The Implication of Coronary Artery Calcium Testing for Cardiovascular Disease Prevention and Diabetes

Over the last two decades coronary artery calcium (CAC) scanning has emerged as a quick, safe, and inexpensive method to detect the presence of coronary atherosclerosis. Data from multiple studies has shown that compared to individuals who do not have any coronary calcifications, those with severe calcifications (i.e., CAC score \u3e300) have a 10-fold increase in their risk of coronary heart disease events and cardiovascular disease. Conversely, those that have a CAC of 0 have a very low event rate (~0.1%/year), with data that now extends to 15 years in some studies. Thus, the most notable implication of identifying CAC in individuals who do not have known cardiovascular disease is that it allows targeting of more aggressive therapies to those who have the highest risk of having future events. Such identification of risk is especially important for individuals who are not on any therapies for coronary heart disease, or when intensification of treatment is being considered but has an uncertain role. This review will highlight some of the recent data on CAC testing, while focusing on the implications of those findings on patient management. The evolving role of CAC in patients with diabetes will also be highlighted

Cost-effectiveness of coronary artery calcium testing for coronary heart and cardiovascular disease risk prediction to guide statin allocation: the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND: The Multi-Ethnic Study of Atherosclerosis (MESA) showed that the addition of coronary artery calcium (CAC) to traditional risk factors improves risk classification, particularly in intermediate risk asymptomatic patients with LDL cholesterol levels /dL. However, the cost-effectiveness of incorporating CAC into treatment decision rules has yet to be clearly delineated.OBJECTIVE: To model the cost-effectiveness of CAC for cardiovascular risk stratification in asymptomatic, intermediate risk patients not taking a statin. Treatment based on CAC was compared to (1) treatment of all intermediate-risk patients, and (2) treatment on the basis of United States guidelines.METHODS: We developed a Markov model of first coronary heart disease (CHD) and cardiovascular disease (CVD) events. We modeled statin treatment in intermediate risk patients with CAC≥1 and CAC≥100, with different intensities of statins based on the CAC score. We compared these CAC-based treatment strategies to a treat all strategy and to treatment according to the Adult Treatment Panel III (ATP III) guidelines. Clinical and economic outcomes were modeled over both five- and ten-year time horizons. Outcomes consisted of CHD and CVD events and Quality-Adjusted Life Years (QALYs). Sensitivity analyses considered the effect of higher event rates, different CAC and statin costs, indirect costs, and re-scanning patients with incidentalomas.RESULTS: We project that it is both cost-saving and more effective to scan intermediate-risk patients for CAC and to treat those with CAC≥1, compared to treatment based on established risk-assessment guidelines. Treating patients with CAC≥100 is also preferred to existing guidelines when we account for statin side effects and the disutility of statin use.CONCLUSION: Compared to the alternatives we assessed, CAC testing is both effective and cost saving as a risk-stratification tool, particularly if there are adverse effects of long-term statin use. CAC may enable providers to better tailor preventive therapy to patients\u27 risks of CVD

Obesity, metabolic syndrome and cardiovascular prognosis: from the Partners coronary computed tomography angiography registry

OBJECTIVE: To investigate the relationship among body mass index (BMI), cardiometabolic risk and coronary artery disease (CAD) among patients undergoing coronary computed tomography angiography (CTA). METHODS: Retrospective cohort study of 1118 patients, who underwent coronary CTA at two centers from September 2004 to October 2011. Coronary CTA were categorized as normal, nonobstructive CAD (\u3c50%), or obstructive CAD (≥50%) in addition to segment involvement (SIS) and stenosis scores. Extensive CAD was defined as SIS \u3e 4. Association of BMI with cardiovascular prognosis was evaluated using multivariable fractional polynomial models. RESULTS: Mean age of the cohort was 57 ± 13 years with median follow-up of 3.2 years. Increasing BMI was associated with MetS (OR 1.28 per 1 kg/m2, p \u3c 0.001) and burden of CAD on a univariable basis, but not after multivariable adjustment. Prognosis demonstrated a J-shaped relationship with BMI. For BMI from 20-39.9 kg/m2, after adjustment for age, gender, and smoking, MetS (HR 2.23, p = 0.009) was more strongly associated with adverse events. CONCLUSIONS: Compared to normal BMI, there was an increased burden of CAD for BMI \u3e 25 kg/m2. Within each BMI category, metabolically unhealthy patients had greater extent of CAD, as measured by CCTA, compared to metabolically healthy patients

Systolic Blood Pressure Response in SPRINT (Systolic Blood Pressure Intervention Trial) and ACCORD (Action to Control Cardiovascular Risk in Diabetes): A Possible Explanation for Discordant Trial Results

