Cardiac risk stratification: role of the coronary calcium score

Patient-Specific Numerical Simulations of Coronary Artery Hemodynamics and Biomechanics: A Pathway to Clinical Use

PURPOSE

Numerical models that simulate the behaviors of the coronary arteries have been greatly improved by the addition of fluid-structure interaction (FSI) methods. Although computationally demanding, FSI models account for the movement of the arterial wall and more adequately describe the biomechanical conditions at and within the arterial wall. This offers greater physiological relevance over Computational Fluid Dynamics (CFD) models, which assume the walls do not move or deform. Numerical simulations of patient-specific cases have been greatly bolstered by the use of imaging modalities such as Computed Tomography Angiography (CTA), Magnetic Resonance Imaging (MRI), Optical Coherence Tomography (OCT), and Intravascular Ultrasound (IVUS) to reconstruct accurate 2D and 3D representations of artery geometries. The goal of this study was to conduct a comprehensive review on CFD and FSI models on coronary arteries, and evaluate their translational potential.

METHODS

This paper reviewed recent work on patient-specific numerical simulations of coronary arteries that describe the biomechanical conditions associated with atherosclerosis using CFD and FSI models. Imaging modality for geometry collection and clinical applications were also discussed.

RESULTS

Numerical models using CFD and FSI approaches are commonly used to study biomechanics within the vasculature. At high temporal and spatial resolution (compared to most cardiac imaging modalities), these numerical models can generate large amount of biomechanics data.

CONCLUSIONS

Physiologically relevant FSI models can more accurately describe atherosclerosis pathogenesis, and help to translate biomechanical assessment to clinical evaluation.

Feasibility and limitations of deep learning-based coronary calcium scoring in PET-CT: a comparison with coronary calcium score CT

OBJECTIVE

This study aimed to determine the feasibility and limitations of deep learning-based coronary calcium scoring using positron emission tomography-computed tomography (PET-CT) in comparison with coronary calcium scoring using ECG-gated non-contrast-enhanced cardiac computed tomography (CaCT).

MATERIALS AND METHODS

A total of 215 individuals who underwent both CaCT and PET-CT were enrolled in this retrospective study. The Agatston method was used to calculate the coronary artery calcium scores (CACS) from CaCT, PET-CT(reader), and PET-CT(AI) to analyse the effect of using different modalities and AI-based software on CACS measurement. The total CACS and CACS classified according to the CAC-DRS guidelines were compared between the three sets of CACS. The differences, correlation coefficients, intraclass coefficients (ICC), and concordance rates were analysed. Statistical significance was set at p < 0.05.

RESULTS

The correlation coefficient of the total CACS from CaCT and PET-CT(reader) was 0.837, PET-CT(reader) and PET-CT(AI) was 0.894, and CaCT and PET-CT(AI) was 0.768. The ICC of CACS from CaCT and PET-CT(reader) was 0.911, PET-CT(reader) and PET-CT(AI) was 0.958, and CaCT and PET-CT(AI) was 0.842. The concordance rate between CaCT and PET-CT(AI) was 73.8%, with a false-negative rate of 37.3% and a false-positive rate of 4.4%. Age and male sex were associated with an increased misclassification rate.

CONCLUSIONS

Artificial intelligence-assisted CACS measurements in PET-CT showed comparable results to CACS in coronary calcium CT. However, the relatively high false-negative results and tendency to underestimate should be of concern.

CLINICAL RELEVANCE STATEMENT

Application of automated calcium scoring to PET-CT studies could potentially select patients at high risk of coronary artery disease from among cancer patients known to be susceptible to coronary artery disease and undergoing routine PET-CT scans.

KEY POINTS

• Cancer patients are susceptible to coronary disease, and PET-CT could be potentially used to calculate coronary artery calcium score (CACS). • Calcium scoring using artificial intelligence in PET-CT automatically provides CACS with high ICC to CACS in coronary calcium CT. • However, underestimation and false negatives of CACS calculation in PET-CT should be considered.

