Objectives

This study examines whether the coronary artery calcium (CAC) score can be used to define the target population to treat with a polypill.

Background

Prior studies have suggested a single polypill to reduce cardiovascular disease (CVD) at the population level.

Methods

Participants from MESA (Multi-Ethnic Study of Atherosclerosis) were stratified using the criteria of 4 polypill studies (TIPS [The Indian Polycap Study], Poly-Iran, Wald, and the PILL [Program to Improve Life and Longevity] Collaboration). We compared coronary heart disease (CHD) and CVD event rates and calculated the 5-year number needed to treat (NNT) after stratification based on the CAC score.

Results

Among MESA participants eligible for TIPS, Poly-Iran, Wald, and the PILL Collaboration, CAC = 0 was observed in 58.6%, 54.5%, 38.9%, and 40.8%, respectively. The rate of CHD events among those with CAC = 0 varied from 1.2 to 1.9 events per 1,000 person-years, those with CAC scores from 1 to 100 had event rates ranging from 4.1 to 5.5, and in those with CAC scores >100 the event rate ranged from 11.6 to 13.3. The estimated 5-year NNT to prevent 1 CVD event ranged from 81-130 for patients with CAC = 0, 38-54 for those with CAC scores from 1 to 100, and 18-20 for those with CAC scores >100.

Conclusions

In MESA, among individuals eligible for treatment with the polypill, the majority of CHD and CVD events occurred in those with CAC scores >100. The group with CAC = 0 had a very low event rate and a high projected NNT. The avoidance of treatment in individuals with CAC = 0 could allow for significant reductions in the population considered for treatment, with a more selective use of the polypill and, as a result, avoidance of treatment in those who are unlikely to benefit.

Aims

The European Society of Cardiology (ESC) guideline on cardiovascular risk assessment considers coronary artery calcium a class B indication for risk assessment. We evaluated the degree to which coronary artery calcium can change the recommendation for individuals based on a change in estimated risk.

Methods and results

We stratified 5602 MESA participants according to the ESC recommendation as: no lipid-lowering treatment recommended ( N = 2228), consider lipid-lowering treatment if uncontrolled ( N = 1686), or lipid-lowering treatment recommended ( N = 1688). We evaluated the ability of coronary artery calcium to reclassify cardiovascular risk. Among the selected sample, 54% had coronary artery calcium of zero, 25% had coronary artery calcium of 1-100 and 21% had coronary artery calcium greater than 100. In the lipid-lowering treatment recommended group 31% had coronary artery calcium of zero, while in the lipid-lowering treatment if uncontrolled group about 50% had coronary artery calcium of zero. The cardiovascular mortality rate was 1.7%/10 years in the lipid-lowering treatment if uncontrolled, and 7.0%/10 years in the lipid-lowering treatment recommended group. The absence of coronary artery calcium was associated with 1.4%/10 years in the lipid-lowering treatment if uncontrolled group and 3.0%/10 years in the lipid-lowering treatment recommended group. Compared with coronary artery calcium of zero, any coronary artery calcium was associated with significantly higher cardiovascular mortality in the lipid-lowering treatment recommended group (9.0%/10 years), whereas only coronary artery calcium greater than 100 was significantly associated with a higher cardiovascular mortality in the lipid-lowering treatment if uncontrolled group (3.2%/10 years).

Conclusion

The absence of coronary artery calcium is associated with a low incidence of cardiovascular mortality or coronary heart disease events even in individuals in whom lipid-lowering therapy is recommended. A significant proportion of individuals deemed to be candidates for lipid-lowering therapy might be reclassified to a lower risk group with the use of coronary artery calcium.

Objectives

The aim of this study was to evaluate the impact of coronary artery calcium (CAC) burden and regional distribution on the need for and type of future coronary revascularization-percutaneous versus surgical (coronary artery bypass graft [CABG])-among asymptomatic subjects.

Background

The need for coronary revascularization and the chosen mode of revascularization are thought to be functions of disease burden and anatomic distribution. The association between the baseline burden and regional distribution of CAC and the risk and type of future coronary revascularization remains unknown.

Methods

A total of 6,540 participants in the MESA (Multi-Ethnic Study of Atherosclerosis) (subjects aged 45 to 84 years, free of known baseline cardiovascular disease) with vessel-specific CAC measurements were followed for a median of 8.5 years (interquartile range: 7.7 to 8.6 years). Annualized rates and multivariate-adjusted hazard ratios for revascularization and revascularization type were analyzed according to CAC score category, number of vessels with CAC (0 to 4, including the left main coronary artery), and involvement of individual coronary arteries.

