Influence of age and gender on the presence of coronary calcium detected by ultrafast computed tomography

Women With Nonalcoholic Fatty Liver Disease Lose Protection Against Cardiovascular Disease: A Longitudinal Cohort Study

OBJECTIVES

Cardiovascular (CV) disease is the top cause of mortality in patients with nonalcoholic fatty liver disease (NAFLD). Female sex is protective against CV disease. We aimed to determine whether female sex remains a protective factor against CV disease (myocardial infarction, angina, and stroke) in NAFLD.

METHODS

We identified all adults diagnosed with NAFLD in Olmsted County, Minnesota, between 1997 and 2014 and selected an age- and sex-matched (1:4) referent cohort from the general population. NAFLD was ascertained using a code-based algorithm with high validity tested by medical record review. The impact of female sex on incident CV events was examined using Cox proportional hazards regression analysis stratified by standard clinical risk factors.

RESULTS

A total of 3,869 NAFLD and 15,209 age- and sex-matched referent subjects were identified. After a median follow-up time of 7 (range 1-20) years, 3,851 CV events were recorded. Female sex was protective for ischemic CV events in the general population (hazard ratio = 0.71, 95% confidence interval 0.62-0.80, P < 0.001), but the impact was significantly diminished among those with NAFLD (hazard ratio = 0.90, 95% confidence interval 0.74-1.08, P = 0.25), even after stratification by time-dependent CV risk factors and control for diagnostic testing (liver enzymes and ultrasound) during routine medical evaluations, as a surrogate of access to care. Among those with NAFLD, excess events were higher in women than in men: CV disease (18% vs 9%) and mortality (9% vs 6%).

DISCUSSION

Women with NAFLD lose the CV protection conferred by the female sex, and their risk is underestimated by current estimating methods in clinical practice.

Relation of heart rate recovery after exercise testing to coronary artery calcification

BACKGROUND

We examined whether slow heart rate recovery (HRR) after exercise testing as an estimate of impaired autonomic function is related to coronary artery calcification (CAC), an emerging marker of coronary atherosclerosis.

METHODS

We evaluated 2088 men who participated in a health-screening program that included measures of CAC and peak or symptom-limited cardiopulmonary exercise testing. HRR was calculated as the difference between peak heart rate (HR) during exercise testing and the HR at 2 min of recovery after peak exercise. We measured CAC using multidetector computed tomography to calculate the Agatston coronary artery calcium score. Advanced CAC was defined as a mean CAC >75th percentile for each age group.

RESULTS

HRR was negatively correlated with CAC (r = -.14, p < .01). After adjusting for conventional risk factors, participants in the lowest quartile of HRR (<38 bpm) were 1.59 times (95% CI: 1.17-2.18; p < .05) more likely to have advanced CAC than their counterparts in the highest quartile of HRR (>52 bpm). Each 1 bpm decrease in HRR was associated with 1% increase in advanced CAC after adjusting for potential confounders.

CONCLUSIONS

An attenuated HRR after exercise testing is associated with advanced CAC, independent of coronary risk factors and other related hemodynamic response. KEY MESSAGES Slow heart rate recovery (HRR) after maximal exercise testing, indicating decreased autonomic function, is associated with an increased risk of cardiovascular event and mortality. Slow HRR has been linked with the occurrence of malignant ventricular arrhythmias, but it remains unclear whether slow HRR is associated with an increased risk of coronary artery calcification (CAC), an emerging marker of coronary atherosclerosis. An attenuated HRR after exercise testing was associated with advanced CAC, independent of coronary risk factors and other potential hemodynamic confounder, supporting the hypothesis that slow HRR is related to the burden of atherosclerotic coronary artery disease.

Colonic Necrosis Following Laparoscopic High Anterior Resection for Sigmoid Colon Cancer: Case Report and Review of the Literature

We report a patient who experienced colonic necrosis after laparoscopic high anterior resection for sigmoid colon cancer, and review the literature to evaluate the clinical features of colonic necrosis following surgery for sigmoid colon and rectal cancer. A 76-year-old man with sigmoid colon cancer underwent laparoscopic high anterior resection. The operation included high ligation of the inferior mesenteric artery and end-to-end anastomosis using circular staples. Pathology findings revealed a pT4N2M0 lesion. Beginning on postoperative day (POD) 1, the patient experienced a high, spiking fever, and gradually developed leukocytosis and high inflammatory condition. The patient complained of abdominal distention, but had no signs of peritonitis. Abdominal computed tomography on POD4 showed wall thickness of the proximal colon from the anastomosis site and ascites with free air. An anastomotic leakage was suspected. Emergency laparotomy revealed a disrupted anastomosis without feces in the abdomen and a gangrenous 15 cm segment of the colon proximal to the anastomosis. The affected area of the colon was excised and Hartmann's procedure was performed. His postoperative period was uneventful. Our review of the literature demonstrates that elderly male patients with cardiovascular and pulmonary complications undergoing laparoscopic sigmoid and rectal cancer surgery with high ligation have high risk of postoperative colonic necrosis. We experienced colonic necrosis following laparoscopic high anterior resection for sigmoid colon cancer and required immediate resection. Elderly male patients with cardiovascular and pulmonary complications undergoing laparoscopic sigmoid and rectal cancer surgery with high ligation should be carefully monitored for postoperative colonic necrosis.

High levels of serum vitamin D are associated with a decreased risk of metabolic diseases in both men and women, but an increased risk for coronary artery calcification in Korean men

Background

There are conflicting results for relationships between serum vitamin D levels and metabolic diseases. The aim of this study was to investigate whether serum vitamin D levels were associated with various metabolic diseases including insulin resistance (IR), metabolic syndrome (MS), fatty liver (FL), and coronary artery calcification (CAC), along with assessing gender differences for these relationships in Korean adults.

Methods

A total of 180,918 subjects (98,412 men and 82,506 women) who participated in a comprehensive health examination in the 2012–2013 period at Kangbuk Samsung Hospital, College of Medicine, Sungkyunkwan University were included. Serum vitamin D and metabolic markers were analyzed and CAC was estimated. Subjects were divided according to quartile groups of serum vitamin D. To examine the relationships of serum vitamin D to metabolic diseases and metabolic factors, multivariate logistic analysis was conducted.

Results

High levels of serum vitamin D was associated with lower ORs for MS, IR and FL both in men and women (all p < 0.05). For men, ORs for CAC were significantly higher in third and the highest quartile groups for serum vitamin D in all the analyzed models (all p < 0.05). However, women showed no significant results between serum vitamin D and CAC.

Conclusions

High levels of serum vitamin D were associated with lower risk of MS, IR and FL in both Korean men and women, but were associated with higher risk of CAC only in men, and not in women.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0432-3) contains supplementary material, which is available to authorized users.

