Coronary Artery Calcium Versus Pooled Cohort Equations Score for Primary Prevention Guidance: Randomized Feasibility Trial

Will DANCAVAS be the most important screening trial in the last 50 years?

Screening trials for cardiovascular disease have not demonstrated a reduction in all-cause mortality. The Danish Cardiovascular Screening trial (DANCAVAS) involved men aged 65-74 years old who were randomized to an invitation to undergo screening or not. While the 5-year interim analysis did not show a statistically significant benefit in the primary outcome of all-cause mortality, HR 0.95 (CI 0.90-1.00), a sub-group analysis of men age 65-69 did show a lower hazard ratio of 0.89 (CI 0.83-0.96). Given the widening difference between screened and un-screened participants, as well as the benefit in younger subjects, it is likely that the next analysis will demonstrate a statistically-significant benefit of screening. In this commentary we argue why this trial will almost certainly become one of the most influential screening trials and why heeding its most important lesson, the use of coronary artery calcium scoring, has the potential to save countless lives.

Rationale and Design of SCOT-HEART 2 Trial: CT Angiography for the Prevention of Myocardial Infarction

Coronary artery disease continues to be the leading cause of death globally. Identifying patients who are at risk of coronary artery disease remains a public health priority. At present, the focus of cardiovascular disease prevention relies heavily on probabilistic risk scoring despite no randomized controlled trials demonstrating their efficacy. The concept of using imaging to guide preventative therapy is not new, but has previously focused on indirect measures such as carotid intima-media thickening or coronary artery calcification. In recent trials, patients found to have coronary artery disease on computed tomography (CT) coronary angiography were more likely to be started on preventative therapy and had lower rates of cardiac events. This led to the design of the SCOT-HEART 2 (Scottish Computed Tomography of the Heart 2) trial, which aims to determine whether screening with the use of CT coronary angiography is more clinically effective than cardiovascular risk scoring to guide the use of primary preventative therapies and reduce the risk of myocardial infarction.

Framework of the strengths and challenges of clinically integrated trials: An expert panel report

The limitations of the explanatory clinical trial framework include the high expense of implementing explanatory trials, restrictive entry criteria for participants, and redundant logistical processes. These limitations can result in slow evidence generation that is not responsive to population health needs, yielding evidence that is not generalizable. Clinically integrated trials, which integrate clinical research into routine care, represent a potential solution to this challenge and an opportunity to support learning health systems. The operational and design features of clinically integrated trials include a focused scope, simplicity in design and requirements, the leveraging of existing data structures, and patient participation in the entire trial process. These features are designed to minimize barriers to participation and trial execution and reduce additional research burdens for participants and clinicians alike. Broad adoption and scalability of clinically integrated trials are dependent, in part, on continuing regulatory, healthcare system, and payer support. This analysis presents a framework of the strengths and challenges of clinically integrated trials and is based on a multidisciplinary expert "Think Tank" panel discussion that included representatives from patient populations, academia, non-profit funding agencies, the U.S. Food and Drug Administration, and industry.

Current and Emerging Approaches for Primary Prevention of Coronary Artery Disease Using Cardiac Computed Tomography

PURPOSE OF REVIEW

To summarize the current use of cardiac computed tomography (CT) technologies as well as their pertinent evidence in regards to prevention of coronary artery disease (CAD).

RECENT FINDINGS

Cardiac CTA has now become a main non-invasive method for the evaluation of symptomatic CAD. In addition to coronary calcium score, other CT technologies such as atherosclerotic plaque analysis, fractional flow reserve estimation by CT, pericoronary fat attenuation, and endothelial wall shear stress have emerged. Whether the use of CT modalities can enhance risk prediction and prevention in CAD has not been fully answered. We discuss the evidence for coronary artery calcium scoring and coronary CT angiography in primary prevention and the current barriers to their use. We attempt to delineate what can be done to expand use and what studies are needed to broaden adoption in the future. We also examine the potential roles of emerging CT technologies. Finally, we describe potential clinical approaches to prevention that would incorporate cardiac CT technologies.

Thoracic versus coronary calcification for atherosclerotic cardiovascular disease events prediction

This study compared the prognostic value of quantified thoracic artery calcium (TAC) including aortic arch on chest CT and coronary artery calcium (CAC) score on ECG-gated cardiac CT.