Coronary Artery Calcium Score directed risk stratification of patients with Type-2 diabetes mellitus

BACKGROUND AND AIMS

This study aimed to review the available data on the role of coronary artery calcium (CAC) scoring as the preferred adjunct modality to improve risk prediction and reduce the incidence of major adverse cardiac events and mortality in T2DM patients.

METHODS

We reviewed the findings of 21 studies.

RESULTS

This study revealed that the CAC scoring system could enhance cardiovascular disease (CVD) risk stratification and positively affect the medical management of patients with T2DM.

CONCLUSION

A CAC scoring approach is necessary to reduce the incidence and prevalence of preventable CVD events in patients with type 2 diabetes.

The Role of Imaging in Health Screening: Screening for Specific Conditions

There are well-established and emerging screening examinations aimed at identifying malignant and nonmalignant conditions at early, treatable stages. The Radiology Research Alliance's "Role of Imaging in Health Screening" Task Force provides a comprehensive review of specific imaging-based screening examinations. This work reviews and serves as a reference for screening examinations for breast and colon cancer in a healthy population along with screening for lung cancer, hepatocellular carcinoma, and the use of whole body magnetic resonance imaging in at-risk individuals. American College of Radiology scoring systems, along with case-based examples, are included to illustrate the different disease entities. The future of screening is discussed, particularly in the context of artificial intelligence.

Genome-wide transcriptome study using deep RNA sequencing for myocardial infarction and coronary artery calcification

BACKGROUND

Coronary artery calcification (CAC) is a noninvasive measure of coronary atherosclerosis, the proximal pathophysiology underlying most cases of myocardial infarction (MI). We sought to identify expression signatures of early MI and subclinical atherosclerosis in the Framingham Heart Study (FHS). In this study, we conducted paired-end RNA sequencing on whole blood collected from 198 FHS participants (55 with a history of early MI, 72 with high CAC without prior MI, and 71 controls free of elevated CAC levels or history of MI). We applied DESeq2 to identify coding-genes and long intergenic noncoding RNAs (lincRNAs) differentially expressed in MI and high CAC, respectively, compared with the control.

RESULTS

On average, 150 million paired-end reads were obtained for each sample. At the false discovery rate (FDR) < 0.1, we found 68 coding genes and 2 lincRNAs that were differentially expressed in early MI versus controls. Among them, 60 coding genes were detectable and thus tested in an independent RNA-Seq data of 807 individuals from the Rotterdam Study, and 8 genes were supported by p value and direction of the effect. Immune response, lipid metabolic process, and interferon regulatory factor were enriched in these 68 genes. By contrast, only 3 coding genes and 1 lincRNA were differentially expressed in high CAC versus controls. APOD, encoding a component of high-density lipoprotein, was significantly downregulated in both early MI (FDR = 0.007) and high CAC (FDR = 0.01) compared with controls.

CONCLUSIONS

We identified transcriptomic signatures of early MI that include differentially expressed protein-coding genes and lincRNAs, suggesting important roles for protein-coding genes and lincRNAs in the pathogenesis of MI.

Genetic Variants and Haplotypes in OPG Gene Are Associated with Premature Coronary Artery Disease and Traditional Cardiovascular Risk Factors in Mexican Population: The GEA Study

Basic and clinical research have demonstrated that osteoprotegerin (OPG) plays an important role in the development and progression of cardiovascular diseases. The aim of this study was to evaluate the association of four polymorphic sites (rs2073618, rs3134069, rs3134070, and rs3102735) of OPG gene with premature coronary artery disease (pCAD), and with cardiometabolic parameters. The polymorphisms were genotyped using 5' exonuclease TaqMan genotyping assays with real-time PCR in 1098 individuals with pCAD and 1041 healthy controls. rs2073618 polymorphism was associated with a high risk of developing pCAD according to different inheritance models: additive (p = 0.001; odds ratio [OR] = 1.283), dominant (p = 0.006; OR = 1.383), recessive (p = 0.011; OR = 1.423), and codominant 2 (p = 0.001; OR = 1.646). The four polymorphisms were associated with different cardiovascular risk factors in individuals with pCAD and controls. Our results suggest that OPG rs2073618 polymorphism is associated with an increased risk of pCAD. In addition, two haplotypes were associated with pCAD, one increasing the risk (CACT) and another one as protective (GACC).