The Challenges of Prevention, Diagnosis and Treatment of Ischemic Heart Disease in Women

Increasing evidence suggests that there are significant differences in the presentation, diagnosis and treatment of ischemic heart disease in women compared to men. Women often present with atypical symptoms, and this, in association with a consistent underestimation of their risk for ischemic heart disease, leads to underdiagnosis and undertreatment in women. Cardiovascular risk factors unique to women have only recently been recognized, and moreover, traditional risk factors have recently been shown to have greater impacts on women. Consequently, women suffer more disability and poorer clinical outcomes, with higher cardiovascular morbidity and mortality. These discrepancies may in part be secondary to the higher prevalence of nonobstructive coronary artery disease in women with persistent chest pain symptoms as compared to men when evaluated invasively. Focused diagnostic and therapeutic strategies unique to women are thus needed, but unfortunately, such sex-specific guidelines do not yet exist, largely due to lack of awareness, both on the part of providers and patients, as well as a paucity of evidence-based research specific to women. Although underutilized in women, diagnostic modalities, including functional and anatomic cardiac tests as well as physiologic assessments of endothelial and microvascular function, are useful for establishing the diagnosis and prognosis of suspected ischemic heart disease in women. This review discusses the current challenges of prevention, diagnosis and treatment of ischemic heart disease in women.

Focused Cardiovascular Care for Women: The Need and Role in Clinical Practice

Over the past decade, an emerging clinical research focus on cardiovascular (CV) disease (CVD) risk in women has highlighted sex-specific factors that are uniquely important in the prevention and early detection of coronary atherosclerosis in women. Concurrently, a 30% decrease in the number of female deaths from CVD has been observed. Despite this, CVD continues to be the leading cause of death in women, outnumbering deaths from all other causes combined. Clinical practice approaches that focus on the unique aspects of CV care for women are needed to provide necessary resources for the prevention, diagnosis, and treatment of CVD in women. In addition to increasing opportunities for women to participate in CV research, Women's Heart Clinics offer unique settings in which to deliver comprehensive CV care and education, ensuring appropriate diagnostic testing, while monitoring effectiveness of treatment. This article reviews the emerging need and role of focused CV care to address sex-specific aspects of diagnosis and treatment of CVD in women.

Marginal artery stump pressure in left colic artery-preserving rectal cancer surgery: a clinical trial

BACKGROUND

The aim of this clinical trial is to evaluate the influence of high and low ligation of the inferior mesenteric artery with apical lymph node dissection on the anastomotic blood supply, lymph node retrieval rate, operative time and anastomotic leakage rate in rectal cancer surgery.

METHODS

A total of 57 Chinese patients were randomly distributed into group A and group B and underwent radical resection of rectal cancer. Patients in group A underwent high ligation of the inferior mesenteric artery, and patients in group B underwent apical lymph node resection around the root of the inferior mesenteric artery with preservation of the left colic artery. The marginal artery stump pressure was measured after colon and artery reconstruction. Systemic pressure, distal colon length, operative time and lymph node retrieval rate were measured and recorded. The results were analysed and related to patient characteristics and post-operative complications.

RESULTS

The anastomotic blood supply negatively and linearly correlated with age and distal colon length and showed a positive linear correlation with systemic pressure. Patients who received low ligation with apical lymph node dissection had a better anastomotic blood supply than those who received high ligation. No differences were found in lymph node retrieval rate, operative time and anastomotic leakage rate. Anastomotic leakage was associated with a worse anastomotic blood supply.

CONCLUSIONS

Low ligation with apical lymph node dissection in rectal cancer treatment provides better anastomotic blood supply but is not associated with differences in node retrieval rate or operation time.

Diagnosing and characterizing coronary artery disease in women: developments in noninvasive and invasive imaging techniques

Cardiovascular disease is the leading cause of death in men and women in the USA; yet, coronary artery disease (CAD) continues to be underrecognized and underdiagnosed in women. Noninvasive and invasive imaging techniques are constantly being developed in order to more accurately assess CAD. At the same time, the impact of gender on the interpretation and accuracy of these studies is still being elucidated. Furthermore, new imaging techniques have improved our understanding of CAD pathophysiology and progression and have begun to reveal gender differences in the development of CAD. This article will review current imaging techniques and their application to diagnosing and understanding CAD in women.

Hyperuricemia and the risk for subclinical coronary atherosclerosis--data from a prospective observational cohort study

Introduction

Our purpose was to test the hypothesis that hyperuricemia is associated with coronary artery calcification (CAC) among a relatively healthy population, and that the extent of calcification is directly proportional to the serum uric acid (sUA) concentration.

Methods

Data from 2,498 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study were analyzed using logistic regression models. Subjects were free of clinical heart disease, diabetes, and renal impairment. The main measure was the presence of any CAC by computerized tomography (Agatston score >0).

Results

Forty-eight percent of the study participants were male and 45% were African-American. Mean (± SD) age was 40 ± 4 years, body mass index 28 ± 6 kg/m², Framingham risk score -0.7 ± 5%, blood pressure 113 ± 14/75 ± 11 mmHg, alcohol consumption 12 ± 27 ml/day, and sUA 297 ± 89 μmol/L (5.0 ± 1.5 mg/dL). Prevalence of CAC increased with sUA concentration among both men and women. Adjusted for age, gender, race, lipoproteins, triglycerides, smoking, blood pressure, presence of metabolic syndrome, C-reactive protein, waist circumference, alcohol use, creatinine, and serum albumin, the highest quartile of sUA (>393 μmol/L [6.6 mg/dL] for men and >274 μmol/L [4.6 mg/dL] for women) was associated with an odds ratio of 1.87 (1.19-2.93) compared to the lowest quartile (<291 μmol/L [4.9 mg/dL] for men and <196 μmol/L [3.3 mg/dL] for women). Among those with any CAC, each unit increase in sUA was associated with a 22% increase in Agatston score (P = 0.008) after adjusting for the above covariates.

Conclusions

Hyperuricemia is an independent risk factor for subclinical atherosclerosis in young adults.

Assessment of subclinical atherosclerosis and cardiovascular risk

Conventional cardiac risk factors do not fully explain the incidence of coronary artery disease and coronary events. Risk stratification and therapy based solely on these conventional risk factors may exclude a population who would otherwise benefit from lifestyle and risk factor modification. Recent efforts to improve our ability to recognize individuals and populations at increased risk of coronary events have focused on the noninvasive imaging of atherosclerosis, both in coronary and extracoronary arterial beds, or the identification of "non-traditional" serum markers. We review the complimentary role of these newer methods of risk stratification in the context of conventional risk factor evaluation.

Modulation of calcification of vascular smooth muscle cells in culture by calcium antagonists, statins, and their combination

Background Vascular calcification is an organized process in which vascular smooth muscle cells (VSMCs) are implicated primarily. The purpose of the present study was to assess the effects of calcium antagonists and statins on VSMC calcification in vitro. Methods VSMC calcification was stimulated by incubation in growth medium supplemented with 10 mmol/l β-glycerophosphate, 8 mmol/l CaCl₂, 10 mmol/l sodium pyruvate, 1 μmol/l insulin, 50 μg/ml ascorbic acid, and 100 nmol/l dexamethasone (calcification medium). Calcification, proliferation, and apoptosis of VSMCs were quantified. Results Calcium deposition was stimulated dose-dependently by β-glycerophosphate, CaCl₂, and ascorbic acid (all P < 0.01). Addition of amlodipine (0.01–1 μmol/l) to the calcification medium did not affect VSMC calcification. However, atorvastatin (2–50 μmol/l) stimulated calcium deposition dose-dependently. Combining treatments stimulated calcification to a degree similar to that observed with atorvastatin alone. Both atorvastatin and amlodipine inhibited VSMC proliferation at the highest concentration used. Only atorvastatin (50 μmol/l) induced considerable apoptosis of VSMCs. Conclusion In vitro calcification of VSMCs is not affected by amlodipine, but is stimulated by atorvastatin at concentrations ≥10 μmol/l, which could contribute to the plaque-stabilizing effect reported for statins.

