Purpose of review

The purpose is to review the use of coronary computed tomography (CT) angiography to assess coronary plaque burden/progression and to discuss about recent clinical trials that have utilized this imaging modality to study the effect of new pharmacotherapies on plaque burden/progression.

Recent findings

There are numerous clinical trials that have utilized coronary CT angiography to demonstrate the potential benefits of statins, apixaban, rivaroxaban, aged garlic extract, biologic agents, and omega-3 fatty acids to reduce coronary plaque progression. Coronary CT angiography can identify high-risk plaques and can also quantify total plaque burden, both of which are independent risk factors to predict major adverse cardiac events.

Summary

Coronary heart disease remains one of the leading cause of mortality in the world. Utilizing coronary CT angiography, it is possible to identify rupture-prone plaques and also to quantify the total plaque burden. New pharmacotherapies that have the potential to reduce plaque progression have been used in clinical trials and these trials have utilized coronary CT angiography to track coronary atheroma progression. In future, we will see frequent utilization of coronary CT angiography to track coronary atheroma.

The results of the ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approach) trial were presented at the American Heart Association Scientific Sessions in November, 2019 in Philadelphia, Pennsylvania, and recently published on March 30, 2020 in the New England Journal of Medicine. After an average follow-up of 3.5 years, invasive therapy did not reduce the major adverse cardiac event (MACE) rate compared with optimal medical therapy (OMT) in patients with stable ischemic heart disease. However, the ISCHEMIA trial results might stem from the revascularization of inappropriate vessels and from the lack of a lesion-specific ischemia detection algorithm to guide revascularization instead of conventional stress testing. The utilization of an initial computed tomography (CT) angiogram with or without fractional flow reserve CT could have produced better revascularization results.

Cardiovascular disease (CVD) is the leading cause of death worldwide, and accounts for over 30% of annual global fatality. Coronary artery calcium (CAC) screening, a highly distinct marker of coronary atherosclerosis, serves as an important arbitrator of atherosclerotic cardiovascular disease (ASCVD). Particularly in asymptomatic individuals, CAC testing offers a model for initiating or prolonging preventative statin therapies and subsequently up- or down-risking of patients. Though recent 2018 ACC/AHA Guidelines on Blood Cholesterol recommend CAC as an arbitrator of statin use, it remains uncertain whether these recommendations have been universally followed. Thus, we present a thorough discussion about CAC as an important determinator of ASCVD risk. In this regard we highlight the key points behind coronary artery calcium scoring, as a critical platform for stratifying risk and guiding future preventative treatments. This review paper supplies a background for the 2018 Cholesterol Guidelines: the rationalization behind CAC as a crucial arbitrator of cardiovascular risk. This paper will first (1) outline the role of CAC in reclassifying ASCVD risk. Next, it will (2) discuss studies that illustrate CAC's markedly novel reduction in the number needed to treat (NNT) to ameliorate one major cardiac event. Being years removed from 2018 Guidelines provides this paper the lens to (3) elucidate upcoming value-based advantages, cost effectiveness, and patient adherence brought by CAC. Last, this paper will also (4) extend the utility of CAC beyond that of the general population, and (5) discuss pertinent limitations brought by CAC score. By summarizing the framework behind recent cholesterol guidelines for ASCVD risk assessment, this review will address the debate of use of CAC for both the clinical setting and preventative therapy applications.

Coronary computed tomography angiography has emerged as an important diagnostic modality for evaluation of acute chest pain in the emergency department for patients at low to intermediate risk for acute coronary syndromes. Several clinical trials have shown excellent negative predictive value of coronary computed tomography angiography to detect obstructive coronary artery disease. Cardiac biomarkers such as troponins and creatine kinase MB, along with history, electrocardiogram, age, risk factors, troponin score, and Thrombolysis in Myocardial Infarction score should be used in conjunction with coronary computed tomography angiography for safe and rapid discharge of patients from the emergency department. Coronary computed tomography angiography along with high-sensitivity troponin assays could be effective for rapid evaluation of acute chest pain in the emergency department, but high-sensitivity troponins are not always available. Emergency department physicians are not quite comfortable making clinical decisions, especially if the coronary stenosis is in the range of 50% to 70%. In these cases, further evaluation with functional testing, such as nuclear stress testing or stress echocardiogram, is a common approach in many centers; however, newer methods such as fractional flow reserve computed tomography could be safely incorporated in coronary computed tomography angiography to help with clinical decision-making in these scenarios.

