Association of coronary artery calcium with severity of myocardial ischemia in left anterior descending, left circumflex, and right coronary artery territories

Background: An increasing coronary artery calcium score is associated with a higher likelihood of myocardial ischemia. Hypothesis: The association of the coronary calcium score with myocardial ischemia in different coronary arteries needed to be investigated. Methods: We correlated the coronary artery calcium (CAC) score with the severity of myocardial ischemia diagnosed by myocardial perfusion imaging in the left anterior descending (LAD), left circumflex (LCX), and right coronary artery (RCA) territories in 206 patients, mean age 66 years, without cardiac stents or coronary artery surgery. Results: The mean CAC score in the LAD coronary artery was 160 ± 218 in patients with no or mild ischemia and 336 ± 379 in patients with moderate or severe ischemia (P = 0.039). The mean CAC score in the LCX coronary artery was 57 ± 117 in patients with no or mild ischemia and 161 ± 191 in patients with moderate or severe ischemia (P = 0.018). The mean CAC score in the RCA was 114 ± 237 in patients with no or mild ischemia and 261 ± 321 in patients with moderate or severe ischemia (P = 0.045). Stepwise linear regression analysis showed that male gender (P < 0.0001), age (P < 0.0001), and moderate or severe ischemia (P = 0.023) were significantly associated with high LAD coronary artery CAC scores. Male gender (P < 0.0001), age (P = 0.0002), and moderate or severe ischemia (P = 0.006) were significantly associated with high LCX coronary artery CAC scores. Male gender (P < 0.0001) and age (P < 0.0001) were significantly associated with high RCA CAC scores. Conclusions: Higher CAC scores are significantly associated with moderate or severe ischemia in the LAD and LCX coronary arteries.