Laser Doppler assessment of the influence of division at the root of the inferior mesenteric artery on anastomotic blood flow in rectosigmoid cancer surgery

AIMS

The aim of this study is to evaluate the influence of dividing the inferior mesenteric artery (IMA) and preserving the left colic artery (LCA) on rectosigmoid cancer surgery.

PATIENTS AND METHODS

Colonic blood flow at the proximal site of the anastomosis was measured by laser Doppler flowmetry in 96 patients with cancer of the rectum and sigmoid colon while clamping IMA or LCA. Results were analyzed with patient characteristics and postoperative complications.

RESULTS

Blood flow was significantly decreased by either IMA or LCA clamping, and its reduction rate was 38.5 +/- 1.8%, ranged from 0 to 82.8%, or 16.4 +/- 1.8%, ranged from 0 to 66.2%, respectively. For multivariate analyses, aging and male gender were predictive factors of high blood flow reduction by IMA clamping. The reduction rate was significantly correlated with aging in male patients, while no such correlation was observed in women. Aging correlation in men was more significant in ultralow anterior resection cases. Three elderly male patients received IMA high ligation among 19 patients who demonstrated more than 50% blood flow reduction by IMA clamping. Among these, two patients, those who underwent ultralow anterior resection, suffered severe anastomotic ischemia.

CONCLUSIONS

Colonic blood flow at the proximal site of the anastomosis was significantly decreased by either IMA or LCA clamping. Patients with high reduction by IMA clamping need intraoperative efforts to prevent anastomotic ischemia, particularly in elderly male patients who undergo ultralow anterior resection.

Volumetric quantification of atherosclerotic plaque in CT considering partial volume effect

Coronary artery calcification (CAC) is quantified based on a computed tomography (CT) scan image. A calcified region is identified. Modified expectation maximization (MEM) of a statistical model for the calcified and background material is used to estimate the partial calcium content of the voxels. The algorithm limits the region over which MEM is performed. By using MEM, the statistical properties of the model are iteratively updated based on the calculated resultant calcium distribution from the previous iteration. The estimated statistical properties are used to generate a map of the partial calcium content in the calcified region. The volume of calcium in the calcified region is determined based on the map. The experimental results on a cardiac phantom, scanned 90 times using 15 different protocols, demonstrate that the proposed method is less sensitive to partial volume effect and noise, with average error of 9.5% (standard deviation (SD) of 5-7mm(3)) compared with 67% (SD of 3-20mm(3)) for conventional techniques. The high reproducibility of the proposed method for 35 patients, scanned twice using the same protocol at a minimum interval of 10 min, shows that the method provides 2-3 times lower interscan variation than conventional techniques.

Coronary calcium scanning

While there is no doubt that high-risk patients (those with more than a 20% 10-year risk of a future cardiovascular event) need more aggressive preventive therapy, a majority of cardiovascular events occur in individuals at intermediate risk (10%-20% 10-year risk). Data suggest that it will be most cost-effective to concentrate screening efforts on this group of patients. Coronary artery calcium has been shown to be highly specific for atherosclerosis, occurring only in the intima of the coronary arteries. There is evidence to show that elevated coronary calcium scores are predictive of cardiovascular events, both independently of and incrementally to conventional cardiovascular risk factors. Based on current available data, patients with increased plaque burdens (increased coronary calcium scores) are approximately 10 times more likely to suffer a cardiac event over the next 3-5 years. Coronary calcium scores have outperformed conventional risk factors, high sensitivity C-reactive protein, and carotid intima-media thickness as a predictor of cardiovascular events. Both electron beam tomography and multidetector computed tomography can accurately detect and quantify the coronary calcium scores. In summary, coronary calcium detection significantly improves the accuracy of global cardiovascular risk prevention, the noninvasive tracking of the atherosclerotic burden, and the prediction of cardiovascular events.

Noninvasive diagnosis of coronary artery disease in women

Cardiovascular disease is the leading cause of mortality and significant morbidly among women in the United States. The frequent absence of antecedent symptoms, the potential for an initial fatal cardiac event and the limitations of currently available noninvasive diagnostic tests pose challenges to healthcare practitioners as they try to optimally risk stratify patients. Therefore, the purpose of this article is to discuss the accuracy of noninvasive tests for CAD diagnosis in women.

Endothelial lipase concentrations are increased in metabolic syndrome and associated with coronary atherosclerosis

BACKGROUND

Endothelial lipase (EL), a new member of the lipase family, has been shown to modulate high-density lipoprotein (HDL-C) metabolism and atherosclerosis in mouse models. We hypothesized that EL concentrations would be associated with decreased HDL-C and increased atherosclerosis in humans.

METHODS AND FINDINGS

Healthy individuals with a family history of premature coronary heart disease (n = 858) were recruited as part of the Study of the Inherited Risk of Atherosclerosis. Blood was drawn in the fasting state before and, in a subgroup (n = 510), after administration of a single dose of intravenous heparin. Plasma lipids were measured enzymatically, lipoprotein subclasses were assessed by nuclear magnetic resonance, and coronary artery calcification (CAC) was quantified by electron beam computed tomography. Plasma EL mass was measured using a newly developed enzyme-linked immunosorbent assay. Median EL mass in pre-heparin plasma was 442 (interquartile range = 324-617) ng/ml. Median post-heparin mass was approximately 3-fold higher, 1,313 (888-1,927) ng/ml. The correlation between pre-heparin EL mass and post-heparin EL mass was 0.46 (p < 0.001). EL mass concentrations in both pre- and post-heparin plasma significantly correlated with all NCEP ATPIII-defined metabolic syndrome factors: waist circumference (r = 0.28 and 0.22, respectively, p < 0.001 for each), blood pressure (r = 0.18 and 0.24, p < 0.001 for each), triglycerides (r = 0.22, p < 0.001; and 0.13, p = 0.004), HDL cholesterol (r = -0.11, p = 0.002; and -0.18, p < 0.001), and fasting glucose (r = 0.11 and 0.16, p = 0.001 for both). EL mass in both routine (odds ratio [OR] = 1.67, p = 0.01) and post-heparin (OR = 2.42, p = 0.003) plasma was associated with CAC as determined by ordinal regression after adjustment for age, gender, waist circumference, vasoactive medications, hormone replacement therapy (women), and established cardiovascular risk factors.

CONCLUSIONS

We report, to our knowledge for the first time, that human plasma EL concentrations, in both post-heparin and routine pre-heparin plasma, are significantly associated with metabolic syndrome features and with subclinical atherosclerosis. EL may be a pro-atherogenic factor in humans, especially in overweight individuals and those with metabolic syndrome.

Clinical Significance of the Coronary Calcification Score by Multidetector Row Computed Tomography for the Evaluation of Coronary Stenosis in Japanese Patients

BACKGROUND

The coronary artery calcification (CAC) score measured by multidetector row computed tomography (MDCT) has emerged as a marker for predicting coronary artery disease (CAD). To evaluate the clinical significance of the CAC score, coronary artery stenosis as assessed by coronary angiography (CAG) was compared with the CAC score determined by MDCT, risk factors and medications.