METHODS

A total of 2412 participants who underwent both chest CT and ECG-gated cardiac CT at the same period were included in the Multi-Ethnic Study of Atherosclerosis Exam 5. All participants were monitored for incident atherosclerotic cardiovascular disease (ASCVD) events. TAC is defined as calcification in the ascending aorta, aortic arch and descending aorta on chest CT. The quantification of TAC was measured using the Agatston method. Time-dependent receiver-operating characteristic (ROC) curves were used to compare the prognostic value of TAC and CAC scores.

RESULTS

Participants were 69±9 years of age and 47% were male. The Spearman correlation between TAC and CAC scores was 0.46 (p<0.001). During the median follow-up period of 8.8 years, 234 participants (9.7%) experienced ASCVD events. In multivariable Cox regression analysis, TAC score was independently associated with increased risk of ASCVD events (HR 1.31, 95% CI 1.09 to 1.58) as well as CAC score (HR 1.82, 95% CI 1.53 to 2.17). However, the area under the time-dependent ROC curve for CAC score was greater than that for TAC score in all participants (0.698 and 0.641, p=0.031). This was particularly pronounced in participants with borderline/intermediate and high 10-year ASCVD risk scores.

CONCLUSION

Our study demonstrated a significant association between TAC and CAC scores but a superior prognostic value of CAC score for ASCVD events. These findings suggest TAC on chest CT provides supplementary data to estimate ASCVD risk but does not replace CAC on ECG-gated cardiac CT.

Coronary Calcium Is Elevated in Patients with Myocardial Infarction without Standard Modifiable Risk Factors

Objectives: Recent reports have highlighted myocardial infarction (MI) patients without standard modifiable risk factors (SMRF), noting them to be surprisingly common and to have a substantial risk of adverse outcomes. The objective of this study was to address the challenge of identifying at-risk patients without SMRF and providing preventive therapy. Methods: Patients presenting between 2001 and 2021 to Intermountain Health catheterization laboratories with a diagnosis of MI were included if they also had a coronary artery calcium (CAC) scan by computed tomography within 2 years. SMRF were defined as a clinical diagnosis or treatment of hypertension, hyperlipidemia, diabetes, or smoking. The co-primary endpoints in SMRF-less patients were: (1) proportion of patients with an elevated (>50%ile) CAC score, and (2) an indication for statin therapy (i.e., CAC ≥ 100 AU or ≥75%ile). The 60-day and long-term major adverse cardiovascular events were determined. A comparison set included MI patients with SMRF. Results: We identified 429 MI patients with a concurrent CAC scan, of which 60 had no SMRF. SMRF status did not distinguish most risk factors or interventions. No-SMRF patients had a high CAC prevalence and percentile (82% ≥ 50%ile; median, 80%ile), and 77% met criteria for preventive therapy. As expected, patients with SMRF had high CAC scores and percentiles. Outcomes were more favorable for No-SMRF status and for lower CAC scores. Conclusions: Patients without SMRF presenting with an MI have a high prevalence and percentile of CAC. Wider application of CAC scans, including in those without SMRF, is promising as a method to identify an additional at-risk population for MI and to provide primary preventive therapy.

Impact of Active vs Passive Statin Selection for Primary Prevention: The CorCal Vanguard Trial

Background

Statins can improve outcomes in high-risk primary prevention populations. However, application in clinical practice has lagged.

Objectives

The objective of this study was to compare an active vs a passive strategy (ie, usual care) to statin prescription for primary prevention of atherosclerotic cardiovascular disease (ASCVD).

Methods

A total of 3,770 patients ≥50 years of age without a history of ASCVD or statin use were invited to enroll in CorCal, with 601 consenting to participate. These patients were randomized 1:1 to statin initiation guided by the pooled cohort equation or by coronary artery calcium scoring (CACS). Outcomes (2.8-year follow-up) compared patients managed actively vs passively (randomly invited but declined or did not respond).

