Relationship of subclinical coronary atherosclerosis and National Cholesterol Education Panel guidelines in asymptomatic Brazilian men

Increased statin eligibility based on ACC/AHA versus NCEP guidelines for high cholesterol management in Chile

BACKGROUND

In 2013, the American College of Cardiology and the American Heart Association (ACC/AHA) jointly released new guidelines for cardiovascular risk assessment and cholesterol management that substantially modified the previous recommendations proposed by the National Cholesterol Education Program (NCEP) in 2001. The relative impact of these new guidelines on potential statin use has not been estimated in Latin American populations.

OBJECTIVE

To estimate and compare eligibility for statin therapy based on ACC/AHA and NCEP guidelines in adult Chilean population.

METHODS

Using data from the last National Health Survey (2009-2010 NHS), we conducted a cross-sectional analysis in a ​representative sample of the Chilean adult population and calculated the proportion of individuals that would receive statins under each set of guidelines.

RESULTS

According to ACC/AHA guidelines, the population eligible for statin treatment increased from 21.7% (NCEP guidelines) to 33.2% (overall 53% increase). This effect was more pronounced among women (29.6% under ACC/AHA vs 15.6% under NCEP) and with those of advanced age (75% of the subjects >60 years of age compared with 46% under NCEP). The newly eligible group included more women and older subjects and individuals with lower LDL cholesterol levels.

CONCLUSION

Compared with NCEP recommendations, the new ACC/AHA guidelines significantly increased the number of Chilean adults eligible for statin therapy. Full implementation of the new recommendations may have important public health implications in Chile and other Latin American countries, as more women and older subjects without cardiovascular disease would qualify for statin treatment.

Interplay of coronary artery calcification and traditional risk factors for the prediction of all-cause mortality in asymptomatic individuals

BACKGROUND

Current guidelines recommend the use of coronary artery calcium (CAC) scoring for intermediate-risk patients; however, the potential role of CAC among individuals who have no risk factors (RFs) is less established. We sought to examine the relationship between the presence and burden of traditional RFs and CAC for the prediction of all-cause mortality.

METHODS AND RESULTS

The study cohort consisted of 44,052 consecutive asymptomatic individuals free of known coronary heart disease referred for computed tomography for the assessment of CAC. The following RFs were considered: (1) current cigarette smoking, (2) dyslipidemia, (3) diabetes mellitus, (4) hypertension, and (5) family history of coronary heart disease. Patients were followed for a mean of 5.6 ± 2.6 years for the primary end point of all-cause mortality. Among individuals who had no RF, Cox proportional model adjusted for age and sex identified that increasing CAC scores were associated with 3.00- to 13.38-fold higher mortality risk. The lowest survival rate was observed in those with no CAC and no RF, whereas those with CAC ≥ 400 and ≥3 RFs had the highest all-cause fatality rate. Notably, individuals with no RF and CAC ≥ 400 had a substantially higher mortality rate compared with individuals with ≥3 RFs in the absence of CAC (16.89 versus 2.72 per 1000 person-years).

CONCLUSIONS

By highlighting that individuals without RFs but elevated CAC have a substantially higher event rates than those who have multiple RFs but no CAC, these findings challenge the exclusive use of traditional risk assessment algorithms for guiding the intensity of primary prevention therapies.

Vascular preventive measures: the progression from asymptomatic to symptomatic atherosclerosis management. Evidence on usefulness of early diagnosis in women and children

This review reports our experience in evaluating the progression from asymptomatic to symptomatic atherosclerosis in an evidence-based context. In particular, studies published in the last 5 years were analyzed in more detail and their relevance to cardiovascular prevention in women and children is discussed. The evaluation of carotid artery intima-media thickness by ultrasonography and the measurement of coronary artery calcification using computed tomography scanning can provide evidence for the presence and extent of atherosclerosis in adults. Intima-media thickness was demonstrated to predict prognosis and help in clinical decision making. Computed tomography estimates of advanced coronary atherosclerosis are markers of advanced atherosclerosis and are of value for screening adult men, but their value in women and children is doubtful owing to radiation risk. Intima-media thickness measurement, even when acknowledging its limitations, is a preferred approach, with the promising perspective of the availability of portable devices of lower cost in the near future. Further evaluation of the potential role for the emerging biomarkers and imaging techniques could clarify the clinical relevance of emerging risk profiles such as the metabolic syndrome. Ultrasound methods provide information regarding the extent and progression of early atherosclerotic abnormalities in women and in children and predict cardiovascular prognosis.