METHODS AND RESULTS

Subjects included 374 consecutive patients who underwent ECG-gate CT angiography using MDCT. The accuracy in patients with a CAC score >or=400 was 84%, and significantly lower than that in patients with a CAC score =0. In addition 92 patients (68 males, 24 females; mean age, 63+/-11 years) who underwent both MDCT and CAG within a 1-month period were selected for further investigation. Patients with significant coronary stenosis had a significantly higher CAC score than those without stenosis. In addition, a higher number of stenosed vessels was associated with a higher CAC score. The subjects were divided into 3 groups according to the CAC score: low (0-12), intermediate (13-444) and high (>or=445). The CAC score was significantly associated with age, and plasma levels of total cholesterol and hemoglobinA1c, and logistic regression analysis revealed that significant coronary stenosis as assessed by CAG was most closely correlated with the CAC score (p=0.03).

CONCLUSIONS

The CAC score determined by MDCT can predict CAD independent of other factors, such as age, metabolic diseases and medications, when coronary stenosis can not be diagnosed because of severe calcification.

The relationship between coronary artery calcification detected by non-gated multi-detector CT in patients with suspected ischemic heart disease and myocardial ischemia detected by thallium exercise stress testing

OBJECTIVE

To examine whether we could predict myocardial ischemia when coronary artery calcification is detected by non-gated multidetector CT in patients with suspected ischemic heart disease.

METHODS

Eighty-three patients suspected of having ischemic heart disease (55 men, 28 women; age range 36-83 years; mean age 68 years) underwent multidetector CT and T1-201 single photon emission computed tomography. Prediction of myocardial ischemia by coronary arterial calcification detected on CT was evaluated by comparing the coronary artery territories that showed calcification with the area of myocardial ischemia determined by SPECT. The sensitivity, specificity, positive predictive value, and negative predictive value of multidetector CT for predicting myocardial ischemia were calculated. Coronary angiography was also examined and compared with multidetector CT. Risk factors, including hypertension, smoking, hyperlipidemia, diabetes, and family history, were compared for evidence of coronary artery calcification detected by multidetector CT and myocardial ischemia detected by thallium nuclear scans.

RESULTS

For analysis by patients, the sensitivity, specificity, positive predictive value, and negative predictive value of coronary artery calcification for myocardial ischemia detection were 65, 63, 56, and 71%, respectively. Similarly, for analysis by coronary arterial territories, those values were 56, 77, 41 and 86%, respectively. Coronary stenosis on CAG was also related to the ischemia determined by SPECT and calcification on multidetector CT. Ischemia was better influenced by risk factors than was coronary arterial calcification.

CONCLUSIONS

For analysis by coronary arterial territories, the specificity and negative predictive value of coronary arterial calcification seen by multidetector CT are relatively high.

Evaluation of coronary artery calcification by multi-detector row computed tomography for the detection of coronary artery stenosis in Japanese patients

BACKGROUND

The development of an efficient noninvasive examination to detect coronary atherosclerosis is needed as a strategy to prevent coronary heart disease. To evaluate the usefulness of calcium score measured by multi-detector row computed tomography (MDCT), we compared calcium score derived from MDCT with findings of coronary artery stenosis assessed by coronary angiography (CAG).

METHODS

In 108 patients (94 men, 14 women; average age, 65.7 years), we performed unenhanced CT scans and calculated coronary artery calcium score in 259 vessels without previous intervention and severe motion artifact to determine the correlation with the degree of coronary stenosis by CAG.

RESULTS

The sensitivity and the specificity of calcification (calcium score 0.1+) for severe stenosis (75+%) were 89% and 43%, respectively. All four vessels with calcium score 1000+ had a severe stenosis. The areas under the receiver operating characteristics curve of calcium score for severe stenosis were 0.80 +/- 0.04, indicating the efficacy of this technique.

CONCLUSIONS

Coronary artery calcification and calcium score determined by MDCT were associated with coronary arteries with severe stenosis. This technique appears to be useful for the evaluation of coronary atherosclerosis.

Update on using coronary calcium screening by computed tomography to measure risk for coronary heart disease

Coronary artery disease (CAD) is the number one killer of adults in the United States, claiming one-half million deaths annually. Early detection and prevention strategies clearly remain a top priority for health care providers in order to reduce the high mortality rate of heart disease. As an unequivocal reflection of arteriosclerosis, coronary arterial calcium (CAC) may provide a means to qualitatively assess the overall disease severity and likewise serve as a means to assess risk for CHD. It is known that patients with heavy calcium burdens have more advanced CAD, a concomitantly a higher likelihood of coronary stenoses, and a concomitant higher risk for acute cardiac events. Computed tomography has been shown to be an accurate, non-invasive method to quantify coronary calcification burden in patients. Evidence shows that calcium measurements by CT correlate well with histological plaque analyses, and that CAC measurements accurately reflect disease severity and can be useful to assess individual risk for CHD. The purpose of this article is to summarize the currently available evidence that has attempted to validate CAC screening as a screening exam and risk predictor for coronary heart disease.

Coronary heart disease in women: what do we know now?

Coronary heart disease is the single leading cause of death in women in the USA, and there is growing recognition that gender-specific efforts must be made to fully understand and appropriately treat the disease in the female population. While increasing attention is being focused on the prevalence of cardiovascular disease in women so that preventive as well as treatment efforts can be marshaled to combat this epidemic, much remains to be carried out. Although risk factors for coronary heart disease are generally similar between men and women, the magnitude of various factors may differ between the genders. Emerging data suggest that coronary heart disease may be a different entity in women compared with men, requiring different preventive, diagnostic and treatment strategies.

A greater reduction in high-frequency heart rate variability to a psychological stressor is associated with subclinical coronary and aortic calcification in postmenopausal women

OBJECTIVE

Reduced cardiac parasympathetic activity, as indicated by a reduced level of clinic or ambulatory high-frequency heart rate variability (HF-HRV), is associated with an increased risk for atherosclerosis and coronary artery disease. We tested whether the reduction in HF-HRV to a psychological stressor relative to a baseline level is also associated with subclinical coronary or aortic atherosclerosis, as assessed by calcification in these vascular regions.

METHOD

Spectral estimates of 0.15 to 0.40 Hz HF-HRV were obtained from 94 postmenopausal women (61-69 years) who engaged in a 3-minute speech-preparation stressor after a 6-minute resting baseline. A median of 282 days later, electron beam tomography (EBT) was used to measure the extent of coronary and aortic calcification.

RESULTS

In univariate analyses, a greater reduction in HF-HRV from baseline to speech preparation was associated with having more extensive calcification in the coronary arteries (rho = -0.29, p = .03) and in the aorta (rho = -0.22, p = .06). In multivariate analyses that controlled for age, education level, smoking status, hormone therapy use, fasting glucose, high-density lipoproteins, baseline HF-HRV, and the stressor-induced change in respiration rate, a greater stressor-induced reduction in HF-HRV was associated with more calcification in the coronary arteries (B = -1.21, p < .05), and it was marginally associated with more calcification in the aorta (B = -0.92, p = .09).