Evidence suggests that asymptomatic and mild SARS-CoV-2 infections comprise > 95% of all cases. Developing a test that indicates past infection and possible immunity against the virus is important. We administered 244 antibody tests to three groups of high-risk population. The test consisted of an IgG component and an IgM component. The overall IgM/IgG positivity for patients with none, mild, moderate, and severe symptoms were 21.1%, 21.8%, 14.2%, and 26.9%, respectively. Those with moderate or severe symptoms were no more or less likely to have positive antibody tests than those with no or mild symptoms.

Background

Blue zones are longevity hotspots around the world characterized by highest concentrations of healthy centenarians. Certified blue zone communities are designed by implementation of environmental and policy changes that promote healthy behaviors.

Objective

To examine the trends of prevalence of zero CAC, a marker of ideal cardiovascular and overall health status and burden of cardiovascular risk factors in Beach Cities/certified blue zones of Southern California and rest of California.

Methods

This is a population-based cohort study of persons aged 50 years or older in California, who underwent CAC screening between 2000 and 2019. A total of 3864 participants from Beach Cities of Southern California were identified by Zip Codes and compared with 35,537 participants from rest of California. We compared trends of prevalence of zero CAC and cardiovascular risk factors between the two groups, in 5-year intervals.

Results

Among 39,401 participants (mean age, 58.1 years; 36% women), 13,374 (34%) had zero CAC. The prevalence of CAC ​= ​0 was significantly higher in Beach Cities compared to the rest of California (p ​< ​0.001). Across the study period, the prevalence of cardiac risk factors including obesity, smoking, diabetes and hypertension remain significantly lower in Beach Cities. (p ​< ​0.001).

Conclusions

This study, shows for the first time, that higher prevalence of zero CAC in Beach Cities of California, adds validity to excellent prognosis and longevity in these areas. The impact of policy implementation and environmental changes on lifestyle patterns, cardiovascular health and healthy ageing needs to be evaluated.

Background and aims

Previously, osteoporosis and coronary artery disease were considered unrelated. However, beyond age, these two conditions appear to share common etiologies that are not yet fully understood. We examined the relationship between thoracic spine bone mineral density (BMD) and severity of coronary artery calcium (CAC) score.

Methods and results

MESA is a prospective cohort study of 6814 men and women between the ages of 45 and 84 years, without clinical cardiovascular disease. This study included participants who underwent non-contrast chest CT scans to determine CAC score and thoracic spine BMD. The thoracic spine BMD was categorized into osteoporosis (defined as T score: ≤ -2.5), osteopenia (T-score between: -2.5 and -1) and normal BMD (T-score ≥ -1). There were 3392 subjects who had CAC >0 at baseline. The prevalence of CAC >0 was 36% in normal BMD group, 49% in the osteopenia and 68% in osteoporosis group. After adjusting for risk factors of atherosclerosis, in multivariate regression models we found a significant association between CAC and osteoporosis (OR: 1.40, 95% CI 1.16-1.69, p value < 0.0004). Furthermore, we stratified our results by gender and found a statistically significant association in both men and women.

Conclusion

Results from this cross-sectional analysis of a large population based ethnically diverse cohort indicate a significant inverse relationship between thoracic BMD and CAC in both genders independent of other cardiovascular risk factors. Future studies need to explore the underlying pathophysiological mechanisms relating BMD and coronary artery calcification.

Background

Aortic arch calcium (AAC), which is frequently detected on ungated lung computed tomography (CT) due to a large field of view, can serve as a marker of subclinical atherosclerotic burden. Our study sought to validate novel cardiac screening metrics of subclinical atherosclerosis by evaluating the inter- and intra-observer reproducibility of AAC measurements with ungated lung CT.

Methods

The authors randomly selected 100 ungated lung CT scans from the Multi-Ethnic Study of Atherosclerosis cohort. A Bland-Altman plot analysis was used to test inter- and intra-reader reproducibility, after measuring the total arch calcium score and arch calcium volume.

Results

The intra-reader reproducibility for the total arch calcium score and arch calcium volume in all subjects was excellent at 99% and 97%, respectively. The inter-reader reproducibility for the total arch calcium score and volume in all subjects was similarly excellent at 97% and 96%, respectively.

Conclusions

The high reproducibility of ungated lung CT suggests a potential new method of stratifying the atherosclerotic cardiovascular disease risk among patients undergoing lung CT without requiring additional scanning. This methodology helps promote routine reporting of AAC and coronary artery calcium based on millions of ungated CT images acquired for lung screening purposes.