Increased subcutaneous fat accumulation has a protective role against subclinical atherosclerosis in asymptomatic subjects undergoing general health screening

PURPOSE

To evaluate the clinical role of subcutaneous fat accumulation in subclinical arteriosclerosis, using computed tomography (CT), we measured the subcutaneous fat area (SFA), the visceral fat area (VFA) and the VFA/SFA ratio and compared these with the calcium score of the whole aorta (CSWA) in asymptomatic subjects who were undergoing general health screening.

METHODS

122 consecutive asymptomatic subjects (40 female, mean age 56.2+/-8.4 years) were analyzed. Whole-body low-dose CT scan (mAs=50, slice thickness=5 mm) was performed. The SFA and VFA were measured at the umbilical level. Calcification of whole aorta was defined as an area with >90 HU and 1 mm(2), and CSWA was calculated using the modified Agatston method.

RESULTS

Mean+/-SD of SFA, VFA and log CSWA were 158+/-67.1 cm(2), 94.0+/-44.8 cm(2), and 7.93+/-1.08, respectively. SFA was significantly and inversely correlated with log CSWA (r=-0.219, P=0.015) but VFA was not (r=0.105, P=0.250) and as a result, the VFA/SFA ratio was significantly and positively correlated with log CSWA (r=0.221, P=0.015). Subsequently, all predictor variables were used in a stepwise multiple regression model with log CSWA as dependent variable, and age, SFA and fasting plasma glucose significantly influenced log CSWA (P<0.001) by the multiple regression formula Y=0.046X1***-0.005X2**+0.015X3*+4.426, (***P<0.001, **P<0.01, and *P<0.05) where Y=log CSWA, X1=age, X2=SFA, and X3=fasting plasma glucose).

CONCLUSIONS

SFA was significantly and inversely associated with log CSWA, in an independent fashion. These results suggest that subcutaneous fat accumulation might have a protective role against atherosclerosis in asymptomatic subjects.

Psychological stress, insulin resistance, inflammation and the assessment of heart disease risk. Time for a paradigm shift?

There is growing evidence that the present risk assessment protocol for coronary heart disease appears to underestimate the risk in general and the presence and progression of atherosclerosis in particular. Little or no correlation has been found between the 10-year risk based on the Framingham model and the extent or progression of coronary calcification. In addition, a number of studies find the protocol based on current guidelines leads to an under appreciation of the risk of symptomatic coronary heart disease or the associated fatal and non-fatal events, especially in younger asymptomatic individuals and women. Furthermore, the current guidelines give secondary importance to insulin resistance and inflammation and do not include psychosocial stress and depression, both of which are established and important risk factors for coronary heart disease. An alternative approach to risk assessment is proposed which emphasizes insulin resistance and psychological stress and depression and gives much greater recognition to inflammation as a root cause and target for intervention than is found in current guidelines. Consistent with this view, a revised assessment protocol is suggested which is still appropriate to the primary care setting and which might provide a different and perhaps more effective and relevant approach to primary prevention and risk reduction.

The differential associations between HDL, non-HDL and total cholesterols and atherosclerotic calcium deposits in multiple vascular beds

BACKGROUND

The purpose of this study was to determine the magnitude of associations between four different cholesterol measures and systemic atherosclerotic calcification.

METHODS

One thousand and seventy-eight consecutive patients were evaluated by electron beam computed tomography for the extent of calcified atherosclerosis in the carotids, coronaries, thoracic aorta, abdominal aorta, renals and iliacs, as well as the mitral and aortic annuli. HDL, non-HDL and total cholesterol were measured using the Cholestec LDX system.

RESULTS

Overall, the prevalence of calcium in the carotids, coronaries, thoracic aorta, abdominal aorta, iliacs, renals, mitral annulus and aortic annulus was 31.6, 58.7, 40.5, 55.0, 16.8, 57.0, 8.3 and 23.6%, respectively. After multivariable adjustment, a 1-S.D. interval in the total to HDL cholesterol ratio in men was significantly associated with 36 and 29% higher odds for any calcium in the abdominal aorta and iliac arteries, respectively. In women, this same interval was significantly associated with odds ratios of 1.66 and 1.41 for the presence of any calcium in the thoracic and abdominal aorta, respectively.

CONCLUSION

Measurement of HDL and non-HDL cholesterols, as well as calculation of the total cholesterol to HDL ratio, may provide a practical means for stratifying the risk for extra-coronary calcified atherosclerosis.