Mammographically detectable breast arterial calcification and atherosclerosis

Opportunistic screening at chest computed tomography: literature review of cardiovascular significance of incidental findings

Background and Objective

Several incidental cardiovascular findings are present in a routine chest computed tomography (CT) scan, many of which do not make it to the final radiology report. However, these findings have important clinical implications, particularly providing prognosis and risk-stratification for future cardiovascular events. The purpose of this article is to review the literature on these incidental cardiovascular findings in a routine chest CT and inform the radiologist on their clinical relevance.

Methods

A time unlimited review of PubMed and Web of Science was performed by using relevant keywords. Articles in English that involved adults were included.

Key Content and Findings

Coronary artery calcification (CAC) is the most common incidental cardiac finding detected in a routine chest CT and is a significant predictor of cardiovascular events. Noncoronary vascular calcifications in chest CT include aortic valve, mitral annulus, and thoracic aortic calcifications (TAC). Among these, aortic valve calcification (AVC) has the strongest association with coronary artery disease and cardiovascular events. Additional cardiac findings such as myocardial scar and left ventricular size and noncardiac findings such as thoracic fat, bone density, hepatic steatosis, and breast artery calcifications can also help in risk stratification and patient management.

Conclusions

The radiologist interpreting a routine chest CT should be cognizant of the incidental cardiovascular findings, which helps in the diagnosis and risk-stratification of cardiovascular disease. This will guide appropriate referral and management.

Associations of Breast Arterial Calcifications with Cardiovascular Disease

Cardiovascular diseases (CVD), including coronary artery disease (CAD), continue to be the leading cause of global mortality among women. While traditional CVD/CAD prevention tools play a significant role in reducing morbidity and mortality among both men and women, current tools for preventing CVD/CAD rely on traditional risk factor-based algorithms that often underestimate CVD/CAD risk in women compared with men. In recent years, some studies have suggested that breast arterial calcifications (BAC), which are benign calcifications seen in mammograms, may be linked to CVD/CAD. Considering that millions of women older than 40 years undergo annual screening mammography for breast cancer as a regular activity, innovative risk prediction factors for CVD/CAD involving mammographic data could offer a gender-specific and convenient solution. Such factors that may be independent of, or complementary to, current risk models without extra cost or radiation exposure are worthy of detailed investigation. This review aims to discuss relevant studies examining the association between BAC and CVD/CAD and highlights some of the issues related to previous studies' design such as sample size, population types, method of assessing BAC and CVD/CAD, definition of cardiovascular events, and other confounding factors. The work may also offer insights for future CVD risk prediction research directions using routine mammograms and radiomic features other than BAC such as breast density and macrocalcifications.

Breast Arterial Calcification Rates in a Diverse, Urban Group of Screening Mammography Patients

PURPOSE

Breast arterial calcifications (BAC), detected by digital mammography are a potential marker of coronary artery disease (CAD). Past BAC research has been limited by having primarily racially and ethnically homogeneous samples, samples at higher risk for CAD, and neglecting to explore the influence of women's health factors. The purpose of this study was to evaluate the prevalence of, and factors associated with, BAC in an ethnically and racially diverse group.

METHODS

We conducted a retrospective chart review on 17,237 screening mammography patients. Mammography results and patient responses to a demographic and medical history questionnaire were abstracted. Logistic regression was used.

RESULTS

BAC prevalence was 12.3%. Age was a significant risk factor, with the odds of BAC approximately doubling every decade. Age-adjusted analyses showed: 1) higher BAC prevalence among Hispanic, Black, and Ashkenazi women; 2) lower BAC prevalence among nulliparous and pre-menopausal women, those with dense breasts and breast implants, and those currently using HRT; and 3) no association between BAC prevalence and BMI or age at menarche.

CONCLUSIONS

BAC prevalence differs according to age, ethnicity, race, women's health, and breast-specific factors. Communication of BAC information in clinical settings could potentially prompt women to engage in preventive care.