Low Iliofemoral Calcium Score May Predict Higher Survival after EVAR and FEVAR

BACKGROUND

Abdominal aortic aneurysm is associated with an increased mortality, mostly cardiovascular events. Moreover, aortoiliac calcification is associated with increased mortality in patients with peripheral occlusive disease. The aim of this study is to assess the potential association between iliofemoral calcification, assessed by calcium score, in patients undergoing infrarenal (endovascular aneurysm repair [EVAR]) or fenestrated endovascular aortic repair (FEVAR) and long-term mortality, particularly caused by cardiac events.

METHODS

All patients with preoperative noncontrast-enhanced computed tomographic scans who underwent infrarenal EVAR and FEVAR of nonruptured abdominal aortic aneurysm between 2004 and 2012 at a single tertiary center were screened for inclusion. Agatston calcium score was measured from the aortic bifurcation to common femoral arteries using a dedicated postprocessing software. The values are presented as median and interquartile range.

RESULTS

About 404 (62.05%) of 651 patients who underwent EVAR and FEVAR had sufficient imaging quality to be included. There was no difference in survival between included and excluded patients (P = 0.33). Nine patients (2.2%) died within 30 days of the operation, whereas the remaining were followed up for 6.3 (4.7-8.4) years. The iliofemoral calcium score was 8348 (3830-14,179). Estimated overall survival at 5 years was 73 ± 2%. Patients within the lowest quartile of iliofemoral calcium score had significantly higher overall survival (5 years: 79 ± 4% vs. 71 ± 3%; P = 0.01) and cardiac event-free survival (5 years: 95 ± 2% vs. 91 ± 2%; P = 0.033) when compared with the remaining ones. Calcium score was associated with neither univariate regression analysis with survival (odds ratio, 1.016 [0.988-1.045]; P = 0.268) nor cardiac event-free survival (odds ratio, 1.024 [0.986-1.063]; P = 0.222).

CONCLUSIONS

Low iliofemoral calcium score may be associated with lower incidence of fatal cardiac events and all-cause long-term mortality after EVAR and FEVAR. This may be partially a reflection of aging and cardiovascular comorbidity but needs to be studied further.

Vascular Calcification: Current Genetics Underlying This Complex Phenomenon

OBJECTIVE

Vascular calcification is the consequence of the complex interaction between genetic, environmental, and vascular factors, which ultimately lead to the deposition of calcium in the tunica intima (atherosclerotic calcification) or tunica media (Mönckenberg's sclerosis). Vascular calcification is also closely related to other pathologies, such as diabetes mellitus, dyslipidemia, and chronic kidney disease. It has been concluded that the degree of vascular calcification may vary from person to person, even if the associated pathologies and environmental factors are the same. Therefore, this suggests an important genetic contribution to the development of vascular calcification. This review aimed to find the most recent evidence about vascular calcification pathophysiology regarding the genetic aspects and molecular pathways.

DATA SOURCES

We conducted an exhaustive search in Scopus, EBSCO, and PubMed with the keywords "genetics and vascular calcification", "molecular pathways, genetic and vascular calcification" and included the main articles from January 1995 up to August 2016. We focused on the most recent evidence about vascular calcification pathophysiology regarding the genetic aspects and molecular pathways.

STUDY SELECTION

The most valuable published original and review articles related to our objective were selected.

RESULTS

Vascular calcification is a multifactorial disease; thus, its pathophysiology cannot be explained by a single specific factor, rather than by the result of the association of several genetic variants, molecular pathway interactions, and environmental factors that promote its development.

CONCLUSION

Although several molecular aspects of this mechanism have been elucidated, there is still a need for a better understanding of the factors that predispose to this disease.