Results

Patient demographics were well matched. Statin recommendation was common among enrolled patients (41.7%). During follow-up, 25.3% of active patients were taking a statin vs 9.8% managed passively (P < 0.0001). Active patients had more lipid panels (median 2.0 vs 1.0), lower low-density lipoprotein cholesterol (109 vs 117 mg/dL) (both P < 0.0001), and a low rate of major adverse cardiovascular events during follow-up (0.6% vs 1.0%, P = 0.47). Statistical comparisons included t-tests, chi-squared tests, nonparametric tests, and time-to-event tests as appropriate.

Conclusions

An active approach to statin selection for primary ASCVD prevention identified a large treatment opportunity and led to over twice as many patients on statins compared to passive (usual care) management. A large CorCal Outcomes Trial is underway to more definitively assess the impact on outcomes of active management of statins for primary prevention.

The Role of Imaging in Preventive Cardiology in Women

PURPOSE OF REVIEW

The prevalence of CVD in women is increasing and is due to the increased prevalence of CV risk factors. Traditional CV risk assessment tools for prevention have failed to accurately determine CVD risk in women. CAC has shown to more precisely determine CV risk and is a better predictor of CV outcomes. Coronary CTA provides an opportunity to determine the presence of CAD and initiate prevention in women presenting with angina. Identifying women with INOCA due to CMD with use of cPET or cMRI with MBFR is vital in managing these patients. This review article outlines the role of imaging in preventive cardiology for women and will include the latest evidence supporting the use of these imaging tests for this purpose.

RECENT FINDINGS

CV mortality is higher in women who have more extensive CAC burden. Women have a greater prevalence of INOCA which is associated with higher MACE. INOCA is due to CMD in most cases which is associated with traditional CVD risk factors. Over half of these women are untreated or undertreated. Recent study showed that stratified medical therapy, tailored to the specific INOCA endotype, is feasible and improves angina in women. Coronary CTA is useful in the setting of women presenting with acute chest pain to identify CAD and initiate preventive therapy. CAC confers greater relative risk for CV mortality in women versus (vs.) men. cMRI or cPET is useful to assess MBFR to diagnose CMD and is another useful imaging tool in women for CV prevention.

Statin therapy for primary prevention in men: What is the role for coronary artery calcium?

Current cholesterol guidelines for primary prevention of atherosclerotic cardiovascular disease (ASCVD) base statin treatment decisions on multiple risk factor algorithms (e.g., Pooled Cohort Equations [PCEs]). By available PCEs, most older middle-aged men are statin eligible. But several studies cast doubt on predictive accuracy of available PCEs for ASCVD risk assessment. Recent studies suggest that accuracy can be improved by measurement of coronary artery calcium (CAC). This method has the advantage of identifying men at low risk in whom statin therapy can be delayed for several years, provided they are monitored periodically for progression of CAC. Thus, there are two approaches to statin therapy in men ≥ 55 years: first all men could be treated routinely, or second, treatment can be based on the extent of coronary calcium. The latter could allow a sizable fraction of men to avoid treatment for several years or indefinitely. Whether with initial CAC scan or with periodic rescanning, a CAC score ≥ 100 Agatston units is high enough to warrant statin therapy. In otherwise high-risk men (e.g., diabetes, severe hypercholesterolemia, 10-year risk by PCE ≥ 20%), a statin is generally indicated without the need for CAC; but in special cases, CAC measurement may aid in treatment decisions.

Eradicating Atherosclerosis: Should We Start Statins at Younger Ages and at Lower LDL-Cs

PURPOSE OF REVIEW

Given the increasing burden of cardiovascular disease, we review the literature for earlier initiation of statin therapy at younger ages and lower low-density lipoprotein cholesterol (LDL-C) levels, with the goal of preventing the development of atherosclerosis prior to clinical events.

RECENT FINDINGS

There is a rising prevalence of dyslipidemia among younger adults. Although guidelines offer recommendations for adults over 40, there is little guidance for the management of younger adults with moderately elevated LDL-C levels. Earlier and more aggressive statin use may slow progression, or even halt atherosclerosis, and may likewise be beneficial and cost-effective on a population level. Further research is needed to define the exact age and LDL-C level at which to start statin therapy. Until then, more detailed risk stratification with lab testing and imaging should be used to identify younger adults at the highest risk.