Use of electron beam tomography data to develop models for prediction of hard coronary events

Association between skin autofluorescence and coronary calcification in the general population

OBJECTIVE

To address the relationship between tissue accumulation of advanced glycation end-products, assessed by skin autofluorescence (SAF), and subclinical atherosclerosis quantified with coronary artery calcium score (CACS) in the general Dutch population.

METHODS

A total of 3,839 participants of the LifeLines Cohort Study without diabetes or cardiovascular disease were included in this cross-sectional evaluation. They underwent SAF measurement and cardiac computed tomography to measure CACS. Associations between SAF and CACS was assessed using regression models. Participants at elevated risk for cardiovascular disease were selected by either CACS≥100, or SAF value in the top 15%; overlap and cardiovascular risk profile of these participants were compared.

RESULTS

In univariate analysis, every 1 arbitrary unit (AU) increase in SAF resulted in an odds ratio of 2.91 (95% confidence interval 2.44-3.48, p<0.001) for coronary calcification. After adjustment for cardiovascular risk factors, there was still 20% higher odds of coronary calcification with 1 AU increase in SAF, but significance was lost. In total, 1025 (27%) participants either had high SAF and/or high CACS, of these 441 (12%) had only high SAF, 450 (12%) had only high CACS and 134 (3%) participants had high SAF and high CACS.

CONCLUSION

In a population-based Dutch cohort, SAF was associated with the degree of coronary calcification. This association was largely explained by classical cardiovascular risk factors. Limited overlap was found in subgroups with high SAF or high CACS, indicating that SAF and CACS may have complementary role in identifying individuals at elevated cardiovascular risk.

Radiologist opinions regarding reporting incidental coronary and cardiac calcification on thoracic CT

Objectives

Coronary and cardiac calcification are frequent incidental findings on non-gated thoracic computed tomography (CT). However, radiologist opinions and practices regarding the reporting of incidental calcification are poorly understood.

Methods

UK radiologists were invited to complete this online survey, organised by the British Society of Cardiovascular Imaging (BSCI). Questions included anonymous information on subspecialty, level of training and reporting practices for incidental coronary artery, aortic valve, mitral and thoracic aorta calcification.

Results

The survey was completed by 200 respondents: 10% trainees and 90% consultants. Calcification was not reported by 11% for the coronary arteries, 22% for the aortic valve, 35% for the mitral valve and 37% for the thoracic aorta. Those who did not subspecialise in cardiac imaging were less likely to report coronary artery calcification (p = 0.005), aortic valve calcification (p = 0.001) or mitral valve calcification (p = 0.008), but there was no difference in the reporting of thoracic aorta calcification. Those who did not subspecialise in cardiac imaging were also less likely to provide management recommendations for coronary artery calcification (p < 0.001) or recommend echocardiography for aortic valve calcification (p < 0.001), but there was no difference for mitral valve or thoracic aorta recommendations.

Conclusion

Incidental coronary artery, valvular and aorta calcification are frequently not reported on thoracic CT and there are differences in reporting practices based on subspeciality.

Advances in knowledge

On routine thoracic CT, 11% of radiologists do not report coronary artery calcification. Radiologist reporting practices vary depending on subspeciality but not level of training.

Coronary artery calcification progression and long-term cardiovascular outcomes in renal transplant recipients: an analysis by the joint model

Background

Compared with the general population, the risk of death is substantially higher in renal transplant recipients than in age- and sex-matched individuals in the general population. In the general population, coronary artery calcification (CAC) predicts all-cause and cardiovascular mortality. In this study we aimed to analyse these relationships in renal transplant recipients.

Methods

We examined 178 renal transplant patients in this prospective observational cohort study. We measured CAC with multidetector spiral computed tomography using the Agatston score at multiple time points. Overall, 411 scans were performed in 178 patients over an average 12.8 years follow-up. The clinical endpoint was a composite including all-cause death and non-fatal cardiovascular events. Data analysis was performed by the joint model.

Results

During a follow-up of 12.8 ± 2.4 years, coronary calcification progressed over time (P < 0.001) and the clinical endpoint occurred in 54 patients. In the analysis by the joint model, both the baseline CAC score and the CAC score progression were strongly associated with the incidence rate of the composite event [hazard ratio 1.261 (95% confidence interval 1.119–1.420), P = 0.0001].

Conclusions

CAC at baseline and coronary calcification progression robustly predict the risk of death and cardiovascular events in renal transplant recipients. These findings support the hypothesis that the link between the calcifying arteriopathy of renal transplant patients and clinical end points in these patients is causal in nature.

De-risking primary prevention: role of imaging

Atherosclerotic cardiovascular disease (ASCVD) is a common disease among the general population, and includes four major areas: (1) coronary heart disease (CHD), manifested by stable angina, unstable angina, myocardial infarction (MI), heart failure, and coronary death; (2) cerebrovascular disease, manifested by transient ischemia attack and stroke; (3) peripheral vascular disease, manifested by claudication and critical limb ischemia; and (4) aortic atherosclerosis and aortic aneurysm (thoracic and abdominal). CHD remains the leading cause of death for both men and women in the United States. So, it is imperative to identify people at risk of CHD and provide appropriate medical treatment or intervention to prevent serious complications and outcomes including sudden cardiac death. Coronary artery calcification (CAC) is a marker of subclinical coronary artery disease. Therefore, coronary artery calcium score is an important screening method for Coronary artery disease (CAD). In this article, we performed a comprehensive review of current literatures and studies assessing the prognostic value of CAC for future cardiovascular disease (CVD) events. We searched PubMed, MEDLINE, Google Scholar, and Cochrane library. We also reviewed the 2018 American College of Cardiology (ACC)/American Heart Association (AHA) guideline on the assessment of CVD risk. A CAC score of zero corresponds to very low CVD event rates (∼1% per year) and hence a potent negative risk marker. This has been referred to as the ‘power of zero’ and affords the lowest risk of any method of risk calculation. It is now indicated in the 2018 ACC/AHA Cholesterol guidelines to be used to avoid statins for 5–10 years after a score of zero, and then re-assess the patient.