Comparison of the Coronary Artery Calcium Score and Number of Calcified Coronary Plaques for Predicting Patient Mortality Risk

Multiple coronary artery calcium (CAC) parameters have recently been proposed to improve risk prediction in patients with intermediate clinical risk based on CAC scoring, but outcome data that assess these variables are relatively sparse. We analyzed data from 11,633 consecutive asymptomatic patients undergoing CAC scanning that were followed for 8.8 ± 3.5 years for all-cause mortality (ACM). The patients who had coronary artery calcification were grouped by the number of calcified coronary plaques: 0, 1 to 5, 6 to 20, and >20 plaques. We examined the independent prognostic value of plaque number and its synergistic prognostic value when added to the CAC score. We observed a stepwise increase in ACM with increasing plaque number. In patients with a CAC score of 1 to 99, 6 plaques or more were associated with increased mortality. In patients with CAC scores of 100 to 399, there was a stepwise increase in ACM with increasing plaque number. For CAC >400, the risk of ACM was high regardless of plaque number. After risk adjustment, the number of plaques was a significant predictor of risk for ACM in the patients with an intermediate CAC score. In these patients, additional consideration of plaque number improved net reclassification improvement for predicting ACM by 29%. In conclusion, the number of calcified plaques adds to risk stratification beyond the CAC score in patients with intermediate CAC scores.

The Use of Primary Prevention Statin Therapy in Those Predisposed to Atherosclerosis

PURPOSE OF REVIEW

Many guidelines exist for the use of statins in the primary prevention of atherosclerotic cardiovascular disease (ASCVD). Few have focused on disease specific states that predispose to ASCVD. This review is intended to focus on the recommendations and evidence in inflammatory diseases that predispose to an increased risk of ASCVD beyond what conventional cardiac risk scores would predict.

RECENT FINDINGS

Certain autoimmune inflammatory diseases such as rheumatoid arthritis (RA), systemic lupus erythematous (SLE), and psoriasis/psoriatic arthritis have all been shown to increase the risk of ASCVD. Other diseases such as human immunodeficiency virus (HIV) and mediastinal radiation have also been correlated with increased ASCVD. In RA and HIV, the evidence suggests a benefit to added statin therapy and society guidelines favor early initiation. The evidence for statin therapy in RA is limited to observational studies with small secondary analysis. In HIV, there is a large ongoing clinical trial to assess efficacy. In those with psoriasis and psoriatic arthritis, there is limited evidence for or against statin therapy independent of a calculated cardiac risk score. Finally, in SLE and in those with exposure to mediastinal radiation, cardiac events remain high, but evidence is limited on the beneficial effects of statin therapy. There are many individuals who have an increased risk for ASCVD above what is predicted from a cardiac risk score. It would be beneficial to create risk prediction models with statin therapy recommendations that are tailored to those predisposed to accelerated atherosclerosis.

Correlation between Osteoprotegerin Serum Level and Coronary Calcification Using Coronary Artery Calcium Score in Patient with Moderate-Severe Cardiovascular Risk Factor

Coronary artery calcification is a part of atherosclerosis process associated with coronary heart disease. Recently, coronary artery calcification assessment using computed tomography (CT) is still the best noninvasive imaging with high sensitivity and specificity. Osteoprotegerin (OPG) is one of vascular calcification marker that through its role to bind receptor activator of nuclear factor-κβ ligand and inhibit osteoclastogenesis is suspected of playing a role for coronary calcification in atherosclerosis process. The objective of this study was to prove a positive correlation between OPG serum level and coronary calcification using coronary artery calcium (CAC) score in patient with moderate-severe cardiovascular (CV) risk factor. This is a cross-sectional study with purposive sampling technique. Thirty-three subjects participate in this research and each subject underwent a multislice computed tomography (MSCT) examination to assess coronary calcification and their blood samples were collected for OPG measurement. This study is analyzed with Spearman's correlation test. The mean of OPG serum level in this study was 5.89 ± 2.1 pmol/L for moderate-risk Framingham risk score (FRS) and the mean of OPG serum level for high-risk FRS was 7.27 ± 3.4. There was a positive, moderate, and significant correlation between OPG serum level and coronary calcification using CAC score in patient with moderate-severe CV risk factor ( r  = 0.694; p  < 0.001).