Breast artery calcification as an opportunistic predictor of cardiovascular disease

BACKGROUND

Atherosclerotic cardiovascular disease is still the leading cause of mortality for women. Breast cancer screening with mammography is recommended in all women aged over 40 years.

AIMS

Whether breast artery calcification (BAC) is associated with cardiovascular disease is not clear. We aimed to evaluate the association between BAC and the presence of coronary atherosclerosis determined by CT.

METHODS

All patients who underwent both mammography and coronary CT angiography between January 2010 and December 2016 were screened, and patients with a duration of less than 12 months between CT and mammography were included.

RESULTS

A total of 320 women were included and BAC was detected in 47 (14.6%) patients. BAC was correlated with age and CT coronary calcium score. Both the frequency of critical coronary artery stenosis (34% vs 10.6%; p = 0.001) and CT coronary calcium score (5.5 vs 0; p = 0.001) was significantly higher in patients with BAC. The absence of BAC was a strong predictor of the absence of significant coronary artery disease (p = 0.001). BAC was independently associated with all-cause mortality after excluding patients with breast cancer (HR: 5.32; p = 0.013).

CONCLUSION

Breast artery calcification is associated with coronary calcium score and significant coronary stenosis. A high BAC score is related to increased mortality.

Breast arterial calcifications as an indicator of atherosclerotic cardiovascular disease: comparative analysis of coronary computed tomography scoring systems and carotid intima-media thickness

BACKGROUND

Breast arterial calcification (BAC) is easily detected and commonly observed on screening mammography. That is more frequent among people with diabetes, and these people are at risk of coronary artery disease. The incidence of BAC increases with advancing age. We aimed to determine whether BAC detected by mammography is associated with the development of coronary atherosclerosis in asymptomatic women. It can help reduce morbidity and mortality secondary to atherosclerotic cardiovascular disease.

METHODS

We included one hundred and eighty women over the age of 40 who underwent mammography screening in this multi-modality study. Mammography evaluated the presence of calcifications, the number of involved arteries, and the distribution. We questioned the patients about cardiovascular risk factors such as hypertension and diabetes. The coronary artery disease severity was assessed according to both Agatston and calcium scores on coronary computed tomography (CT). Besides, the relationship between these scores and correlation with carotid artery intima-media thickness was investigated. We stated mean and standard deviation (SD) for continuous variables and reported frequency distributions and percentages. SPSS software version 25.0 was used to perform the analysis.

RESULTS

Overall, 302 of 3,600 cases were positive for BAC. However, 120 of them could be included in the study by the eligibility criteria of our research. In univariate analysis, age, hyperlipidemia, DM, HT, and smoking history were risk factors that significantly affected BAC development. The impact of age and diabetes were maintained in the logistic regression analysis (P<0.005), while the significant effect of the other variables was vanished (P>0.02). Furthermore, moderate and high BAC scores were correlated with higher coronary atherosclerosis scores.

CONCLUSIONS

BAC may predict an additional risk factor for coronary artery disease, particularly in patients having higher scores. That may be an accurate indicator for subsequent development of coronary arterial calcifications so that it may be possible to reduce morbidity and mortality associated with coronary atherosclerosis.

Breast Arterial Calcifications: Reporting Preferences and Impact on Screening for Coronary Artery Disease

OBJECTIVE

Breast arterial calcifications (BAC) have been shown to correlate with measures of coronary artery disease risk stratification, although reporting of BAC is optional by BI-RADS guidelines. The purpose of this study is to determine referring provider preferences in BAC reporting on mammography reports and if such reporting has any impact on patient management.

METHODS

This study was approved by the local institutional review board. A voluntary eight-question survey regarding the preferences and outcomes of BAC reporting on mammography was distributed to 1085 primary care physicians, obstetrics and gynecologists, medical oncologists, and breast and general surgeons in our health system via a secure online platform. Data analysis including Pearson chi-square was performed with a P-value of <0.05 for significance.