Role of coronary artery calcium score in the primary prevention of cardiovascular disease

First developed in 1990, the Agatston coronary artery calcium (CAC) score is an international guideline-endorsed decision aid for further risk assessment and personalized management in the primary prevention of atherosclerotic cardiovascular disease. This review discusses key international studies that have informed this 30 year journey, from an initial coronary plaque screening paradigm to its current role informing personalized shared decision making. Special attention is paid to the prognostic value of a CAC score of zero (the so called "power of zero"), which, in a context of low estimated risk thresholds for the consideration of preventive therapy with statins in current guidelines, may be used to de-risk individuals and thereby inform the safe delay or avoidance of certain preventive therapies. We also evaluate current recommendations for CAC scoring in clinical practice guidelines around the world, and past and prevailing barriers for its use in routine patient care. Finally, we discuss emerging approaches in this field, with a focus on the potential role of CAC informing not only the personalized allocation of statins and aspirin in the general population, but also of other risk-reduction therapies in special populations, such as individuals with diabetes and people with severe hypercholesterolemia.

The cardiovascular-dialysis nexus: the transition to dialysis is a treacherous time for the heart

Chronic kidney disease (CKD) patients require dialysis to manage the progressive complications of uraemia. Yet, many physicians and patients do not recognize that dialysis initiation, although often necessary, subjects patients to substantial risk for cardiovascular (CV) death. While most recognize CV mortality risk approximately doubles with CKD the new data presented here show that this risk spikes to >20 times higher than the US population average at the initiation of chronic renal replacement therapy, and this elevated CV risk continues through the first 4 months of dialysis. Moreover, this peak reflects how dialysis itself changes the pathophysiology of CV disease and transforms its presentation, progression, and prognosis. This article reviews how dialysis initiation modifies the interpretation of circulating biomarkers, alters the accuracy of CV imaging, and worsens prognosis. We advocate a multidisciplinary approach and outline the issues practitioners should consider to optimize CV care for this unique and vulnerable population during a perilous passage.

Use of Coronary Artery Calcium Scoring to Improve Cardiovascular Risk Stratification and Guide Decisions to Start Statin Therapy in People Living With HIV

BACKGROUND

Cardiovascular disease (CVD) risk assessment remains a critical step in guiding decisions to initiate primary prevention interventions in people living with HIV (PLWH).

SETTING

We investigated whether coronary artery calcium (CAC) scoring allowed a more accurate selection of patients who may benefit from statin therapy, compared with current risk assessment tools alone.

METHODS

Cross-sectional analysis of PLWH over 50 years old who underwent CAC scoring between 2009 and 2019. Framingham Risk score (FRS), QRISK2 and D:A:D scores were calculated for each participant at the time of CAC scoring and statin eligibility determined based on current European guidelines on the prevention of CVD in PLWH.

RESULTS

A total of 739 patients were included (mean age 56 ± 5, 92.8% male, 84% white). Among 417 (56.4%) candidates for statin therapy based on FRS ≥10%, 174 (23.5%) had no detectable calcification (CAC = 0). Conversely, 145 (19.6%) patients with detectable calcification (CAC > 0) were identified as low-risk (FRS < 10%). When compared with FRS, CAC scoring reclassified CVD risk in 43.1% of patients, 145 (19.6%) to a higher risk group that could benefit from statin therapy and 174 (23.5%) statin candidates to a lower risk group. QRISK2 and D:A:D scores performed similarly to FRS, underestimating the presence of significant coronary calcification in 21.1% and 24.9% respectively and overestimating risk in 16.9% and 18.8% patients with CAC = 0.

CONCLUSIONS

Establishing a decision-model based on the combination of conventional risk tools and CAC scoring improves risk assessment and the selection of PLWH who would benefit from statin therapy.

Gender Differences in the Atherosclerosis Profile by Coronary CTA in Coronary Artery Calcium Score Zero Patients

Background: The coronary artery calcium score (CACS) is a powerful tool for cardiovascular risk stratification. Coronary computed tomography angiography (CTA) allows for a more distinct analysis of atherosclerosis. The aim of the study was to assess gender differences in the atherosclerosis profile of CTA in patients with a CACS of zero. Methods: A total of 1451 low- to intermediate-risk patients (53 ± 11 years; 51% females) with CACS <1.0 Agatston units (AU) who underwent CTA and CACS were included. Males and females were 1:1 propensity score-matched. CTA was evaluated for stenosis severity (Coronary Artery Disease - Reporting and Data System (CAD-RADS) 0-5: minimal <25%, mild 25-49%, moderate 50-69%, severe ≥70%), mixed-plaque burden (G-score), and high-risk plaque (HRP) criteria (low-attenuation plaque, spotty calcification, napkin-ring sign, and positive remodeling). All-cause mortality, cardiovascular mortality, and major cardiovascular events (MACEs) were collected. Results: Among the patients, 88.8% had a CACS of 0 and 11.2% had an ultralow CACS of 0.1-0.9 AU. More males than females (32.1% vs. 20.3%; p < 0.001) with a CACS of 0 had atherosclerosis, while, among those with an ultralow CACS, there was no difference (88% vs. 87.1%). Nonobstructive CAD (25.9% vs. 16.2%; p < 0.001), total plaque burden (2.2 vs. 1.4; p < 0.001), and HRP were found more often in males (p < 0.001). After a follow-up of mean 6.6 ± 4.2 years, all-cause mortality was higher in females (3.5% vs. 1.8%, p = 0.023). Cardiovascular mortality and MACEs were low (0.2% vs. 0%; p = 0.947 and 0.3% vs. 0.6%; p = 0.790) for males vs. females, respectively. Females were more often symptomatic for chest pain (70% vs. 61.6%; p = 0.004). (4) Conclusions: In patients with a CACS of 0, males had a higher prevalence of atherosclerosis, a higher noncalcified plaque burden, and more HRP criteria. Nonetheless, females had a worse long-term outcome and were more frequently symptomatic.

Reporting incidental coronary, aortic valve and cardiac calcification on non-gated thoracic computed tomography, a consensus statement from the BSCI/BSCCT and BSTI

Incidental coronary and cardiac calcification are frequent findings on non-gated thoracic CT. We recommend that the heart is reviewed on all CT scans where it is visualised. Coronary artery calcification is a marker of coronary artery disease and it is associated with an adverse prognosis on dedicated cardiac imaging and on non-gated thoracic CT performed for non-cardiac indications, both with and without contrast. We recommend that coronary artery calcification is reported on all non-gated thoracic CT using a simple patient-based score (none, mild, moderate, severe). Furthermore, we recommend that reports include recommendations for subsequent management, namely the assessment of modifiable cardiovascular risk factors and, if the patient has chest pain, assessment as per standard guidelines. In most cases, this will not necessitate additional investigations. Incidental aortic valve calcification may also be identified on non-gated thoracic CT and should be reported, along with ancillary findings such as aortic root dilation. Calcification may occur in other parts of the heart including mitral valve/annulus, pericardium and myocardium, but in many cases these are an incidental finding without clinical significance.