Possible role of intronic polymorphisms in the PHACTR1 gene on the development of cardiovascular disease

Cardiovascular disease (CVD) is a complex multifactorial and polygenetic disease in which the interaction of numerous genes, genetic variants, and environmental factors plays a major role in its development. In an attempt to demonstrate the association between certain genetic variants and CVD, researchers have run large genomic wild association studies (GWAS) in recent decades. These studies have correlated several genomic variants with the presence of CVD. Recently, certain polymorphisms in the phosphatase and actin regulator 1 (PHACTR1) gene have been shown to be associated with CVD (i.e., coronary artery disease, coronary artery calcification, early onset myocardial infarction, cervical artery dissection and hypertension) in different ethnic groups. It is important to state that all of the described PHACTR1 genetic variants associated with CVD are located in non-translating gene regions known as introns. Thus, the purpose of this article is to hypothesize the effect of certain intronic polymorphisms in the PHACTR1 gene on pathological processes in the cardiovascular system. In addition, we present compelling evidence that supports this hypothesis as well as a methodology that could be used to assess the allelic effect using in vitro and in vivo models, which will ultimately demonstrate the pathophysiological contribution of PHACTR1 intronic polymorphisms to the development of CVD.

Correlation between serum parathyroid hormone levels and coronary artery calcification in patients without renal failure

The aim of the present study was to investigate the correlation between serum parathyroid hormone (PTH) levels and coronary artery calcification (CAC) in patients without renal failure, as well as to determine independent risk factors of CAC score (CACS). A total of 157 patients who underwent coronary computed tomography angiographic examination at the 101th Hospital of the People's Liberation Army between December 2013 and February 2015 were retrospectively evaluated. The correlation between PTH levels and CACS was determined using a Pearson correlation analysis. A receiver operating characteristic (ROC) curve was drawn to determine the best cutoff PTH level for prediction of CAC. The independent association between serum PTH levels and CAC was analyzed by using a logistic regression analysis model with the response variable Be binary class. The results revealed that PTH levels in patients in the CAC group were significantly higher than those of patients in the non-calcification group. PTH levels were positively correlated with CACS (r=0.288, P<0.001). The ROC curve suggested that a PTH level of ≥31.05 pg/ml was the best cut-off point for the prediction of CAC, with a sensitivity of 80.88%, specificity of 60.67% and an area under the curve of 0.761. After including predictive factors for CAC (gender, age, smoking status, diabetes, hypertension, hyperlipidemia, body mass index, glomerular filtration rate and calcium, phosphorus, calcium-phosphorus product, magnesium, PTH, total cholesterol, low-density lipoprotein cholesterol, triglyceride, high-density lipoprotein cholesterol and C-reactive protein levels), the odds ratio of the serum PTH levels regarding the prediction of CAC was 1.050 (95% confidence interval, 1.027-1.074; P<0.001). In conclusion, the present study suggested that serum PTH levels are correlated with CAC in patients without renal failure and may thus be used as a reliable predictor of CAC.

Brazilian adult individuals with untreated isolated GH deficiency do not have accelerated subclinical atherosclerosis

GH and its principal mediator IGF1 have important effects on metabolic and cardiovascular (CV) status. While acquired GH deficiency (GHD) is often associated with increased CV risk, the consequences of congenital GHD are not known. We have described a large group of patients with isolated GHD (IGHD) due to a homozygous mutation (c.57+1G>A) in the GH releasing hormone receptor gene, and shown that adult GH-naïve individuals have no evidence of clinically evident premature atherosclerosis. To test whether subclinical atherosclerosis is anticipated in untreated IGHD, we performed a cross-sectional study of 25 IGHD and 27 adult controls matched for age and gender. A comprehensive clinical and biochemical panel and coronary artery calcium scores were evaluated by multi-detector tomography. Height, weight, IGF1, homeostasis model assessment of insulin resistance, creatinine and creatininekinase were lower in the IGHD group. Median and interquartile range of calcium scores distribution was similar in the two groups: IGHD 0(0) and control 0(4.9). The vast majority of the calcium scores (20 of 25 IGHD (80%) and 18 of 27 controls (66.6%)) were equal to zero (difference not significant). There was no difference in the calcium scores classification. None of IGHD subjects had minimal calcification, which were present in four controls. Three IGHD and four controls had mild calcification. There were two IGHD individuals with moderate calcification and one control with severe calcification. Our study provides evidence that subjects with congenital isolated lifetime and untreated severe IGHD do not have accelerated subclinical coronary atherosclerosis.