RESULTS

A response rate of 19.1% (207/1085) was attained, with 21/207 (10.1%) of respondents indicating they do not routinely order mammograms excluded from further analysis. A total of 62.4% (116/186) of ordering physicians indicated a preference for reporting of BAC in both the body and impression of the radiology report, with 82.3% (153/186) of respondents placing importance on the quantity of atherosclerotic calcifications. Most participants (148/186, 79.6%) reported that the presence of BAC would prompt further investigation for coronary artery disease and associated risk factors.

CONCLUSION

The majority of responding physicians indicated a preference for detailed reporting of BAC and that such reporting would impact patient care. Understanding referring provider preferences regarding ancillary findings of BAC will allow for improved communication and value in mammography.

Mammographic features are associated with cardiometabolic disease risk and mortality

Aims

In recent years, microcalcifications identified in routine mammograms were found to be associated with cardiometabolic disease in women. Here, we aimed to systematically evaluate the association of microcalcifications and other mammographic features with cardiometabolic disease risk and mortality in a large screening cohort and to understand a potential genetic contribution.

Methods and results

This study included 57 867 women from a prospective mammographic screening cohort in Sweden (KARMA) and 49 583 sisters. Cardiometabolic disease diagnoses and mortality and medication were extracted by linkage to Swedish population registries with virtually no missing data. In the cardiometabolic phenome-wide association study, we found that a higher number of microcalcifications were associated with increased risk for multiple cardiometabolic diseases, particularly in women with pre-existing cardiometabolic diseases. In contrast, dense breasts were associated with a lower incidence of cardiometabolic diseases. Importantly, we observed similar associations in sisters of KARMA women, indicating a potential genetic overlap between mammographic features and cardiometabolic traits. Finally, we observed that the presence of microcalcifications was associated with increased cardiometabolic mortality in women with pre-existing cardiometabolic diseases (hazard ratio and 95% confidence interval: 1.79 [1.24–2.58], P = 0.002) while we did not find such effects in women without cardiometabolic diseases.

Conclusions

We found that mammographic features are associated with cardiometabolic risk and mortality. Our results strengthen the notion that a combination of mammographic features and other breast cancer risk factors could be a novel and affordable tool to assess cardiometabolic health in women attending mammographic screening.

Mammographic Screening as a Tool for Cardiovascular Risk Assessing. Part 2. Association of Breast Arterial Calcification and Cardiovascular Diseases

Prospects for the use of mammographic detection of breast arterial calcification (BAC) to improve the stratification of cardiovascular risk in the female population are of increasing interest. The purpose of the 2 part of the review is the analysis of modern literature on the relationship of the BAC with the prevalence and mortality from cardiovascular diseases (CVD). The presence of BAC on mammograms is associated with a higher likelihood of myocardial infarction, death from coronary heart disease (CHD) and CVD, as well as a 3.5-fold increase in the risk of CHD and a 5-year coronary incident (p=0.003). Women with BAC have a higher likelihood of coronary artery disease detected during angiography than women without BAC (p<0.001). Severe BAC has a stronger association with CVD than mild calcification. The association of BAC with cerebrovascular diseases and a 1.4-fold increase in the risk of ischemic stroke (p=0.004), atheromatosis of the carotid arteries and an increase in the thickness of the intima-media complex is shown. BAC is associated with atherosclerotic lesions of peripheral arteries and a decrease in the ankle-brachial index <0.9 (p=0.048). In women with chronic kidney disease, the presence of BAC indicates a 4.5-fold increase in the risk of complications associated with impaired blood flow in peripheral arteries. It is shown that the addition of BAC to the generally accepted (standard) vascular risk assessment algorithms Framingham Risk Score and Pooled Cohort Equation significantly increases the accuracy of prediction of CHD (p=0.02 and p=0.010, respectively). The detection of BAC on mammographic screening is a new promising direction for cardiovascular prophylaxis in women and opens up new opportunities for identifying groups of people with subclinical forms of CVD and high cardiovascular risk.