Point of Care Clinical Risk Score to Improve the Negative Diagnostic Utility of an Agatston Score of Zero: Averting the Need for Coronary Computed Tomography Angiography

BACKGROUND

Coronary artery calcification is a marker of underlying atherosclerotic vascular disease. The absence of coronary artery calcification is associated with a low prevalence of obstructive coronary artery disease (CAD), but it cannot be ruled out completely. We sought to develop a clinical tool that can be added to Agatston score of zero to rule out obstructive CAD with high accuracy.

METHODS

We developed a clinical score retrospectively from a cohort of 4903 consecutive patients with an Agatston score of zero. Patients with prior diagnosis of CAD, coronary percutaneous coronary intervention, or surgical revascularization were excluded. Obstructive CAD was defined as any epicardial vessel diameter narrowing of ≥50%. The score was validated using an external cohort of 4290 patients with an Agatston score of zero from a multinational registry.

RESULTS

The score consisted of 7 variables: age, sex, typical chest pain, dyslipidemia, hypertension, family history, and diabetes mellitus. The model was robust with an area under the curve of 0.70 (95% CI, 0.65-0.76) in the derivation cohort and 0.69 (95% CI, 0.65-0.72) in the validation cohort. Patients were divided into 3 risk groups based on the score: low (≤6), intermediate (7-13), and high (≥14). Patients who score ≤6 have a negative likelihood ratio of 0.42 for obstructive CAD, whereas those who score ≥14 have a positive likelihood ratio of >5.5 for obstructive CAD. The outcome was ruled out in >98% of patients with a score ≤6 in the validation cohort.

CONCLUSIONS

We developed a score that may be used to identify the likelihood of obstructive CAD in patients with an Agatston score of zero, which may be used to direct the need for additional testing. However, the results of this retrospective analysis are hypothesis generating and before clinical implementation should be validated in a trial with a prospectively collected data.

International and Racial Differences in Mineral and Bone Disorder Markers and Treatments Over the First 5 Years of Hemodialysis in the Dialysis Outcomes and Practice Patterns Study

RATIONALE & OBJECTIVE

Normalization of parathyroid hormone (PTH), serum calcium, and phosphorus levels may prevent coronary and bone disease in hemodialysis (HD) patients. We describe the trajectory of these mineral bone disorder parameters and treatments during the first 5 years of HD by international region and race.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

33,517 US black/African American, US non-black/African American, European, and Japanese HD patients from the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 4 to 5 (2009-2015).

PREDICTOR

Time since HD initiation.

OUTCOMES

Monthly cross-sections of mineral bone disorder parameters (PTH, serum calcium, and phosphorus) and medications (cinacalcet, active vitamin D, and phosphate binders).

RESULTS

Mean PTH levels declined precipitously during the first 4 months of HD in all 4 groups, then steadily increased during the next 4.5 years in the United States/Europe but not in Japan. 3 years after HD initiation (month 36), mean PTH level was highest in US black/African Americans (496 pg/mL), despite greater prescription of cinacalcet (23%) and active vitamin D (85%), and lowest in Japan (151 pg/mL). Mean serum calcium and phosphorus levels increased during the first 4 months of HD. By month 36, the mean calcium level was lower in Japan (8.8 mg/dL) than United States/Europe (9.0-9.1 mg/dL), while the mean phosphorus level was lower in Europe (4.8 mg/dL) than United States/Japan (5.1-5.3 mg/dL).

LIMITATIONS

Lack of data for medication dosages; most patients were not followed from HD onset.

CONCLUSIONS

Large differences exist in the levels, trajectories, and therapies for PTH, calcium, and phosphorus by country and race in the first 5 years of HD. Higher PTH levels were observed in the United States, especially among black/African American patients, despite greater use of cinacalcet and active vitamin D than in Japan or Europe. Potential contributors to differences in PTH levels should be explored to study their impact on PTH management strategies and consequent bone and cardiovascular complications.

Diabetes, subclinical atherosclerosis and multiple cardiovascular risk factors in hard-to-reach asymptomatic patients

AIM

To examine the association of cardiovascular disease risk factors with and their cumulative effect on coronary artery calcium in hard-to-reach asymptomatic patients with diabetes.

METHODS

A total of 2563 community-dwelling asymptomatic subjects from Central Appalachia participated in coronary artery calcium screening at a heart centre. Binary variable was used to indicate that coronary artery calcium was either present or absent. Independent variables consisted of demographic and modifiable risk factors and medical conditions. Descriptive statistics and multinomial logistic regression analyses were conducted.

RESULTS

In total, 55.8% and 13.7% of study participants had subclinical atherosclerosis (coronary artery calcium ⩾1) and diabetes, respectively. The presence of coronary artery calcium was higher in subjects with diabetes (68.5%) than those without (53.8%). Compared to subjects without diabetes with coronary artery calcium = 0, obesity, hypertension, hypercholesterolaemia and smoking increased the odds of the presence of coronary artery calcium (coronary artery calcium score ⩾1) regardless of diabetes status; however, with larger odds ratios in subjects with diabetes. Compared to subjects without diabetes with coronary artery calcium score = 0, having 3, 4 and ⩾5 risk factors increased the odds of presence of coronary artery calcium in subjects with diabetes by 14.06 (confidence interval = 3.26-62.69), 32.30 (confidence interval = 7.41-140.82) and 47.12 (confidence interval = 10.35-214.66) times, respectively.

CONCLUSION

There is a need for awareness about subclinical atherosclerosis in patients with diabetes and more research about coronary artery calcium in subpopulations of patients.

A Controlled Increase in Dietary Phosphate Elevates BP in Healthy Human Subjects

Background Despite epidemiologic evidence for increased cardiovascular morbidity and mortality associated with both high dietary and serum phosphate in humans with normal renal function, no controlled phosphate intervention studies of systemic hemodynamics have been reported. Higher serum 25(OH) vitamin D levels are associated with better cardiovascular outcomes, but vitamin D increases intestinal phosphate absorption.Methods We conducted a prospective outpatient study with blinded assessment in 20 young adults with normal renal function randomized to high phosphate (regular diet plus 1 mmol/kg body wt per day of Na as neutral sodium phosphate) or low phosphate (regular diet plus lanthanum, 750 mg thrice/day, plus 0.7 mmol/kg body wt per day of Na as NaCl) for 11 weeks. After 6 weeks, all subjects received vitamin D₃ (600,000 U) by intramuscular injection. Outcome parameters were 24-hour ambulatory systolic and diastolic BP (SBP and DBP), pulse rate (PR), biomarkers, and measures of endothelial and arterial function.Results Compared with the low-phosphate diet group, the high-phosphate diet group had a significant increase in mean±SEM fasting plasma phosphate concentration (0.23±0.11 mmol/L); 24-hour SBP and DBP (+4.1; 95% confidence interval [95% CI], 2.1 to 6.1; and +3.2; 95% CI, 1.2 to 5.2 mm Hg, respectively); mean 24-hour PR (+4.0; 95% CI, 2.0 to 6.0 beats/min); and urinary metanephrine and normetanephrine excretion (54; 95% CI, 50 to 70; and 122; 95% CI, 85 to 159 µg/24 hr, respectively). Vitamin D had no effect on any of these parameters. Neither high- nor low-phosphate diet nor vitamin D affected endothelial function or arterial elasticity.Conclusions Increased phosphate intake (controlled for sodium) significantly increases SBP, DBP, and PR in humans with normal renal function, in part, by increasing sympathoadrenergic activity.