The association between coronary calcification and adenomatous polyps of colon in Korean adults

BACKGROUND AND OBJECTIVE

Adenomatous polyps of colon is a precancerous lesion. Many studies have shown that the adenomatous polyps of colon and cardiovascular disease share several common risk factors. This cross-sectional study aimed to investigate whether coronary calcification is associated with the adenomatous polyps of colon.

METHODS

Among 1637 Korean adults, we examined the association between coronary calcium score (CCS) as a measurement of coronary calcification and the presence of adenomatous polyps of colon via multi-detected row computed tomography (MDCT) and colonoscopy, respectively. CCS values were categorized as follows: 0, 1-17, 18-105, or≥106. The odds ratios (ORs) and 95% confidence intervals (CIs) for the presence of adenomatous polyps of colon were calculated across CCS groups.

RESULTS AND CONCLUSIONS

After adjusting for confounding variables, the adjusted ORs (95% CIs) for the presence of adenomatous polyps of colon in each of the four CCS groups were 1.00 (reference), 1.44 (0.91-2.33), 1.88 (1.15-3.01) and 3.61 (2.23-5.74). And higher CCS values were associated with multiple polyps (P≤0.001), villous histologic features or high-grade dysplasia (P=0.02), and advanced adenomatous polyps (P≤0.001). A higher level of CCS was found to be strongly and independently associated with the presence of adenomatous polyps of colon in Korean adults. This finding suggests that people at high risk for coronary atherosclerosis through MDCT should be considered for further evaluation of adenomatous polyps.

CT coronary angiography in low- to intermediate-risk patients: less radiation, less invasive angiography, and less revascularisation

OBJECTIVES

We investigated whether any change in the use of invasive coronary angiography and coronary revascularisation after CT coronary angiography in patients with a low to intermediate pre-test probability of coronary artery disease could be explained from alterations in patient characteristics.

DESIGN

A cohort study based on data samples from the Western Denmark Heart Registry. Follow-up ended on 11 March 2014.

RESULTS

A total of 3541 persons were examined during the period of January 2010-December 2013. The median radiation dose was reduced from 4.2 to 2.2 mSv (p < 0.001) due to improved technology. The immediate referral rate for subsequent myocardial perfusion scans was increased from 2.8% to 10.0% (p < 0.001), while the immediate referral rate for invasive coronary angiography decreased from 25.3% to 10.8% (p < 0.001). The revascularisation rate diminished from 10.4% to 6.3%. The multivariable adjusted hazard ratio (95% confidence interval) for invasive coronary angiography during follow-up after CT coronary angiography was 0.59 (0.47-0.74) and that for coronary revascularisation was 0.66 (0.45-0.97) in 2013 compared to that in 2010.

CONCLUSIONS

The radiation dose diminished considerably. The reductions in the use of invasive coronary angiography and coronary revascularisation could not be explained by changes in patient characteristics but are driven by an increased use of perfusion scans in combination with increasing use of measurement of functional coronary flow reserve.

From circulating biomarkers to genomics and imaging in the prediction of cardiovascular events in the general population

Cardiovascular disease (CVD) is the leading cause of death and disability worldwide. In the last decades numerous markers have been considered and investigated for the prediction of CV events, but only a few of them resulted in improved global risk assessment beyond traditional risk factors when incorporated into coronary evaluation scores. Recent genetic studies have pointed out a few but consistent loci or genes which are independently associated with CV risk. The idea is fascinating that these genetic markers could lead to improved individual CV risk assessment and tailored pharmacological interventions. In this brief review we will not make a systematic review of all non-genetic and genetic markers of CV risk but we will try to make a brief overview of the most interesting ones with the aim to underline potential 'pros' and 'cons' of their implementation in clinical practice.

Incremental prognostic value of different components of coronary atherosclerotic plaque at cardiac CT angiography beyond coronary calcification in patients with acute chest pain

PURPOSE

To systematically evaluate the incremental predictive value of cardiac computed tomographic (CT) angiography beyond the assessment of coronary artery calcium (CAC) in patients who present with acute chest pain but without evidence of acute coronary syndrome (ACS).