CONCLUSION

In postmenopausal women, a greater reduction in cardiac parasympathetic activity to a psychological stressor from baseline may be an independent correlate of subclinical atherosclerosis, particularly in the coronary arteries.

Aortic calcification

OBJECTIVES

Vascular calcification is a complicating factor observed in advanced atherosclerosis. This review summarises the present knowledge regarding abdominal aortic calcification.

DESIGN

Literature review.

METHODS

A literature review was carried using MEDLINE and PUBMED with the search terms 'abdominal', 'aortic' and 'calcification'. Articles were assessed for data regarding mechanisms, measurement, risk factors and outcomes of aortic calcification.

RESULTS

Thirty relevant studies were identified. These demonstrated a positive correlation between abdominal aortic calcification and the following factors: older age, hypertension, and smoking. Further studies are required to critically assess other risk factors such as gender, diabetes mellitus and renal failure. Calcification of the abdominal aorta is associated with an increased risk of mortality, coronary heart disease and stroke.

CONCLUSION

Aortic calcification predicts an increased incidence of cardiovascular events, however, the reasons for this association requires further investigation. Accurate measurement of aortic calcification is likely to be increasingly used to determine the risk of cardiovascular events.

Predictors of type and site of first acute myocardial infarction in men and women

BACKGROUND

The importance of pathophysiological mechanisms involved in onset of acute myocardial infarction (AMI) differs with age, gender, and risk profiles. Diversity in the triggering of cardiovascular events has been observed, particularly between men and women. Therefore, we investigated the relationship between age, gender, and risk factors and location of AMI and the presence of Q waves in ECG.

PATIENTS AND METHODS

Data was obtained from a chart review of 2958 patients with first AMI: 770 (26%) patients with non-Q-wave AMI and 2188 (74%) patients with Q-wave AMI. Four clinical groups were formed by predetermined criteria (anterior Q-wave, anterior non-Q-wave, inferior Q-wave, inferior non-Q-wave). A logistic regression was performed to assess independent predictors of AMI type and site.

RESULTS

Key findings were: 1) inferior non-Q-wave AMI was more frequent in young women (P<0.001); 2) inferior Q-wave AMI was more common in young men (P<0.001); 3) anterior non-Q-wave AMI was more common in older men (P<0.001). Multivariate analysis revealed that independent predictors of anterior non-Q-wave AMI were age over 65 (P=0.002), male gender (P=0.04) and hypercholesterolemia (P=0.0003), and that predictors of inferior Q-wave AMI were male gender (P<0.0001), smoking (P=0.04) and diabetes (P=0.049). In the gender-subgroup analyses, age <45 years (P=0.04), hypecholesterolemia (P=0.02) and smoking (P=0.01) were independent predictors of inferior Q-wave AMI whereas age >65 years (P<0.0001) and smoking (P=0.0003) were predictors of anterior non-Q-wave AMI in men. In women, age <45 years (P<0.0001) and smoking (P=0.02) were independent predictors of non-Q-wave AMI and hypercholesterolemia (P=0.02) was a predictor of inferior Q-wave AMI.

CONCLUSION

The link between particular types and the site of AMI and age, gender and risk factors suggest that the importance of pathophysiological mechanisms for onset of AMI differs according to sex and age subgroup.

Coronary artery calcium by digital cinefluoroscopy in patients with pain suggestive of an acute coronary syndrome

BACKGROUND

Detection of coronary calcium may be a useful noninvasive approach for detecting coronary artery disease (CAD) in subjects presenting to the emergency department with chest pain.

HYPOTHESIS

We tried to assess the diagnostic value of coronary artery calcium (CAC) detection by digital cinefluoroscopy in patients with new-onset chest pain suggestive of an acute coronary syndrome.

METHODS

In 97 consecutive patients (70 men, 27 women, mean standard deviation [SD] age 55 (11) and 60 (8) years, respectively), with new-onset chest pain suggestive of an acute coronary syndrome, nondiagnostic electrocardiogram, and normal initial creatine kinase (CK)-MB, digital cinefluoroscopy was performed for CAC detection.

RESULTS

All patients underwent routine clinical evaluation with treadmill exercise test, thallium scintigraphy, dobutamine stress echocardiography, and coronary angiography, as needed clinically and blinded to the cinefluoroscopy results. Coronary artery calcium was present in 27 of 33 (81.8%) of patients with and in 10 of 64 (15.6%) of patients without CAD, p < 0.0001. The presence of CAC had 82% sensitivity, 84% specificity, 73% positive predictive value, and 90% negative predictive value for CAD diagnosis (odds ratio = 24.3, 95% confidence interval 7.98-73.94).

CONCLUSIONS

In patients with acute chest pain, nondiagnostic electrocardiogram and normal initial enzyme evaluation, CAC detection by digital cinefluoroscopy appears to have high sensitivity, specificity, and negative predictive value for CAD diagnosis.

Association among plasma levels of monocyte chemoattractant protein-1, traditional cardiovascular risk factors, and subclinical atherosclerosis

OBJECTIVES

We sought to evaluate the association between plasma levels of monocyte chemoattractant protein (MCP)-1 and the risk for subclinical atherosclerosis.

BACKGROUND

Monocyte chemoattractant protein is a chemokine that recruits monocytes into the developing atheroma and may contribute to atherosclerotic disease development and progression. Plasma levels of MCP-1 are independently associated with prognosis in patients with acute coronary syndromes, but few population-based data are available from subjects in earlier stages of atherosclerosis.

METHODS

In the Dallas Heart Study, a population-based probability sample of adults in Dallas County </=65 years old, plasma levels of MCP-1 were measured in 3,499 subjects and correlated with traditional cardiovascular risk factors, high-sensitivity C-reactive protein (hs-CRP), and coronary artery calcium (CAC) measured by electron beam computed tomography.

RESULTS

Higher MCP-1 levels were associated with older age, white race, family history of premature coronary disease, smoking, hypertension, diabetes, hypercholesterolemia, and higher levels of hs-CRP (p < 0.01 for each). Similar associations were observed between MCP-1 and risk factors in the subgroup of participants without detectable CAC. Compared with the subjects in the lowest quartile of MCP-1, the odds of prevalent CAC (CAC score >/=10) for subjects in the second, third, and fourth quartiles were 1.30 (95% confidence interval [CI] 0.99 to 1.73), 1.60 (95% CI 1.22 to 2.11), and 2.02 (95% CI 1.54 to 2.63), respectively. The association between MCP-1 and CAC remained significant when adjusted for traditional cardiovascular risk factors, but not when further adjusted for age.

CONCLUSIONS

In a large population-based sample, plasma levels of MCP-1 were associated with traditional risk factors for atherosclerosis, supporting the hypothesis that MCP-1 may mediate some of the atherogenic effects of these risk factors. These findings support the potential role of MCP-1 as a biomarker target for drug development.

Accelerated Progression of Coronary Calcification: Four-year Follow-up in Patients with Stable Coronary Artery Disease

PURPOSE

To prospectively assess the 4-year progression rate of coronary artery calcium (CAC) in patients with clinically stable coronary artery disease (CAD) with multi-detector row computed tomography (CT).