Nontraditional Risk Factors in Cardiovascular Disease Risk Assessment: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Incorporating nontraditional risk factors may improve the performance of traditional multivariable risk assessment for cardiovascular disease (CVD).

OBJECTIVE

To systematically review evidence for the US Preventive Services Task Force on the benefits and harms of 3 nontraditional risk factors in cardiovascular risk assessment: the ankle-brachial index (ABI), high-sensitivity C-reactive protein (hsCRP) level, and coronary artery calcium (CAC) score.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for studies published through May 22, 2017. Surveillance continued through February 7, 2018.

STUDY SELECTION

Studies of asymptomatic adults with no known cardiovascular disease.

DATA EXTRACTION AND SYNTHESIS

Independent critical appraisal and data abstraction by 2 reviewers.

MAIN OUTCOMES AND MEASURES

Cardiovascular events, mortality, risk assessment performance measures (calibration, discrimination, or risk reclassification), and serious adverse events.

RESULTS

Forty-three studies (N = 267 244) were included. No adequately powered trials have evaluated the clinical effect of risk assessment with nontraditional risk factors on patient health outcomes. The addition of the ABI (10 studies), hsCRP level (25 studies), or CAC score (19 studies) can improve both discrimination and reclassification; the magnitude and consistency of improvement varies by nontraditional risk factor. For the ABI, improvements in performance were the greatest for women, in whom traditional risk assessment has poor discrimination (C statistic change of 0.112 and net reclassification index [NRI] of 0.096). Results were inconsistent for hsCRP level, with the largest analysis (n = 166 596) showing a minimal effect on risk prediction (C statistic change of 0.0039, NRI of 0.0152). The largest improvements in discrimination (C statistic change ranging from 0.018 to 0.144) and reclassification (NRI ranging from 0.084 to 0.35) were seen for CAC score, although CAC score may inappropriately reclassify individuals not having cardiovascular events into higher-risk categories, as determined by negative nonevent NRI. Evidence for the harms of nontraditional risk factor assessment was limited to computed tomography imaging for CAC scoring (8 studies) and showed that radiation exposure is low but may result in additional testing.

CONCLUSIONS AND RELEVANCE

There are insufficient adequately powered clinical trials evaluating the incremental effect of the ABI, hsCRP level, or CAC score in risk assessment and initiation of preventive therapy. Furthermore, the clinical meaning of improvements in measures of calibration, discrimination, and reclassification risk prediction studies is uncertain.

A methodology review on the incremental prognostic value of computed tomography biomarkers in addition to Framingham risk score in predicting cardiovascular disease: the use of association, discrimination and reclassification

BACKGROUND

Computed tomography (CT) biomarkers claim to improve cardiovascular risk stratification. This review focuses on significant differences in incremental measures between adequate and inadequate reporting practise.

METHODS

Studies included were those that used Framingham Risk Score as a baseline and described the incremental value of adding calcium score or CT coronary angiogram in predicting cardiovascular risk. Searches of MEDLINE, EMBASE, Web of Science and Cochrane Central were performed with no language restriction.

RESULTS

Thirty five studies consisting of 206,663 patients (men = 118,114, 55.1%) were included. The baseline Framingham Risk Score included the 1998, 2002 and 2008 iterations. Selective reporting, inconsistent reference groupings and thresholds were found. Twelve studies (34.3%) had major and 23 (65.7%) had minor alterations and the respective Δ AUC were significantly different (p = 0.015). When the baseline model performed well, the Δ AUC was relatively lower with the addition of a CT biomarker (Spearman coefficient = - 0.46, p < 0.0001; n = 33; 76 pairs of data). Other factors that influenced AUC performance included exploration of data analysis, calibration, validation, multivariable and AUC documentation (all p < 0.05). Most studies (68.7%) that reported categorical NRI (n = 16; 46 pairs of data) subjectively drew strong conclusions along with other poor reporting practices. However, no significant difference in values of NRI was found between adequate and inadequate reporting.

CONCLUSIONS

The widespread practice of poor reporting particularly association, discrimination, reclassification, calibration and validation undermines the claimed incremental value of CT biomarkers over the Framingham Risk Score alone. Inadequate reporting of discrimination inflates effect estimate, however, that is not necessarily the case for reclassification.

Prospective comparison of non-invasive risk markers of major cardiovascular events in COPD patients

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is an independent risk factor for cardiovascular (CV) disease, one of the most frequent causes of death in COPD patients. The goal of the present study was to evaluate the prognostic value of non-invasive CV risk markers in COPD patients.

METHODS

CV risk was prospectively evaluated in 287 COPD patients using non-invasive markers including the Framingham score, the Systematic Coronary Risk Evaluation (SCORE) charts, coronary arterial calcium (CAC), epicardial adipose tissue (EAT), as well as clinical, biochemical and physiological variables. The predictive power of each parameter was explored using CV events as the main outcome.

RESULTS

During a median follow up of 65 months (ICR: 36-100), 44 CV events were recorded, 12 acute myocardial infarctions (27.3%), 10 ischemic heart disease/angina (22.7%), 12 peripheral artery disease events requiring surgery (27.3%) and 10 strokes (22.7%). A total of 35 CV deaths occurred during that period. Univariable analysis determined that age, hypertension, CRP, total Cholesterol, LDL-Cholesterol, Framingham score and CAC were independently associated with CV events. Multivariable analysis identified CAC as the best predictor of CV events (HR; 95%CI: 1.32; 1.19-1.46, p < 001).

CONCLUSIONS

In COPD patients attending pulmonary clinics, CAC was the best independent non-invasive predictor of CV events. This tool may help evaluate the risk for a CV event in patients with COPD. Larger studies should reproduce and validate these findings.