Breast arterial calcification on mammography and risk of coronary artery disease: a SCOT-HEART sub-study

AIM

To assess the prevalence of breast arterial calcification (BAC) in patients who also underwent routine surveillance mammography, and to determine the association with cardiovascular risk factors, coronary artery calcification, and coronary artery disease on coronary computed tomography angiography (CCTA).

MATERIALS AND METHODS

Four hundred and five female participants were identified who had undergone CCTA and subsequent mammography in the SCOT-HEART randomised controlled trial of CCTA in patients with suspected stable angina. Mammograms were assessed visually for the presence and severity of BAC.

RESULTS

BAC was identified in 93 (23%) patients. Patients with BAC were slightly older (63±7 versus 59±8 years, p<0.001), with a higher cardiovascular risk score (19±11 versus 16±10, p=0.022) and were more likely to be non-smokers (73% versus 49%, p<0.001). In patients with BAC, coronary artery calcification was present in 58 patients (62%; relative risk [RR] 1.26, 95% confidence intervals [CI]: 1.04, 1.53; p=0.02), non-obstructive coronary artery disease in 58 (62%; RR 1.27, 95% CI: 1.04 to 1.54, p=0.02), and obstructive coronary artery disease in 19 (20%; RR 1.62, 95% CI: 0.98, 2.66; p=0.058). Patients without BAC were very unlikely to have severe coronary artery calcification (negative predictive value 95%) but the diagnostic accuracy of BAC to identify coronary artery disease was poor (AUC 0.547).

CONCLUSION

Although BAC is associated with the presence and severity of coronary artery calcification, the diagnostic accuracy to identify patients with coronary artery disease or obstructive coronary artery disease is poor.

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Breast arterial calcification occurs in a fifth of patients referred for CCTA who tend to be older non-smokers.

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It is associated with higher coronary artery calcium but this is predominantly dependent on age and cardiovascular risks.

•

Absence of breast arterial calcification excludes severe coronary artery calcification, negative predictive value of 95%.

A Review of the Role of Breast Arterial Calcification for Cardiovascular Risk Stratification in Women

Cardiovascular disease continues to be the leading cause of death among women in the United States. One of the barriers to improving cardiovascular disease outcomes in women is the lack of reliable, effective screening modalities. Breast arterial calcification has emerged as a potential risk stratification tool. Localized deposition in the media of the artery, known as Mönckeberg medial calcific sclerosis, is notably different from the intimal atherosclerotic process commonly associated with coronary artery disease. Nonetheless, studies favor a correlation between breast arterial calcification and cardiovascular risk factors or coronary artery disease, defined as coronary artery calcification on computed tomography scan or both nonobstructive and obstructive lesions on angiography. Since a majority of women over the age of 40 undergo yearly breast cancer screening with mammography, measurement of breast arterial calcification may offer a personalized, noninvasive approach to risk-stratify women for cardiovascular disease at no additional cost or radiation. Mammography has the potential to alter the course of the leading cause of death in women, heart disease, through the evaluation of breast arterial calcification and identification of opportunities for prevention. Current evidence supports the universal reporting of breast arterial calcifications and personalized patient-provider discussions to more aggressively treat cardiac risk factors through targeted medical therapies or healthy lifestyle changes.

The correlation of SYNTAX score by coronary angiography with breast arterial calcification by digital mammography

AIM

To evaluate the hypothesis that breast arterial calcification (BAC) may predict coronary artery disease (CAD) severity.

MATERIALS AND METHODS

The study comprised 102 women >45 years (mean age 62±8 years) referred for digital mammography after coronary angiography. BAC was assessed using the Likert scale and CAD severity was assessed using the SYNTAX (SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery trial) score.