MATERIALS AND METHODS

The study group consisted of 382 consecutive patients. All underwent baseline dual-sector spiral CT, and CT was repeated at 2 and 4 years later. Progression of CAC was assessed with measurement of the increase in total calcium score (TCS) and with repeated-measures analysis and multivariate linear regression models. Logistic regression model was used to predict incidence of new lesions.

RESULTS

Eighty-seven percent (333 of 382) of the study group were men, with mean age of 65 years +/- 11, and 13% (49 of 382) were women, with mean age of 68 years +/- 11. The average TCS increased after 4 years by sixfold from baseline in the 1st quartile, and by four-, two- and 1.5-fold in the 2nd, 3rd, and 4th quartiles of baseline TCS (P <.01), respectively. Multiple linear regression analysis included age; sex; natural logarithm of baseline TCS; history of hypertension, diabetes mellitus, current smoking, hypercholesterolemia, and lipid-lowering therapy with cholesterol synthesis enzyme inhibitor (statin); and family history of premature CAD. Results demonstrated that natural logarithm of baseline TCS and history of current smoking were independent predictors of the 4th-year natural logarithm of TCS levels (R(2) = 0.85, P <.001). New lesions were diagnosed in 56 (15%) patients. History of statin therapy (odds ratio = 0.35; 95% confidence interval [CI]: 0.16, 0.77; P <.01), age with an increment of 5 years (odds ratio = 0.76; 95% CI: 0.64, 0.90; P =.01), and natural logarithm of baseline TCS (odds ratio = 0.73; 95% CI: 0.62, 0.86; P <.01) were independent predictors for new calcific lesions during 4 years.

CONCLUSION

Accelerated progression of CAC during 4 years was found in clinically stable patients with CAD.

Myocardial perfusion scintigraphy: the evidence

This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by comparison with the numbers of revascularisations and coronary angiograms performed. Furthermore, MPS activity levels in this country fall far short of those in comparable European countries, with about half as many scans being undertaken per year. Currently, the number of MPS studies performed annually in the UK is 1,200/million population/year. We estimate the real need to be 4,000/million/year. The current average waiting time is 20 weeks and we recommend that clinically appropriate upper limits of waiting time are 6 weeks for routine studies and 1 week for urgent studies.

Imaging of coronary calcification by computed tomography

As an unequivocal biomarker for arteriosclerosis, the presence of coronary calcium serves as a qualitative reflection of the severity of coronary artery disease (CAD). Greater calcium burdens correlate with more advanced disease, a higher likelihood of coronary stenoses, and a higher risk for coronary heart disease (CHD). Empirically, the quantification of coronary calcium not only provides an accurate reflection of disease severity, but also has great potential as a screening tool for CHD. Computed tomography (CT) has been shown to be capable of providing accurate, noninvasive measurements of coronary calcification. Evidence shows that calcium measurements by CT correlate well with histological plaque analyses, and that calcium burdens accurately reflect disease severity and can be used to assess individual risk for CHD. The purpose of this review article is to examine the accumulated evidence that has attempted to validate CT as a diagnostic tool for CAD and as a screening exam for CHD.

Imaging of the vulnerable plaque: new modalities

Atherosclerosis is currently considered to be an inflammatory and thus a systemic disease affecting multiple arterial beds. Recent advances in intravascular imaging have shown multiple sites of atherosclerotic changes in coronary arterial wall. Traditionally, angiography has been used to detect and characterize atherosclerotic plaque in coronary arteries, but recently it has been found that plaques that are not significantly stenotic on angiography cause acute myocardial infarction. As a result, newer imaging and diagnostic modalities are required to predict which of the atherosclerotic plaque are prone to rupture and hence distinguish "stable" and "vulnerable" plaques. Intravascular ultrasound can identify multiple plaques that are not seen on coronary angiography. Thermography has shown much promise and is based on the concept that the inflammatory plaques are associated with increased temperature and can also identify "vulnerable patients." Of all these newer modalities, magnetic resonance imaging has shown the most promise in identification and characterization of vulnerable plaques. In this article, we review the newer coronary artery imaging modalities and discuss the limitations of traditional coronary angiography.

Increased prevalence of coronary artery calcification in patients with suspected pulmonary embolism

RATIONALE AND OBJECTIVES

The authors explored the possibility that patients with suspected pulmonary embolism are at high risk for coronary artery disease. To this purpose, they compared the presence of coronary artery calcification on computed tomography (CT) in patients suspected of pulmonary embolism with age- and gender-matched controls.

MATERIALS AND METHODS

The CT scans of 214 patients were reviewed. Of those, 107 consecutive patients (50%) had pulmonary CT angiography for suspected pulmonary embolism (PE group). The remaining 107 age- and gender-matched patients were scanned for reasons other than pulmonary embolism (non-PE group). All CT scans were performed with the same 8-detector-row multislice scanner. Two radiologists reviewed scans of 5-mm slices using a five-grade modified coronary calcium scoring system: 1 = no calcification; 2 = minimal calcification; 3 = mild calcification; 4 = moderate calcification; and 5 = severe calcification. The Marginal Homogeneity test was used to compare the distribution and severity of calcification in the two groups.

RESULTS

Of 107 patients in the PE group, seven (6.54%) had pulmonary embolism detected on CT. Coronary artery calcification was detected in 61 patients (57%) in the PE group compared with 42 patients (39%) in the non-PE group. The Marginal Homogeneity test showed that patients with pulmonary embolism symptoms were 2.9 times more likely to have calcification detected compared with those patients who had chest CT for some other reason (P = .0034). However, in patients in whom coronary artery calcification was detected, the distribution of severity of calcification was the same in both groups.

CONCLUSION

Assuming coronary artery calcification indicated coronary atherosclerosis, patients undergoing CT for suspected pulmonary embolism may be at high risk for coronary artery disease.

Relation of thoracic aorta calcification on computed tomography and coronary risk factors to obstructive coronary artery disease on angiography

The aim of this study was to investigate whether thoracic aorta calcification (TAC) on computed tomography (CT) and coronary risk factors had any correlation with obstructive coronary artery disease (CAD) on angiography. A total of 225 consecutive Japanese patients underwent both thoracic conventional helical CT and coronary angiography. The thoracic aorta was divided into 4 locations according to the aortic anatomy (inner curve of the aortic arch, aortic arch but not on the inner curve, ascending aorta, and thoracic descending aorta). The classified TAC and coronary risk factors were evaluated for the presence or absence of obstructive CAD. TAC was detected in 185 patients; 141 of 225 patients had significant obstructive CAD. All of the 13 patients with no TAC and no coronary risk factors had no CAD. The obstructive CAD rate with 1 thoracic calcified location and with no, 1, or 2 coronary risk factors was 10%, 58%, and 90%, respectively, and each showed a significant difference (p < 0.0001). The combinations of TAC and coronary risk factors with obstructive CAD were 1 or 2 thoracic calcified locations with 3 coronary risk factors, and 3 thoracic calcified locations with more than 2 coronary risk factors. Increasing thoracic calcified locations and increasing coronary risk factors indicated a higher likelihood of CAD.

Valvular and thoracic aortic calcium as a marker of the extent and severity of angiographic coronary artery disease

BACKGROUND

The presence of calcified extracoronary structures as a useful indicator of underlying coronary artery disease (CAD) has not yet been established. The purpose of this study was to evaluate whether valvular and thoracic aortic calcification is associated with obstructive CAD.