BACKGROUND: SPRINT (Systolic Blood Pressure Intervention Trial) and the ACCORD (Action to Control Cardiovascular Risk in Diabetes) blood pressure trial used similar interventions but produced discordant results. We investigated whether differences in systolic blood pressure (SBP) response contributed to the discordant trial results. METHODS AND RESULTS: We evaluated the distributions of SBP response during the first year for the intensive and standard treatment groups of SPRINT and ACCORD using growth mixture models. We assessed whether significant differences existed between trials in the distributions of SBP achieved at 1 year and the treatment-independent relationships of achieved SBP with risks of primary outcomes defined in each trial, heart failure, stroke, and all-cause death. We examined whether visit-to-visit variability was associated with heterogeneous treatment effects. Among the included 9027 SPRINT and 4575 ACCORD participants, the difference in mean SBP achieved between treatment groups was 15.7 mm Hg in SPRINT and 14.2 mm Hg in ACCORD, but SPRINT had significantly less between-group overlap in the achieved SBP (standard deviations of intensive and standard groups, respectively: 6.7 and 5.9 mm Hg in SPRINT versus 8.8 and 8.2 mm Hg in ACCORD; P\u3c0.001). The relationship between achieved SBP and outcomes was consistent across trials except for stroke and all-cause death. Higher visit-to-visit variability was more common in SPRINT but without treatment-effect heterogeneity. CONCLUSIONS: SPRINT and ACCORD had different degrees of separation in achieved SBP between treatment groups, even as they had similar mean differences. The greater between-group overlap of achieved SBP may have contributed to the discordant trial results

Comparison of Prevalence, Awareness, Treatment, and Control of Cardiovascular Risk Factors in China and the United States

BACKGROUND: The reasons for China\u27s high stroke prevalence are not well understood. The cardiovascular risk factor profiles of China and the United States have not been directly compared in nationally representative population samples. METHODS AND RESULTS: Using data from the CHARLS (China Health and Retirement Longitudinal Study) and the NHANES (US National Health and Nutrition Examination Survey), we compared cardiovascular risk factors from 2011 to 2012 among people aged 45 to 75 years between the 2 countries (China, 12 654 people; United States, 2607 people): blood pressure, cholesterol, body mass index, waist circumference, fasting plasma glucose, hemoglobin A1c, and high-sensitivity C-reactive protein. Compared with the United States, China had a lower prevalence of hypertension but a higher mean blood pressure and a higher proportion of patients with severe hypertension (≥160/100 mm Hg) (10.5% versus 4.5%). China had substantially lower rates of hypertension treatment (46.8% versus 77.9%) and control (20.3% versus 54.7%). Dyslipidemia was less common in China, but lipid levels were not significantly different because dyslipidemia awareness and control rates in China were 3- and 7-fold lower than US rates, respectively. High-sensitivity C-reactive protein, body mass index, and waist circumference were significantly lower in China than in the United States. Clustering of hypertension with other cardiovascular risk factors was more common in China. CONCLUSIONS: Hypertension is more common in the United States, but blood pressure levels are higher in China, which may be responsible for China\u27s high stroke prevalence. The low rates of awareness, treatment, and control of hypertension provide an exceptional opportunity for China to reduce risk in its population

Statin Eligibility, Coronary Artery Calcium, and Subsequent Cardiovascular Events According to the 2016 United States Preventive Services Task Force (USPSTF) Statin Guidelines: MESA (Multi-Ethnic Study of Atherosclerosis)

BACKGROUND: The potential impact of the 2016 United States Preventive Services Task Force (USPSTF) guidelines on statins for primary prevention of atherosclerotic cardiovascular disease (ASCVD) warrants further analysis. METHODS AND RESULTS: We studied participants from MESA (Multi-Ethnic Study of Atherosclerosis) aged 40 to 75 years and not on statins. We compared statin eligibility at baseline (2000-2002) and over follow-up between USPSTF and the 2013 American College of Cardiology/American Heart Association (ACC/AHA) guidelines. Coronary artery calcium (CAC) was measured at baseline. Absolute ASCVD event rates were calculated according to eligibility categories for each guideline. Among 4962 MESA participants (aged 59.3±8.8 years, 47.2% female), compared with ACC/AHA guidelines, baseline statin eligibility by USPSTF was significantly lower (34.4% versus 49.1%) and increased less over time (39.1% versus 59.1%) at examination 5 [years 2010-2012]). Compared with ACC/AHA, participants eligible by USPSTF were less likely to have zero CAC at baseline (36.6% versus 41.2%) and had higher rates of hard ASCVD events per 1000 person-years (11.6 [95% confidence interval, 10.2-13.3] versus 10.0 [8.9-11.3]). The hard ASCVD event rate in those eligible by ACC/AHA but not USPSTF was 6.5 (4.9-8.5) events per 1000 person-years, with the rate varying significantly according to baseline CAC (4.2 [2.7-6.7] events in those with CAC=0, 12.8 [8.3-19.9] events in those with CAC \u3e100). CONCLUSIONS: In MESA, compared with ACC/AHA, the USPSTF statin guidelines resulted in a 15% absolute decrease in eligibility. Participants with discordant eligibility had ASCVD rates that varied significantly according to baseline CAC, suggesting CAC could aid clinical decision making for statins in these individuals