Progression of coronary artery calcification at the crossroads: sign of progression or stabilization of coronary atherosclerosis?

Coronary artery calcification (CAC) has been strongly established as an independent predictor of adverse events, with a significant incremental prognostic value over traditional risk stratification algorithms. CAC progression has been associated with a higher rate of events. In parallel, several randomized studies and meta-analysis have shown the effectiveness of statins to slow progression and even promote plaque regression. However, evidence regarding the effect of routine medical therapy on CAC has yielded conflicting results, with initial studies showing significant CAC regression, and contemporaneous data showing rather the opposite. Accordingly, there is currently a great controversy on whether progression of CAC is a sign of progression or stabilization of coronary artery disease (CAD). The finding of inexorable CAC progression despite the implementation of intensive contemporaneous medical therapy suggests that further understanding of this phenomenon should be undertaken before the implementation of CAC as a surrogate endpoint for longitudinal studies, or for prospective follow-up of patients under routine medical treatment.

Defining the non-vulnerable and vulnerable patients with computed tomography coronary angiography: evaluation of atherosclerotic plaque burden and composition

The shift from coronary plaque stability to plaque instability remains poorly understood despite enormous efforts and expenditures have been assigned to the study of the subject. On the other hand, there have been serious advances in imaging helping us to characterizenon-vulnerable patients The latter has much more value in the clinical decision-making process since it provides high certainty that the patient's probability of a future acute event is low and treatment decisions should be made accordingly. Although coronary plaque rupture is still recognized as the main source of acute thrombotic events, numerous studies have shown that the prediction of events on an individual basis is far more complex and demands a more open approach aimed at characterizing patient risk rather than assessing the risk of thrombosis of a single plaque. Computed tomography coronary angiography (CTCA) has the ability to evaluate non-invasively the extent, burden, severity, and characteristics of coronary artery disease (CAD) and has a close relationship to intravascular ultrasound. On the basis of an excellent negative predictive value with an annualized event rate of ∼0.20% assessed over more than 6000 patients, thus providing a 5-year warranty period, CTCA has been identified as the finest non-invasive tool to exclude CAD. This means that CTCA is able to reliably characterize the non-vulnerable patient. Conversely, in the past few years, several studies have attempted to establish CTCA-derived predictors of acute coronary syndromes, both from a lesion level and a patient level basis with very low positive predictive value, thus questioning the vulnerable patient/plaque concept.

Coronary artery calcium score and CT angiography in asymptomatic elderly patients with high pretest probability for coronary artery disease

PURPOSE

To evaluate the role of coronary artery calcium scoring (CACS) and/or coronary CT angiography (CCTA) in asymptomatic elderly patients with high pretest probability for coronary artery disease (CAD).

MATERIALS AND METHODS

Forty-eight consecutive asymptomatic elderly (>65 years) subjects who had a high pretest probability and underwent CACS/CCTA were included. Each CCTA was evaluated for adequacy for assessment of coronary stenosis. Significant stenosis (>50% diameter narrowing) was assessed on evaluable CT images and by invasive catheter angiography (ICA).

RESULTS

All subjects were men with mean CACS of 880 ± 1779. Among those with low (0-99), intermediate (100-399), and high (400-999) CACS, ICA-verified significant stenosis was present in 8% (1/13), 23% (2/13), and 67% (8/12), respectively. Among those with very high CACS (≥ 1000) (n = 10), 90% of CCTAs were not evaluable for stenosis.

CONCLUSION

In asymptomatic elderly subjects with high pretest probability, CACS followed by CCTA may be considered for those with intermediate to high CACS.

Pathophysiology of Vascular Calcification

Vascular calcification can lead to cardiovascular morbidity and mortality. The initiating factors and clinical consequences depend on the underlying disease state and location of the calcification. The pathogenesis of vascular calcification is complex and involves a transformation of vascular smooth muscle cells to an osteo/chondrocytic cell that expresses RUNX2 and produces matrix vesicles. The imbalance of promoters (such as hyperphosphatemia and hypercalcemia) and inhibitors (e.g., fetuin-A) is critical in the development of vascular calcification. The altered mineral metabolism and deficiency in inhibitors are common in patients with chronic kidney disease (CKD) and is one reason why vascular calcification is so prevalent in that population.

Coronary Artery Calcification Score as A Predictor of All-Cause Mortality and Cardiovascular Outcome in Peritoneal Dialysis Patients

♦

BACKGROUND

This study aimed to examine whether the coronary artery calcification score (CaCS) was associated with the prognosis of peritoneal dialysis (PD) patients. ♦

METHODS

Adult PD patients who were clinically stable for at least 2 months were recruited for this prospective, observational cohort study. Coronary artery calcification was assessed using multislice spiral computed tomography and was recorded according to the Agatston score. The endpoints including all-cause mortality, cardiovascular events, and cardiovascular mortality were assessed. Multivariate Cox regression was used to identify independent predictors of all-cause mortality, cardiovascular events (CVEs), and cardiovascular mortality. ♦

RESULTS

A total of 179 PD patients (86 men) with a mean age of 63.5 ± 14.8 years were recruited for this study. Coronary artery calcification scores ranging from 0 to 5,257 were stratified as follows: no (CaCS = 0, n = 54), low (0 < CaCS < 400, n = 72), and high (CaCS ≥ 400, n = 53) calcification. The follow-up duration was 30.6 ± 16.2 (24-63) months. Compared with the no calcification group, patients with a higher CaCS were older and had lower diastolic blood pressure, residual renal function, and serum albumin, and higher HbA1C and serum insulin. Multivariate Cox regression revealed that the CaCS was an independent predictor for all the 3 endpoints after adjustment in PD patients. ♦

CONCLUSIONS

CaCS was an independent predictor of all-cause mortality, cardiovascular events, and cardiovascular mortality in patients receiving peritoneal dialysis.

Mitral Annular and Coronary Artery Calcification Are Associated with Mortality in HIV-Infected Individuals

BACKGROUND

HIV infection increases cardiovascular risk. Coronary artery calcification (CAC) and mitral annular calcification (MAC) identify patients at risk for cardiovascular disease (CVD). The purpose of this study was to examine the association between MAC, CAC and mortality in HIV-infected individuals.

