Angina risk differs among patients with severe CAC
MedWire News: Very high coronary artery calcification (CAC) may predispose to an increased risk for progressive cardiovascular disease leading to the development of angina, but not to acute ischemic events, compared with less severe disease, suggests an analysis of MESA.
The researchers found that patients with very high CAC (≥1000 AU) were more likely to develop angina than those with high CAC (400-900 AU), but not the combined endpoint of myocardial infarction (MI), resuscitated cardiac arrest, and coronary heart disease (CHD) death.
However, both high and very high CAC were associated with an elevated risk for total CHD events,notes the team.
Using data from MESA (Multi-Ethnic Study of Atherosclerosis; n=6814), Wendy Post (John Hopkins University, Baltimore, Maryland, USA) and colleagues identified 420 (6.2%) individuals with high and 257 (3.8%) individuals with very high CAC, and compared CHD risk factors and event rates between the two groups.
During a median of 68 months follow-up, a total of 98 first CHD events occurred among MESA participants with severe CAC (≥400 AU).
Participants with very high CAC were significantly older, more likely to be male (81% vs 64%, respectively), and to have chronic kidney disease than those with high CAC.
In addition, both very high and high CAC were associated with an elevated risk for clinical CHD events.
However, those with very high CAC were at a 65% greater risk for developing angina than those with high CAC; individuals with very high CAC experienced angina at a rate of 2.5 per 100 person-years while those with high CAC experience an angina event rate of 1.5 per 100 person-years. This relationship remained significant when adjusting for traditional CHD risk factors, notes the team.
In contrast, very high CAC was not associated with a significantly higher risk for the combined endpoint of MI, resuscitated cardiac arrest, or CHD death compared with high CAC.
"Although these data demonstrate that the presence of CAC ≥100, compared to CAC 400-900, does not differentiate risk for MI, resuscitated cardiac arrest, or CHD death, it is clearly demonstrated that individuals with severe CAC are at elevated risk for cardiac events compared to those with less CAC," say Post et al.
These individuals warrant aggressive preventive strategies, they conclude in the journal Atherosclerosis.
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By Nikki Withers