Left Main Coronary Artery Calcium and Diabetes Confer Very-High-Risk Equivalence in CAC more than 1,000: Study

Not all patients with very high levels of CAC are created equal when it comes to CV risk, with the research published in JACC: Cardiovascular Imaging providing some clues on how to identify a particularly high-risk patient who could benefit from aggressive primary prevention strategies across several domains, including low-density lipoprotein-cholesterol lowering.

Although coronary artery calcium of ≥1,000 is a subclinical atherosclerosis threshold to consider combination lipid-lowering therapy, differentiating very high from high ASCVD risk in this patient population is not well-defined. Therefore, Alexander C. Razavi, Emory Clinical Cardiovascular Research Institute, Emory University School of Medicine, Atlanta, Georgia, USA, and colleagues aimed to identify risk factors equating with very high-risk ASCVD mortality rates among people with a CAC of ≥1,000.

For this purpose, the researchers studied 2,246 asymptomatic patients with a CAC of ≥1,000 from the CAC Consortium without a prior ASCVD event. The mean age was 66.6 years; 14% were female, and 10% were non-White. During a median follow-up of 11.3 years, Cox proportional hazards regression modelling was performed for ASCVD mortality.

Crude ASCVD mortality rates were compared with those reported for secondary prevention trial patients classified as very high risk, defined by ≥2 major ASCVD events or 1 major event and ≥2 high-risk conditions (1.4 per 100 person-years).

The study led to the following findings:

• The median CAC score was 1,592, and 6% had severe left main (LM) CAC (vessel-specific CAC ≥300).
• Diabetes (HR: 2.04) and severe LM CAC (HR: 2.32) were associated with ASCVD mortality.
• The ASCVD mortality per 100 person-years for all patients was 0.8, although higher rates were observed for diabetes (1.4), severe LM CAC (1.3), and both diabetes and severe LM CAC (7.1).

"Among asymptomatic patients with a CAC of ≥1,000 without a prior index event, diabetes, and severe LM CAC define very high-risk atherosclerotic cardiovascular disease, identifying individuals who may benefit from more intensive prevention therapies across several domains, including LDL-cholesterol lowering," the researchers wrote.

Reference:

Razavi AC, Shaw LJ, Berman DS, Budoff MJ, Wong ND, Vaccarino V, van Assen M, De Cecco CN, Quyyumi AA, Mehta A, Muntner P, Miedema MD, Rozanski A, Rumberger JA, Nasir K, Blumenthal RS, Sperling LS, Mortensen MB, Whelton SP, Blaha MJ, Dzaye O. Left Main Coronary Artery Calcium and Diabetes Confer Very-High-Risk Equivalence in Coronary Artery Calcium >1,000. JACC Cardiovasc Imaging. 2024 Feb 12:S1936-878X(24)00026-3. doi: 10.1016/j.jcmg.2023.12.006. Epub ahead of print. PMID: 38385932.