METHODS AND RESULTS

We studied 152 asymptomatic HIV-infected individuals with transthoracic echocardiography (TTE) and computed tomography (CT). MAC was identified on TTE using standardized criteria. Presence of CAC, CAC score and CAC percentiles were determined using the modified Agatston criteria. Mortality data was obtained from the Social Security and National Death Indices (SSDI/NDI). The median age was 49 years; 87% were male. The median duration of HIV was 16 years; 84% took antiretroviral therapy; 64% had an undetectable viral load. CVD risk factors included hypertension (35%), smoking (62%) and dyslipidemia (35%). Twenty-five percent of individuals had MAC, and 42% had CAC. Over a median follow-up of 8 years, 11 subjects died. Subjects with CAC had significantly higher mortality compared to those with MAC only or no MAC. The Harrell's C-statistic of CAC was 0.66 and increased to 0.75 when MAC was added (p = 0.05). MAC, prior CVD, age and HIV viral load were independently associated with higher age- and gender-adjusted CAC percentiles in an adjusted model (p < 0.05 for all).

CONCLUSION

In HIV patients, the presence of MAC, traditional risk factors and HIV viral load were independently associated with CAC. Presence of CAC and MAC may be useful in identifying HIV-infected individuals at higher risk for death.

Novel contributions of multimodality imaging in hypertension: A narrative review

Hypertension is currently one of the most prevalent illnesses worldwide, and is the second most common cause of heart failure, only behind ischemic cardiomyopathy. The development of novel multimodality imaging techniques in recent years has broadened the diagnostic methods, risk stratification and monitoring of treatment of cardiovascular diseases available for clinicians. Cardiovascular magnetic resonance (CMR) has a great capacity to evaluate cardiac dimensions and ventricular function, is extremely useful in ruling-out ischemic cardiomyopathy, the evaluation of the vascular system, in making the differential diagnosis for resistant hypertension and risk stratification for hypertensive cardiomyopathy and constitutes today, the method of choice to evaluate left ventricular systolic function. Computed tomography (CT) is the method of choice for the evaluation of vascular anatomy, including coronary arteries, and is also able to provide both functional and structural information. Finally, nuclear cardiology studies have been traditionally used to evaluate myocardial ischemia, along with offering the capacity to evaluate ventricular, endothelial and cardiac innervation function; information that is key in directing the treatment of the patient. In this narrative review, the most recent contributions of multimodality imaging to the patient with hypertension (CMR, CT and nuclear cardiology) will be reviewed.

[Screening and risk factors of cardiac calcification in hemodialysis: contribution of ultra-fast multi-slice scanner and transthoracic echocardiography]

INTRODUCTION

Cardiovascular disease is the first leading cause of death in hemodialysis patients. In this population, cardiovascular calcifications occur at an earlier age and progress faster than in general population.

PATIENTS AND METHODS

In order to determine the prevalence and risk factors of cardiac calcifications, 49 patients on chronic hemodialysis were screened in the coronary arteries and cardiac valves by the 64 multi-slice ultra-fast CT and the transthoracic echocardiography. Different clinical and biological parameters were studied by the SPSS 10.0 statistical software to determine risk factors.

RESULT

Cardiac calcifications were identified in 81.6% of cases in at least one of the two studied sites. The coronary artery involvement was more common than valvular and concerned 69.4% of cases. The mean Agatston coronary artery calcium score (ACACS) was 331.1 and 522.2 in coronary patients and was correlated to alteration of systolic function of LV (r=-0.287, P=0.045). The severity of CACS was positively correlated with age (r=0.332, P=0.02). Coronary calcifications were associated with cardiovascular risk common to those of the general population (age, male sex, systolic blood pressure, diabetes, history of ischemic heart disease), but also to a lesser quality of dialysis. Valvular calcifications were present in 49% of cases and were correlated with left ventricular hypertrophy (P=0.006). The exclusive involvement of the aortic valve was the most common valvular abnormality. Phosphocalcic and lipid parameters, levels of hemoglobin, CRP and uric acid did not predisposed to cardiac calcifications in our patients.

DISCUSSION

In hemodialysis patients, the pathogenesis of cardiovascular calcification is complex and cannot be attributed to a passive process. This process involves several factors that can promote or inhibit calcification. The new multi-slice ultra-fast scanner is a very sensitive method for topographic and quantitative assessment of coronary calcification and is a better alternative to invasive techniques.

CONCLUSION

Our study confirms the high prevalence of cardiac calcification in hemodialysis, and highlights the importance of early screening and treatment of predisposing factors.

Association of circulating sclerostin with vascular calcification in Afro-Caribbean men

OBJECTIVE

Sclerostin, a Wingless (Wnt) pathway antagonist, is an established regulator of bone mineralization in humans but its potential importance in the regulation of vascular calcification is less clear. Therefore, our objective was to assess the relationship of serum sclerostin levels with coronary and aortic artery calcification (CAC and AAC, respectively) in Afro-Caribbean men on the island of Tobago.

METHODS

Serum sclerostin levels and computed tomography of CAC and AAC were measured in 191 men (age mean(SD): 62.9(8.0)years) recruited without regard to health status. Multivariable logistic regression models were used to assess the cross-sectional association of sclerostin with prevalent arterial calcification.

RESULTS

Mean(SD) sclerostin was 45.2 pmol/L (15.6 pmol/L). After adjusting for risk factors including age, physical and lifestyle characteristics, comorbidities, lipoproteins and kidney function, 1 SD greater sclerostin level was associated with a 1.61-times (95%CI 1.02-2.53) greater odds of having CAC. Sclerostin was not associated with AAC in any model.

CONCLUSIONS

This is the first study to show that, among Afro-Caribbean men, greater serum sclerostin concentrations were associated with prevalence and extent of CAC. Further studies are needed to better define the role of the Wnt signaling pathway in arterial calcification in humans.

Association of volumetric bone mineral density with abdominal aortic calcification in African ancestry men

SUMMARY

We tested for association between cortical and trabecular volumetric bone mineral density (vBMD) with abdominal aortic calcification (AAC) prevalence in 278 Afro-Caribbean men. AAC was present in 68.3 % of the men. Greater cortical, but not trabecular, vBMD was associated with significantly decreased odds of AAC independent of traditional risk factors.

INTRODUCTION

The aim of this study is to assess the prevalence and correlates of AAC in a sample of 278 Afro-Caribbean men (mean age 56) and to test for a largely unexplored association between cortical and trabecular vBMD with AAC prevalence.

METHODS

Men were recruited consecutively as part of an ongoing prospective cohort study of body composition in men aged 40+. For this analysis, AAC was assessed by computed tomography of the abdomen from L3 to S1. Aortic calcium was scored using the Agatston method, and prevalence was defined as a score ≥10 to rule out false positives. Men also had BMD assessed using peripheral quantitative computed tomography at 4 % (trabecular vBMD) and 33 % (cortical vBMD) of the radius and tibia.