RESULTS

In comparison to the low SYNTAX score group (≤22) patients with a intermediate-to-high SYNTAX score (>22) were older (p=0.001), they more often had hypercholesterolaemia (p<0.001), diabetes (p=0.021), and a history of smoking (p=0.048). They also had a statistically higher level of fasting blood glucose (p<0.001), glycated haemoglobin (HbA1C; p<0.001), triglycerides (p=0.002), fibrinogen (p=0.001), whereas high-density lipoprotein (HDLc) was lower than in the group with a SYNTAX score ≤22 (p=0.005). BAC was significantly higher in patients with a SYNTAX score >22 (p<0.001). At multivariate analysis, BAC (odds ratio [OR] 34.24, 95% confidence interval [CI]: 8.05-145.7, p<0.001), hypercholesterolaemia (OR 22.65, 95% CI: 4.18-122.81, p<0.001) and fibrinogen (OR 2.55, 95% CI: 1.28-5.07, p=0.008) were independent predictive factors for patients with intermediate-to-high SYNTAX score.

CONCLUSIONS

In women >45 years, there was a significant correlation between the severity of CAD as evaluated by the SYNTAX score and BAC as evaluated by the Likert scale. BAC, hypercholesterolaemia, and fibrinogen may be used as an additional diagnostic tool to predict the presence and severity of CAD.

Breast Arterial Calcifications on Mammography Do Not Predict Myocardial Ischemia on Myocardial Perfusion Single-Photon Emission Computed Tomography

Background

The aim of this study was to determine if breast arterial calcification (BAC) on mammography predicts myocardial ischemia (MI) on stress myocardial perfusion single-photon emission computed tomography (MPS). BAC is a type of medial artery calcification that can be seen incidentally on mammography, but the relationship between coronary artery calcification and MI on MPS is yet unknown.

Methods

A total of 435 consecutive women underwent mammography and stress MPS within 1 year of each other. BAC was quantitatively evaluated (0 - 13). Patients with known coronary artery diseases (CADs) such as coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), MI, positive coronary angiogram or positive MPS were excluded from the study. Risk factors for CAD were obtained from a chart review.

Results

The mean age was 58 ± 8 years. BAC was found in 258 (59%) of the study population. BAC-positive patients were significantly older than BAC-negative patients (P < 0.0001), there were strong associations between BAC and hypertension (P = 0.0309), chronic kidney disease (CKD) (P = 0.0001), and diabetes (P = 0.0309), but there were significant associations between BACV and hyperlipidemia, family history of CAD, and smoking (P = 0.6856, P = 0.9642, and P = 0.087, respectively). The mean score of BAC was 5 ± 5 in patients with normal MPS and was 6 ± 6 in patients with abnormal MPS. There were no associations between total BAC and MPS results (P = 0.2095), and between BAC categories and MPS result (P = 0.3069).

Conclusions

Based on our study, the presence and severity of BAC on screening or diagnostic mammography do not predict MI on stress MPS, and further cardiac workup based on the presence of BAC is not warranted. BAC is very common in mammography up to 59% and associated with age, diabetes, CKD, and hypertension. In contrast, the prevalence of MI is only 13% in women with BAC and associated with age, diabetes, CKD, hyperlipidemia, and impaired left ventricular function.

Breast arterial calcification association with coronary artery calcium scoring and implications for cardiovascular risk assessment in women

Breast arterial calcification (BAC) is a type of medial artery calcification that can be seen incidentally on mammography. Studies have suggested association of BAC with cardiovascular risk factors, coronary artery disease (CAD), and cardiovascular morbidity and mortality. Recently published studies have also suggested a modest correlation of BAC with coronary artery calcium (CAC) scoring. Roughly 40 million mammograms are already performed annually in the United States with overlap in patients that undergo CAD screening via CAC scoring. Thus, identification of cardiovascular risk by demonstrating an association between BAC and CAC may enable an instrumental sex-specific methodology to identify asymptomatic women at risk for CAD. The purpose of this article is to review the current state of the literature for BAC and its association with CAC, to review contemporary breast cancer screening guidelines, and to discuss the clinical implications of these findings.