MATERIALS AND METHODS

The human research committee approved this study and waived the need for individual written informed consent. The study was HIPAA compliant. A total of 458 patients (36% male; mean age, 55 years ± 11) with acute chest pain at low to intermediate risk for coronary artery disease underwent coronary calcification assessment with cardiac CT angiography. All patients who did not experience ACS at index hospitalization were followed for instances of a major adverse cardiac event (MACE), such as a myocardial infarct, revascularization, cardiac death, or angina requiring hospitalization. CAC score and cardiac CT angiography were used to derive the presence and extent of atherosclerotic plaque (calcified, noncalcified, or mixed), and obstructive lesions (>50% luminal narrowing) were related to outcomes by using univariate and adjusted Cox proportional hazards models.

RESULTS

Of the 458 patients, 70 (15%) experienced MACE (median follow-up, 13 months). Patients with no plaque at cardiac CT angiography remained free of events during the follow-up period, while 11 (5%) of 215 patients with no CAC had MACE. The extent of plaque was the strongest predictor of MACE independent of traditional risk factors (hazard ratio [HR], 151.77 for four or more segments containing plaque as compared with those containing no plaque; P < .001). Patients with mixed plaque were more likely to experience MACE (HR, 86.96; P = .002) than those with exclusively noncalcified plaque (HR, 58.06; P = .005) or exclusively calcified plaque (HR, 32.94; P = .02).

CONCLUSION

The strong prognostic value of cardiac CT angiography is incremental to its known diagnostic value in patients with acute chest pain without ACS and is independent of traditional risk factors and CAC.

Low-density lipoprotein particle number predicts coronary artery calcification in asymptomatic adults at intermediate risk of cardiovascular disease

BACKGROUND

Clinicians require more discriminating measures of cardiovascular risk than those currently used in most clinical settings. A promising avenue of research concerns the relationship of low-density lipoprotein (LDL) subfractions to subclinical atherosclerosis.

OBJECTIVE

To assess cross-sectional associations between subfractions of LDL cholesterol and coronary artery calcification (CAC).

METHODS

The study sample comprised 284 asymptomatic clinic patients who were at intermediate risk of cardiovascular disease, aged 40-69 years, who were not taking a statin or niacin. Lipoprotein subclass measures were obtained by the use of proton nuclear magnetic resonance spectroscopy. CAC was assessed with computed tomography angiography (CTA). The analyses modeled the presence or absence of CAC.

RESULTS

Total LDL particle number (LDL-P) had a stronger association with CAC than the traditional lipoprotein measures. Patients in the highest tercile of total LDL-P (1935-3560 nmol/L) were 3.7 times more likely to exhibit coronary artery calcification as those in the lowest tercile (620-1530 nmol/L). The independent effects of small LDL-P remained significant after adjustment for LDL-cholesterol, high-density lipoprotein (HDL), triglycerides, non-HDL, and large LDL-P. HDL and non-HDL were not significant, independent predictors of CAC.

CONCLUSION

Small LDL-P was a strong, independent predictor of the presence of CAC. Large prospective studies are needed to examine the effect of LDL particle number and size on coronary artery calcification.

Primary prevention of coronary heart disease: integration of new data, evolving views, revised goals, and role of rosuvastatin in management. A comprehensive survey