METHODS

We evaluated 99 patients who underwent both coronary angiography and electron beam tomography (EBT) coronary scanning. We identified the presence, absence, and amount of calcification in the aortic valve (AVC), mitral annulus (MAC), descending aorta (DAC), and ascending aorta (AAC). The extent of CAD was graded according to the number of vessels diseased (VD).

RESULTS

Patients with multivessel disease (MVD) had a higher proportion of DAC. The presence of DAC significantly increased the specificity of EBT to detect CAD (58% with a calcium score >0 to 88% for calcium score>0 and DAC >0, P <.001). Both AAC and DAC were associated with a significantly higher rate of MVD in women (DAC, 63% in MVD vs 19% without, P <.01.; AAC, 65% vs 22%, P <.05). MAC had no relationship to either stenosis severity or the presence of obstructive CAD. AVC was the strongest predictor of the severity of CAD and predicted the presence of 3-vessel disease.

CONCLUSION

AVC and thoracic aortic calcification as detected with EBT are associated with the angiographic extent and severity of CAD and add incremental diagnostic value to the coronary artery calcium score. MAC does not add incremental value.

Relationship of peripheral arterial compliance and standard cardiovascular risk factors

Abnormalities of peripheral arterial compliance are clinically useful markers of atherosclerosis and risk of vascular events. Local peripheral arterial compliance can be easily and accurately assessed in the clinic by computer-controlled pulse volume recordings (air plethysmography). The purpose of this study was to investigate the relationship between clinical cardiovascular risk factors, a surrogate of atherosclerotic burden, and peripheral arterial compliance in the thigh and calf determined by quantification of local pulse volume recordings in patients undergoing coronary angiography. Peripheral arterial compliance in the thigh and calf was measured in 346 patients undergoing diagnostic cardiac catheterization at 4 centers. Demographic and cardiovascular risk factor data were collected, and their relationship to local arterial compliance examined using a new device that assesses maximal local arterial volume change in an extremity segment. Pulse volume recordings detected decreased local arterial compliance in the thigh associated with a history of hypertension (p < 0.0001), diabetes mellitus (p = 0.0001), and hyperlipidemia (p = 0.0007). In the calf, this arterial compliance measure was associated with a history of hypertension (p < 0.0001) and diabetes mellitus (p = 0.002). Females had lower arterial compliance than males in the thigh (p = 0.003) and calf (p < 0.0001). Limited evidence of lower arterial compliance in the thigh was found for those with obesity (p = 0.07). This procedure also demonstrated that subjects with multiple cardiovascular risk factors had lower arterial compliance in the thigh than subjects with no or 1 risk factor (p = 0.0001). Peripheral arterial compliance determined by air plethysmography is strongly associated with standard cardiovascular risk factors. The noninvasive measurement of local arterial compliance by regional pulse volume recording may be a useful adjunct for cardiovascular risk stratification early in the course of the disease as well as for monitoring vascular response to therapy.

Coronary calcium detected by digital cinefluoroscopy and coronary artery disease in patients undergoing coronary arteriography: effects of age and sex

BACKGROUND

Coronary artery calcium, detected non-invasively, correlates well with angiographically documented coronary artery disease (CAD). This study was conducted to evaluate the diagnostic efficacy of coronary artery calcium detected by digital cinefluoroscopy for CAD and assess the effects of age and sex on it.

METHODS

In 242 patients who underwent coronary angiography, coronary calcium status was determined and related to angiographic findings.

RESULTS

Calcium detection had a sensitivity 85%, specificity 52%, positive predictive value 92%, negative predictive value 33% and diagnostic accuracy 81% for significant CAD. There was a better positive predictive value in men (95% vs. 80%) and negative predictive value in women (65% vs. 16%), while a higher sensitivity and diagnostic accuracy was found in older than in younger (90% and 86% vs. 78% and 74%). The sensitivity of the method increased with the number of the diseased vessels.

CONCLUSIONS

Coronary calcium can be quite accurately detected by digital cinefluoroscopy. This, however, should be made in the context of sex and age.

Calcium begets calcium: progression of coronary artery calcification in asymptomatic subjects

PURPOSE

To test the hypothesis that the rate of coronary artery calcium progression is sex specific, namely, that it is greater in men than in women, and that it is age related, particularly in women.

MATERIALS AND METHODS

This was a retrospective study of the progression of coronary artery calcium in 217 consecutive asymptomatic subjects who underwent at least two electron-beam computed tomographic studies of the heart. Calcium in the distribution of the epicardial arteries was quantified by using both the conventional coronary artery calcium score (CCS) and the calcium volume score (CVS). Linear regression models were used to judge the joint influence of various risk factors, including sex and age, on rates of coronary artery calcium progression.

RESULTS

This study included 103 women and 114 men. The mean interval between the subjects' first and last studies was 25 months +/- 11 (SD). Regression analyses clearly demonstrated that the amount of coronary artery calcium present at the initial study was the most important determinant of calcium progression. This was true when coronary artery calcium was quantified by using the conventional CCS (P <.001) or CVS (P <.001). Neither sex nor age was a significant predictor of coronary artery calcium progression. Among traditional risk factors, only hypertension (P =.02) and diabetes (P =.01) were significant independent factors for calcium progression.

CONCLUSION

In asymptomatic subjects, the initial CCS and CVS were the most important factors that affected rate of coronary artery calcium progression. Neither age nor sex was as important as these factors in determination of coronary artery calcium progression.

Coronary calcium scanning adds incremental value to patients with positive stress tests

BACKGROUND

The sensitivity of coronary calcification by electron beam tomography (EBT) for the detection of coronary atherosclerosis is well-established. Combining the anatomic information of EBT with the functional information of stress testing might reduce the high false-positive result rate seen with treadmill stress test (TMST) alone. No studies have reported the additive value of a negative EBT result (no coronary calcium) for excluding obstructive coronary artery disease (OCAD) in patients with a positive TMST result. This study evaluated the negative predictive value and potential clinical utility of EBT to identify patients with a falsely abnormal TMST.

METHODS

A coronary calcium score was determined by EBT for 153 symptomatic patients who underwent coronary angiography because of a positive TMST. The sensitivity, specificity, and predictive values of EBT were determined. A multiple logistic regression analysis compared conventional cardiac risk factors with coronary calcification by EBT for predicting OCAD. A receiver operating characteristic curve was generated plotting sensitivity versus false-positive rate.

RESULTS

The false-positive rate of the TMST compared with angiography was 27% (41 of 153). The sensitivity of a nonzero coronary calcium score for OCAD was 98% (110 of 112), with a negative predictive value of 93%. According to multiple logistic regression, coronary calcification by EBT was a stronger predictor of OCAD than any conventional cardiac risk factor. EBT calcium added incremental value to the results of the TMST. Receiver operating characteristic curve analysis found an area under the curve of 0.91 (P <.001).

CONCLUSIONS

The absence of coronary calcification by EBT reliably identified patients with a false-positive TMST result. The combination of EBT with TMST is a potentially useful diagnostic strategy to reduce the number of false-positive test results.

Detection of subclinical cardiovascular disease: the emerging role of electron beam computed tomography

BACKGROUND

Although extraordinary advances have been made in the management of advanced coronary artery disease, little progress has been made in its prevention. Traditional screening methods utilizing risk factor profiles and exercise treadmill tests have failed to identify populations who will subsequently have coronary events with a high degree of predictive accuracy.