Reducing false positives of microcalcification detection systems by removal of breast arterial calcifications

PURPOSE

In the past decades, computer-aided detection (CADe) systems have been developed to aid screening radiologists in the detection of malignant microcalcifications. These systems are useful to avoid perceptual oversights and can increase the radiologists' detection rate. However, due to the high number of false positives marked by these CADe systems, they are not yet suitable as an independent reader. Breast arterial calcifications (BACs) are one of the most frequent false positives marked by CADe systems. In this study, a method is proposed for the elimination of BACs as positive findings. Removal of these false positives will increase the performance of the CADe system in finding malignant microcalcifications.

METHODS

A multistage method is proposed for the removal of BAC findings. The first stage consists of a microcalcification candidate selection, segmentation and grouping of the microcalcifications, and classification to remove obvious false positives. In the second stage, a case-based selection is applied where cases are selected which contain BACs. In the final stage, BACs are removed from the selected cases. The BACs removal stage consists of a GentleBoost classifier trained on microcalcification features describing their shape, topology, and texture. Additionally, novel features are introduced to discriminate BACs from other positive findings.

RESULTS

The CADe system was evaluated with and without BACs removal. Here, both systems were applied on a validation set containing 1088 cases of which 95 cases contained malignant microcalcifications. After bootstrapping, free-response receiver operating characteristics and receiver operating characteristics analyses were carried out. Performance between the two systems was compared at 0.98 and 0.95 specificity. At a specificity of 0.98, the sensitivity increased from 37% to 52% and the sensitivity increased from 62% up to 76% at a specificity of 0.95. Partial areas under the curve in the specificity range of 0.8-1.0 were significantly different between the system without BACs removal and the system with BACs removal, 0.129 ± 0.009 versus 0.144 ± 0.008 (p<0.05), respectively. Additionally, the sensitivity at one false positive per 50 cases and one false positive per 25 cases increased as well, 37% versus 51% (p<0.05) and 58% versus 67% (p<0.05) sensitivity, respectively. Additionally, the CADe system with BACs removal reduces the number of false positives per case by 29% on average. The same sensitivity at one false positive per 50 cases in the CADe system without BACs removal can be achieved at one false positive per 80 cases in the CADe system with BACs removal.

CONCLUSIONS

By using dedicated algorithms to detect and remove breast arterial calcifications, the performance of CADe systems can be improved, in particular, at false positive rates representative for operating points used in screening.

Association of breast arterial calcification with stroke and angiographically proven coronary artery disease: a meta-analysis

OBJECTIVE

We conducted a meta-analysis of the current literature to deduce the strength of association between breast arterial calcification (BAC) and coronary artery disease (CAD) and/or stroke.

METHODS

PubMed, Google Scholar, ClinicalTrials.gov, and Ovid were searched for English-language literature up to August 2013 using the terms "breast arterial calcification," "breast vascular calcification," "coronary artery disease," "coronary heart disease," "cardiovascular disease," "abnormal coronary angiography," and "stroke." A hand search of the reference lists of key articles was performed to supplement the literature search. Our literature search revealed 75 articles for further abstract review. Limiting our search to articles that quantitatively assessed the correlation between BAC and stroke or angiographically proven CAD, we reviewed 35 full manuscripts. Of these articles, 14 were included in the final analysis.

RESULTS

We analyzed 10 cross-sectional studies (n = 3,952) with CAD as the primary outcome (diagnosed by coronary angiography). The odds ratio (95% CI) for CAD in those with BAC versus those without BAC is 3.86 (3.25-4.59) (P < 0.0001). For stroke, six cross-sectional studies were analyzed (n = 18,888). The odds ratio (95% CI) for stroke in those with BAC versus those without BAC is 1.54 (1.25-1.90) (P < 0.0001).

CONCLUSIONS

These results suggest that BAC is significantly associated with both CAD and stroke. Although more prospective studies are warranted to clarify whether BAC is truly a predictor of the future development of CAD and stroke, the concept that BAC is a benign finding is waning.

