A comparison of outcomes with coronary artery calcium scanning in unselected populations: The Multi-Ethnic Study of Atherosclerosis (MESA) and Heinz Nixdorf RECALL study (HNR)

Abstract

Background The Multi-Ethnic Study of Atherosclerosis (MESA) and the Heinz Nixdorf Recall Study (HNR)) differed in regards to informing physicians and patients of the results of their subclinical atherosclerosis. Objective This study investigates whether the association of coronary artery calcium (CAC) with incident non-fatal and fatal cardiovascular (CVD) events is different among these two large, population-based observational studies. Methods All Caucasian subjects aged 45–75 years, free of baseline cardiovascular disease were included (n=2232 in MESA, n=3119 HNR participants). We studied the association between CAC and event rates at 5 years, including hard cardiac events (MI, cardiac death, resuscitated cardiac arrest), and separately added revascularizations, and strokes (fatal and non-fatal) to determine adjusted hazard ratios (HR). Results Both cohorts demonstrated very low CHD (including revascularization) rates with zero calcium (1.13 and 1.16% over 5 years in MESA and HNR respectively) and increasing significantly in both groups with CAC 100–399 (6.71 and 4.52% in MESA and HNR) and CAC >400 (12.5 and 13.54% in MESA and HNR respectively) and demonstrating strong independent predictive values for scores of 100–399 and >400, despite multivariable adjustment for risk factors. Risk factor adjusted five year revascularization rates were nearly identical for HNR and MESA, and generally low for both studies (1.4% [45/3119] for HNR and 1.9% [43/2232] for MESA) over 5 years. Conclusions Across two culturally diverse populations, CAC >400 is a strong predictor of events. High CAC did not determininistically result in revascularization and knowledge of CAC did not increase revascularizations.

Imaging Atherosclerosis in Diabetes: Current State

“…Its relation to coronary artery atherosclerosis have been confirmed by histopathologic studies [16] and it has been shown to be strong predictor of incident coronary heart disease and improve predictive information compared to standard risk factors in large multi ethnic cohort studies. [17,18].…”

Coronary Artery Calcification, Intima-Media Thickness, and Ankle-Brachial Index Are Complementary Stroke Predictors

“…3 By contrast, 9.8% (ie, ≈10%) of subjects revealed CAC scores ≥400, which is commonly considered as cut off for the highest CAC category. 1,14,15 To further evaluate effects of atherosclerosis markers on stroke risk, we calculated crude stroke incidence rates for categories below and above the 90th CIMT percentile and categories above and below the 10th ABI percentile, equivalent to the CAC ≥400 cut off (Figure 1). These analyses revealed that both CIMT and ABI provided additional information about stroke risk when combined with CAC ( Figure 1A and 1B), as did CIMT combined with ABI ( Figure 1C).…”

“…In the HNR cohort, 9.8% and 27.2% of subjects revealed CAC scores ≥400 and ≥100, respectively, which are widely used as cut offs for the highest and second-highest CAC category. 1,14,15 ABI differs from CAC and CIMT with respect to that low ABI values are rare in the general population, representing a hallmark of advanced atherosclerosis. Thus, only 4.8% of subjects in the 3 Although reflecting a simple risk predictor that does not require expensive technical equipment, its practical use is limited by the fact that >20 subjects in the general population need to be screened in order that a single subject with reduced ABI is detected.…”

Headed in the Right Direction But at Risk for Miscalculation

“…High event rates similar to rates in secondary prevention populations have been noted for CAC scores >100 (29,32), and that alternate threshold may also be considered for determining eligibility for statin therapy. Furthermore, a CAC >75th percentile score does not confer the same very high risk status as a score >300 or >100, although these are viewed as equivalent options in the RAG.…”