosis compared to CAC of the LAD, the left circumflex artery (LCx) or the right coronary artery (RCA).
Methods 493 consecutive symptomatic patients with an intermediate risk of coronary artery disease who were referred for CTA evaluation in an outpatient setting were studied. Individuals with known coronary artery disease, myocardial infarction and prior revascularization were excluded. Follow up was an average of 40 months. Cardiac events were defined as myocardial infarctions or cardiac death. CAC score per vessel was obtained for each patient. The HR associated with each vessel’s CAC score was adjusted for age, gender, diabetes, hypertension, hypercholesterolemia and total calcium score and CAC score of each other vessel by stepwise multivariate model.
Results We found that CAC of the LM is associated with 9.75 fold increase in risk of having a cardiac event (p<0.0001). CAC of the LAD and RCA were not significantly associated with risk of cardiac event, and CAC of the LCx was assocated with a 2.2 fold risk (p=0.005) (see Table 1⇓).
Conclusions We conclude that LM CAC on CTA is associated with an approximate 10 fold increase in risk of cardiac events, independent of the total calcium score. Consider for further stratification may be warranted based upon presence of left main CAC.