Prevalence of coronary artery disease evaluated by coronary CT angiography in women with mammographically detected breast arterial calcifications

To assess the correlation between breast arterial calcifications (BAC) on digital mammography and the extent of coronary artery disease (CAD) diagnosed with dual source coronary computed tomography angiography (CTA) in a population of women both symptomatic and asymptomatic for coronary artery disease. 100 consecutive women (aged 34 – 86 years) who underwent both coronary CTA and digital mammography were included in the study. Health records were reviewed to determine the presence of cardiovascular risk factors such as hypertension, hyperlipidemia, diabetes mellitus, and smoking. Digital mammograms were reviewed for the presence and degree of BAC, graded in terms of severity and extent. Coronary CTAs were reviewed for CAD, graded based on the extent of calcified and non-calcified plaque, and the degree of major vessel stenosis. A four point grading scale was used for both coronary CTA and mammography. The overall prevalence of positive BAC and CAD in the studied population were 12% and 29%, respectively. Ten of the 12 patients with moderate or advanced BAC on mammography demonstrated moderate to severe CAD as determined by coronary CTA. For all women, the positive predictive value of BAC for CAD was 0.83 and the negative predictive value was 0.78. The presence of BAC on mammography appears to correlate with CAD as determined by coronary CTA (Spearman’s rank correlation coefficient = 0.48, p<.000001). Using logistic regression, the inclusion of BAC as a feature in CAD predication significantly increased classification results (p=0.04).

Breast arterial calcifications: a systematic review and meta-analysis of their determinants and their association with cardiovascular events

OBJECTIVE

Breast arterial calcifications (BAC), regularly observed at mammography, are medial calcifications and as such an expression of arteriosclerosis. Our objective was to evaluate and summarize the available evidence on the associations of BAC with cardiovascular risk factors and cardiovascular risk.

METHODS

A systematic literature review and meta-analysis were conducted. Embase and PubMed databases were searched. After critical appraisal, odds ratios were extracted from studies of moderate or good quality that examined risk factors for BAC or associations of BAC with cardiovascular disease. Random effects model meta-analyses were used to calculate pooled odds ratios and 95% confidence intervals (95%CIs).

RESULTS

BAC prevalence is around 12.7% among women in breast cancer screening programs. Increasing age (pooled OR 2.98 [95%CI 2.31-3.85] for every 10 years), diabetes (pooled OR: 1.88 [95%CI 1.36-2.59]) and parity as opposed to nulliparity (pooled OR 3.43 [95%CI 2.23-5.27]) are associated with higher BAC prevalence. Smoking is associated with lower BAC prevalence (pooled OR 0.48 [95%CI 0.39-0.60]). No associations were found with hypertension, obesity or dyslipidemia. Although longitudinal studies (n = 3) were scarce, BAC appear to be associated with an increased risk of cardiovascular disease events (adjusted hazard ratios for coronary heart disease ranging from 1.32 [95%CI 1.08-1.60] to 1.44 [95%CI1.02-2.05]).

CONCLUSION

BAC appear to be associated with an increased risk of cardiovascular disease events, while only being associated with some of the known cardiovascular risk factors, illustrating that medial arterial calcification might contribute to cardiovascular disease through a pathway distinct from the intimal atherosclerotic process.

The predictive value of arterial and valvular calcification for mortality and cardiovascular events

A review of the predictive ability of arterial and valvular calcification has shown an additive effect of calcification in more than 1 location in predicting mortality and coronary heart disease, with mitral annual calcification being a particularly strong predictor. In individual arteries and valves there is a clear association between calcification presence, extent and progression and future cardiovascular events and mortality in asymptomatic, symptomatic and high risk patients, although adjustment for calcification in other arterial beds generally renders associations non-significant. Furthermore, in acute coronary syndrome, culprit plaque is normally not calcified. This would tend to reduce the validity of calcification as a predictor and suggest that the association with cardiovascular events and mortality may not be causal. The association with stroke is less clear; carotid and intracranial artery calcification show little predictive ability, with symptomatic plaques tending to be uncalcified.