METHODS

We review the pathobiologic basis and clinical utility of electron beam computed tomography (EBCT) to detect coronary artery calcium as a screening tool for subclinical coronary artery disease. Because EBCT is able to perform subsecond imaging of the heart, it can detect and quantitate coronary artery calcium with a high degree of precision. Coronary artery calcium is a marker of complex atherosclerosis.

RESULTS

Over 4,000 asymptomatic patients in several series have been studied with EBCT and followed prospectively for an average of 42 months (range 37-72 months). A positive scan is associated with a risk ratio for future coronary events of 8.7 (95% confidence interval 2.67 to 28.13). These data indicate that EBCT has the ability to detect subclinical coronary artery disease and predict future coronary events better than any previous existing method or technology.

CONCLUSION

EBCT coronary artery screening may prove to be a valuable adjunct to the traditional methods for the detection of subclinical coronary artery disease and to identify those who would benefit from focused preventive therapies.

Women exhibit a greater age-related increase in proximal aortic stiffness than men

BACKGROUND

Large artery mechanical properties are a major determinant of pulse pressure and cardiovascular outcome. Sex differences in these properties may underlie the variation in cardiovascular risk profile between men and women, in relation to age.

OBJECTIVE

To investigate sex differences in the age-related stiffening of large arteries.

DESIGN

Cross-sectional.

METHODS

One hundred and twenty healthy men and women were recruited and divided equally into tertiles by age: young (mean +/- SD, 23 +/- 5 years), middle-age (47 +/- 3 years) and older (62 +/- 7 years). Lipids, mean arterial pressure and heart rate were matched within each tertile. Carotid tonometry and Doppler velocimetry were used to measure indices of large artery stiffness.

RESULTS

There was no sex difference in systemic arterial compliance (SAC) in the young group (mean +/- SEM, 0.61 +/- 0.05 arbitrary compliance units (ACU) in women compared with 0.67 +/- 0.04 ACU in men), but in the older population women had lower SAC than men (0.27 +/- 0.03 ACU compared with 0.57 +/- 0.04 ACU respectively; P < 0.001). Measures independent of aortic geometry (distensibility index and aortic impedance) indicated that stiffness was lower in young women than in men (P < 0.05), but the reverse was true in the older population (P < 0.01). This paralleled the brachial and carotid pulse pressures, which were lower in young (P < 0.01) and higher in older women compared with those in men (P < 0.05). Follicle stimulating hormone concentrations correlated strongly (r values 0.39-0.65) with all indices of central, but not peripheral, arterial function, whereas concentrations of luteinizing hormone, progesterone and oestradiol correlated less strongly.

CONCLUSIONS

In men and women matched for mean pressures, the age-related stiffening of large arteries is more pronounced in women, which is consistent with changes in female hormonal status.

Diagnostic strategies for women with suspected coronary artery disease

The clinician evaluating a woman with symptoms potentially indicative of coronary heart disease faces the challenge of choosing the appropriate diagnostic test. The use of noninvasive testing in women has been controversial due to a perception of diminished accuracy, limited female representation, and technical limitations that compromise efficacy. Recent meta-analyses and large observational series report marked improvements in accuracy for women undergoing exercise treadmill, echocardiography, and nuclear testing. Electron beam computed tomography is a relatively new technique, and the body of evidence is still developing. An adequate body of evidence supports the use of noninvasive testing for intermediate risk, symptomatic women and may result in improved diagnostic and therapeutic decision making.

Correlation of coronary calcification and angiographically documented stenoses in patients with suspected coronary artery disease: results of 1,764 patients

OBJECTIVES

This study correlated the electron beam computed tomographic (EBCT) calcium scores with the results of coronary angiography in symptomatic patients in order to assess its value to predict or exclude significant coronary artery disease (CAD).

BACKGROUND

Electron beam computed tomography is a sensitive method to detect coronary calcium. However, it is unclear whether it may play a role as a filter before invasive procedures in symptomatic patients.

METHODS

A total of 1,764 patients (1,225 men and 539 women) with suspected CAD from a single center were included in our study. All patients underwent calcium screening with EBCT (C150XP Imatron) and conventional coronary angiography.

RESULTS

Fifty-six percent of men and 47% of women revealed significant coronary stenoses (> or =50%). Total exclusion of coronary calcium (14% of the study group) was associated with an extremely low probability of stenosis (<1%). With calcium scores > or =20th, > or =100th or > or =75th percentile of age groups, the sensitivity to detect stenoses decreased to 97%, 93% and 81%, respectively, in men and to 98%, 82% and 76%, respectively, in women. At the same time, the specificity increased up to 77% in men and women. There was a significant difference in coronary calcium between men and women in all age groups; however, receiver-operating characteristic curves indicated that the test can be performed with equal accuracy in all of these subgroups.

CONCLUSIONS

Calcium screening with EBCT is a highly sensitive and moderately specific test to predict stenotic disease. Exclusion of coronary calcium defines a substantial subgroup of patients, albeit symptomatic, with a very low probability of significant stenoses.

Sex differences in morphology of coronary artery plaque assessed by intravascular ultrasound

BACKGROUND

Results of autopsy studies have suggested that there are sex differences in morphology of coronary-artery plaques, but these differences have yet to be adequately evaluated in vivo.

DESIGN AND METHODS

We performed preintervention intravascular ultrasound (IVUS) measurements on coronary plaques in a consecutive series of 76 men and 30 women with unstable angina pectoris. Both the target lesion and an adjacent reference site were evaluated. Arterial, plaque, and luminal areas were measured by planimetry. Plaques were classified as either calcified or uncalcified, and relative density of plaque was quantitatively assessed by videodensitometry, using a linear gray scale normalized with respect to density of adventitia.

RESULTS

Although women were older than men (mean age 55.0 +/- 10.9 versus 60.4 +/- 12.2 years, P = 0.02), their target lesions were less dense (74.6 +/- 23.4 versus 86.2 +/- 22.2% of adventitial density, P = 0.02) and less often found to be calcified (20.0 versus 38.2%, P = 0.05). Similarly, reference sites in female subjects were less dense (77.6 +/- 15.3 versus 97.1 +/- 19.4% of adventitial density, P = 0.01). There was no sex difference in the severity of coronary stenosis.

CONCLUSIONS

Both qualitative and quantitative sex differences in in-vivo morphology of coronary plaques morphology were detected by IVUS measurement. Plaques in women appear less videodense and are less often calcified than are those in men. Future studies employing sequential IVUS examinations are needed in order to determine whether these morphologic differences relate to a delay in initiation of plaques, slower progression of plaques, or other sex-specific modulators of plaque composition.

Imaging of coronary calcium: a case for electron beam computed tomography

Coronary arterial calcification has unequivocally been shown to be a marker of atherosclerosis. To date, much research interest has been generated regarding the quantification of coronary calcification by electron beam computed tomography, and how best to use such measurements to identify and predict those at greatest risk for an adverse cardiac event. This article represents an attempt to provide an objective review of the literature regarding the potential role electron beam computed tomography (EBCT) has as an accurate and cost effective screening modality for coronary arterial disease, as well as a predictor for coronary heart disease.