Atherosclerotic cardiovascular disease events among statin eligible individuals with and without long-term healthy arterial aging

Nontraditional Risk Markers for Incident Coronary Artery Calcium Among Persons ≥65 Years of Age

Background

The initiation of coronary artery calcium (CAC) is an important physiologic milestone associated with increased cardiovascular disease risk. However, traditional risk factors (RF) do not perform well for predicting incident CAC among the 54 million older U.S. adults.

Objectives

The authors sought to assess the association between nontraditional cardiovascular disease RF and incident CAC in older persons.

Methods

There were 815 MESA (Multi-Ethnic Study of Atherosclerosis) participants ≥65 years of age who had CAC = 0 at Visit 1 and a follow-up CAC scan. Multivariable adjusted Cox hazards ratios (aHR) and C-statistics were calculated to examine the association of nontraditional RF with incident CAC.

Results

The mean age was 70.2 years and 67% were women. The median follow-up time to repeat CAC scan was 3.6 years (IQR: 2.6-9.2 years) and 45% of participants developed incident CAC. Albuminuria (aHR: 1.50, 95% CI: 1.07-2.09), carotid plaque (aHR: 1.32, 95% CI: 1.04-1.66), and thoracic aortic calcification (TAC) (aHR: 1.38, 95% CI: 1.10-1.75) were significantly associated with incident CAC, while higher levels of nontraditional RF including apolipoprotein-B, lipoprotein(a), high-sensitivity troponin T, and N-terminal pro-brain natriuretic peptide were not. When added to demographics, albuminuria, carotid plaque, and TAC provided a greater C-statistic improvement (+0.047, P = 0.004) vs all traditional RF combined (+0.033, P = 0.05).

Conclusions

Among nontraditional RF and measures of subclinical atherosclerosis, only albuminuria, carotid plaque, and TAC were significantly associated with incident CAC in persons ≥65 years of age. Identification of albuminuria or extracoronary atherosclerosis may help guide the timing of repeat CAC scoring in older persons with baseline CAC = 0.

Coronary artery calcium: from risk prediction to treatment allocation and clinical trials

Coronary artery calcium (CAC) is a direct measure of an individual's coronary atherosclerotic burden. Higher levels of CAC are strongly associated with an increased risk of cardiovascular disease (CVD) events and individuals with very high CAC levels have a CVD risk similar to stable persons with a prior CVD event. Conversely, the absence of CAC (CAC=0) is associated with a low long-term risk of CVD, even among groups classified as high risk based on traditional risk factors. Accordingly, the guideline-based role of CAC in allocation of CVD prevention therapies has expanded to include both statin and non-statin medications. Beyond prevention therapies, it is now widely recognised that the total burden of atherosclerosis is a stronger risk factor for CVD than a sole focus on coronary stenosis. Furthermore, evidence is accruing to support expanding the value of CAC=0 among low-risk symptomatic patients given its very high negative predictive value for ruling out obstructive coronary artery disease. There is now an appreciation of the value of routine assessment of CAC on all non-gated chest CTs and with the advent of artificial intelligence, automated interpretation is now possible. Additionally, CAC is now firmly established in randomised trials as a tool to identify high-risk patients most likely to benefit from pharmacotherapies. Future studies incorporating measures of atherosclerosis beyond the Agatston score will lead to continued refinement of CAC scoring, further improvements in personalisation of CVD risk prediction and more individualised allocation of prevention therapies to the patients at highest CVD risk.

Coronary artery calcium testing in young adults

PURPOSE OF REVIEW

To provide a summary of recent literature on coronary artery calcium testing (CAC) for risk stratification in young adults <45 years old.

RECENT FINDINGS

One of every ten young adults in the general population, and one out of every three young adults with traditional atherosclerotic cardiovascular disease (ASCVD) risk factors, have CAC. While the definition of premature CAC has yet to be formally defined in guidelines, it has become increasingly clear that any prevalent CAC among adults <45 years old should be considered premature. Traditional risk factors are strong predictors of CAC in young adults; however, this association has been found to wane over the life course which suggests that the onset and severity of risk factors for calcific atherosclerosis varies as individuals age. Though CAC is a robust predictor of both ASCVD and cancer-related mortality in old age, CAC in young adults confers a stepwise higher risk uniquely for incident ASCVD mortality, and not for non-ASCVD causes. New tools are available to assist in interpretation of CAC in the young, and for estimating the ideal age to initiate CAC scoring.