RESULTS

Abdominal aortic calcification was present in 68.3 % of the men. Significant independent predictors of AAC prevalence were increased age, increased BMI, hypertension, and current smoking. Age was the strongest predictor, with each SD (7.8 year) increase in age conferring 2.7 times increased odds of having AAC (P < 0.0001). A one SD greater cortical, but not trabecular, vBMD was associated with a significant decreased odds of AAC prevalence independent of other traditional risk factors (OR 0.65; 95 % CI 0.45-0.92).

CONCLUSIONS

Cortical vBMD is inversely associated with AAC presence. This finding suggests that there may be shared physiology between cortical bone compartment remodeling and vascular calcification.

Frequency of unrecognized, unreported, or underreported coronary artery and cardiovascular calcification on noncardiac chest CT

BACKGROUND

Coronary artery calcification (CAC) is correlated with cardiovascular outcomes and, therefore, can change management. Such calcifications are identifiable on noncardiac chest CT (NCCT), although there is no standard for interpretation. However, no data are published on the frequency of these findings being reported during NCCT interpretation.

METHODS

To obtain population with a high likelihood of CAC, we identified 355 patients with known (n = 136) or suspected (n = 219) coronary artery disease in whom single-photon emission CT myocardial perfusion imaging and NCCT were ordered within 1 month of each other; their mean age was 63 years, and 204 were women. Single-photon emission CT reports, NCCT reports, and retrospective NCCT image interpretations were performed by the investigators independently.

RESULTS

CAC was present in 207 of the 355 patients (58% of the group) but was recorded in the final radiology report as present in only 44% of these subjects. CAC in the left main coronary artery was evident on review in 139 patients but was specified in the final report in only 1 patient. Left anterior descending CAC was evident in 188 patients but reported in only 3%.

CONCLUSIONS

In this observational study, CAC on NCCT in this enriched population was often unreported. Although NCCT can indicate presence and location of CAC, these features are rarely reported, even when involving locations such as the left main coronary artery or left anterior descending artery. In view of its diagnostic and prognostic importance, evaluation of CAC should become a routine part of the interpretation of NCCT.

Impact of diabetes on cardiovascular disease: an update

Cardiovascular diseases are the most prevalent cause of morbidity and mortality among patients with type 1 or type 2 diabetes. The proposed mechanisms that can link accelerated atherosclerosis and increased cardiovascular risk in this population are poorly understood. It has been suggested that an association between hyperglycemia and intracellular metabolic changes can result in oxidative stress, low-grade inflammation, and endothelial dysfunction. Recently, epigenetic factors by different types of reactions are known to be responsible for the interaction between genes and environment and for this reason can also account for the association between diabetes and cardiovascular disease. The impact of clinical factors that may coexist with diabetes such as obesity, dyslipidemia, and hypertension are also discussed. Furthermore, evidence that justify screening for subclinical atherosclerosis in asymptomatic patients is controversial and is also matter of this review. The purpose of this paper is to describe the association between poor glycemic control, oxidative stress, markers of insulin resistance, and of low-grade inflammation that have been suggested as putative factors linking diabetes and cardiovascular disease.

Role of nonenhanced multidetector CT coronary artery calcium testing in asymptomatic and symptomatic individuals

Arteriosclerotic cardiovascular disease is the leading cause of death in the United States, with coronary artery disease (CAD) accounting for half of all cardiovascular disease deaths. Current risk assessment approaches for coronary heart disease, such as the Framingham risk score, substantially misclassify intermediate- to long-term risk for the occurrence of CAD in asymptomatic individuals. A screening modality such as a simple non-contrast-enhanced, or noncontrast, computed tomographic (CT) detection of coronary artery calcium (CAC) improves the ability to accurately predict risk in vulnerable groups and adds information above and beyond global risk assessment as shown by the recent Multi-Ethnic Study of Atherosclerosis. In addition, absence of CAC is associated with a very low risk of future CAD and as a result can be used to identify a group among which further testing and pharmacotherapies can be avoided. The Expert Consensus Document by the American College of Cardiology Foundation and the American Heart Association now recommends screening individuals at intermediate risk but did not find enough evidence to recommend CAC testing and further stratification of those in the low- or high-risk categories for CAD. In addition, emerging guidelines have suggested that absence of CAC can act as a "gatekeeper" for further testing among low- and intermediate-risk patients presenting with chest pain. This review of the current literature outlines the role of CAC testing in both asymptomatic and symptomatic individuals.

Vascular calcification: pathophysiology and risk factors

Vascular calcification can occur in nearly all arterial beds and in both the medial and intimal layers. The initiating factors and clinical consequences depend on the underlying disease state and location of the calcification. The best studied manifestation is coronary artery calcification, in part because of the obvious clinical consequences, but also because of CT-based imaging modalities. In the general population, the presence of coronary artery calcification increases cardiovascular risk above that predicted by traditional Framingham risk factors, suggesting the presence of nontraditional risk factors. In patients with chronic kidney disease (CKD), coronary artery calcification is more prevalent and markedly more severe than in the general population. In these CKD patients, nontraditional risk factors such as oxidative stress, advanced glycation end products, and disordered mineral metabolism are also more prevalent and more severe and offer mechanistic insight into the pathogenesis of vascular calcification.

Coronary artery calcification score is associated with mortality in Japanese hemodialysis patients

OBJECTIVE

Coronary artery calcification has been associated with higher mortality in coronary artery disease and chronic kidney disease. This study aimed to correlate coronary artery calcification score (CACS) with all-cause and cardiovascular mortalities in hemodialysis (HD) patients.

DESIGN, SETTING, SUBJECTS

A survival analysis was conducted in 200 HD patients. CACS was assessed by multidetector-row computed tomography and stratified as tertiles: group 1 (0∼105 U), group 2 (110∼1067 U), and group 3 (1094∼15481 U). The duration of follow-up was 7 years and 4 months. Kaplan-Meier method and Cox proportional hazard analysis adjusted for age and HD duration were performed to examine the impact of CACS on survival.

MAIN OUTCOME MEASURE

All-cause and cardiovascular mortalities were measured.

RESULTS

The cumulative all-cause and cardiovascular mortalities of group 1 were significantly lower than those of groups 2 and 3 (all-cause mortality: 7.6% vs. 43.3% and 52.2%, respectively, cardiovascular mortality: 3.0% vs. 22.4% and 26.9%, respectively). Cox proportional hazard analysis adjusted for age and HD duration revealed that all-cause and cardiovascular mortalities of group 1 were significantly lower than those of groups 2 and 3.