A recent explosion in the amount of cardiovascular risk and incipient, undetected subclinical cardiovascular pathology has swept across the globe. Nearly 70% of adult Americans are overweight or obese; the prevalence of visceral obesity stands at 53% and continues to rise. At any one time, 55% of the population is on a weight-loss diet, and almost all fail. Fewer than 15% of adults or children exercise sufficiently, and over 60% engage in no vigorous activity. Among adults, 11%-13% have diabetes, 34% have hypertension, 36% have prehypertension, 36% have prediabetes, 12% have both prediabetes and prehypertension, and 15% of the population with either diabetes, hypertension, or dyslipidemia are undiagnosed. About one-third of the adult population, and 80% of the obese, have fatty livers. With 34% of children overweight or obese, prevalence having doubled in just a few years, type 2 diabetes, hypertension, dyslipidemia, and fatty livers in children are at their highest levels ever. Half of adults have at least one cardiovascular risk factor. Not even 1% of the population attains ideal cardiovascular health. Despite falling coronary death rates for decades, coronary heart disease (CHD) death rates in US women 35 to 54 years of age may now be increasing because of the obesity epidemic. Up to 65% of patients do not have their conventional risk biomarkers under control. Only 30% of high risk patients with CHD achieve aggressive low density lipoprotein (LDL) targets. Of those patients with multiple risk factors, fewer than 10% have all of them adequately controlled. Even when patients are titrated to evidence-based targets, about 70% of cardiac events remain unaddressed. Undertreatment is also common. About two-thirds of high risk primary care patients are not taking needed medications for dyslipidemia. Poor patient adherence, typically below 50%, adds further difficulty. Hence, after all such fractional reductions are multiplied, only a modest portion of total cardiovascular risk burden is actually being eliminated, and the full potential of risk reduction remains unrealized. Worldwide the situation is similar, with the prevalence of metabolic syndrome approaching 50%. Primordial prevention, resulting from healthful lifestyle habits that do not permit the appearance of risk factors, is the preferred method to lower cardiovascular risk. Lowering the prevalence of obesity is the most urgent matter, and is pleiotropic since it affects blood pressure, lipid profiles, glucose metabolism, inflammation, and atherothrombotic disease progression. Physical activity also improves several risk factors, with the additional potential to lower heart rate. Given the current obstacles, success of primordial prevention remains uncertain. At the same time, the consequences of delay and inaction will inevitably be disastrous, and the sense of urgency mounts. Since most CHD events arise in a large subpopulation of low- to moderate-risk individuals, identifying a high proportion of those who will go on to develop events with accuracy remains unlikely. Without a refinement in risk prediction, the current model of targeting high-risk individuals for aggressive therapy may not succeed alone, especially given the rising burden of risk. Estimating cardiovascular risk over a period of 10 years, using scoring systems such as Framingham or SCORE, continues to enjoy widespread use and is recommended for all adults. Limitations in the former have been of concern, including the under- or over-estimation of risk in specific populations, a relatively short 10-year risk horizon, focus on myocardial infarction and CHD death, and exclusion of family history. Classification errors may occur in up to 37% of individuals, particularly women and the young. Several different scoring systems are discussed in this review. The use of lifetime risk is an important conceptual advance, since ≥90% of young adults with a low 10-year risk have a lifetime risk of ≥39%; over half of all American adults have a low 10-year risk but a high lifetime risk. At age 50 the absence of traditional risk factors is associated with extremely low lifetime risk and significantly greater longevity. Pathological and epidemiological data confirm that atherosclerosis begins in early childhood, and advances seamlessly and inexorably throughout life. Risk factors in childhood are similar to those in adults, and track between stages of life. When indicated, aggressive treatment should begin at the earliest indication, and be continued for years. For those patients at intermediate risk according to global risk scores, C-reactive protein (CRP), coronary artery calcium (CAC), and carotid intima-media thickness (CIMT) are available for further stratification. Using statins for primary prevention is recommended by guidelines, is prevalent, but remains underprescribed. Statin drugs are unrivaled, evidence-based, major weapons to lower cardiovascular risk. Even when low density lipoprotein cholesterol (LDL-C) targets are attained, over half of patients continue to have disease progression and clinical events. This residual risk is of great concern, and multiple sources of remaining risk exist. Though clinical evidence is incomplete, altering or raising the blood high density lipoprotein cholesterol (HDL-C) level continues to be pursued. Of all agents available, rosuvastatin produces the greatest reduction in LDL-C, LDL-P, and improvement in apoA-I/apoB, together with a favorable safety profile. Several recent proposals and methods to lower cardiovascular risk are reviewed. A combination of approaches, such as the addition of lifetime risk, refinement of risk prediction, guideline compliance, novel treatments, improvement in adherence, and primordial prevention, including environmental and social intervention, will be necessary to lower the present high risk burden.