SUMMARY

The identification of premature CAC is important because it suggests that calcific plaque can be detected with modern imaging earlier in the natural history than previously thought. Taken together, these findings underline a utility of selective use of CAC scoring on non-contrast computed tomography among at-risk young adults to facilitate timely lifestyle modification and pharmacotherapies for the prevention of later life ASCVD.

Transient left bundle branch block associated with very high coronary artery calcium: a case report

Coronary artery calcium (CAC) is the measure of subclinical coronary artery atherosclerosis most strongly associated with atherosclerotic cardiovascular disease (ASCVD) risk. However, CAC is rarely reported in the inpatient setting to guide chest pain management. We present a case of very high CAC in a 64-year-old woman with hypertension, type 2 diabetes, and hyperlipidemia presenting with dyspnea. Initial electrocardiogram (ECG) demonstrated normal conduction with a heart rate of 76 beats/min, but new T-wave inversions in V1-V4 and a high-sensitivity troponin-I (hsTnI) value of 6 ng/L (normal < 6 ng/L). Repeat ECG in the emergency department showed normal sinus rhythm (heart rate of 80 beats/min); however, it subsequently demonstrated a left bundle branch block (LBBB) with a repeat hsTnI of 7 ng/L. Stress testing with pharmacologic single-photon emission computerized tomography did not show scintigraphic evidence of ischemia but noted extensive CAC and a concern for balanced ischemia. Subsequent coronary computed tomography angiography (CCTA) showed nonobstructive disease and a total Agatston CAC score of 1262. Invasive evaluation with left heart catheterization was deferred given the patient's unchanged symptoms and CCTA findings. Statin therapy was intensified and aspirin, metoprolol succinate, and antihypertension therapies were continued. Initiation of glucose-lowering therapy and lipoprotein(a) testing was strongly recommended on follow-up. Our case suggests that CAC ⩾ 1000 may be incidentally associated with transient LBBB during the workup of coronary artery disease. Here, we specifically show that functional testing that incorporates measurement of CAC burden can help to improve ASCVD-preventive pharmacotherapy initiation and intensification beyond the identification of obstructive disease alone.

Evolving Role of Calcium Density in Coronary Artery Calcium Scoring and Atherosclerotic Cardiovascular Disease Risk

Coronary artery calcium (CAC) is a specific marker of coronary atherosclerosis that can be used to measure calcified subclinical atherosclerotic burden. The Agatston method is the most widely used scoring algorithm for quantifying CAC and is expressed as the product of total calcium area and a quantized peak calcium density weighting factor defined by the calcification attenuation in HU on noncontrast computed tomography. Calcium density has emerged as an important area of inquiry because the Agatston score is upweighted based on the assumption that peak calcium density and atherosclerotic cardiovascular disease (ASCVD) risk are positively correlated. However, recent evidence demonstrates that calcium density is inversely associated with lesion vulnerability and ASCVD risk in population-based cohorts when accounting for age and plaque area. Here, we review calcium density by focusing on 3 main areas: 1) CAC scan acquisition parameters; 2) pathophysiology of calcified plaques; and 3) epidemiologic evidence relating calcium density to ASCVD outcomes. Through this process, we hope to provide further insight into the evolution of CAC scoring on noncontrast computed tomography.

Statin therapy for the primary prevention of cardiovascular disease: Pros

The initiation of statins for the primary prevention of atherosclerotic cardiovascular disease (ASCVD) remains a debated subject, despite decades worth of clinical trial data demonstrating efficacy, effectiveness, and safety. Statin therapy, in addition to blood pressure-lowering drugs and efforts to reduce cigarette smoking, was a key component of the preventive cardiology renaissance that achieved a dramatic reduction in ASCVD-related mortality from the 1950s to 2010. However, deaths attributable to ASCVD have increased by approximately 13% in recent years, which are in part driven by incomplete treatment of risk factor burden starting in youth. Statins are a cornerstone of preventive cardiology practice, not only due to their lipid-lowering properties, but also in part due to their ability to exert pleiotropic effects that promote atherosclerotic plaque stability which reduces the likelihood of atherothrombotic clinical events. While the benefit of statin therapy undoubtedly depends on the presence and degree of atherosclerotic plaque burden, a broader statin allocation strategy on a population-based level should be considered especially in younger communities that are disproportionately affected by ASCVD risk factors. Thus, the era of precision medicine must be balanced with a pragmatic, cost-effective approach that maximizes ASCVD prevention across the life course. Herein, we examine the pros of statin pharmacotherapy in primary prevention while examining over three decades worth of basic science, translational, and clinical research in the setting of clinical practice guidelines.