CONCLUSION

CACS is helpful to predict prognosis of HD patients independently of age and HD duration.

Added value of CAC in risk stratification for cardiovascular events: a systematic review

BACKGROUND

Identification of individuals at high risk for cardiovascular disease (CVD) is important to initiate adequate treatment and to prevent future events. Moreover, identification of low-risk individuals is important to refrain from unneeded therapy. Current risk prediction models do not accurately predict the risk of CVD in individuals, and new markers have been sought to improve the risk assessment in individuals. Coronary artery calcification (CAC) is a marker of atherosclerosis that might improve current risk assessment when added to traditional risk factors.

MATERIALS AND METHODS

We performed a systematic review on PubMed search (1 February 2011) on studies reporting on the added value of CAC in risk prediction in asymptomatic individuals.

RESULTS

Of 39 publications on CAC and CVD, nine studies were carried out in asymptomatic individuals. All studies showed an increase in area under the curve ranging from 0.05 to 0.20 when CAC was added to the risk model. Four studies reported on improvements of individuals in low-, intermediate-, and high-risk categories. Addition of CAC to the risk model resulted in a net reclassification improvement ranging from 14% to 30%, meaning that CAC measurement reclassified a substantial proportion of individuals into correct risk categories. This improvement was most pronounced in those at intermediate Framingham risk.

CONCLUSIONS

The available studies consistently showed that CAC scoring improves risk stratification in CVD risk categories when added to traditional risk factors only, especially among individuals at intermediate risk for CVD. Cost-effectiveness analyses together with a randomized controlled trial are needed before widespread introduction of CAC in clinical care.

The association of Framingham and Reynolds risk scores with incidence and progression of coronary artery calcification in MESA (Multi-Ethnic Study of Atherosclerosis)

OBJECTIVES

The purpose of this study was to compare the association of the Framingham risk score (FRS) and Reynolds risk score (RRS) with subclinical atherosclerosis, assessed by incidence and progression of coronary artery calcium (CAC).

BACKGROUND

The comparative effectiveness of competing risk algorithms for identifying subclinical atherosclerosis is unknown.

METHODS

MESA (Multi-Ethnic Study of Atherosclerosis) is a prospective cohort study of 6,814 participants free of baseline cardiovascular disease. All participants underwent risk factor assessment, as well as baseline and follow-up CAC testing. We assessed the performance of the FRS and RRS to predict CAC incidence and progression using relative risk and robust linear regression.

RESULTS

The study population included 5,140 individuals (mean age 61 ± 10 years, 47% males, mean follow-up: 3.1 ± 1.3 years). Among 53% of subjects (n = 2,729) with no baseline CAC, 18% (n = 510) developed incident CAC. Both the FRS and RRS were significantly predictive of incident CAC (relative risk: 1.40 [95% confidence interval (CI): 1.29 to 1.52] and 1.41 [95% CI: 1.30 to 1.54] per 5% increase in risk, respectively) and CAC progression (mean CAC score change: 6.92 [95% CI: 5.31 to 8.54] and 6.82 [95% CI: 5.51 to 8.14] per 5% increase). Discordance in risk category classification (<10% or >10% per 10-year coronary heart disease risk) occurred in 13.7%, with only the RRS consistently adding predictive value for incidence and progression of CAC. These subclinical atherosclerosis findings are supported by a coronary heart disease events analysis over a mean follow-up of 5.6 ± 0.7 years.

CONCLUSIONS

Both the RRS and FRS predict onset and progression of subclinical atherosclerosis. However, the RRS may provide additional predictive information when discordance between the scoring systems exists.

Progression of coronary artery calcification in renal transplant recipients

BACKGROUND

Cardiovascular disease is the leading cause of mortality among renal transplant recipients. In the general population, coronary artery calcification (CAC) and progression of CAC are predictors of future cardiac risk. We conducted a study to determine the progression of CAC in renal transplant recipients; we also examined the factors associated with progression and the impact of the analytic methods used to determine CAC progression.

METHODS

We used multi-detector computed tomography to examine CAC in 150 prevalent renal transplant recipients, who did not have a documented cardiovascular disease. A baseline and a follow-up scan were performed and changes in CAC scores were evaluated in each patient individually, to calculate the incidence of CAC progression. Multivariate logistic regression analysis was used to evaluate the determinants of CAC progression.

RESULTS

Baseline CAC prevalence was 35.3% and the mean CAC score was 60.0 ± 174.8. At follow-up scan that was performed after an average of 2.8 ± 0.4 years, CAC prevalence increased to 64.6% and the mean CAC score to 94.9 ± 245.7. Progression of individual CAC score was found between 28.0 and 38.0%, depending on the method used to define progression. In patients with baseline CAC, median annualized rate of CAC progression was 11.1. Baseline CAC, high triglyceride and bisphosphonate use were the independent determinants of CAC progression.

CONCLUSIONS

Renal transplantation does not stop or reverse CAC. Progression of CAC is the usual evolution pattern of CAC in renal transplant recipients. Beside baseline CAC, high triglyceride level and bisphosphonate use were associated with progression of CAC.

Genetic mapping of vascular calcified plaque loci on chromosome 16p in European Americans from the diabetes heart study

A linkage peak for carotid artery calcified plaque (CarCP) on chromosome 16p (LOD 4.39 at 8.4 cM) in families with type 2 diabetes mellitus (T2DM) from the Diabetes Heart Study (DHS) has been refined. Fine mapping encompassed 104 single-nucleotide polymorphisms (SNPs) in 937 subjects from 315 families; including 45 SNPs in six candidate genes (CACNA1H, SEPX1, ABCA3, IL32, SOCS1, CLEC16A). Linkage and association analyses using variance components analysis adjusting for age, gender, body mass index (BMI), and diabetes status refined the CarCP linkage into two distinct peaks (LODs: 3.89 at 6.9 cM and 4.86 at 16.0 cM). Evidence of linkage for coronary calcified plaque (LOD: 2.27 at 19 cM) and a vascular calcification principle component (LOD: 3.71 at 16.0 cM) was also observed. The strongest evidence for association with CarCP was observed with SNPs in the A2BP1 gene region (rs4337300 P= 0.005) with modest evidence of association with SNPs in CACNA1H (P= 0.010-0.033). Bayesian quantitative trait nucleotide (BQTN) analysis identified a SNP, rs1358489, with either a functional effect on CarCP or in linkage disequilibrium (LD) with a functional SNP. This study refined the 16p region contributing to vascular calcification. The causal variants remain to be identified, but results are consistent with a linkage peak that is due to multiple common variants, though rare variants cannot be excluded.