Results

A total of 265 revascularizations (4.2%) occurred during follow-up, and 206 (78% of the total) were preceded by adjudicated symptoms. Revascularization was uncommon when CAC score was 0.0 (0.6%), with a graded increase over both rising CAC burden and increasingly diffuse CAC distribution. The revascularization rates per 1,000 person-years for CAC scores of 1 to 100, 101 to 400, and >400 were 4.9, 11.7, and 25.4, respectively; for 1, 2, 3, and 4 vessels with CAC, the rates were 3.0, 8.0, 16.1, and 24.8, respectively. In multivariate models adjusting for CAC score, the number of vessels with CAC remained predictive of revascularization and mode of revascularization. Independent predictors of CABG versus percutaneous coronary intervention included 3- or 4-vessel CAC, higher CAC burden, and involvement of the left main coronary artery. Risk for CABG was extremely low with <3-vessel baseline CAC. Results were similar when considering only symptom-driven revascularizations.

Conclusions

In this multiethnic cohort of asymptomatic subjects, baseline CAC was highly predictive of future coronary revascularization procedures, with measures of CAC burden and distribution each independently predicting need for percutaneous coronary intervention versus CABG over an 8.5-year follow-up.

Objectives

This study sought to quantify and model conversion of a normal coronary artery calcium (CAC) scan to an abnormal CAC scan.

Background

Although the absence of CAC is associated with excellent prognosis, progression to CAC >0 confers increased risk. The time interval for repeated scanning remains poorly defined.

Methods

This study included 3,116 participants from the MESA (Multi-Ethnic Study of Atherosclerosis) with baseline CAC = 0 and follow-up scans over 10 years after baseline. Prevalence of incident CAC, defined by thresholds of CAC >0, CAC >10, or CAC >100, was calculated and time to progression was derived from a Weibull parametric survival model. Warranty periods were modeled as a function of sex, race/ethnicity, cardiovascular risk, and desired yield of repeated CAC testing. Further analysis was performed of the proportion of coronary events occurring in participants with baseline CAC = 0 that preceded and followed repeated CAC testing at different time intervals.

Results

Mean participants' age was 58 ± 9 years, with 63% women, and mean 10-year cardiovascular risk of 14%. Prevalence of CAC >0, CAC >10, and CAC >100 was 53%, 36%, and 8%, respectively, at 10 years. Using a 25% testing yield (number needed to scan [NNS] = 4), the estimated warranty period of CAC >0 varied from 3 to 7 years depending on sex and race/ethnicity. Approximately 15% of participants progressed to CAC >10 in 5 to 8 years, whereas 10-year progression to CAC >100 was rare. Presence of diabetes was associated with significantly shorter warranty period, whereas family history and smoking had small effects. A total of 19% of all 10-year coronary events occurred in CAC = 0 prior to performance of a subsequent scan at 3 to 5 years, whereas detection of new CAC >0 preceded 55% of future events and identified individuals at 3-fold higher risk of coronary events.

Conclusions

In a large population of individuals with baseline CAC = 0, study data provide a robust estimation of the CAC = 0 warranty period, considering progression to CAC >0, CAC >10, and CAC >100 and its impact on missed versus detectable 10-year coronary heart disease events. Beyond age, sex, race/ethnicity, diabetes also has a significant impact on the warranty period. The study suggests that evidence-based guidance would be to consider rescanning in 3 to 7 years depending on individual demographics and risk profile.

Context

The internet is gaining popularity as a means of delivering employee-based cardiovascular (CV) wellness interventions though little is known about the cardiovascular health outcomes of these programs. In this review, we examined the effectiveness of internet-based employee cardiovascular wellness and prevention programs.

Evidence acquisition

We conducted a systematic review by searching PubMed, Web of Science and Cochrane library for all published studies on internet-based programs aimed at improving CV health among employees up to November 2012. We grouped the outcomes according to the American Heart Association (AHA) indicators of cardiovascular wellbeing--weight, BP, lipids, smoking, physical activity, diet, and blood glucose.

Evidence synthesis

A total of 18 randomized trials and 11 follow-up studies met our inclusion/exclusion criteria. Follow-up duration ranged from 6-24 months. There were significant differences in intervention types and number of components in each intervention. Modest improvements were observed in more than half of the studies with weight related outcomes while no improvement was seen in virtually all the studies with physical activity outcome. In general, internet-based programs were more successful if the interventions also included some physical contact and environmental modification, and if they were targeted at specific disease entities such as hypertension. Only a few of the studies were conducted in persons at-risk for CVD, none in blue-collar workers or low-income earners.

Conclusion

Internet based programs hold promise for improving the cardiovascular wellness among employees however much work is required to fully understand its utility and long term impact especially in special/at-risk populations.